Summary: Bicuspid aortic valve (BAV) is an independentrisk factor for aneurysm and dissection of the ascending aorta. Despite this association, routine imaging of the aorta has not been recommended for patients with BAV. We describe two young men who developed life-threatening aneurysm or dissection ofthe ascending aorta; one had a normally functioning BAV and the other was 10 years after valve replacement. The pathology ofthis condition is very similar to that found in the Marfan syndrome. We recommend echocardiographic surveillance ofthe ascending aorta at regular intervals, and considcration of beta-adrenergic blockade among patients with significant dilation.

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Isolated mitral valve prolapse (MVP) may represent one end of a spectrum of disease involving dysfunction of multiple cardiac valves. Eighty-nine consecutive patients with MVP diagnosed by two-dimensional echocardiography (2-D echo) were prospectively studied specifically to determine the incidence of tricuspid valve prolapse (TVP) and its clinical correlations. Criteria for prolapse of the atrioventricular (A-V) valves by 2-D echo included extension of the valve leaflets behind an imaginary line defining the valve annulus. Forty-one of 82 patients with MVP had associated TVP. No significant differences existed between patients with isolated MVP and combined A-V valve prolapse with regard to sex, clinical history, symptoms, or physical examination. The parasternal long axis view was more sensitive than the apical four chamber view in diagnosing prolapse of either mitral or tricuspid valves. Thus, TVP is a frequent concomitant of MVP and occurs with equal frequency in both young and old patients.

Intravenous nitroglycerin (IV-NTG) has gained wide use in the manage ment of critically ill patients, yet little is known regarding dose-response hemodynamics in man. Therefore, we studied 10 patients, all Class III or IV New York Heart Association Classification with pulmonary artery wedge pressures of 15 torr or greater. A special delivery system designed to prevent drug absorption Nitrostat® IV Infusion Kit was used and assessed. Multiple hemodynamic values were recorded before, during, and after the infusion. Administration of IV-NTG was started at 0.125 mcg/kg/min and was doubled every 15 minutes to a maximum dose of 2.0 mcg/kg/min. The infusion was stopped if the pulmonary artery wedge pressure dropped below 10 torr, or arterial pressure dropped below 90/60 torr, or if the mean artery pressure fell more than 10 torr, or if significant side effects occurred. Samples for blood levels were collected. Only one patient noted any untoward effects and he recovered quickly upon cessation of infusion. The mean infusion rate was 0.6125 mcg/kg/min. A significant drop in mean arterial blood pressure, mean pulmonary artery pressure, mean pulmonary artery wedge pressure, heart rate, and arterial oxygenation was noted. Cardiac output did not change significantly. Pulmonary vascular resistance index, as well as several other indices, decreased significantly in all patients. Nitrostat IV® appears to be very safe and to work by dilating preload capacitance vessels, followed by a drop in arterial pressure without an adverse lowering of cardiac output.

Three forms of carotid sinus hypersensitivity are recognized clinically (cardio-inhibitory, vasodepressor, and mixed). The cardio-inhibitory form has been managed successfully with pacemaker therapy. The vasodepressor element has been difficult to manage clinically whether in its pure form or in combination with the cardio-inhibitory type. We review the various pharmacologic methods previously reported and present our experience with a new pharmacologic alternative, which is the combined use of ephedrine and propranolol to induce unopposed alpha stimulation.