Echo

Question 1

What are typical echo findings of mitral stenosis on 2D Echo?

Answer 1

• Diastolic “doming” of the anterior mitral valve leaflet - “hockey stick” appearance (best seen on parasternal long axis view)
• Commisural fusion - “fish mouth appearance” (best seen on parasternal short axis view)
• Left atrial dilatation
• Left atrial spontaneous echo contrast - “smoke”

Question 2

Define Aliasing

Answer 2

• imaging error which occurs due to under-sampling
• Occurs in PW doppler where there is an upper limit of doppler shift which can be displayed - Nyquist limit
• US system is trying to image an event that is occuring faster than the rate we are sampling it
• As a result the system is uncertain about the direction of the signal and displays this as heading in the opposite direction
• Occurs in both color and spectral Doppler, where the velocity exceeds the Nyquist limit
• “Wagon-wheel” effect (wheels turning in the opposite direction as it turns at a faster rate)

Question 3

Define Nyquist Limit

Answer 3

• Half of the sampling rate of a discrete signal processing system
• Sometimes known as “folding frequency”
  *

Question 4

What is the PISA method for determining MVA?

Answer 4

MVA cm² =

• 6.28 x r² x Aliasing velocity
• Mitral ValveE Wave Velocity (Vmax)

Question 5

What is the equation for MVA by P 1/2 time?

Answer 5

MVA cm² = 220 / PHT

Question 6

What are the Level 1 ASE recommendations for Mitral stenosis?

Answer 6

• MVA planimetry
  
  • using the parasternal short axis of the mitral level in mid-diastole
• MVA using PHT method
• Mean pressure gradient

Question 7

What are teh Level 2 ASE recommendations for evaluation of mitral stenosis?

Answer 7

• MVA by continuity equation
• MVA by PISA method
• MVA and SPAP with stress echocardiography

Question 8

What situations can PHT method overestimate MVA?

Answer 8

• Decreased PHT
  
  • Significant AR
  • ASD
  • Decreased LV compliance
  • Sudden change in LA compliance (fever, anemia, tachycardia, acute MR, exercise)

Question 9

What situations can PHT method underestimate MVA?

Answer 9

• Increased PHT
  
  • Decreased rate of LV relaxation
  • Immediately following PMBV

Question 10

What situations will result in a discrepancy between the MVA by PHT and planimetry?

Answer 10

• MR
• High-cardiac output
• Tachycardia

***increased transmitral flow can raise the gradient out of proportion to the calculated and planimetered MVA

Question 11

What are the branches of the aortic arch (in order)?

Answer 11

• brachiocephalic
  
  • Right subclavian
  • Right common carotid
• Left common carotid
• Left Subclavian

Question 12

What are the key elements of standard echocardiographic systems?

Answer 12

• transducer with piezoelectric crystals
  
  • transmits ultrasound waves and receives ultrasound echoes produced when the ultrasound waves reflect back off of human tissue
• computerized system tha programs the generation of ultrasound waves, processes the received signals, and stores the data
• display for visualization and interpretation of data, either in real-time or offline.

Question 13

What is the equation for describing the behavior of ultrasound waves?

Answer 13

λ = c/f

• λ = wavelength or peak-to-peak
• c = velocity of the us wave
• f = frequency of the us wave

Question 14

What is the velocity of US waves in human tissues?

Answer 14

1540 m/sec (1.54 mm/μsec)

• localization of objects is based fundamentally on the speed of propagation of sound waves

Question 15

What determines the fundamental limit of resolution in ultrasound?

Answer 15

Wavelength

• approximately 2x wavelength

Question 16

Explain advantages / disadvantages of higher frequency?

Answer 16

• better image resolution
• decreased penetrance (only penetrate a short distance in the body)

Question 17

Define acoustic impedance

Answer 17

• physical property of tissue
• describes how much resistance an ultrasound beam encounters as it passes through a tissue
• dependent on the density of the tissue

Question 18

Sound waves cannot travel through this?

Answer 18

vacuum

• pressure waves can be transmitted only trhough physical media consisting of molecules that interact with each other

Question 19

Ultrasound is a pressure wave with a frequency that is above the limit of human hearing, which is?

Answer 19

20, 000 Hz or 20 kHz

Question 20

The frequency of a sound wave is measured in Hz and is defined as?

Answer 20

number of times particles vibrate each second in the direction of wave propagation

Question 21

Ultrasound imaging is usually performed using frequencies in this range?

Answer 21

1-30 MHz

• lower frequencies in this range are used to image large organs or deeper structures that require significant penetration depth
• higher frequencies in this range are used for smaller and more superficial structures that require less depth but better spatial resolution

Question 22

Define Pressure Half-Time

Answer 22

the time interval in milliseconds between the maximum mitral gradient in early diastole and the time point where the gradient is half the maximum initial value.

Question 23

Define Bruce Protocol

Answer 23

• Developed in 1963 by Robert A. Bruce
• standardized multistage treadmill test for assessing cardiovascular health
• patient walks on an uphill treadmill in a graded exercise test with electrodes on the chest to monitor the EKG.
• Every 3 minutes, the speed and incline of the treadmill are increased (3 Mets increase)
• 7 stages, only very fit athletes can complete all 7 stages
• Modified Bruce Protocol –> treadmill initially horizontal, instead of sloped

Question 24

What are two of the most serios contraindications to ETT that can sometimes be overlooked?

Answer 24

• Aortic dissection
• Pulmonary Embolus

Question 25

What are the absolute contraindications to ETT?

Answer 25

* CHF, uncontrolled * High-risk UA * Arrhythmia, uncontrolled * Aortic Dissection * Acute MI * Myocarditis / Pericarditis * Pulmonary Embolus * Severe symptomatic AS

Question 26

What are the relative contraindications to ETT?

Answer 26

* Stenotic heart disease (moderate) * Tachy/bradyarrythmia * Electrolyte abnormalities * AV block (high-degree) * LMCA disease * Hypertension (BP \> 200/110 mmHg) * HOCM

Question 27

What are indications to stop ETT?

Answer 27

* Patien'ts desire to stop * CNS symptoms * Moderate angina * Arrhythmias (serious) * ST-elevation \> 1.0mm * Hypotension (SBP drop \> 10 mmHg below baseline) * Hypertension (SBP \> 220 mmHg)

Question 28

What is the hallmark of an abnormal ETT? How is this abnormal response defined?

Answer 28

* ST-segment depression * ≥ 1.0mm horizaontal or downsloping ST-segment depression measured 0.08 seconds after the J point

Question 29

What are additional features of an ETT that increase the likelihood of a true-positive test result?

Answer 29

- Occurrence at a low exercise workload - Involvement of several EKG leads - Greater magnitude of depression - Longer persistence in the recovery period.

Question 30

What is the significance of ST-depression that occurs only in the recovery period?

Answer 30

same diagnostic accuracy as ST-segment depression during exercise

Question 31

What are the most frequently identified lead abnormalities on ETT?

Answer 31

* Positive responses in V4-V6 ( \> 90%) regardless of site of anatomical CAD * ST-depression confined to inferior leads --\> usually represents false positive findings

Question 32

When does ST-elevation usually show up on ETT? What does this mean?

Answer 32

* Can be arrythmogenic if exercise continues. * Can localize site of myocardial ischemia (unlike ST-depression) and usually indicates high-grade stenosis

Question 33

What EKG findings preclude interpretation of exercise EKG?

Answer 33

* Paced ventricular rhythm * Pre-excitation (WPW) * LBBB * Reduce specicity --\> ST-T abnormalities, Digoxin use, LVH

Question 34

Can ETT/EKG interpretation be performed in the setting of RBBB?

Answer 34

* Yes * Right precordial leads (V1-V3) must be ignored and interpretation is confined to left precordial leads (V4-V6)

Question 35

What are the three clinical CAD risk categories defined by the ACC/AHA?

Answer 35

* Low ( \< 1% mortality rate) * Intermediate ( 1-3% mortality rate) * High ( \> 3% mortality rate)

Question 36

What is the most important/strognest prognostic ETT variable?

Answer 36

* Exercise capacity / duration * patient's at high risk for left main/three-vessel CAD * high clinical event rate

Question 37

What are clinical variables in ETT that identify higher-risk patients?

Answer 37

* Poor exercise capacity * Hypotension, exercise induced * Chronotropic incompetence * during exercise or or post-exercise * Ventricular ectopy * ST-depression (weaker than other variables)

Question 38

Define Duke Treadmill Score (DTS)

Answer 38

* weighted index combining: * treadmill exercise time using standard Bruce protocol * maximum net ST segment deviation (depression or elevation) * exercise-induced angina. * Developed to provide accurate diagnostic and prognostic information for the evaluation of patients with suspected coronary heart disease. * Typical observed range of DTS is from -25 (highest risk) to +15 (lowest risk).

Question 39

What is the equation for the DTS?

Answer 39

Question 41

What are the recommendations for pre-operative stress testing?

Answer 41

* Elevated risk and poor functional capacity --\> pharmacologic stress testing, if it will change management (Class IIa) * Elevated risk and unknown functional capacity --\> exercise testing to assess functional capacity if it will change management (Class IIb) * Elevated risk and poor ( \< 4 METS) or unknown functional capacity --\> exercise testing with cardiac imaging to assess for myocardial ischemia if it will change management (Class IIb) * Testing not recommended for low-risk surgery (Class III) * Reasonable to forgo exercise testing and proceed to surgery in patients with elevated risk and excellent functional capacity, defined as \> 10 METS (Class IIa) * Reasonable to forgo exercise testing and proceed to surgery in patients with elevated risk and moderate to good functional capacity, defined as 4-10 METS (Class IIb)

Question 42

In what groups of patients should stress imaging be the initial testing modality?

Answer 42

* inability to exercise with requirement for pharmacologic stress * significant abnormalities on resting EKG that preclude interpretation of the stress EKG * high pretest probability of CAD

Question 43

What are the Class I indications for stress testing?

Answer 43

* Standard ETT in patients at intermediate pretest probability of CAD who can exercise and have interpretable EKG * Exercise imaging in patients at intermediate or high pretest probability of CAD who can exercise and have an uniterpretable EKG * Pharmacologic imaging in patients with intermediate or high pretest probability of CAD who are unable to exercise.

Question 44

How to obtain the parasternal long axis view?

Answer 44

* Position the TTE transducer: * 3rd-4th intercostal space * at left parasternal border * index marker pointing toward the right shoulder (11 o'clock) * Adjust sector depth to: * 10-16 cm to see the descending aorta in SAX * increase to 20cm to assess for a left pleural effusion

Question 45

What are the assessment goals in parasternal long axis?

Answer 45

* LV size and function * RV size * Mitral valve * Aortic valve * Left pleural effusion * Pericardial effusion * Aortic dissection

Question 46

What structures can be identified in parasternal long axis view?

Answer 46

* Aortic Valve * Descending aorta (Ao) * Inter-ventricular septum (IVS) * Left atrium (LA) * LV * Mitral valve * RVOT

Question 47

What structures can be identified in parasternal short axis view?

Answer 47

* Anterolateral papillary muscle (AL) * Inter-ventricular septum (IVS) * LV * Posteromedial Papillary Muscle (PM) * RV

Question 48

What should parasternal short axis be used to assess?

Answer 48

* LV size and function * RV size and function * Pericardial effusion

Question 49

How to obtain parasternal short axis view?

Answer 49

* Position the TTE transducer * 3rd-4th intercostal space * left parasternal border * index marker poiting towards the left shoulder (2 oclock) * view can easily be obtained by rotating the probe 90 degrees clockwise from the parasternal LAX view and tilting the probe downards * Adjust the sector deptht to: * 10-16 cm to see the entire LV

Question 50

What structures should be identified in the apical four chamber view?

Answer 50

* Descending Aorta (Ao) * Inter-atrial septum (IAS) * LA * Left lower pulmonary vein (LLPV) * LV * MV * RA * Right upper pulmonary vein (RUPV) * RV * TV

Question 51

How to obtain apical four chamber view?

Answer 51

* Position the TTE transducer * 4th or 5th intercostal space * midclavicular line or at the point of apical pulsation * index marker pointing towards the left (3 oclock) * Adjust the sector depth to: * 14-18cm to image the atria * 6-10 cm to assess the LV apex

Question 52

What should the apical four chamber view be used to assess?

Answer 52

* LV, RV size and function * RA and LA size and function * MV and TV's * Pericardial effusion

Question 53

What should the subcostal four chamber view be used to assess?

Answer 53

* LV, RV size and function * MV and TV's * RA, LA size and function * Pericardial effusion * Cardiac motion during code blue

Question 54

What structures should be identified on subcostal four chamber view?

Answer 54

* Inter-atrial septum (IAS) * Inter-ventricular septum (IVS) * LA * RA * MV * TV * RV * LV * Liver

Question 55

How to obtain subcostal four chamber view?

Answer 55

* Position the TTE transducer: * subxiphoid region of the abdomen * flat and push down with a slight tile to the patients right * index marker pointing towards the left (3 oclock) * Adjust the sector depth to: * 16-24cm to image the entire LA and LV

Question 56

How to obtain the subcostal IVC view?

Answer 56

* Position the TTE transducer: * in the subxiphoid region of the abdomen * tilt to the patient's left * index marker pointing towards the head (12 oclock) * view can easily be obtained by rotating the probe 90 degrees counterclockwise from the subcostal 4C view * Adjust the sector depth to: * 16-24cm to image the entire IVC

Question 57

What should the subcostal IVC view be used to assess?

Answer 57

* IVC size (measure in mm or cm) * change in IVC size with respiration (use m-mode)

Question 58

What structures should be identified on the subcostal IVC view?

Answer 58

* IVC * Liver * RA

Question 59

What are the most common indications for TEE?

Answer 59

* left atrial thrombus evaluation * endocarditis * prosthetic valve function * perioperative cardiac surgery complications * providing guidance in transcatheter procedures

Question 60

What are the major complications associated with TEE?

Answer 60

* Cervical spine immobility * Recent Upper GI surgeries * Esophageal strictures * Prior perforated upper GI structures * Upper GI bleed (active)

Question 61

TEE terms: - Advance - Withdraw - Turn - Flexion - Extension - Rotation

Answer 61

- Advance: vertical forward motion of probe - Withdraw: vertical backward motion of probe - Turn: rotation of entire probe - Flexion/Extension: motion of tipe of the probe in a plane parallel to the long-axis of the probe, controlled by a large dial at the base of the probe - Rotation: electronic movement of the image plane in a circular fasion, controlled by a button on the probe and displayed as an angle on the image

Question 62

Describe the difference (incidence, location, degree of injury) in CHB in anterior vs. inferior MI?

Answer 62

Inferior * 4% of patients, may be transient * associated with higher location of AV block (typically the AV node) * lesser degree of myocardial injury Anterior * 1% of patients, serious complication of anterior MI, poorer short term outcomes (including survival) * associated with lower location of block is usually below the AV node --\> higher long-term block * greater degree of myocardial injury

Question 63

What is the starting view for TEE? How to obtain this view?

Answer 63

* Mid-esophageal 4-chamber view * Mid-esophageal positioning, 0 degree rotation, maximum depth to show the entire LV, probe extended to include as much of the apex as possible

Question 64

What are the second and third images obtained on a TEE?

Answer 64

After obtaining ME apical 4-chamber view: * 2nd --\> ME, apical, 2 chamber view --\> rotating to 60 degrees * 3rd --\> ME, apical, Long axis (LAX) view --\> rotating to 120 degrees

Question 65

TEE views utilized to assess regional LV function / EF?

Answer 65

* lateral wall and inferior septum --\> ME, A4C * anterior and inferior walls --\> ME, A2C * anterior septum and inferior lateral wall --\> ME, ALAX

Question 66

Quantitative EF measurements in TEE can be made utilizing what methods?

Answer 66

* 3D full volume acquisition with automated border detection * Biplane approach with tracing of endocardial borders at end-diastole and end-systole in A4C ad A2C views

Question 67

What TEE view is this? How to obtain the view? What is this view used for?

Answer 67

- ME, Bicaval view - Obtain ME, A4C --\> rotate to 90-100 degrees and turn probe right - ASD (secundum, sinus venosus), Atrial pathology, Lines/wires, Venous cannula (SVC, IVC)

Question 68

What is the best TEE view for evluating the LAA?

Answer 68

- ME, A2C - imaged in two orthogonal planes (0 and 90 degrees)

Question 70

What are the branches of the celiac trunk?

Answer 70

* Splenic artery * Left gastric * Common Hepatic