We studied the time course of three electrophysiologic effects of propranolol after intravenous and oral administration and their relationship with plasma levels within the same subjects. Ten patients who had undergone cardiac catheterization for diagnostic purposes received 0.1 mg/kg of propranolol intravenously. Blood was drawn at intervals for 12 hr and heart rate and the effective refractory periods of the atrium (ERPA) and the atrioventricular node (ERPAVN) were determined at the same time. Eight patients continued treatment with propranolol by the oral route for up to 4 days (40 mg every 12 hr). Blood was sampled after each morning dose. Plasma concentrations of propranolol were measured by gas chromatography. Maximal lengthening of ERPA after propranolol (15.1% i.v. and 9.4% oral) was much less marked than that of ERPAVN (23.2% i.v. and 19.4% oral). Heart rate decreased 23.5% (i.v.) and 13.1% (oral). Effects were seen much sooner after intravenous (5-8 min) than after oral administration (86-146 min), but they lasted about twice as long after oral as after intravenous treatment.

Administration, Oral↗

PubMedDate not supplied

Routine coronary angioplasty with autoperfusion balloon catheter: Can prolonged inflations reduce myocardial ischemia and preserve myocardial function?

Percutaneous transluminal coronary angioplasty (PTCA) is an established technique in the management of patients with angina pectoris or acute myocardial infarction. One of the major problems related to PTCA is myocardial ischemia following balloon catheter occlusion of the coronary artery. A new device utilized in an attempt to counteract myocardial ischemia is the perfusion balloon catheter which allows passive transmission of pulsatile blood flow to the distal myocardial bed. Our purpose was to compare immediate results following traditional PTCA and autoperfusion balloon PTCA in two groups randomly assigned to receive one of the two treatments (total patients n. = 158). The results show that coronary angioplasty was successfully performed in 98.87% of patients treated with autoperfusion PTCA and in 97.10% of those treated with conventional PTCA. In the autoperfusion PTCA group we observed a lower incidence (statistically significant) of ST elevation and of minor complications. We conclude that autoperfusion balloon catheter angioplasty may be recommended for its immediate success rate with good patient tolerance and lower incidence of in-hospital complications.

Adult↗