Medici A

Treatment of angina at rest with nifedipine: A short-term controlled study

The effectiveness of nifedipine in treating angina pectoris at rest was evaluated in 14 patients with frequent ischemic episodes associated with S-T segment elevation or depression. The trial consisted of (1) a 48 hour control period; (2) a placebo period and a period of treatment with nifedipine of 48 hours each; and (3) a second placebo period and a second period of treatment with nifedipine of 24 hours each. The efficacy of treatment was evaluated by continuous electrocardiographic recording to detect painless ischemic episodes. During coronary angiography coronary spasm was demonstrated in five patients. The ergonovine maleate test was positive in seven of eight patients. No statistically significant difference was found in the mean daily number of ischemic episodes between the control period and the first placebo period, or between the control and the second placebo periods. Nifedipine produced a highly significant reduction in the mean daily number of episodes compared with the response to placebo during the first as well as the second period. Nifedipine is effective in angina at rest caused by coronary arterial spasm. The prevention of ischemia may be related to the ability of nifedipine to decrease calcium-dependent coronary muscle tone and to prevent coronary spasm.

Dipyridamole Test in Angina Pectoris: Diagnostic Value and Pathophysiological Implications

The value of the dipyridamole test (0.75 mg/kg i.v.) in the diagnosis of angina pectoris was studied in 54 patients with angina pectoris (35 with angina on effort associated or not associated with rest angina and 19 with angina only at rest) and in 12 control subjects. The test induced electrocardiographic signs of ischemia (positive test) in 74% of patients with angina on effort, while it was negative in all cases with angina only at rest and in control subjects. All anginal patients with normal coronary arteries or less than 50% stenosis had a negative test; a positive response was observed in 36, 79 and 60% of cases with one-, two-or three-vessel disease, respectively. Hemodynamic changes with a marked arteriolar vasodilatation were observed both in the negative and in the positive tests. In the positive tests no significant change of double product, blood pressure and left ventricular end-diastolic pressure occurred before ischemia appeared. The results of the study show that dipyridamole as a diagnostic test in angina pectoris has a high specificity but a lower sensitivity than exercise test. The hemodynamic and eletrocardiographic findings in the positive tests suggest that dipyridamole-induced ischemia is due to a flow maldistribution with selective subendocardial ischemia secondary to the coronary arteriolar dilatation caused by the drug.

Treatment of vasospastic angina pectoris at rest with nitroglycerin ointment: A short-term controlled study in the coronary care unit

The effectiveness of nitroglycerin ointment in vasospastic angina pectoris at rest was evaluated in 10 patients selected for study. The study was performed after a 24 hour control period, and a randomized single-blind crossover experimental design was followed. Two percent nitroglycerin ointment (15 mg) or placebo ointment was administered every 6 hours for a period of 48 hours each; the first treatment period was followed by a second in which each preparation was used for a 24 hour period. All patients were hospitalized in the coronary care unit; an objective evaluation was carried out using a multichannel electrocardiographic recording to assure recognition of the painless ischemic episodes. Coronary angiography showed critical stenosis of one or two vessels in 9 of the 10 patients; spasm was demonstrated in 3. Results of the ergonovine test were positive in nine of nine patients. Nitroglycerin ointment produced a significant reduction in the mean daily number of episodes during the first (12.5 +/- 3.9 versus 0.5 +/- 0.4, p less than 0.02) as well as the second treatment period (10.6 +/- 3.8 versus 0.6 +/- 0.4, p less than 0.02). These results demonstrate that nitroglycerin ointment provides effective, long-lasting protection against angina due to coronary spasm.