Auxiliary Heart Transplantation

At the present time, the major obstacles in the successful clinical application of heart transplantation are the immunological attack on the allograft, the treatment of complications resulting from immunosuppression, and the supply of transplantable hearts. Recently, auxiliary heart transplantation has been proved to be a successful technique for treatment of end-stage myocardial failure in humans. Here we review the experimental work in auxiliary heart transplantation leading to the preent technique used in humans.     

Minocycline and generalized cutaneous pigmentation

The recent literature contains sporadic mention of localized pigmentary accumulations in skin, bones, teeth, and thyroid tissue, presumably related to the use of systemic minocycline hydrochloride. It is our purpose to report the occurrence of generalized, cutaneous, dark blue-gray hyperpigmentation that developed in a woman while she was being treated with minocycline (Minocin) for acne vulgaris. We believe this pigmentary change to be minocycline-induced.     

Myocardial revascularization in women.

During the period January, 1970, through June, 1977, 1,541 patients underwent coronary artery bypass grafting; 241 of them were women (15.6%). Operative mortality rates for the entire study were 2.4% in men and 3.7% in women, but they showed a marked decline in women during 1975 to mid-1977, with only 2 deaths in 140 patients (1.4%). Women comprised a larger percentage of patients (16.7%) in these later years. Women were slightly older, received fewer grafts, had better preservation of ventricular function on preoperative studies, and had more severe anginal symptoms than men. Patency rates were significantly lower in women at 1 month, 1 year, and 3 years. Five-year survival was not significantly different between women (88.3%) and men (93.5%). Many of these findings may be explained on the basis of women having smaller coronary arteries than men. These favorable results differ from earlier reports of higher mortality rates in women and indicate that myocardial revascularization should not be withheld from female patients.     

Hemodynamics of multiple versus single 50 percent coronary arterial stenoses

The purpose of this study was to compare coronary blood flow in the presence of multiple fixed coronary arterial stenoses with that in the presence of a single stenosis of equivalent length and diameter. The study was performed using an in vitro pulse duplicating system. The aortic root section consisted of an acrylic mold of the root of the aorta of a calf. The coronary system was designed to produce coronary flow with physiologic magnitudes and phasic patterns. Aortic and left ventricular pressures as well as the reduction in pressure across the coronary test section containing the stenotic segments were measured with catheter-tip micromanometers. Coronary flow was measured with a cannulating electromagnetic flow transducer. The fluid viscosity was 0.04 poise. Studies were performed sequentially with one 2 mm long arterial segment with a stenosis of 50 percent of luminal diameter, two such stenotic segments and three such stenotic segments in series. A single 4 mm long, 50 percent diameter stenotic segment and a 6 mm long, 50 percent diameter stenotic segment were also studied. The heart rate was 71 beats/min, stroke volume 80 ml and aortic pressure $\text{140}\text{75}\text{mm Hg}$. A single 2 mm long, 50 percent stenotic segment caused a 6 percent reduction of coronary flow; three such stenoses in series caused a 19 percent reduction of coronary flow. In contrast, a single 6 mm long, 50 percent diameter stenotic segment caused only an 8 percent reduction of coronary flow. The results suggest that in a maximally dilated coronary bed, a greater reduction of coronary flow would occur in the presence of multiple short stenoses than in the presence of a single stenosis of equivalent length and diameter.