surgery and to enhance our understanding of the pathophysiology of mitral stenosis. Although surgery produced a significant increase in calculated mitral valve area, the degree of improvement varied markedly. The younger patients had the greater increase in mitral valve area. The change in cardiac index and pulmonary vascular resistance correlated well with the change in mitral valve area. Only...

In an attempt to produce substantial reductions in pulmonary arterial pressure and pulmonary vascular resistance in patients with primary pulmonary hypertension, a new treatment strategy using high doses of calcium channel-blocking drugs was developed. Thirteen patients were given an initial test dose of 60 mg diltiazem or 20 mg nifedipine followed by consecutive hourly doses until a 50% fall i...

surgery and to enhance our understanding of the pathophysiology of mitral stenosis. Although surgery produced a significant increase in calculated mitral valve area, the degree of improvement varied markedly. The younger patients had the greater increase in mitral valve area. The change in cardiac index and pulmonary vascular resistance correlated well with the change in mitral valve area. Only...

SUMMARY During cardiac catheterization in nine patients with ventricular septal defect and seven patients with truncus arteriosus, all with severe pulmonary vascular obstructive disease, hemodynamics were compared while they were breathing first room air and then 100% oxygen. Patients with higher pulmonary vascular resistance had higher systemic vascular resistances. With 100% oxygen, pulmonary...

objective(s) diabetes related dysfunction of resistance vessels is associated with vascular occlusive diseases. vasorelaxant agents may have a role in control of diabetic cardiovascular complications. gamma aminobutyric acid (gaba) has demonstrated to cause vasorelaxation. the present study was designed to determine i) the vasorelaxatory effect of gaba on diabetic vessels and ii) the role of en...

To examine whether endothelial nitric oxide formation contributes to the vascular tone of resistance coronary vessels in vivo, we administered NG-nitro-L-arginine methyl ester (L-NAME) (10 and 100 micrograms/kg/min), a nitric oxide synthase inhibitor, as well as D-enantiomer into the left circumflex artery in normal dogs. Intracoronary L-NAME, which was associated with dose-related reductions i...

The haemodynamic effects of oral prazosin and hydralazine were evaluated in patients with refractory heart failure and compared with those of intravenous nitroprusside in the same patients. Both oral agents were well tolerated and appeared to have beneficial haemodynamic effects. Prazosin and hydralazine produced similar increases in cardiac output associated with a similar decrease in systemic...

The effect of sympathetic nerve stimulation on the pulmonary circulation was studied in a hemodynamically separated dog lung in which blood flow was maintained constant with a pump. Electrical stimulation of the stellate ganglia at 3, 10, and 30 cps produced a significant increase in mean lobar arterial perfusion pressure. Since lobar blood flow and left atrial pressure did not change during ne...

The peripheral vascular response to severe exercise in eight dogs with heart failure produced by tricuspid avulsion and progressive pulmonary stenosis was compared to the response determined in eight control dogs. After full recovery from implantation of Doppler flow probes and miniature pressure gauges, measurements of arterial blood pressure and blood flow were telemetered from untethered dog...

BACKGROUND Although postprandial hypotension is a common cause of falls and syncope in elderly persons and in patients with autonomic insufficiency, the pathophysiology of this disorder remains unknown. METHODS AND RESULTS We examined the hemodynamic, splanchnic blood pool, plasma norepinephrine (NE), and heart rate (HR) power spectra responses to a standardized 400-kcal mixed meal in 11 heal...