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