Total excision of the right atrium with a minimal cuff of left atrium remaining around the four pulmonary veins, followed by direct anastomoses on venae cavae, has been proposed as an alternative to the standard procedure described by Shumway and Lower for orthotopic cardiac transplantation. To investigate whether this "anatomic" transplantation should be proposed as the optimal procedure, we prospectively randomized 78 patients having 81 procedures since 1991 into two groups: group I, standard transplantation (n = 40), and group II, "anatomic" transplantation (n = 41). The two groups were statistically similar in recipient age, sex, weight, disease, and status at the time of transplantation. Also similar were donor age, sex, weight, and drug dependency at the time of harvesting. All patients could be weaned from cardiopulmonary bypass with comparable graft ischemic times (group I, 136 +/- 46 minutes; group II, 138 +/- 51 minutes). Immediate recovery of sinus rhythm occurred in 20 cases of group I and 36 cases of group II. Delayed recovery of sinus rhythm in the first postoperative week occurred in 15 cases of group I and 5 cases of group II. Persistence of atrial arrhythmia occurred in 5 cases of group I and never in group II. These differences were highly significant (p < 0.001). Postoperative hemodynamics showed a higher cardiac index at day 1 in group II (4.12 +/- 0.85 L/min per square meter) than in group I (3.77 +/- 0.65 L/min per square meter) (p = 0.04). There were 13 early deaths in group I and 8 early deaths in group II. One death in group I was related to an acute atrioventricular block at 3 weeks with no evidence of cardiac rejection at histologic examination. Two patients in group I (5%) required definitive pacemaker implantation for prolonged sinus node dysfunction. Echocardiographic and Doppler studies of survivors have been performed 2 to 3 months after transplantation. Right atrial area was significantly reduced (p < 0.01) in group II (18 +/- 4.7 cm2) versus group I (24 +/- 7 cm2), as was left atrial area (group I, 24 +/- 4.5 cm2; group II, 20 +/- 5 cm2) (p = 0.01). Mild tricuspid regurgitation was observed in 82% of group I patients versus 57% of group II patients (p < 0.05), inasmuch as mitral regurgitation was comparable (71% in group I, 67% in group II).(ABSTRACT TRUNCATED AT 400 WORDS)
Moderate cardiac hypertrophy (CH) was produced in rats by abdominal aorta constriction for 5, 8, 15, 21, and 28 days. Aortic constriction release after 5, 8, and 15 days led to CH regression, which was complete within 15 days. A study of left ventricular papillary muscle mechanics during CH development demonstrated an early but transitory decrease in both maximum isometric force (Po) and maximum muscle shortening velocity (max V); in addition, the time-to-peak tension increased, and there was a decrease in isometric relaxation rate and in force-frequency relationship (negative staircase.) After CH regression, isometric relaxation and negative staircase were similar to controls, whereas the prolonged duration of contraction persisted. After release of the aortic constriction at 8 and 15 days, Po and max V were normal; however, after the earlier release (5 days), Po was higher than control, when muscle thickness was taken into consideration. These findings suggest 1) that an alteration in muscle mechanics may be related to the hypertrophy itself; 2) that anomalous excitation-contraction coupling might persist after CH regression.
Heart hypertrophy remains an important topic since research into its mechanism evokes similar questions to those related to heart insufficiency.A brief review of some of the important questions from a morphological point of view will be discussed.
These data indicate that in human transplanted denervated hearts, coronary vasodilation in response to sympathetic stimulation by cold exposure is impaired shortly after operation.
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