Actions of cromakalim in isolated human saphenous vein.

The present study was performed to evaluate the effect of cromakalim on human vein in vitro. Branches of human saphenous vein (leftovers), obtained from patients undergoing heart revascularization surgery, were cut into rings and suspended in an organ chamber filled with Krebs-Ringer solution for the measurement of isometric contractile force. Concentration-response curves to norepinephrine and serotonin were constructed before and after pretreatment with cromakalim. The concentration-response curves to norepinephrine and serotonin were displaced to the right, and the maximal responses to both agonists were significantly inhibited by cromakalim in a concentration-dependent manner. Following sustained contraction induced by prostaglandin F2 alpha or 20 mM KCl, the cumulative addition of cromakalim to the organ chamber produced a concentration-dependent relaxation. However, in veins precontracted with 60 mM KCl the addition of cromakalim in concentrations of up to 10(-5) M did not induce relaxation. The relaxation induced by cromakalim in veins precontracted with prostaglandin F2 alpha was significantly inhibited by glibenclamide. These results indicate that cromakalim has a dilator effect in human vein that may play a helpful role in the treatment of angina. The venodilator effect of cromakalim in human saphenous vein probably involves activation of adenosine triphosphate-regulated potassium channels.

Isolated tricuspid stenosis: report of a case submitted to valvular commissurotomy.

In this report, a rare case of tricuspid stenosis uncomplicated by other valve lesions is presented, with clinical, hemodynamic, echocardiographic, and angiographic studies. The patient was markedly incapacitated, mostly as a result of a restricted cardiac output. Tricuspid commissurotomy was performed, with a stenotic deformity of a bicuspid atrioventricular valve, probably of congenital origin, found at surgery. Considerable improvement was observed, notwithstanding the persistence of some signs of residual tricuspid obstruction as a result of an incomplete commissurotomy, to avoid increasing the slight degree of preexistent valvular regurgitation.

Obstrucao sifilitica do ostio: coronaria esquerda. / Syphilitic obstruction of the ostium: left coronary

E apresentado um caso de aortite luetica complicada de insuficiencia aortica e obstrucao total do ostio da coronaria esquerda. Os autores chamam a atencao para o papel protetor da circulacao colateral que se desenvolveu em funcao da obstrucao do ostio coronariano, a qual possibilitou ao paciente qualidade de vida razoavel, preservacao da funcao ventricular e trans e pos-operatorio sem intercorrencias graves.O caso representa, pelo menos em nosso meio, o primeiro em que a obstrucao sifilitica do ostio coronariano foi confirmado atraves do estudo cinecoronariografico

Subvalvular left ventricular pseudoaneurysm: a rare complication of mitral valve replacement.

A patient who developed a subvalvular left ventricular pseudoaneurysm following mitral valve replacement is presented, the fourth such case in the literature. The etiology of this uncommon complication is felt to be caused by excessive surgical resection of the diseased mitral valve, which may weaken or cause rupture of the heart at the mitral annulus. The diagnosis can only be made by left ventriculography. Surgical treatment is indicated, because rupture of the pseudoaneurysm can occur.