It was previously shown that red blood cells release ATP when blood oxygen tension decreases. ATP acts on microvascular endothelial cells to produce a retrograde conducted vasodilation (presumably via gap junctions) to the upstream arteriole. These observations form the basis for an ATP hypothesis of local metabolic control of coronary blood flow due to vasodilation in microvascular units where...

We developed a radioimmunoassay for plasma thromboxane B,, the metabolite of the coronary vasoconstrictor thromboxane A,. To see if thromboxane A, is produced during myocardial ischemia, we used atrial pacing to study 14 patients with greater than 75% occlusive coronary artery disease proved by arteriography. Paired samples were taken from the coronary sinus (CS) and an artery (A) for lactate a...

Assessment of coronary blood flow and the vasodilator reserve capacity of individual coronary arteries in the catheterization laboratory has been hampered by methodologic limitations. We have developed and validated a small Doppler catheter that can subselectively measure phasic coronary blood flow velocity (CBFV). In seven anesthetized calves, CBFV was varied from 0.1 to 5.7 times control CBFV...

The effects on coronary dynamics of propranolol and atenolol were studied in 12 patients undergoing cardiac catheterisation for suspected coronary artery disease. Myocardial blood flow was measured using the coronary sinus continuous thermodilution technique. Data were obtained immediately after drug administration and during rapid atrial pacing. The immediate effects were similar for both drug...

Assessment of coronary blood flow and the vasodilator reserve capacity of individual coronary arteries in the catheterization laboratory has been hampered by methodologic limitations. We have developed and validated a small Doppler catheter that can subselectively measure phasic coronary blood flow velocity (CBFV). In seven anesthetized calves, CBFV was varied from 0.1 to 5.7 times control CBFV...

Effects of H1-receptor stimulation on coronary arterial diameter and coronary hemodynamics were examined in 11 patients with angiographically normal coronary arteries and without variant angina or resting angina. Selective H1-receptor stimulation was achieved by infusing histamine into the left coronary artery at a rate of 2.0 1£g/min for 5 minutes after pretreatment with cimetidine (25 mg/kg)....

BACKGROUND AND OBJECTIVES Many clinicians believe that low-dose dopamine (LDD) [2 micro g/kg/min] increases renal blood flow (RBF) and medium-dose norepinephrine (MD-NE) [0.4 micro g/kg/min] decreases RBF. They also believe that MD-NE might induce mesenteric and/or coronary ischemia. In fact, the effects of these drugs on renal and vital organ blood flow are poorly understood. The aim of this s...

The combination of coronary arteriovenous fistula to the coronary sinus (CS), dilatation of the entire length of coronary artery, coronary aneurysm and persistent left superior vena cava (PLSVC) is very rare. We present the case of a 63-year-old female admitted for dyspnea on exertion, orthopnea, and facial edema. Echocardiography detected a giant coronary artery with shunt flow, dilated CS and...

Background and objectives: Many clinicians believe that low-dose dopamine (LDD) [2 g/kg/min] increases renal blood flow (RBF) and medium-dose norepinephrine (MD-NE) [0.4 g/kg/min] decreases RBF. They also believe that MD-NE might induce mesenteric and/or coronary ischemia. In fact, the effects of these drugs on renal and vital organ blood flow are poorly understood. The aim of this study was to...

A 61-year-old man was admitted to the hospital because of orthopnea and was diagnosed with heart failure with a continuous heart murmur. A transthoracic echocardiogram revealed turbulent flow from the right coronary sinus of Valsalva to the right atrium throughout the cardiac cycle. Aortography confirmed the presence of a shunt jet from the right coronary sinus of Valsalva to the right atrium. ...