AIMS To assess the effect of experimentally induced atrial fibrillation on coronary flow in humans. METHODS AND RESULTS In 16 patients (10 men, mean age 43+/-13 years) with normal coronary vessels, baseline and hyperaemic blood pressure and Doppler phasic coronary flow velocity were measured, using a 0.014 inch intracoronary Doppler flow wire, during sinus rhythm, experimentally induced atria...

We examined the late coronary vascular response to carotid chemoreceptor reflex activation in normal, conscious dogs instrumented for the measurement of right main and left circumflex coronary artery blood flows, arterial and right ventricular pressures, and arterial and coronary sinus blood gases and O2 contents. With heart rate held constant by electrical stimulation, and with respiration con...

The effects of intravenous injections of aminophylline on the coronary blood flow, cardiac oxygeni consumption, cardiac work, and cardiac rate were studied by catheterization of the right ventricle and coronary sinus in anesthetized dogs. There was no substantial increase in coronary flow when cardiac activity increased following injection of the drug; this suggested that the oxygenation of the...

Systemic and coronary hemodynamics were assessed before and during a reduction in carotid transmural pressure. This reduction was induced by means of a pneumatic neck chamber in 15 normal subjects and 15 hypertensive patients with a normal coronary arteriogram. A reduced baroreflex responsiveness was demonstrated in hypertensive patients as compared with normal subjects by evaluating both the r...

Q measurement of coronary blood flow by indicator-dilution methods has been attempted by various groups within the past five years. The theory upon which these studies have been based is that after injection into either the pulmonary artery or left ventricle, the first activated blood to reach the right ventricle on recirculation returns by way of the coronary vessels. Henly and eo-workers rapi...

We examined the late coronary vascular response to carotid chemoreceptor reflex activation in normal, conscious dogs instrumented for the measurement of right main and left circumflex coronary artery blood flows, arterial and right ventricular pressures, and arterial and coronary sinus blood gases and O2 contents. With heart rate held constant by electrical stimulation, and with respiration con...

The responses of eicosanoids to acute myocardial ischemia induced by either exercise stress testing (EX) or percutaneous transluminal coronary angioplasty (PTCA) were investigated in 23 patients with effort angina pectoris (EAP). EX was useful procedure to determine the therapeutic plan in each cases, and PTCA is the novel therapeutic operation for EAP. The relations between these metabolites a...

Analysis of factors which may influence oxygen metabolism of the heart has received much attention since the early part of this century (1). Quantitative measurements of coronary blood flow and myocardial oxygen consumption (MVO,) have been accumulated from both human and animal studies (2, 3). These studies were uniformily concerned with adults, however, and virtually no information is availab...

OBJECTIVE To determine whether, when the vasomotor capacity of the coronary arterioles is exhausted at rest, myocardial blood volume decreases in order to maintain a normal capillary hydrostatic pressure, even at the expense of myocardial oxygen delivery. METHODS 18 dogs were studied. In group 1 (n = 9), coronary driving pressure (CDP) was reduced by 10-80 mm Hg below normal by a stenosis; in...