ECG

Question 1

Describe the basic components of an ECG and their significance in assessing cardiac function.

Answer 1

An electrocardiogram (ECG) records the electrical activity of the heart over time, represented by a series of waves and intervals:

• P wave: This represents atrial depolarization. The P wave shows the electrical activity associated with the contraction of the atria. It is typically upright and rounded. Abnormalities in the P wave can indicate atrial enlargement or atrial arrhythmias.
• QRS complex: This represents ventricular depolarization, where the ventricles contract. A normal QRS complex lasts around 0.06-0.10 seconds. Widened QRS complexes indicate abnormal ventricular conduction, such as bundle branch blocks or ventricular ectopy.
• T wave: This represents ventricular repolarization, where the ventricles recover after contraction. Abnormal T waves (e.g., inverted or peaked) can indicate ischemia or electrolyte imbalances, especially hyperkalemia.
• PR interval: This measures the time taken for the electrical impulse to travel from the atria to the ventricles via the AV node (normally 0.12-0.20 seconds). A prolonged PR interval suggests first-degree heart block, while a shortened PR interval is seen in conditions like Wolff-Parkinson-White syndrome.
• ST segment: This is the flat section between the end of the QRS complex and the beginning of the T wave. Elevation or depression of the ST segment is crucial in diagnosing myocardial ischemia or infarction. ST elevation is seen in acute myocardial infarction (STEMI), while ST depression may indicate ischemia or digoxin toxicity.
• QT interval: It represents the total time taken for both depolarization and repolarization of the ventricles. A prolonged QT interval is a risk factor for arrhythmias like torsades de pointes.

Understanding these basic components helps in identifying a wide range of cardiac abnormalities, from arrhythmias to ischemic heart disease

Question 2

. Explain the pathophysiological basis of arrhythmias and how they are detected on an ECG.

Answer 2

Arrhythmias are disturbances in the heart’s electrical activity and can be broadly categorized as tachyarrhythmias or bradyarrhythmias. The pathophysiology often involves:

• Abnormal automaticity: Pacemaker cells (e.g., in the SA node) may generate impulses too quickly (e.g., in sinus tachycardia) or too slowly (e.g., in sinus bradycardia). This is often influenced by autonomic nervous system imbalances, ischemia, or electrolyte disturbances.
• Re-entry circuits: These occur when an electrical impulse continues to propagate around a circular pathway, such as in atrial flutter, where a “reentrant” circuit causes rapid atrial depolarizations. Ventricular tachycardia (VT) is another example, where abnormal re-entry in the ventricles leads to rapid contractions.
• Triggered activity: Early after-depolarizations or delayed after-depolarizations (often due to electrolyte imbalances or drug toxicity) lead to spontaneous, extra beats, seen as ectopic beats or premature ventricular complexes (PVCs).
• Conduction blocks: These occur when the normal electrical pathway is interrupted. For instance, AV blocks (e.g., first, second, or third-degree) slow or completely block conduction from atria to ventricles, detectable by prolonged PR intervals or dropped QRS complexes on the ECG.
• ECG detection of arrhythmias: Different arrhythmias present distinct patterns:
• Atrial fibrillation (AF): Characterized by an irregularly irregular rhythm and absence of distinct P waves.
• Ventricular tachycardia (VT): Shows wide QRS complexes (>0.12s) at a rate >100 bpm.
• Supraventricular tachycardia (SVT): Narrow QRS complexes with rapid heart rates (>150 bpm) and usually absent or hidden P waves.

Arrhythmias range from benign to life-threatening, with the ECG providing critical diagnostic information

Question 3

*Discuss the ECG changes seen in myocardial ischemia and infarction.**

Answer 3

Myocardial ischemia and infarction cause distinct changes on the ECG, and these changes evolve over time:

• Ischemia:
• ST depression and/or T wave inversion indicate subendocardial ischemia (the inner layer of the heart wall). ST depression is seen in conditions like unstable angina or non-ST elevation myocardial infarction (NSTEMI).
• Acute infarction (STEMI):
• ST elevation: In a full-thickness myocardial infarction (STEMI), there is ST segment elevation in leads that correspond to the infarcted area. For example, ST elevation in leads II, III, and aVF suggests an inferior wall infarction.
• Q waves: Pathological Q waves develop as a marker of myocardial necrosis. These waves are wide and deep and suggest an old or completed infarct. For example, significant Q waves in leads V1-V3 can indicate a prior anterior wall infarction.
• T wave inversions: These are often seen after the acute phase of infarction and indicate ongoing ischemia or previous injury.

Recognizing these patterns is critical for the prompt diagnosis and treatment of myocardial ischemia and infarction

Question 4

Explain the role of the ECG in diagnosing electrolyte disturbances such as hyperkalemia and hypokalemia.

Answer 4

Electrolyte imbalances significantly alter cardiac electrical activity, and the ECG can be a valuable tool for diagnosis:

• Hyperkalemia:
• Peaked T waves are the earliest sign of hyperkalemia. As potassium levels rise, the T waves become tall and narrow.
• Widened QRS complexes develop as hyperkalemia worsens, potentially leading to a sine-wave pattern and eventual cardiac arrest if untreated.
• Flattening or absence of P waves may also occur in severe cases.
• Hypokalemia:
• Flattened or inverted T waves and the presence of U waves are characteristic findings in hypokalemia.
• Prolonged QT interval: This can predispose to torsades de pointes, a life-threatening ventricular arrhythmia.

Both hyperkalemia and hypokalemia require prompt recognition and correction to prevent serious cardiac complications

Question 5

Describe the ECG findings in various types of heart blocks.**

Answer 5

Heart blocks represent delays or complete interruptions in the conduction system, and different types can be identified by distinct ECG patterns:

• First-degree AV block: Prolongation of the PR interval (>0.20 seconds) without any dropped beats. This often reflects a delay in conduction through the AV node.
• Second-degree AV block (Mobitz I/Wenckebach): The PR interval progressively lengthens until a QRS complex is dropped. This type of block is usually benign and can be seen in athletes or during sleep.
• Second-degree AV block (Mobitz II): There is no progressive lengthening of the PR interval, but sudden, unexpected dropped QRS complexes. Mobitz II is more serious and can progress to complete heart block.
• Third-degree (complete) AV block: There is no conduction between the atria and ventricles, resulting in atrial (P waves) and ventricular (QRS complexes) activity that occurs independently of each other. This requires urgent management, often with a pacemaker

Question 6

6. Eplain the significance of axis deviation on the ECG and its clinical implications.**

Answer 6

The cardiac axis refers to the overall direction of the heart’s electrical depolarization. It is determined by looking at the QRS complex in the frontal leads:

• Normal axis: The QRS complex is positive in both leads I and aVF (between -30° and +90°).
• Left axis deviation (LAD): This occurs when the axis shifts between -30° and -90°. Causes include left ventricular hypertrophy, left bundle branch block, and inferior myocardial infarction.
• Right axis deviation (RAD): Occurs when the axis is shifted between +90° and +180°. Common causes include right ventricular hypertrophy, pulmonary embolism, and chronic lung disease.

Understanding axis deviation helps in diagnosing underlying conditions such as hypertrophy or infarction

Question 7

7 Discuss the role of ECG in diagnosing and managing congenital heart diseases such as atrial septal defect (ASD) and ventricular septal defect (VSD).

Answer 7

ECG findings in congenital heart diseases often reflect the altered structure and function of the heart:

• Atrial septal defect (ASD):
• The ECG may show right axis deviation and right atrial enlargement. Incomplete right bundle branch block (RBBB) is often seen.
• Ventricular septal defect (VSD):
• The ECG may show signs of left ventricular hypertrophy or biventricular hypertrophy, depending on the size and significance of the defect.

While echocardiography remains the gold standard for diagnosing congenital heart defects, the ECG provides useful supportive information on the impact of these defects on the electrical activity of the heart

Question 8

Explain the significance of the P wave, QRS complex, and T wave in an ECG, and discuss what abnormalities in each may indicate in terms of cardiac pathology.

Answer 8

ECG provides a graphical representation of the heart’s electrical activity. Each component of the ECG corresponds to different phases of the cardiac cycle:

• P wave: Represents atrial depolarization. Normally, it is a small, smooth upward deflection. Abnormalities in the P wave can indicate issues with atrial size or conduction. For example, a notched or peaked P wave may suggest atrial enlargement, while an absent P wave can be seen in atrial fibrillation.
• QRS complex: Represents ventricular depolarization. The normal duration is less than 120 ms. Abnormalities in the QRS complex, such as a widened QRS, may suggest bundle branch blocks, ventricular hypertrophy, or ventricular pre-excitation (as seen in Wolff-Parkinson-White syndrome).
• T wave: Represents ventricular repolarization. A tall, peaked T wave is typically seen in hyperkalemia, while flattened or inverted T waves may indicate ischemia or electrolyte disturbances.

Abnormalities in these waves can point to various cardiac conditions like ischemia, arrhythmias, or electrolyte imbalances

Question 9

Discuss the role of the ECG in the diagnosis of acute coronary syndromes, with emphasis on ST-segment changes, T wave abnormalities, and the development of Q waves.

Answer 9

In acute coronary syndromes (ACS), ECG is essential for diagnosis and triage. There are three main types of ACS: unstable angina, NSTEMI (non-ST elevation myocardial infarction), and STEMI (ST elevation myocardial infarction).

• STEMI: Shows ST-segment elevation in the affected leads, which indicates transmural ischemia (full thickness of the heart wall). These changes appear within minutes to hours and can progress to the development of Q waves.
• NSTEMI: No ST-segment elevation but T wave inversion or ST depression may be seen. These changes suggest subendocardial ischemia (partial thickness).
• Unstable Angina: Similar to NSTEMI, but without the elevation of cardiac biomarkers. T wave inversion or ST depression may be present.

Q waves typically develop hours to days after a myocardial infarction and indicate irreversible damage to the myocardium

Question 10

Describe the different types of heart block and their ECG manifestations. Include a discussion on first-degree, second-degree (Mobitz type I and II), and third-degree heart blocks.

Answer 10

Heart blocks occur when the electrical signal in the heart is delayed or completely blocked:

• First-degree AV block: Prolonged PR interval (>200 ms) but every P wave is followed by a QRS complex. It is often benign and may not require treatment.
• Second-degree AV block:
• Mobitz Type I (Wenckebach): The PR interval progressively lengthens until a QRS is dropped. This is usually due to reversible causes such as medication.
• Mobitz Type II: A sudden, non-conducted P wave without prior PR lengthening. This is more serious and may require a pacemaker.
• Third-degree (complete) AV block: No relationship between P waves and QRS complexes. The atria and ventricles beat independently. This condition requires urgent intervention with a pacemaker

Question 11

Explain the pathophysiology behind axis deviation in ECGs and discuss its clinical relevance.

Answer 11

The heart’s electrical axis refers to the general direction of the heart’s electrical depolarization:

• Normal axis: Between -30° and +90°.
• Left axis deviation (LAD): The axis is more negative than -30°, which can occur due to left ventricular hypertrophy (LVH), left bundle branch block (LBBB), or inferior wall myocardial infarction.
• Right axis deviation (RAD): The axis is more positive than +90°, often seen in conditions like right ventricular hypertrophy (RVH), pulmonary embolism, or chronic lung diseases.

Axis deviation helps in diagnosing underlying pathologies such as ventricular hypertrophy or myocardial infarction

Question 12

Detail how electrolyte imbalances, such as hyperkalemia and hypokalemia, manifest on an ECG and the potential clinical consequences if left untreated.

Answer 12

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Electrolyte imbalances, particularly potassium and calcium, have distinct effects on the ECG:

• Hyperkalemia: Elevated potassium levels cause peaked T waves, shortened QT intervals, and eventually lead to a widened QRS complex and sine wave pattern in severe cases. If untreated, it can lead to fatal arrhythmias.
• Hypokalemia: Causes U waves, T wave flattening, and prolongation of the QT interval. This can predispose to torsades de pointes, a type of polymorphic ventricular tachycardia.
• Hypocalcemia: Prolongs the QT interval, which increases the risk of arrhythmias.
• Hypercalcemia: Shortens the QT interval

Question 13

Explain how ECG findings are used in the diagnosis of ventricular hypertrophy (both left and right). Discuss the voltage criteria for diagnosing left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH) and the clinical conditions associated with each.

Answer 13

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ECG is useful in diagnosing both left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH):

• Left Ventricular Hypertrophy: Characterized by increased QRS voltage. One commonly used criterion is the Sokolow-Lyon index: if the sum of the S wave in V1 and the R wave in V5 or V6 exceeds 35 mm, LVH is likely. Conditions such as hypertension and aortic stenosis often lead to LVH.
• Right Ventricular Hypertrophy: Seen as tall R waves in V1 and V2, with a rightward shift in the QRS axis (right axis deviation). Conditions like pulmonary hypertension and chronic lung disease contribute to RVH

Question 14

Analyze the ECG changes associated with atrial fibrillation and ventricular tachycardia. Compare their pathophysiology and discuss their implications in terms of management and prognosis.

Answer 14

• Atrial Fibrillation (AF): On ECG, AF is characterized by an absence of P waves and an irregularly irregular rhythm. There are rapid, chaotic atrial electrical impulses, leading to disorganized atrial activity. AF increases the risk of stroke and is managed with rate control, rhythm control, and anticoagulation.
• Ventricular Tachycardia (VT): VT presents as wide QRS complexes with a regular rhythm. It arises from abnormal electrical signals originating in the ventricles. VT can degenerate into ventricular fibrillation, which is life-threatening and requires immediate intervention.

Both conditions represent significant arrhythmias that require different management approaches, but both are associated with significant morbidity and mortality if untreated

Question 15

What’s the function of ecg

Answer 15

Electrocardiogram (ECG)

Purpose:

An ECG records the electrical activity of the heart. It captures the heart’s depolarization (when heart cells are activated and contract) and repolarization (when they relax), reflecting the overall electrical activity.

• Electrical potentials of about 1 mV are generated at the body’s surface, which form the familiar P-QRS-T pattern.
• Use of ECG: It is useful for investigating rhythm disturbances, myocardial and pericardial diseases, electrolyte imbalances, and more

Question 16

What’s the location and placement of a 12 ecg lead

Answer 16

Lead Placement

The standard 12-lead ECG system includes:

• Limb leads: Lie in the frontal plane (Leads I, II, III, aVR, aVL, aVF).
• Precordial (chest) leads: Circle the heart in the transverse plane (V1-V6).

Precordial (Chest) Lead Placement:

• V1: Right sternal border, 4th intercostal space.
• V2: Left sternal border, 4th intercostal space.
• V3: Midway between V2 and V4.
• V4: 5th intercostal space, midclavicular line.
• V5: Anterior axillary line, 5th intercostal space.
• V6: Mid-axillary line, 5th intercostal space

Question 17

What are the Ecg Waves and Intervals: and meaning

Answer 17

• P wave: Represents atrial depolarization (when the atria contract).
• QRS complex: Represents ventricular depolarization (ventricles contracting).
• T wave: Reflects ventricular repolarization (ventricles relaxing).
• PR interval: Time from the beginning of the P wave to the start of the QRS complex. It indicates the time for the electrical impulse to travel from the atria to the ventricles.
• QT interval: Time from the start of the QRS complex to the end of the T wave. It represents the total time of ventricular activity, including depolarization and repolarization

Question 18

How do you do ECG Interpretation:

Answer 18

1. Look at the rhythm strip: Usually lead V1 or lead I.
2. Examine the P waves: Are they similar? Is there a 1:1 relationship between P waves and QRS complexes?
3. Check the rhythm: Is it regular or irregular? For example, in atrial fibrillation (AF), _____ waves are absent? , and the rhythm is irregular.
4. Calculate the heart rate:

• 300 divided by the number of big squares between R-R intervals (for regular rhythms).
• 1500 divided by the number of small squares between R-R intervals.
• For irregular rhythms, count the number of cardiac cycles in 6 seconds and multiply by 10.

5. Assess the axis: The QRS axis represents the direction of the heart’s electrical activity in the frontal plane, usually measured using the QRS complex.

P wave

Question 19

How do you do
Axis Determination (Isoelectric/Equiphasic Approach):

Answer 19

1. Find the transitional lead: The lead where the QRS complex has equal positive and negative components (i.e., isoelectric).
2. Use the hexaxial reference system to find the lead that is perpendicular (90°) to the transitional lead. This will indicate the QRS axis.

Question 20

By thoroughly understanding the placement of ECG leads, interpreting the P-QRS-T waves, and utilizing methods such as axis determination, an ECG can help diagnose a variety of cardiac issues, from rhythm disorders to myocardial infarctions.

Question 21

P wave meaning and which leas is it best seen and it’s xteristic

Answer 21

:

P Wave

• Duration: The P wave represents atrial depolarization (contraction of the atria). It’s best observed in leads II and V1.
• In Lead II, the normal height should be <2.5 mm, and the duration (width) should be <3 small squares (3 mm = 0.12 s).
• In Lead V1, the P wave can be positive, negative, or biphasic. The positive terminal (right atrium) should be <1.5 mm, and the negative terminal (left atrium) should be <1 mm.

Question 22

PR interval normal range and it’s abnormalities indicates

Answer 22

PR Interval

• Normal Range: 0.12 - 0.22 seconds (3-5 small squares).
• A prolonged PR interval suggests a delay in AV conduction and can indicate conditions like:
• First-degree heart block.
• Ischemic heart disease (IHD).
• Acute rheumatic myocarditis.
• Lyme disease.
• Electrolyte abnormalities like hypokalemia.
• Drug effects: digoxin, beta-blockers, calcium channel blockers (CCBs).
• Second-degree AV block Mobitz Type 1 (Wenckebach): The PR interval progressively lengthens until a beat is dropped (one atrial impulse fails to reach the ventricles).

Question 23

What’s qrs complex?
And it’s increase and decrease might indicate?

Answer 23

QRS Complex

• Duration: Should be ≤0.10 seconds (2.5 small squares). It reflects ventricular depolarization (ventricular contraction).
• Low Voltage Complexes (QRS <5 mm in limb leads or <10 mm in chest leads) could indicate:
• Obesity.
• Chronic obstructive pulmonary disease (COPD).
• Pericardial effusion.
• Dilated cardiomyopathy (DCM).
• High Voltage Complexes can indicate:
• Left ventricular hypertrophy (LVH):
• R wave in V5 or V6 >25 mm.
• S wave in V1 or V2 >25 mm.
• Sokolow-Lyon criteria: S in V1 + R in V5/V6 > 35 mm.
• Cornell criteria: S in V3 + R in aVL > 28 mm in men, >20 mm in women.
• Right ventricular hypertrophy (RVH):
• R wave in V1 or V2 >7 mm.
• R/S ratio in V1 or V2 >1.

Question 24

Premature Ventricular Contraction (PVC)

• A PVC represents an early depolarization of the ventricles, producing a wide and abnormal QRS complex, often without a preceding P wave.

Question 25

What's q wave and it's features What's the feature of abnormal q wave and what it indicates

Answer 25

**Q Waves** - **Normal Q waves** are small and indicate **septal depolarization**. - **Abnormal Q waves**: - >2 mm deep, >1 mm wide, or >25% of the R wave amplitude. - Causes of abnormal Q waves include **myocardial infarction (MI)** (especially **transmural MI**), **hypertrophic cardiomyopathy (HCM)**, **left bundle branch block (LBBB)**, and **pulmonary embolism (PE)**.

Question 26

ST segment means It's elevation signifies?

Answer 26

**ST Segment** - The **ST segment** represents the time between ventricular depolarization and repolarization. - **ST elevation**: Typically signifies **myocardial injury** (e.g., **acute MI**). - **Anterior MI**: Leads **V1-V5**. - **Septal MI**: Leads **V1-V2**. - **Lateral MI**: Leads **I, aVL, V5-V6**. - **Inferior MI**: Leads **II, III, aVF**. - **Posterior MI**: Leads **V7-V9**. - **Right ventricular MI**: Leads **V1, V4R**. - Reciprocal changes can appear in opposite leads. For example, **inferior MI** (ST elevation in leads II, III, aVF) shows reciprocal ST depression in leads **I and aVL**. Pericarditis: Generalized ST elevation across multiple leads, not localized to a specific coronary artery territory like an MI.

Question 27

What's qt interval It's normal range for both male and female

Answer 27

**QT Interval** - **Corrected QT interval (QTc)**: The **QT interval** represents the duration of **ventricular depolarization and repolarization**. - **Normal QTc**: - Males: **≤0.44 seconds**. - Females: **≤0.46 seconds**.

Question 28

What are the formulas used in correcting QT interval?

Answer 28

- **Bazett’s formula**: Corrects the QT interval for heart rate using the formula: QTc=QT​/√R-R - **Fridericia’s formula**: Another method to correct the QT interval, especially for faster heart rates: QTc= QT/3√R−R

Question 29

The ECG (Electrocardiogram) measures the heart's electrical activity, which can reveal a variety of heart conditions by analyzing different intervals and waveforms. Here's a breakdown of the key parameters, waveforms, and related conditions: ### P Wave: - **P wave duration**: Normally ≤ 0.12s (3 small squares). - Best seen in **Lead II** and **Lead V1**. - In **Lead II**: Height < 2.5mm; width < 0.12s. - In **Lead V1**: Biphasic, where the positive portion represents the right atrium and the negative portion represents the left atrium. ### PR Interval: - **PR interval duration**: Normal range is 0.12-0.22s. - **Prolonged PR interval (>0.20s)**: Seen in conditions like: - First-degree heart block (HB) - Ischemic heart disease (IHD) - Acute rheumatic myocarditis - Lyme disease - Hypokalemia - Drug-induced (Digoxin, beta blockers, etc.) - **Mobitz Type 1 (Wenckebach)**: Progressive prolongation of PR interval followed by a dropped QRS complex. ### QRS Complex: - **QRS duration**: Normally ≤ 0.10s. - **QRS abnormalities**: - **Low voltage**: Amplitude < 5mm in limb leads or < 10mm in chest leads, seen in conditions like obesity, COPD, pericardial effusion, dilated cardiomyopathy (DCM). - **High voltage**: Increased amplitude, suggesting left or right ventricular hypertrophy (LVH/RVH). - **LVH**: - R wave in V5 or V6 > 25mm. - S wave in V1 or V2 > 25mm. - S V1/V2 + R V5/V6 > 35mm (Sokolow Lyon Criteria). - Cornell Criteria: S in V3 + R in aVL > 28mm (men) or > 20mm (women). - **RVH**: - R wave in V1/V2 > 7mm. - R/S ratio in V1/V2 > 1. ### QT Interval: - **QT duration**: Normal range 320-440ms (8-11 small squares). - **Prolonged QT**: Can be caused by: - Ischemic heart disease (IHD), myocarditis, dilated cardiomyopathy (DCM). - Electrolyte imbalances: ↓ K+, ↓ Mg2+, ↓ Ca2+. - Drugs: Tricyclic antidepressants, antiarrhythmics. - Congenital long QT syndromes. - **Shortened QT**: Occurs in hyperkalemia, hypercalcemia, hyperthermia, or acidosis. ### T Wave: - **T wave amplitude**: - Normally ≤ 5mm in limb leads and ≤ 10mm in chest leads. - **Tall T waves**: Seen in acute myocardial infarction (MI) and hyperkalemia. - **Small T waves**: Associated with hypokalemia, pulmonary embolism (PE), and hypothyroidism. - **Inverted T waves**: - Can be normal in leads aVR, V1-V2 (young individuals), or V3 (in black individuals). - Pathological inversion can be seen in ischemia, ventricular strain, Digoxin toxicity, cardiomyopathies, bundle branch block (BBB), pericarditis, pulmonary embolism, and subarachnoid hemorrhage

Question 30

ST Segment: - The **ST segment** represents the interval between ventricular depolarization and repolarization. - **ST elevation** indicates acute myocardial infarction (MI) and can help localize the infarct. - **Anterior MI**: Elevation in V1-V5. - **Inferior MI**: Elevation in leads II, III, aVF. - **Posterior MI**: Elevation in V7-V9 with reciprocal changes in V1-V3. - **Pericarditis**: Diffuse ST elevation across multiple leads.

Question 31

Bundle Branch Blocks: - **Left Bundle Branch Block (LBBB)** and **Right Bundle Branch Block (RBBB)**: In complete block the QRS complex is? What about incomplete block?

Answer 31

- **Complete block**: QRS duration > 0.12s. - **Incomplete block**: QRS duration 0.10-0.12s.

Question 32

What are the possible causes of l and r bbb?

Answer 32

- **LBBB**: Can occur due to cardiomyopathy, ischemic heart disease, aortic stenosis, hyperkalemia, or idiopathic degeneration. - **RBBB**: Seen in pulmonary embolism, chronic lung disease, cardiomyopathy, or septal defects.

Question 33

U Wave is best seen in what lead? And it occurs in what conditions?

Answer 33

: - **U wave**: Seen best in leads V2-V3. - More prominent in hypokalemia and hypercalcemia

Question 34

Lis other Other ECG Modalities: and their function.

Answer 34

Other ECG Modalities: - **Holter Monitoring**: 24-hour ECG recording for detecting intermittent arrhythmias. - **Echocardiography (Echo)**: Uses ultrasound to visualize the heart's structure and function, assessing conditions like valve disease, heart failure, or wall motion abnormalities. - **M-mode**: Measures wall thickness and chamber size. - **Doppler Echo**: Assesses blood flow and pressure gradients, useful for evaluating valvular stenosis and regurgitation

Question 35

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Question 36

What's **T Wave** Too tall and too short wave can be seen in? Normal and abnormal t wave invertion can be seen in?

Answer 36

The **T wave** reflects **ventricular repolarization**, where the ventricles recover after contraction. The amplitude and shape of the T wave can provide clues to various cardiac and systemic conditions: - **Normal amplitude**: The T wave should not exceed **5 mm in the limb leads** or **10 mm in the chest leads**. - **Too tall T waves** can be seen in: - **Acute myocardial infarction (MI)**. - **Hyperkalemia**. - **Too small T waves** are associated with: - **Hypokalemia**. - **Pulmonary embolism (PE)**. - **Hypothyroidism**. ### **T Wave Inversion** - **Normal T wave inversion** can be seen in: - Leads **aVR**, **V1**, and **V2** in the young. - **V3** in some individuals, especially in **black populations**. - **Abnormal T wave inversion** may suggest various conditions, such as: - **Ischemia** (reduced blood flow to the heart muscle). - **Ventricular strain**. - **Digoxin toxicity**. - **Cardiomyopathies**. - **Bundle branch blocks (BBB)**. - **Pericarditis**. - **Pulmonary embolism**. - **Subarachnoid hemorrhage (SAH)**.

Question 37

What's qt interval and it's normal range Cause of prolonged and shortened qt interval

Answer 37

**QT Interval Abnormalities** The **QT interval** represents the time from the start of ventricular depolarization to the end of ventricular repolarization. The normal range is **320 – 440 ms** (8-11 small squares). - **QT Prolongation**: - Seen in conditions such as: - **Myocarditis**. - **Ischemic heart disease (IHD)**. - **Dilated cardiomyopathy (DCM)**. - **Electrolyte abnormalities**: **Hypokalemia**, **hypomagnesemia**, **hypocalcemia**. - **Hypothermia**. - **Drugs**: tricyclic antidepressants (TCAs), phenothiazines, and class I antiarrhythmics. - **Congenital long QT syndromes**. - **QT Shortening**: - Causes include: - **Hyperkalemia**. - **Hypercalcemia**. - **Hyperthermia**. - **Acidosis**. - **Digitalis effect**.

Question 38

**Bundle Branch Blocks (BBB)** - **Left Bundle Branch Block (LBBB)** and **Right Bundle Branch Block (RBBB)** involve disruptions in the conduction of electrical signals through the left or right bundle branches of the heart, respectively. #### **Left Bundle Branch Block (LBBB)** - **Complete LBBB**: **QRS duration > 0.12 seconds**. - **Incomplete LBBB**: **QRS duration 0.10 - 0.12 seconds**. - Causes include:? L&R

Answer 38

- **Idiopathic degeneration** of the conduction system. - **Cardiomyopathy**. - **Ischemic heart disease (IHD)**. - **Aortic stenosis**. - **Hyperkalemia**. - **Left ventricular hypertrophy (LVH)**. #### **Right Bundle Branch Block (RBBB)** - **Complete RBBB**: **QRS duration > 0.12 seconds**. - **Incomplete RBBB**: **QRS duration 0.10 - 0.12 seconds**. - Causes include: - **Pulmonary embolism (PE)**. - **Chronic lung disease**. - **Cardiomyopathy**. - **Atrial and ventricular septal defects**.

Question 39

U wave is often seen in what lead & is caused by?

Answer 39

**U Wave** The **U wave** is often absent but may appear on the ECG, especially in leads **V2** and **V3**. It is more prominent in: - **Hypokalemia**. - **Hypercalcemia**. - **Hyperthyroidism**.

Question 40

What's v tac

Answer 40

**Ventricular Tachycardia (VT)** - **Ventricular tachycardia** is a rapid heart rhythm originating from the ventricles, often a sign of severe heart disease. It can lead to a life-threatening condition called **ventricular fibrillation** (VF), where the ventricles quiver rather than contract effectively

Question 41

What are the Other ECG Monitoring**

Answer 41

- **24-hour ECG Holter monitoring**: A portable device that records the heart’s electrical activity over 24 hours, used to detect intermittent arrhythmias. - **Implantable loop recorders**: Implanted devices that continuously monitor heart rhythm for long-term detection of arrhythmias. - **Stress ECG**: An ECG performed during physical stress (e.g., treadmill or bicycle ergometer) to assess how the heart responds to exercise. It helps in diagnosing **ischemic heart disease**. ### Summary - **Tall or small T waves**, **T wave inversions**, and **QT interval abnormalities** can provide important clues to electrolyte imbalances, ischemic conditions, or systemic diseases. - **Bundle branch blocks** indicate disturbances in the heart's conduction pathways and are associated with underlying cardiac or pulmonary conditions. - The **U wave** is often a sign of electrolyte imbalances.

Question 42

What's Echocardiography

Answer 42

Echocardiography (Echo)** is a non-invasive diagnostic test that uses ultrasound waves to create images of the heart. It helps assess the structure and function of the heart, including chambers, valves, and blood flow

Question 43

The normal range for hearing sounds are?

Answer 43

. 1. **Ultrasound and Sound Waves**: - The normal frequency range for human hearing is **20 Hz to 20 KHz**. - Any sound frequency above 20 KHz is called **ultrasound**, which is used in echography to visualize the heart. - Electrical energy is converted to sound energy, and the sound waves are transmitted into the body, reflecting off the heart structures to produce an image

Question 44

2. *ECHO Display**: - The **transducer**, which sends and receives the ultrasound waves, is placed at the apex, meaning at the heart’s lower point. - The **right ventricle** is displayed at the upper part of the screen, while the **left ventricle** is seen on the lower screen

Question 45

What's the function of Two-Dimensional Echo & importance

Answer 45

Modalities of Echo 1. **Two-Dimensional Echo (2D Echo)**: - Provides a real-time, two-dimensional view of the heart, allowing the assessment of: - Heart anatomy and relationships between different structures. - Intracardiac masses, pericardial diseases, ventricular wall motion, and valvular leaflet movements. - Measurements like wall thickness, chamber volume, and **ejection fraction (EF)**. - Visualization of valve leaflets and orifices, used in diagnosing structural heart disease

Question 46

What's the function of Motion Mode Echo

Answer 46

. 2. **Motion Mode Echo (M-mode Echo)**: - Gives a one-dimensional image of heart structures over time. - Used to measure cavity size, wall thickness, muscle mass, and the movement of heart walls and valve cusps. - Synchronized with an ECG, it helps in the precise timing of cardiac events

Question 47

List all the modalities of echo

Answer 47

Motion Mode Echo 2 dimentional Doppler Echo 3D Echo Transoesophageal Echo Stress Echocardiography

Question 48

Function/significance of Doppler Echo

Answer 48

. 3. **Doppler Echo**: - This technique uses the Doppler effect to evaluate blood flow in the heart. - **Continuous Wave (CW) Doppler**: Useful for assessing high-velocity blood flow and the severity of **valvular stenosis** and **regurgitation**. - **Pulsed Wave (PW) Doppler**: Assesses blood flow velocity and direction, useful for calculating **stroke volume**, **cardiac output**, and evaluating **diastolic function**.

Question 49

Importance of the other modalities?

Answer 49

- **3D Echo**: Provides a 3-dimensional view of the heart for more complex assessments. - **Transoesophageal Echo (TOE)**: A specialized echo where the transducer is placed in the esophagus, offering clearer images of the heart. - **Stress Echocardiography**: Evaluates heart function under stress (exercise or pharmacologic agents), particularly assessing for ischemia

Question 50

What are the Clinical Applications of Echo

Answer 50

- **2D Echo**: Commonly used to evaluate the heart’s anatomy, ventricular function, and valvular diseases. - **M-mode Echo**: Precise measurements of heart structures and timing of cardiac events. - **CW Doppler**: Key in assessing **valvular stenosis**, **regurgitation**, and **pulmonary artery pressure**. - **PW Doppler**: Evaluates **left ventricular diastolic function**, calculates **stroke volume**, and measures **valvular orifice areas**.

Question 51

What are the Key Echo Parameters:

Answer 51

- **LVIDd**: Left ventricular internal diameter in diastole. - **LVIDs**: Left ventricular internal diameter in systole. - **EF**: **Ejection fraction**, the percentage of blood ejected from the heart during systole. - **LVED**: Left ventricular end-diastolic volume, which indicates the volume of blood in the left ventricle at the end of diastole

Question 52

What are the Other Conditions Assessed by Echo:

Answer 52

- **Mitral and Tricuspid Valve Regurgitation**: Assessed using Doppler techniques to detect and quantify backflow of blood through these valves. - **Aortic Stenosis**: The narrowing of the aortic valve, evaluated by Doppler and 2D imaging. - **Diastolic Dysfunction**: Graded based on the patterns of blood flow through the heart during the filling phase (diastole)

Question 53

What's Electroencephalography (EEG)

Answer 53

**EEG** is a technique used to record the electrical activity of the brain via electrodes placed on the scalp. It is particularly useful in diagnosing **epilepsy** and other disorders affecting brain function

Question 54

. 1. **EEG Basics**: - The brain’s electrical activity is mainly generated by **postsynaptic potentials** in pyramidal cells of the cerebral cortex. - A typical EEG in a relaxed, awake adult shows an **8-13 Hz alpha rhythm**, particularly in the occipital region, which diminishes with eye opening or drowsiness

Question 55

How does **EEG look in Epilepsy**:

Answer 55

- Epilepsy is characterized by **abnormal, repetitive, and rhythmic electrical activity** in the brain. - An abnormal EEG during a **generalized tonic-clonic seizure** will always show electrical disturbances, but during seizure-free periods (interictal), up to 60% of epileptics may have normal EEGs

Question 56

**EEG Features**:

Answer 56

3. - **Hyperventilation**, **photic stimulation**, and **sleep deprivation** can help trigger abnormal EEG patterns in patients with suspected epilepsy. - EEG abnormalities can include **generalized spike-wave activity** in absence seizures or **slow wave activity** in conditions like **encephalitis** or **gliomas**.

Question 57

EEG in Neurological Disorders looks like?

Answer 57

1. **Abnormal EEG**: - **Diffuse slow activity**: Seen in patients with encephalitis or brain swelling, indicating global brain dysfunction. - **Focal slow activity**: Indicates localized brain abnormalities, like a **glioma**. - **Periodic complexes**: Seen in degenerative diseases like **Creutzfeldt-Jakob disease**.

Question 58

What's spirometry and the two main measurements done

Answer 58

Spirometry **Spirometry** is a common test used to assess how well a patient's lungs are working. The patient is asked to breathe in deeply and then exhale forcefully into a spirometer, which measures lung function. There are two main measurements in spirometry: 1. **Forced Expiratory Volume in 1 second (FEV1):** This is the volume of air that can be forcibly exhaled in the first second of a breath. 2. **Forced Vital Capacity (FVC):** This is the total volume of air that can be exhaled after a full inhalation.

Question 59

Interpretation of Spirometry How does it look in normal Restrictive lung dxs and air flow limitation

Answer 59

**Interpretation of Spirometry:** - In normal individuals, the ratio of **FEV1/FVC** is around 75%. - In cases of **airflow limitation** (e.g., obstructive lung diseases like asthma or COPD), FEV1 is reduced more than FVC, leading to a reduced FEV1/FVC ratio. - In **restrictive lung diseases** (such as pulmonary fibrosis), both FEV1 and FVC are reduced proportionally. As a result, the FEV1/FVC ratio may remain normal or be increased due to the enhanced elastic recoil of the lungs

Question 60

What are the patterns in spirometry?

Answer 60

. **Patterns in Spirometry:** - **Obstructive Pattern:** Reduced FEV1/FVC ratio, commonly seen in conditions like asthma and chronic obstructive pulmonary disease (COPD). - **Restrictive Pattern:** Both FEV1 and FVC are reduced, but the FEV1/FVC ratio remains normal or slightly elevated. This pattern is typical of diseases that restrict lung expansion

Question 61

What's endoscopy?

Answer 61

Endoscopy refers to procedures that use an endoscope (a flexible tube with a camera and light) to view internal organs. There are different types of endoscopy, depending on which part of the body is being examined

Question 62

What are the **Key Features of Endoscopy:**

Answer 62

. - **Video Endoscope:** Modern endoscopes transmit high-definition images to a television monitor, allowing doctors to visualize the interior of the body in real-time. - The tip of the endoscope is flexible and can be angulated in all directions, helping to navigate through the body. - The endoscope tube also has various channels for **air insufflation**, **water injection**, **suction**, **biopsy**, and even **injection of treatment**.

Question 63

What's **Oesophagogastroduodenoscopy** it's purpose and how it's performed

Answer 63

**Oesophagogastroduodenoscopy (OGD or Gastroscopy):** - **Purpose:** It is performed to examine the upper gastrointestinal (GI) tract, including the esophagus, stomach, and duodenum. This procedure is used to diagnose conditions such as **reflux esophagitis**, **peptic ulcer disease (PUD)**, **bleeding**, and **cancer**. - **Preparation:** The patient must fast for at least 4 hours prior to the procedure

Question 64

What's **Colonoscopy** it's purpose and how it's performed

Answer 64

- **Purpose:** Colonoscopy is used to visualize the entire colon and the terminal ileum. It is commonly performed to diagnose and screen for conditions like **colorectal cancer**. - **Preparation:** Bowel preparation is required to clear the colon of stool to allow for clear visualization during the procedure

Question 65

Discuss the various indications, methodology, and clinical interpretation of an Electrocardiogram (ECG).

Answer 65

G). **Indications of ECG:** ECG is primarily indicated when a patient presents with chest pain (suspected myocardial infarction or ischemia), palpitations (suspected arrhythmias), shortness of breath, or syncope. It is also used in the routine monitoring of patients with known cardiovascular diseases, electrolyte imbalances (e.g., hyperkalemia, hypokalemia), and those on medications that may affect heart rhythms (e.g., digoxin). **Methodology of ECG:** An ECG records the electrical activity of the heart using electrodes placed on the patient's skin at specific anatomical locations. These electrodes record potential differences generated by depolarization and repolarization of the atria and ventricles. The standard 12-lead ECG records from six limb leads (I, II, III, aVR, aVL, aVF) and six chest leads (V1 to V6). These provide a comprehensive view of the heart's electrical activity from different angles. **Interpretation of ECG Readings:** - **P wave:** Represents atrial depolarization. Abnormalities such as enlarged P waves can indicate atrial enlargement. - **QRS complex:** Represents ventricular depolarization. A widened QRS complex may indicate bundle branch blocks (e.g., LBBB or RBBB) or ventricular hypertrophy. - **ST segment and T wave:** The ST segment represents the period between ventricular depolarization and repolarization. Elevation or depression of the ST segment is indicative of ischemia or infarction. The T wave reflects ventricular repolarization, and abnormalities like tall T waves can suggest hyperkalemia or ischemia. - **QT interval:** Represents the total time for ventricular depolarization and repolarization. A prolonged QT interval can suggest electrolyte imbalances (e.g., hypokalemia, hypocalcemia) or the effects of medications (e.g., antiarrhythmics, antidepressants).

Question 66

Explain the different types of echocardiograms and their clinical applications.

Answer 66

**Types of Echocardiograms:** 1. **Transthoracic Echocardiogram (TTE):** The most common type of echo, non-invasive and uses ultrasound waves transmitted through the chest wall. It provides detailed images of the heart's chambers, valves, and function. TTE is useful in diagnosing heart failure, valvular diseases, and cardiomyopathies. 2. **Transesophageal Echocardiogram (TEE):** A specialized echo where the transducer is placed in the esophagus, providing clearer images of the heart’s posterior structures (e.g., left atrium, aortic root). It is particularly useful in diagnosing conditions like atrial thrombus, prosthetic valve dysfunction, and aortic dissection. **Clinical Applications:** - **Heart valve diseases:** Both TTE and TEE help assess valvular stenosis and regurgitation, enabling evaluation of leaflet motion and the size of orifices. - **Heart failure:** Echocardiography is vital in determining the ejection fraction (EF), which helps classify heart failure as systolic or diastolic. It also assesses wall motion abnormalities indicative of ischemia or infarction. - **Pericardial diseases:** Pericardial effusions or constrictive pericarditis can be evaluated using echocardiography

Question 67

Detail the mechanism of action and diagnostic utility of an Electroencephalogram (EEG)

Answer 67

hanism of Action:** An EEG detects electrical activity generated by neurons in the cerebral cortex, particularly postsynaptic potentials. Electrodes are placed on the scalp, and the EEG records the voltage fluctuations caused by electrical impulses from the brain's pyramidal cells. This activity is presented as waveforms, which vary in frequency and amplitude depending on the brain's state. **Diagnostic Utility:** - **Epilepsy:** EEG is crucial in diagnosing epilepsy, as it captures abnormal, repetitive, and rhythmic activity indicative of seizures. Specific patterns like spike-and-wave discharges are typical in absence epilepsy. - **Sleep Disorders:** EEG helps in diagnosing conditions such as sleep apnea and narcolepsy by identifying sleep-related changes in brain activity. - **Encephalopathy:** EEG can show slow wave activity indicative of diffuse brain dysfunction, as seen in metabolic encephalopathies or encephalitis. - **Coma and Brain Death:** EEG is used to assess the level of brain activity in comatose patients, and in brain death, there may be an absence of electrical activity

Question 68

Compare and contrast Spirometry with other pulmonary function tests, focusing on its role in diagnosing respiratory diseases.

Answer 68

**Spirometry:** Spirometry measures airflow and lung volumes during forced expiration and inspiration, helping to assess lung function. The two primary measurements are Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 second (FEV1). Spirometry is commonly used in the diagnosis of obstructive lung diseases (e.g., asthma, COPD) and restrictive lung diseases (e.g., pulmonary fibrosis). - **Obstructive pattern:** Characterized by a reduced FEV1/FVC ratio (<70%), seen in conditions like asthma and COPD. - **Restrictive pattern:** A reduced FVC but a normal or increased FEV1/FVC ratio, suggestive of lung parenchymal diseases or chest wall abnormalities. **Other Pulmonary Function Tests:** 1. **Plethysmography:** Measures lung volumes, particularly residual volume (RV) and total lung capacity (TLC), which spirometry cannot measure. It is more useful in restrictive lung diseases. 2. **Diffusion Capacity for Carbon Monoxide (DLCO):** Assesses the lung’s ability to transfer gases. A reduced DLCO suggests diseases like interstitial lung disease or pulmonary hypertension

Question 69

Discuss the types of endoscopy, their clinical uses, and the risks involved with each type.

Answer 69

**Types of Endoscopy:** 1. **Upper GI Endoscopy (Esophagogastroduodenoscopy, EGD):** Visualizes the esophagus, stomach, and duodenum. It is used to diagnose conditions such as GERD, peptic ulcers, and malignancies. Biopsies can be taken for histopathological analysis. 2. **Colonoscopy:** Examines the colon and rectum. Indicated for screening colorectal cancer, diagnosing inflammatory bowel diseases (e.g., Crohn’s, ulcerative colitis), and removing polyps. 3. **Bronchoscopy:** Used to visualize the airways. Indicated in cases of persistent cough, hemoptysis, or suspicion of lung cancer. It can also be used for therapeutic purposes, such as removing foreign bodies or secretions. **Risks:** - **Perforation:** The risk of perforation is higher in procedures like colonoscopy, particularly in patients with diverticulitis or when biopsies are taken. - **Infection:** Endoscopies carry a risk of infection, though this is generally low with proper sterilization protocols. - **Sedation Risks:** Endoscopic procedures require sedation, which can lead to complications like respiratory depression or aspiration, especially in high-risk patients

Question 70

Analyze the role of stress echocardiograms in diagnosing coronary artery disease (CAD).

Answer 70

**Stress Echocardiogram:** A stress echocardiogram assesses the heart’s function under physical or pharmacological stress (e.g., exercise or dobutamine). The heart is imaged both at rest and during stress to detect areas of ischemia, indicated by abnormal wall motion. **Diagnostic Utility in CAD:** In CAD, stress induces ischemia in areas of the myocardium supplied by stenotic coronary arteries. This results in abnormal wall motion that can be visualized using echocardiography. Stress echocardiograms can detect significant coronary artery obstructions and are particularly useful in patients with intermediate risk for CAD or those who cannot undergo stress ECG due to baseline abnormalities. **Advantages:** Stress echocardiography provides real-time imaging and does not involve radiation, unlike nuclear stress tests. It also offers insights into valvular function and cardiac contractility

Question 71

Evaluate the clinical utility of transesophageal echocardiogram (TEE) in detecting structural heart abnormalities.

Answer 71

Transesophageal Echocardiogram (TEE):** TEE involves placing an ultrasound transducer in the esophagus, providing high-resolution images of the heart’s posterior structures. This proximity to the heart allows for better visualization of areas that may be obscured by the chest wall or lungs in a transthoracic echo. **Clinical Utility:** - **Left Atrial Thrombus:** TEE is particularly sensitive in detecting thrombi in the left atrium and appendage, which is critical in patients with atrial fibrillation at risk of embolic stroke. - **Aortic Dissection:** TEE can quickly identify dissections in the ascending aorta or aortic arch, guiding emergency surgical intervention. - **Endocarditis:** TEE provides detailed images of heart valves, making it superior for detecting vegetations or abscesses in infective endocarditis. **Risks:** TEE is generally safe but carries risks like esophageal perforation, aspiration, and complications from sedation. These risks are mitigated through careful patient selection and procedural precautions

Question 72

What are the key features of a normal ECG?

Answer 72

A normal ECG shows a regular rhythm and rate (usually 60-100 beats per minute), a P wave preceding each QRS complex, a normal QRS duration (<120 ms), and a flat or isoelectric ST segment. The T wave follows the QRS complex, representing ventricular repolarization.

Question 73

How is left ventricular hypertrophy (LVH) diagnosed using echocardiography?

Answer 73

LVH is diagnosed by measuring the thickness of the left ventricular wall. If the interventricular septum or posterior wall measures more than 1.2 cm in diastole, it indicates LVH. Echo also shows increased mass and reduced compliance in hypertrophied myocardium.

Question 74

What abnormalities might an EEG show in a patient with epilepsy?

Answer 74

In epilepsy, the EEG may show abnormal spikes, sharp waves, or spike-and-wave complexes, which are indicative of abnormal neuronal activity. These patterns are often focal or generalized, depending on the type of epilepsy.

Question 75

How is spirometry used to differentiate between obstructive and restrictive lung disease?

Answer 75

Spirometry shows a decreased FEV1/FVC ratio (<70%) in obstructive diseases (e.g., COPD, asthma). In restrictive lung diseases (e.g., pulmonary fibrosis), both FEV1 and FVC are reduced, but the FEV1/FVC ratio is normal or increased.

Question 76

What are the primary indications for a bronchoscopy?

Answer 76

Bronchoscopy is indicated in persistent cough, hemoptysis, suspicion of lung cancer, or to evaluate airway abnormalities such as strictures or obstructions. It can also be used to obtain tissue samples or remove foreign bodies.

Question 77

What role does endoscopy play in the diagnosis of peptic ulcer disease?

Answer 77

Endoscopy allows direct visualization of the gastric and duodenal mucosa, making it the gold standard for diagnosing peptic ulcers. It also allows for biopsy to rule out malignancy and test for H. pylori infection.

Question 78

What is the clinical significance of the diffusing capacity for carbon monoxide (DLCO) test in pulmonary function?

Answer 78

DLCO measures the lung’s ability to transfer gases from the alveoli into the blood. A reduced DLCO indicates conditions like interstitial lung disease or pulmonary hypertension, while a normal or increased DLCO may be seen in asthma.

Question 79

How does a stress test help in diagnosing coronary artery disease?

Answer 79

A stress test increases the heart's workload through exercise or pharmacologic agents. If coronary arteries are narrowed, ischemia occurs, leading to abnormal ECG changes, reduced wall motion on echocardiography, or perfusion defects on nuclear imaging, helping diagnose coronary artery disease.