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Purpose: To select ideal radiologic projections for mapping and ablation of tachycardias of right ventricular outflow tract (RVOT)., Methods: Ten hearts from human corpses were studied utilizing radiopaque material to identify the pulmonary valve and three distinct sites on this valve: septal anterior (A), septal posterior (P) and free-wall (L). Next, the hearts were filmed in the frontal plane and in oblique projections with 15 degrees increments to the right and to the left. The projections in which the sites were lateralized on the valve, eased radiologic interpretation and were considered ideal for mapping and ablation. Depending on the proximity of the sites to the lateral extremes of the pulmonary valve, the projections were considered ideal ( ), intermediary (++) and inadequate (+)., Results: Projections [table: see text], Conclusion: The A site of RVOT was best indicated in the 60 and 45 degrees left anterior oblique projections; the 0 degree postero anterior projection was best for mapping the P site; the L region was best explored in the 60 degrees right anterior oblique projection.

A 8-year-old female patient with refractory incessant atrial tachycardia, very symptomatic and with left ventricular ejection fraction of 0.25. Electrophysiological study and endocardial mapping localized the site of the origin of atrial tachycardia in the superior right atrium. In this site 2 applications of radiofrequency current (25V, 20 and 50 seconds) resulted in termination of the atrial tachycardia. She was discharged off antiarrhythmic drugs and after 2 months ejection fraction was 0.52. She was completely asymptomatic 6 months after ablation procedure.

Two female patients, 54 and 38 years-old with refractory ventricular tachycardia were undertaken to electrophysiologic study for diagnosis and radiofrequency ablation of their arrhythmias. The tachycardias were only inducible with intravenous isoproterenol infusion. The site of the origin of ventricular tachycardia was localized in the right ventricular outflow tract in both cases. Radiofrequency current was delivered at 40V (40-60s) in each patient and was followed by complete abolition of ventricular arrhythmias.

Purpose: To localize the site of the origin of sustained ventricular tachycardia in chronic chagasic cardiomyopathy patients refractory to antiarrhythmic therapy by radionuclide angiography techniques., Methods: Five patients underwent radionuclide angiography by intravenous administration of 25mCi 99mTc. The images were obtained in sinus rhythm and during sustained ventricular tachycardia induced in the electrophysiologic laboratory for endocardial mapping. Amplitude and phase images were obtained resulting in a contraction wave synchronic to ventricular dispolarization., Results: All patients had haemodynamic stability during the arrhythmia. One patient had incessant ventricular tachycardia. Mean ejection fraction was 0.38. In 4 patients the site of the origin of ventricular tachycardia was posterior and in one it was localized in the interventricular septum. There was identity in the site of the origin of ventricular tachycardia obtained by endocardial mapping or radionuclide angiography in all patients. The therapy was chemical ablation in 3 patients, surgical aneurysmectomy in one and pharmacologic therapy in the last patient., Conclusion: The site of the origin of ventricular tachycardia can be estimated by analyzing the contraction wave obtained by radionuclide angiography techniques in patients with hemodynamic stable sustained ventricular tachycardia.

Purpose: To report our experience on percutaneous vascular foreign body retrieval and to analyse current techniques employed., Methods: From 1985 to 1991, 15 (0.18%) of 7,963 procedures performed in the Cardiac Catheterization Laboratory-Hospital São Paulo were intravascular foreign body retrieval: 9 (60%) intracath, 4 (26.8%) diagnostic catheters, one Swan Ganz catheter entrapped at superior cava vein and one fragment of angioplasty guide-wire in the circumflex branch of the left coronary artery. The snare technique was used in 11 cases, a endomyocardial bioptome device in 1 case and modified snare technique for the intracoronary wire fragment retrieval was used in 1 case. In two cases of embolized fragment in peripheral arteries, no attempt was done for retrieval., Results: All (100%) of the 13 attempted procedures were successful. The two foreign bodies not removed had an uneventful follow-up., Conclusion: The snare technique for percutaneous retrieval of intravascular foreign bodies is safe and has excellent results. The management peripheral fragments is not well defined yet.

Purpose: evaluate the efficacy of radiofrequency catheter ablation in patients with refractory cardiac arrhythmias., Methods: twenty patients with refractory cardiac arrhythmias were undertaken to electrophysiologic studies for diagnosis and radiofrequency catheter ablation of their reentrant arrhythmias. Ten patients were men and 10 women with ages varying from 13 to 76 years (mean = 42.4 years). Nineteen patients had supraventricular tachyarrhythmias: One patient had atrial tachycardia and 1 atrial fibrillation with rapid ventricular rate, 5 patients had reentrant nodal tachycardia, 12 patients had reentrant atrioventricular tachycardia and 1 patient had right ventricular outflow tract tachycardia., Results: the mean time of the procedure was 4.1 hours. The radiofrequency current energy applied was 40-50 V for 30-40 seconds. Ablation was successful in 18/20 (90%) patients; in 15/18 (83%) of successfully treated patients the same study was done for diagnosis and radiofrequency ablation. One patient had femoral arterial occlusion and was treated with no significant sequelae. During a mean follow-up of 4 months no preexcitation or reentrant tachycardia occurred., Conclusions: the results of our experience with radiofrequency catheter ablation of cardiac arrhythmias suggest that this technique can benefit an important number of patients with cardiac arrhythmias.

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.

Chagas disease is a leading cause of heart failure in Latin America. Sudden death occurs in approximately 40% of patients with heart failure due to Chagas disease. We report a single blind, cross-over trial of prolonged treatment with captopril and placebo in 18 Chagas disease patients with class IV NYHA heart failure. Ventricular dimensions, neurohormones, electrolytes and ventricular arrhythmias were analysed in 11 men and seven women receiving stable doses of digoxin and frusemide who were randomly divided into two intervention groups. Group I patients were given increasing doses of captopril up to 150 mg.day-1 maintained for 6 weeks, group II received the placebo. A 24 h Holter, 2-D echocardiogram, urinary catecholamines, plasma renin and electrolyte determinations were performed at the end of each phase. After a 2-week washout period, the two groups crossed over and another period of 6 weeks was observed. Ventricular arrhythmias were analysed by either Mann-Whitney or the Wilcoxon test. Remaining data were assessed by the Student t-test. A significant reduction in heart rate and urinary catecholamine levels, and enhanced plasma levels of renin, together with a reduction in ventricular couplets was found in the captopril-treated group. We conclude that captopril has a beneficial effect on neurohormones with a subsequently reduced heart rate and diminished incidence of ventricular arrhythmias in patients with Chagas disease. This effect might result in a reduction of mortality caused by the disease, suggesting the need for further investigations.

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.

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.

Captopril, a potent inhibitor of angiotensin converting enzyme, was tested in patients with COPD (means forced expired volume in the first second--FEV1 = 0.73 l) and pulmonary hypertension (PAP = 41.3 mmHg). In the first phase of the experiment, patients underwent and incremental exercise test to the limit of tolerance. These were double blind, randomized, cross-over studies, where the patients received oral placebo (Pl) or captopril (Cp) 25 mg, on different days. In a second phase, the patients were submitted to hemodynamic and gasometric studies in the supine position, before placebo, the 60 min after and immediately after exercise (cycling-like leg movements). After 30 min of rest the same protocol was repeated with oral administration of 25 mg of captopril. In the metabolic evaluation (cycloergometry) captopril increased significantly exercise tolerance (means VO2-uptake at maximal exercise: CP = 0.81 vs Pl = 0.73 1/min), associated with a slower heart rate and higher O2-pulse at maximal exercise. In the hemodynamic study, when the effects of Cp and Pl were compared, the mean values of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) were similar at rest, but significantly lower during exercise, after captopril (means PAP Cp = 41.3 vs Pl = 51.2 mmHg; XPVR Cp = 278 vs Pl = 392 dyn. sec. cm5). There were similar systemic hemodynamic effects after Cp, but these were more intense in the pulmonary circulation (lower PVR/SVR ratio post-Cp in relation to post-Pl, during exercise). The cardiac index, systemic O2 transport and arterial and mixed venous blood gases were similar at rest and during exercise, with Pl or Cp.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe aortic regurgitation may be associated with premature aortic valve opening. Several possible etiologies for this diastolic opening have been suggested. We present a patient with hemodynamic data, M-mode and 2-D echocardiography in the setting of severe aortic regurgitation and diastolic aortic valve opening. Our data lead us to conclude that aortic valve opening in this situation is neither from passive flotation nor dependent on atrial systole. We believe that active ventricular recoil mechanisms can facilitate increases in diastolic ventricular pressure which then can transiently exceed aortic pressure in the setting of severe aortic regurgitation. This hemodynamic observation suggests that the valve opening is an active process.