Ragavendra R. Baliga, M.D
Assistant Professor
Division of Cardiology
University Of Michigan

Main Index

Table Of Contents

Question 11 of 39:

Long-acting oral nitrates should be administered early in the management of this patient's acute MI to relieve pain.

You clicked 'False'

Correct!

The totality of evidence from all pertinent randomized clinical studies does not support the routine use of long-term nitrate therapy in patients with uncomplicated myocardial infarction. However, it is prudent to use intravenous nitroglycerin for the first 24 to 48 hours in patients with acute myocardial infarction and recurrent ischemia, CHF or management of hypertension.

Intravenous administration is recommended in the early stage of acute myocardial infarction because of its onset of action, ease of titration, and the opportunity for prompt termination in the event of side effects.

Aside from its known clinical benefit in alleviating ischemic myocardial pain, nitroglycerin is appreciated as having a dilatory effect on vascular smooth muscle in vessels throughout the body. Thus, vasodilataton of the coronary artery themselves (especially at or adjacent sites of recent plaque disruption), peripheral arteries, and the venous capacitance vessels is particularly beneficial to the patients with acute infarction.

However, inadvertent systemic hypotension with resultant worsening of the underlying myocardial ischemia is potentially the most serious adverse consequence of nitrate therapy. Thus patients with ischemic type chest discomfort should receive sublingual nitroglycerin unless the initial systolic blood pressure is <90 mm Hg. It should be avoided in the presence of marked bradycardia (<50 bpm) or tachycardia (Come 1976).

Reference:

Come PC, Pitt B. Nitroglycerin-induced severe hypotension and bradycardia in patients with acute myocardial infarction. Circulation 1976;54:624-628.