Cardiovascular

Question 1

Coronary autoregulation allows coronary blood flow to be primarily driven by myocardial O₂ demand over a wide range of perfusion pressures (60-140 mmHg) and is controlled via release of what?

Answer 1

Adenosine and NO

Question 2

How do you calculate stroke volume (SV) and ejection fraction?

Answer 2

• SV = EDV - ESV
• EF: Stroke Volume / EDV

Question 3

Which acid-base physiological changes are seen when patient is at high altitude and develops altitude sickness?

Answer 3

• Low PiO₂ –> compensatory hyperventilation –> respiratory alkalosis
• Kidneys respond by decreasing HCO₃^- reabsorption and H⁺ secretion —> compensatory metabolic acidosis

Question 4

Sick sinus syndrome most commonly results from what; describe the findings seen on ECG?

Answer 4

• Age-related degeneration of the SA node, located in the RA wall
• ECG findings = bradycardia, sinus pauses (delayed P waves), and sinus arrest (prolonged delayed of a P wave such that P wave is dropped)

Question 5

Which type of breathing pattern is often seen in pt’s with advanced congestive heart failure (CHF)?

Answer 5

Cheyne-Stokes breathing: cyclic breathing pattern in which apnea is following by gradually increasing and then decreasing tidal volumes until next apneic period.

Question 6

Atrial septal defects with left-to-right shunting typically cause what ausculatory finding on PE?

Answer 6

Wide and fixed splitting (no change with respiration) of the 2nd heart sound (S2)

Question 7

How can a paradoxical embolism arise in a patient with net left-to-right shunting?

Answer 7

Transient reversal of the shunt during periods of elevated right-sided pressure (i.e., early ventricular systole, straining during coughing or defecation)

Question 8

The inferior wall of which ventricle forms the majority of the inferior (diaphragmatic) surface of the heart and what is its blood supply?

Answer 8

Inferior wall of LV supplied by posterior descending a. - branch of the right coronary a. (RCA)

Question 9

10% of people have left dominant circulation meaning the posterior descending artery derives from where?

Answer 9

• Circumflex branch of the left main coronary a.

*Typically arises from right main coronary a.

Question 10

Which artery supplies the wall of the RV and may provide collateral circulation in pt’s with LAD occlusion?

Answer 10

Right marginal branch of the RCA

Question 11

Occlusion of the right coronary artery may affect which areas of the heart during MI?

Answer 11

• LV due to inferior wall being supplied by posterior descending a. arising from RCA
• RV due to marginal a. arising from RCA

Question 12

What is the hallmark murmur heard with mitral valve prolapse (MVP)?

Answer 12

Mid-systolic click, often accompanied by late systolic murmur

Question 13

Immunohistochemistry is important diagnostic marker for mesothelioma as nearly all cases stain (+) for what?

Answer 13

Cytokeratins and many also (+) for calretinin

Question 14

When does papillary muscle rupture following an MI typically occur and what are the distinct PE findings?

Answer 14

• Within 3-5 days
• Acute, severe pulmonary edema + severe mitral regurgitation w/ flail leaflet

Question 15

What are the distinct PE findings of an interventricular septum rupture/defect following an MI?

Answer 15

• New holosystolic murmur
• Stepped-up O2 level between the RA and ventricle

Question 16

A loud pulmonic component of S2 and an accentuated, palpable impulse at the left sternal border (left parasternal lift) is seen with what condition?

Answer 16

Pulmonary HTN

Question 17

Which mutation is the most common cause of familial dilated cardiomyopathy?

Answer 17

Truncating mutations (usually nonsense) affecting TTN gene encoding for the sarcomere protein titin

Question 18

Myxomatous changes with pooling of proteoglycans in the media layer of large arteries are found in cystic medial degeneration, which predisposes to the development of what; commonly seen in association with what syndrome?

Answer 18

• Aortic dissections and aortic aneurysms
• Medial degeneration is commonly seen in younger pt’s with Marfan syndrome

Question 19

Which type of angina is more common in younger pt’s (<50) and is characterized by recurrent chest pain at rest or during sleep which resolves in 15 mins or less?

Answer 19

Vasospastic angina (aka Prinzmetal)

Question 20

Where is the most deoxygenated blood in the body found and why?

Answer 20

• Cardiac venous blood in the coronary sinus
• O₂ extraction from the blood by resting myocardium is higher than that extracted by any other tissue

Question 21

Holosystolic murmurs can be associated with what 3 conditions?

Answer 21

• Tricuspid regurgitation (TR): increases w/ inspiration
• Mitral regurgitation (MR): radiates to axilla
• Ventricular septal defct (VSD): loud and accompanied by thrill

Question 22

What structure does a venous catheter traveling from the right femoral vein pass through to get into the left atrium?

Answer 22

Interatrial septum at the site of foramen ovale

Question 23

Why are inferior MI’s often associated with bradycardia?

Answer 23

Due to blockage of RCA, which is responsible for perfusing the SA and AV nodes

Question 24

Coronary dominance is determined by what; what is a right vs. left dominant heart?

Answer 24

• Determined by the coronary artery that supplies blood to the posterior descending artery (PDA)
• Right coronary artery: 70% of population = right dominant
• Left circumflex artery: 10% of population = left dominant

Question 25

How is the murmur associated with hypertrophic cardiomyopathy best differentiated from that of aortic stenosis?

Answer 25

- Using maneuvers that affect **LV preload** - Maneuvers such as **valsalva**, **rapid standing**, and infusion of **nitroglycerin** all _decrease_ **LV preload** ---\> **increasing** intensity of **hypertrophic cardiomyopathy** - Maneuvers such as **passive leg raise** or **squatting** lead to _increased_ **LV preload** --\> **increasing** intensity of **aortic stenosis**

Question 26

Blunt aortic injury (i.e., traumatic aortic rupture) is most commonly associated with injury to which part of the aorta?

Answer 26

Aortic **isthmus**, which is tethered by the **ligamentum arteriosum**

Question 27

In patients with mitral regurgitation what is the best indicator of severe MR with left-sided volume overload?

Answer 27

Audible **S3 gallop**

Question 28

Nonbacterial thrombotic endocarditis (NBTE) is most commonly associated with which 2 underlying conditions?

Answer 28

- **Advanced malignancy**: especially **mucinous adenocarcinoma** - **SLE** --\> **Libman-Sacks endocarditis**

Question 29

What is the most common underlying valvular disease predisposing to the development of infective endocarditis in developed countries?

Answer 29

**Mitral valve prolapse (MVP)**, particularly when it is associated with coexistent **mitral regurgitation**