What is the primary cause of myocardial ischemia?

Choice A rationale
Diltiazem does not increase the contractile force of the heart. In fact, it is classified as a negative inotrope, meaning it decreases the force of heart contractions.
Choice B rationale
While diltiazem can affect heart rhythm, it does not specifically reduce heart palpitations. Its primary effect is to slow the heart rate and relax the blood vessels.
Choice C rationale
Diltiazem is a calcium channel blocker used to manage cardiovascular conditions such as hypertension, chronic stable angina, atrial fibrillation, and Prinzmetal’s angina. It works by inhibiting the calcium influx into cardiac and vascular smooth muscle during depolarization. This results in vasodilation, or the widening of blood vessels, which can help decrease coronary artery spasms, a characteristic feature of Prinzmetal’s angina.
Choice D rationale
Diltiazem does not prevent the formation of plaque in the coronary arteries. It primarily acts to relax the blood vessels and slow the heart rate.

Choice A rationale
Prolonged PR intervals occur with first-degree AV block, not typically with pericarditis.
Choice B rationale
Clubbing of the fingers is a loss of the normal angle between the base of the nail and the skin. This finding can be found in endocarditis, congenital defects, and/or prolonged oxygen deficiency. It is not a typical manifestation of pericarditis.
Choice C rationale
Widened pulse pressure occurs with valvular heart disease, not typically with pericarditis.
Choice D rationale
Pulsus paradoxus is a sign of cardiac tamponade, a serious complication of pericarditis. As the compression of the heart increases, decreased left atrial filling decreases cardiac output.