CSC Cardiac Subspecialty 5 — Questions and Answers
Question 1: A patient with pulmonary arterial hypertension (PAH, Group 1) has WHO functional class III symptoms. Vasoreactivity testing with inhaled nitric oxide shows mean PAP decrease to 32 mmHg with cardiac output increase. What does this indicate?
- Positive vasoreactivity test; candidate for long-term calcium channel blocker therapy (Correct answer)
- Negative vasoreactivity test; initiate combination prostanoid therapy
- Indeterminate result; repeat test with adenosine
- Positive test; proceed directly to lung transplant evaluation
Correct answer: Positive vasoreactivity test; candidate for long-term calcium channel blocker therapy
A positive vasoreactivity test (mPAP decrease ≥10 mmHg to <40 mmHg with increased or unchanged cardiac output) identifies patients likely to benefit from high-dose CCBs.
Question 2: A 55-year-old man undergoes pharmacologic nuclear stress testing with regadenoson. Which adverse effect specific to regadenoson should be monitored for in patients with reactive airway disease?
- Hypertensive crisis
- Prolonged AV block requiring temporary pacing
- Bronchospasm due to adenosine receptor activation (Correct answer)
- Ventricular tachycardia from catecholamine surge
Correct answer: Bronchospasm due to adenosine receptor activation
Regadenoson activates A2A adenosine receptors but can also stimulate A2B receptors in bronchial smooth muscle, potentially causing bronchospasm in susceptible patients.
Question 3: A 67-year-old presents with severe mitral regurgitation (ERO 0.45 cm², regurgitant volume 65 mL) due to a flail posterior leaflet. He is asymptomatic with LVEF 58% and LV end-systolic dimension 39 mm. What is the most appropriate management?
- Medical management with vasodilators and reassess in 1 year
- Mitral valve surgery, preferably repair, given severe MR with flail leaflet (Correct answer)
- Referral for MitraClip procedure given high surgical risk
- Watchful waiting until EF drops below 50%
Correct answer: Mitral valve surgery, preferably repair, given severe MR with flail leaflet
Severe primary MR with a flail leaflet, even in asymptomatic patients, carries a high risk of LV dysfunction and warrants referral to a mitral valve repair center.
Question 4: Which statement best describes the mechanism of action of sacubitril/valsartan (Entresto) in heart failure with reduced ejection fraction?
- Dual ACE inhibition and aldosterone receptor blockade
- Neprilysin inhibition preventing BNP/ANP breakdown combined with AT1 receptor blockade (Correct answer)
- Combined beta-1 and alpha-1 blockade reducing cardiac workload
- Selective aldosterone antagonism preventing cardiac fibrosis and sodium retention
Correct answer: Neprilysin inhibition preventing BNP/ANP breakdown combined with AT1 receptor blockade
Sacubitril inhibits neprilysin (preventing natriuretic peptide degradation) while valsartan blocks AT1 receptors, reducing preload, afterload, and fibrosis.
Question 5: A 62-year-old woman with no cardiac history presents with acute anterior ST elevation MI. Primary PCI is performed at 90 minutes after first medical contact. Post-PCI TIMI flow is 3, but echocardiography shows apical ballooning with hyperkinetic basal segments. What is the most likely diagnosis?
- Takotsubo (stress) cardiomyopathy mimicking STEMI (Correct answer)
- Anterior STEMI with successful reperfusion and wall motion recovery
- Left ventricular thrombus formation
- Right ventricular infarction complicating anterior STEMI
Correct answer: Takotsubo (stress) cardiomyopathy mimicking STEMI
Apical ballooning with basal hyperkinesis (reverse pattern) in the distribution of multiple coronary territories, despite patent arteries, is the hallmark of Takotsubo cardiomyopathy.
Question 6: In which clinical scenario is intravascular ultrasound (IVUS) guidance during PCI most strongly supported by evidence to improve outcomes?
- Stable angina with moderate single-vessel disease and FFR 0.85
- Left main coronary artery PCI and complex bifurcation lesions (Correct answer)
- Small-vessel disease (<2.5 mm reference diameter)
- Uncomplicated right coronary artery stenting in stable patients
Correct answer: Left main coronary artery PCI and complex bifurcation lesions
IVUS guidance during left main PCI improves stent sizing, deployment, and reduces major adverse cardiac events compared to angiography alone.
Question 7: A patient with known Wolff-Parkinson-White (WPW) syndrome develops rapid atrial fibrillation with a ventricular rate of 220 bpm and wide, irregular QRS complexes. Which medication is CONTRAINDICATED?
- Procainamide IV
- Electrical cardioversion
- Ibutilide IV
- Adenosine or calcium channel blocker IV (Correct answer)
Correct answer: Adenosine or calcium channel blocker IV
AV nodal blocking agents (adenosine, CCBs, digoxin, beta-blockers) are contraindicated in WPW with AF as they accelerate conduction down the accessory pathway, potentially causing VF.
CSC Cardiac Subspecialty 5
A patient with pulmonary arterial hypertension (PAH, Group 1) has WHO functional class III symptoms.
Vasoreactivity testing with inhaled nitric oxide shows mean PAP decrease to 32 mmHg with cardiac output increase.
What does this indicate?