Which of the following classes of drugs is most widely used in the treatment of cardiomyopathy?
A. Antihypertensives
B. Beta-adrenergic blockers
C. Calcium channel blockers
D. Nitrates
Correct Answer: B. Beta-adrenergic blockers
By decreasing the heart rate and contractility, beta-blockers improve myocardial filling and cardiac output, which are primary goals in the treatment of cardiomyopathy. Therefore, the chronotropic and inotropic effects on the heart undergo inhibition, and the heart rate slows down as a result. Beta-blockers also decrease blood pressure via several mechanisms, including decreased renin and reduced cardiac output.
Option A: Antihypertensives aren’t usually indicated because they would decrease cardiac output in clients who are already hypotensive. Lowering blood pressure does reduce cardiovascular risks, maintaining systolic blood pressure less than 130 mm Hg has shown to prevent complications in patients with heart failure, diabetes, coronary artery disease, stroke, and other cardiovascular diseases.
Option C: Calcium channel blockers are sometimes used for the same reasons as beta-blockers; however, they aren’t as effective as beta-blockers and cause increased hypotension. Dihydropyridines are more potent as vasodilators and used more for HTN treatment. They have less effect on heart contractility and conduction. For this, they are used more for the management of HTN. Nifedipine and amlodipine are the most used medications in this group.
Option D: Nitrates aren’t used because of their dilating effects, which would further compromise the myocardium. The venodilation increases the venous capacitance and lowers the preload; this subsequently lowers the left ventricular end-diastolic pressure, resulting in a reduction in myocardium workload, which decreases the oxygen demand of the heart.
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