LVOT

Q: All of the following are good choices for medical therapy in Left Ventricular Outflow Obstruction (LVOT)/Hypertrophic cardiomyopathy (HCM) except? 

A) beta blocker 
B) verapamil 
C) disopyramide 
D) nifedipine 
E) diltiazem 


 Answer:  D

Objective of above question is to highlight the drugs which should be avoided in LVOT/HCM. Two major classes of drugs which should ideally be avoided or at least be used with caution are

●Vasodilators
●Diuretics

Vasodilators which includes dihydropyridine calcium channel blockers (eg, nifedipine, amlodipine), nitroglycerin, angiotensin converting enzyme inhibitors (ACE-I), and angiotensin II receptor blockers (ARBs), can cause fatal hemodynmic collapse by producing a fall in peripheral vascular resistance which may increase LVOT obstruction and ventricular filling pressures. Diuretics reduce the preload and so ventricular filling, worsening the LVOT symptoms.

#cardiology
#hemodynamics


References:

1. Veselka J, Anavekar NS, Charron P. Hypertrophic obstructive cardiomyopathy. Lancet 2017; 389:1253. 

2. Rothman RD, Baggish AL, O'Callaghan C, et al. Management strategy in 249 consecutive patients with obstructive hypertrophic cardiomyopathy referred to a dedicated program. Am J Cardiol 2012; 110:1169.