Which medication is used to slow the heart rate and reduce obstruction in hypertrophic obstructive cardiomyopathy?

Which medication is used to slow the heart rate and reduce obstruction in hypertrophic obstructive cardiomyopathy?

• A. Beta blockers
• B. ACE inhibitors
• C. Calcium channel blockers
• D. Nitrates

Answer: (A)

In hypertrophic obstructive cardiomyopathy the obstruction is dynamic and worsens with higher heart rate and stronger contractility. Slowing the heart rate and reducing contractility decreases the left ventricular outflow tract (LVOT) gradient and lessens the systolic anterior motion of the mitral valve, which together improve filling and lessen symptoms. Beta blockers achieve this by blunting sympathetic stimulation, leading to a slower heart rate and decreased contractility. This makes them the preferred first-line option to reduce obstruction and improve exercise tolerance and symptoms. If beta-blockers aren’t tolerated, non-dihydropyridine calcium channel blockers can be used as alternatives because they similarly slow rate and reduce contractility, though they require careful monitoring. Medications that mainly reduce preload or afterload, like nitrates or ACE inhibitors, can worsen obstruction by decreasing LV volume or systemic resistance, so they’re not the main choice for this condition.

In hypertrophic obstructive cardiomyopathy the obstruction is dynamic and worsens with higher heart rate and stronger contractility. Slowing the heart rate and reducing contractility decreases the left ventricular outflow tract (LVOT) gradient and lessens the systolic anterior motion of the mitral valve, which together improve filling and lessen symptoms. Beta blockers achieve this by blunting sympathetic stimulation, leading to a slower heart rate and decreased contractility. This makes them the preferred first-line option to reduce obstruction and improve exercise tolerance and symptoms. If beta-blockers aren’t tolerated, non-dihydropyridine calcium channel blockers can be used as alternatives because they similarly slow rate and reduce contractility, though they require careful monitoring. Medications that mainly reduce preload or afterload, like nitrates or ACE inhibitors, can worsen obstruction by decreasing LV volume or systemic resistance, so they’re not the main choice for this condition.