Effects of exercise training on left ventricular performance and myocardial perfusion in patients with coronary artery disease.

To determine the effects of exercise training on left ventricular performance and myocardial perfusion in coronary artery disease, rest and exercise radionuclide angiocardiography and thallium-201 scintigraphy were performed before and after 12 weeks of training in 16 coronary patients. After training, 15 of the 16 patients had improved exercise tolerance; total treadmill exercise duration increased from (mean +/- standard error of the mean) 491 +/- 37 to 602 +/- 31 seconds (p less than 0.01), and the estimated rate of oxygen consumption (VO2 max) increased from 29.4 +/- 1.4 to 33.8 +/- 1.2 ml/kg per min (p less than 0.001). Resting left ventricular ejection fraction increased from 52 +/- 4 to 57 +/- 4 percent (p less than 0.02); no change occurred in left ventricular functional reserve assessed by ejection fraction and regional wall motion response to exercise at the same rate-pressure product before and after training. Myocardial perfusion at equivalent pre- and post-training cardiac work loads during exercise and on redistribution was unchanged by training. It is concluded that in patients with coronary heart disease, physical training increases exercise tolerance, and results in minimal improvement in resting left ventricular systolic performance. Functional reserve of both left ventricular systolic performance and the coronary circulation appears to be unchanged by exercise training. These data suggest that the beneficial effects of training for 12 weeks in patients with coronary artery disease predominantly result from factors other than improvement in left ventricular pump performance or perfusion.

Recurrent infective endocarditis in a drug addict. Multiple separate episodes in nine years.

Multiple episodes of documented recurrent infective endocarditis occurred in an habitual drug abuser. The six recurrences represent the largest known number reported in a single patient. The case illustrates many characteristics of infective endocarditis and serves to emphasize that recurrent infections are likely if endocarditis risk factors are not eliminated.

Demonstration of training effect during chronic beta-adrenergic blockade in patients with coronary artery disease.

Attenuation of exercise-induced increases in heart rate and cardiac output by chronic beta-adrenergic blockade has been thought to compromise benefit of exercise training in patients with coronary artery disease (CAD). To assess this important issue, 35 CAD patients were evaluated by a 3-month walk-jog-cycle training program: 14 patients received no beta blocker (group 1), 14 received propranolol, 30-80 mg/day (group 2), and seven patients received propranolol, 120-240 mg/day (group 3). The extent of CAD, resting heart rate before training blood pressure and VO2 max were similar (p = NS) in each group. The maximal exercise heart rate (mean +/- SD, 147 +/- 21 beats/min in group 1 vs 120 +/- 10 beats/min in group 2 and 115 +/- 12 beats/min in group 3 (both p less than 0.05 vs group 1). The VO2 max before training was 25 +/- 5.0 ml/kg/min in group 1 vs 23 +/- 3.2 ml/kg/min in group 2 and 26 +/- 2.8 ml/Kg/min in group 3 (all p = NS). Training consisted of three 1-hour periods per week at a heart rate of 70-85% of the maximal pretraining heart rate. In each group, VO2 increased (p less than 0.05) after training: group 1, 27%; group 2, 30%; group 3, 46%. The double product was unchanged after training (p = NS) in each group. These data indicate that substantial training effects may be achieved in CAD patients despite therapeutic doses of beta blockers and a reduced training HR. Thus, there appears to be no indication to reduce beta blockers in CAD patients engaged in cardiac rehabilitation.

Surgery in active infective endocarditis.

Controversy persists concerning the role of early surgical intervention in severe infective endocarditis (IE). We therefore reviewed 163 episodes of well-documented IE in which 32 cardiac operations were performed during the active phase of IE. Congestive heart failure (CHF) was the principal indication for surgery in 88% (28/32); systemic emboli, 1/32; and persisting sepsis, 3/32. Staphylococcus and enterococcus were the most common infecting organisms in the operative group (44% and 16% respectively). Surgical mortality (11/32,37%) did not differ (p greater than 0.05) from medical mortality (26/131,20%). All 11 operative deaths occurred in patients moribund prior to surgery, including three with preoperative cardiac arrest. Surgical patients undergoing preoperative cardiac catheterization demonstrated marked CHF: a mean left ventricular end-diastolic pressure of 25.3 mm Hg. The mean cardiac index in 8/11 surgical deaths was lower (p less than 0.05) vs surgical survivors: 2.21/min/m2 vs. 3.21/min/m2. Postoperative complications were rare in the 21 surgical survivors. There were no episodes of continued infection, prosthetic dehiscence, or advanced heart block; only one paravalvular leak; and one systemic embolus. These findings emphasize the high medical and surgical mortality in patients with IE, suggest that delayed operative intervention may be a major causative factor resulting in a high surgical mortality, and justify an aggressive surgical approach in patients with valve dysfunction and heart failure. These data indicate that survivors of surgical intervention during active IE have eradication of infection and few postoperative complications.