Search

Seven female patients (age 27 to 53 yr) with significant mitral stenosis performed continuous, incremental, maximal treadmill exercise tests the day before and within 3-5 days after catheter-balloon valvuloplasty. Mitral valve area determined by the echo-Doppler method increased from 0.9 +/- 0.3 cm2 to 1.9 +/- 0.7 cm2 (p < 0.02). Mean left atrial pressure was reduced from 24 +/- 8 to 13 +/- 7 mmHg (p < 0.01) and mean pulmonary artery pressure from 36 +/- 13 to 28 +/- 10 mmHg (p < 0.02) with a non-significant increase in cardiac output from 3.6 +/- 1.2 to 4.0 +/- 1.7 l/min. After catheter-balloon valvuloplasty all patients reached a higher maximal workload during exercise, and mean value of oxygen consumption and pulmonary ventilation were significantly lower in submaximal workloads. The calculated ventilatory equivalent for oxygen was significantly reduced in submaximal and in maximal workloads after catheter-balloon valvuloplasty. Peak oxygen consumption and the ventilatory anaerobic threshold were not changed after catheter-balloon valvuloplasty (pre 15.59 +/- 2.72 vs post 16.90 +/- 3.44 and pre 12.10 +/- 2.55 vs post 12.62 +/- 2.71 ml/kg/min, respectively). We concluded that after catheter-balloon valvuloplasty the cost of breathing was reduced and the oxygen consumed was more effectively utilized during exercise. Increases in peak oxygen consumption and in ventilatory anaerobic threshold would require circulatory and metabolic adaptations in response to increased physical activity and were not observed when cardiopulmonary tests were performed early after catheter-balloon valvuloplasty.

Chronic nonparoxysmal sinus tachycardia has been described as an inappropriate and persistent sinus tachycardia that is not related to organic, physiologic and adrenergic states or automatic dysfunction. Some cases are very symptomatic and refractory to conventional therapy. In this report, we describe an unusual therapy for a refractory case of chronic nonparoxysmal sinus tachycardia.

Forty-three consecutive symptomatic patients with chronic Chagasic myocarditis and ventricular tachycardia (VT) underwent clinical evaluation, 24-hour Holter monitoring, left ventricular angiography and electrophysiologic testing including programmed ventricular stimulation at 3 drive cycle lengths at 2 sites in the right ventricle. The mean ejection fraction was 42 +/- 10%. Sixteen patients had clinical sustained VT and 27 nonsustained VT. VT was reproducibly initiated in 13 of 16 (81%) patients with sustained VT and in 14 of 27 (52%) patients with nonsustained VT. Electrocardiographic conduction disturbances were seen in 15 of 16 (94%) patients with sustained VT and in 17 of 27 (63%) patients with nonsustained VT (p less than 0.05). Five of 16 (31%) sustained VT and none of nonsustained VT patients had left ventricular aneurysms (p less than 0.05). These data indicate that VT is frequently inducible in patients with sustained VT and nonsustained VT and chronic Chagasic myocarditis. An association appears to be present between conduction disturbances on the electrocardiogram, left ventricular aneurysms and development of sustained ventricular arrhythmias.

Endomyocardial fibrosis (EMF) is a disease of unknown etiology characterized by progressive fibrosis and obliteration of the right ventricular (RV) or left ventricular (LV) cavities and often associated with atrioventricular valve incompetence. Patients with EMF have a poor prognosis. Surgical treatment usually results in clinical and hemodynamic improvement. 1–6 In this study we present pre- and postoperative clinical and noninvasive follow-up in 15 consecutive patients with EMF.

Infusion of glucose-insulin-potassium during acute myocardial infarction has favorable clinical and hemodynamic effects, presumably as a result of decreased myocardial utilization of free fatty acids. In 14 patients with coronary artery disease, hypertonic glucose (a bolus of 10 g followed by infusion of a 30% glucose solution at a constant rate of 10 mg/kg/min) was infused and arterial and coronary sinus levels of glucose, lactate and free fatty acids were measured before and after 15 and 30 minutes of infusion. Arterial glucose and lactate levels increased significantly after glucose infusion, whereas free fatty acid levels decreased significantly. Modest but significant correlations also existed between glucose arterial levels and the arterial-coronary sinus glucose difference (r = 0.53, p less than 0.001); arterial lactate and the arterial-coronary sinus lactate difference (r = 0.35, p less than 0.01); arterial free fatty acids; and the arterial-coronary sinus free fatty acid difference (r = 0.62, p less than 0.001). These results with a hypertonic glucose infusion are similar to those reported after infusion of glucose-insulin-potassium without the potential for harmful adverse effects from infusions of insulin or potassium. Therefore, infusion of hypertonic glucose may be beneficial in patients with coronary artery disease. Further work is necessary to study its effects in different subgroups of patients with coronary artery disease.