A reduced coronary flow reserve has been reported in patients with ischemialike symptoms and normal coronary arteries. In 13 such patients, both coronary vasomotion and flow reserve were studied. The luminal area of the proximal and distal third of the left anterior descending and left circumflex artery were determined by biplane quantitative coronary arteriography using a computer-assisted sys...

DESCRIPTION A 71-year-old man was admitted with a 2-day history of intermittent palpitations. His initial ECG demonstrated a supraventricular tachycardia with a heart rate of 170 bpm. Following treatment with verapamil he reverted to sinus rhythm. As part of his initial investigations he had a two dimensional transthoracic echocardiogram. The parasternal long axis view demonstrated a well-circu...

BACKGROUND Access to data on the coronary flow in the coronary sinus (CS) can aid in the diagnosis of coronary artery disease (CAD). We tested the hypothesis that assessing the CS flow by transthoracic Doppler echocardiography (TTE) at rest can detect coronary artery stenosis in non-hypertensive patients. METHODS The antegrade phase of coronary flow in the CS was analyzed and compared in 140 ...

On the coronary circulation, the effect of catecholamines was disputed by many investigators, and there is general agreement that catecholamines increase the coronary blood flow. However, some researchers attributed this vasodilatation to myocardial stimulation and consequent metabolic vasodilatation rather than to direct action to the coronary artery1,2,3). On the other hand, ZUBERBUHLER and B...

A 39-year-old man with no significant past medical history and no conventional coronary risk factors presented with a history of gradually progressive exertional dyspnea and a systolic heart murmur. Chest x-ray showed an enlarged cardiac silhouette with pulmonary plethora. Initial assessment by transthoracic echocardiography demonstrated mild mitral regurgitation but also revealed an enlarged c...

A 39-year-old man with no significant past medical history and no conventional coronary risk factors presented with a history of gradually progressive exertional dyspnea and a systolic heart murmur. Chest x-ray showed an enlarged cardiac silhouette with pulmonary plethora. Initial assessment by transthoracic echocardiography demonstrated mild mitral regurgitation but also revealed an enlarged c...

Interruption of oxygen supply in acute myocardial ischaemia reduces venous return of oxygen at the coronary sinus. In this study, the oxygen content of venous return in the coronary sinus was measured by using spectrometry in the near infrared spectrum. The authors developed a new intravascular catheter made of fibre optics. After in vitro calibration by blood flow based on a standard gas mixtu...

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...

BACKGROUND The pressure waveform of coronary sinus in human hearts has never been well described. Retrograde cardioplegia perfusion has become a popular method of myocardial protection in recent years, and identification of the pressure waveform of the coronary sinus might help intubate the coronary sinus in retrograde cardioplegia perfusion by differentiating it from that of the right atrium. ...

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...