Dietary magnesium improves endothelial dependent relaxation of balloon injured arteries in rats.

The purpose of the present study was to examine the importance of magnesium in endothelial function after arterial balloon injury. Male Wistar rats were fed normal, high or low concentrations of magnesium. Three weeks later the animals underwent endothelial injury of the thoracic aorta by a balloon catheter or a sham operation. Biochemical, histological and endothelial function analysis were performed 15 days after the surgical treatment. The animals fed a low magnesium diet presented the lowest level of serum magnesium and the highest ionized blood calcium levels. Histomorphometric analysis revealed no differences among groups neither regarding the magnitude of intimal thickening nor the recovery of endothelial coverage. However, when vasoreactivity responses were compared in the balloon-injured group, those animals fed a high magnesium diet had the better endothelium-dependent vascular relaxation. In conclusion, a higher magnesium level in the diet was beneficial to vessels that underwent endothelial injury by balloon catheter.

Single coronary arteries: two cases with distinct and previously undescribed angiographic patterns.

Single coronary artery is a rare congenital anomaly, sometimes associated with myocardial ischemia. We present the clinical and angiographic features of two symptomatic patients with documented myocardial ischemia and with distinct and previously undescribed patterns of single right coronary arteries. These cases are new variants of the types R-I and R-II-A, in which the most probable mechanisms of ischemia are the insufficient blood supply, due to the long trajectories of the single arteries and the presence of underdeveloped vessels. Also, our second case presented with a fistulae from the LCX to the left ventricle, which is another determinant of myocardial ischemia.

[Assessment of pulmonary arterial pressure in adults with Doppler echocardiography]. / Avaliação da pressão arterial pulmonar em adultos pela Eco-Dopplercardiografia.

PURPOSE: To assess the role of pulsed Doppler echocardiography (PDE) in the indirect assessment of pulmonary artery (PA) pressure (P), analysing the pulmonary velocity blood flow curves (PVBFC) profile. PATIENTS AND METHODS: Sixty-one adults with several kinds of heart disease were submitted to heart catheterization to obtain PAP (systolic, diastolic, mean), and other hemodynamic variables. A PDE examination was performed in all to obtain the PVBFC at the level of the pulmonic annulus. Qualitative features of the curve were analysed (morphological pattern, presence of pulmonic regurgitation) as well as quantitative data (acceleration time = AT, right ventricle ejection time = RVET index, AT/RVET index AT corrected for heart rate = ATC), which were compared to the invasive measurements. RESULTS: An abnormal rapid acceleration of the PVBFC, with triangular configuration, was noted in patient with pulmonary hypertension (PH), in contrast to the dome-like shape of the PVBFC in normal PAP. Pulmonary regurgitation was more frequent (p < 0.05) in patients with severe PH (mean PAP > or = 40 mmHg), comparing with patients with PAP < 40 mmHg. Inverse linear correlations were observed between AT and mean PAP, particularly when sinus rhythm was present (r = 0.89; p < 0.05) excluding patients with atrial fibrillation (19 cases). CONCLUSION: PDE is an useful and noninvasive method for indirect evaluation of PAP in adults, especially during stable sinus rhythm, in heart rate range from 60 to 115 bpm.

[Fascicular block of the His bundle: critical approach for its identification]. / Bloqueios das divisões fasciculares do feixe de His: abordagem crítica para a sua identificação.

The correct identification of the left and right fascicles blocks of the His bundle will permit to explain different patterns of the ECG and VCG. The differentiation between the right peripheral bundle branch and the left bundle branch division is not only important in anatomic and physiologic grounds, but also in a clinic viewpoint. So, trying to refine the diagnostic criteria and improve the recognition of these intraventricular conduction disturbances, we developed this study. Eighty five patients were evaluated and divided into two groups. Group I included 65 patients with cardiac disease; group II consisted of 20 normal subjects taken as a control. Some classic ECG and VCG criteria were tested as well as new ones. We confirmed the significance of the S2/S3 relation to distinguish the right superior divisional block (RSDB) from the left anterior hemiblock (LAH), and added some new criteria: 1) C morphology in horizontal plane (HP) to the right divisional block (RDB); 2) assessment of aVL lead to separate RSDB from LAH--qR pattern in the last, and different one to RSDB; 3) the qR' pattern in L2, L3 and aVF leads associated with left ventricular hypertrophy (LVH) pattern screened the left posterior hemiblock (LPH). We found no significance in R3/R2 relation to the right inferior divisional block (RIDB). Similarly to what happened to the left bundle branch block in the 70's decade, we expect that an adequate assessment of the RDB can permit a better understanding of its real clinical value.

Essential thrombocythemia and acute myocardial infarction treated with rescue coronary angioplasty.

A 48-year-old man with essential thrombocythemia suffered an extensive anterior acute myocardial infarction; this is a rare association. A pharmacological thrombolysis was performed, without success. He subsequently underwent successful rescue coronary angioplasty. To our knowledge, there is no other report in the literature relating the triad of essential thrombocythemia, acute myocardial infarction and rescue coronary angioplasty.

[Acute pulmonary edema secondary to pheochromocytoma. A case report]. / Edema agudo de pulmáo secundário a feocromocitoma. Relato de caso.

Authors report a case of a patient with abdominal pheochromocytoma who presented recurrent episodes of acute pulmonary edema. No cardiopathy was detected either by clinical examination or by electrocardiogram, echograms or invasive cineventricleangiograma. They concluded that a non cardiogenic etiology is possible for the referred clinical manifestations.

[Pulmonary artery pressure evaluation in adults by Doppler echocardiography]. / Avaliação da pressão arterial pulmonar em adultos pela ecodopplercardiografia.

PURPOSE: To assess the role of pulsed Doppler echocardiography (PDE) in the indirect assessment of pulmonary artery (PA) pressure (P), analysing the pulmonary velocity blood flow curves (PVBFC) profile. PATIENTS AND METHODS: Sixty-one adults with several kinds of heart disease were submitted to heart catheterization to obtain PAP (systolic, diastolic, mean), and other hemodynamic variables. A PDE examination was performed in all to obtain the PVBFC at the level of the pulmonic annulus. Qualitative features of the curve were analysed (morphological pattern, presence of pulmonic regurgitation) as well as quantitative data (acceleration time = AT, right ventricle ejection time = RVET index, AT/RVET index AT corrected for heart rate = ATC), which were compared to the invasive measurements. RESULTS: An abnormal rapid acceleration of the PVBFC, with triangular configuration, was noted in patient with pulmonary hypertension (PH), in contrast to the dome-like shape of the PVBFC in normal PAP. Pulmonary regurgitation was more frequent (p less than 0.05) in patients with severe PH (mean PAP greater than or equal to 40 mmHg), comparing with patients with PAP less than 40 mmHg. Inverse linear correlations were observed between AT and mean PAP, particularly when sinus rhythm was present (r = 0.89; p less than 0.05) excluding patients with atrial fibrilation (19 cases). CONCLUSION: PDE is an useful and noninvasive method for indirect evaluation of PAP in adults, especially during stable sinus rhythm, in heart rate range from 60 to 115 bpm.

[Emergency valvuloplasty with a balloon catheter of a tricuspid bioprosthesis in Ebstein's anomaly]. / Valvoplastia de emergência com cateter-balão de bioprótese tricúspide em anomalia de Ebstein.

A case of severe stenosis of a tricuspid bioprosthesis was successfully dilated in a 13 year old young male with Ebstein's anomaly. The patient had congestive heart failure and developed cardiogenic shock; angiography revealed absence of emptying of the right atrium. Multiple size balloons (#4 to 23) were sequentially introduced with successful bioprosthesis dilation and shock resolution. Tricuspid bioprosthesis can be dilated even in critical conditions and, although a palliative procedure, balloon valvuloplasty can be a lifesaving procedure in patients with cardiogenic shock.

[Effects of captopril on hemodynamics, gas exchange and exercise capacity in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease]. / Efeitos do captopril na hemodinâmica, nas trocas gasosas e na capacidade de exercício em portadores de hipertensão pulmonar secundária a doença pulmonar obstrutiva crônica.

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)

[Submitral left ventricular aneurysm in a Brazilian Indian]. / Aneurisma submitral do ventrículo esquerdo em um Indio Brasileiro.

Subvalvar left ventricular aneurysm is a rare disease of unknown etiology, that has been described most often in black Africans. A case of Brazilian indian with heart failure and a murmur of mitral regurgitation is reported. The chest x-ray showed a mild bulge in the left cardiac border and two-dimensional echocardiography demonstrated submitral left ventricular aneurysm, confirmed by left ventricular angiography. Surgical treatment consisted of resection of the aneurysm and mitral valvuloplasty. A perforation of the aneurysm, undetected neither by two-dimensional echocardiography nor by angiography was found at surgery.

[Electrocardiographic changes in accidental hypothermia]. / Alterações eletrocardiográficas na hipotermia acidental.

PURPOSE: Electrocardiographic alterations were evaluated in a group of accidental hypothermia patients, and correlated with values of core temperature, pH and plasmatic concentrations of Na+, K+ and Cl-. METHODS: Conventional 12-lead surface electrocardiograms were obtained in a group of 32 patients with accidental hypothermia after involuntary cold exposure. Cardiac arrhythmias, QRS configuration, ST-T segment and T wave alterations were analyzed. pH, Na+, K+ and Cl- serum concentrations were simultaneously measured. Electrocardiogram and electrolyte abnormalities were then correlated with the core temperature. RESULTS: Twenty-eight patients had abnormal electrocardiogram (90.6%). Sinus bradycardia and idioventricular rhythm were observed in 11 and 3 patients respectively. QT interval enlargement was found in 24 patients and Osborn wave in 28 cases. Altered T waves expressing an abnormal repolarization were observed in 23 cases. A significant negative correlation was obtained when J wave amplitude was correlated with core temperature levels. CONCLUSION: Hypothermia produces electrocardiographic abnormalities characterized by Osborn waves. Other minor findings include sinus bradycardia, idioventricular rhythm and long QT intervals.

[Heart surgery with extracorporeal circulation in pregnant women. Analysis of materno-fetal outcome]. / Cirurgia cardíaca com circulação extracorpórea em gestantes. Análise da evolução materno-fetal.

PURPOSE: To analyze maternal and fetal outcome in pregnant undergone to cardiac surgery. METHODS: We studied the evolution of 30 pregnant women submitted to cardiac surgery at the Hospital São Paulo, between Jan/81 and Dec/92 and, further, attended at this Hospital till the parturition. The following variables were analyzed: cardiopulmonary bypass, time of the procedure and time of the anoxia, patient temperature, surgical complications, and neonatal, maternal and fetal outcomes. RESULTS: All patients had rheumatic heart disease and, in 17, mitral stenosis was the main anatomic abnormality. Mitral commissurotomy was performed in 24 patients, double comissurotomy (mitral and aortic) in 1 patient and valve replacement was performed in 5. Cardiopulmonary bypass was utilized in all procedure; occurrence of surgical complications (p < 0.001) and the prolonged surgical time (p = 0.009) were related to the fetal mortality. There was 4 (13.3%) maternal deaths and 10 (33.3%) fetal deaths related to the surgery. CONCLUSION: The indication of cardiac surgery in pregnant women is heart failure, refractory to conventional therapy; cardiopulmonary bypass is associated with high fetal mortality.

[Acute hemodynamic effects of ibopamine, captopril, and placebo in patients with severe heart failure]. / Efeitos hemodinâmicos agudos da ibopamina, captopril e placebo em pacientes com insuficiência cardíaca grave.

PURPOSE: To evaluate the acute hemodynamic effects of ibopamine (IBO), captopril (CAP) and placebo (PLA) in patients with severe congestive heart failure at rest. METHODS: Twelve male patients in sinus rhythm with dilated cardiomyopathy and NYHA class IV were studied with Swan-Ganz hemodynamics. Drugs were given in a blinded fashion. Rest, 30 min and every hour for 5 h measurements were made after oral ingestion of 100 mg IBO, 25 mg CAP or PLA. Prior to the study, patients were on diuretics as the only medication for at least 48 h. Comparisons were made with analysis of variance of repeated measurements and Duncan's multiple comparisons procedure. RESULTS: Significant increase in cardiac index and stroke volume index and reduction in systemic vascular resistance were observed with IBO and CAP for 2 h after ingestion. IBO however increased right and left filling pressures in the first hour after its administration. Ventricular tachycardia occurred in 2 patients 1 h after IBO administration. CONCLUSION: Both IBO and CAP improved hemodynamic parameters in the first two hours after oral ingestion in patients with dilated cardiomyopathy in class IV.

[Effect of enalaprilat on cardiotoxicity induced by doxorubicin]. / Efeito do enalaprilato na cardiotoxidade induzida pela doxorubicina.

PURPOSE: To evaluate whether the enalaprilat, an angiotensin converting enzyme inhibitor, was able to prevent the myocardial damage induced by doxorubicin (DOX). METHODS: Four groups composed of 10 Wistar rats each were followed for seven weeks: control (CONT); treated with enalaprilat (ENA, 1mg/kg/d/sc) treated with doxorubicin (DOX, 25 mg/kg/d/sc), and treated with doxorubicin plus enalaprilat (DOX+ENA). In eight animals of each group, the left ventricle (LV) was prepared for morphometric study and stained with HE and picro-sírius for identifying muscle fibers and collagen. In each group three fragments of the LV were examined with electronic microscopy (EM). For statistical analysis: the one-way analysis of variance was performed and was followed by multiple comparisons test when the difference between groups were detected p values < or = 0.05 were considered significant. RESULTS: Light microscopy-it was not found any significant difference among the groups for muscle fibers patterns and proportion of collagen fibers of left ventricle. Electronic microscopy-the cristolysis index (proportion between normal and damage mitochondria) demonstrated significant difference between DOX and DOX+ENA groups (30.1 vs 11.6, p < or = 0.01). CONCLUSION: ENA prevented cardiotoxic alterations induced by DOX minimizing the aggression to the mitochondria and these findings, if confirmed in anima nobilis, may open a new clinical use for this type of drug.

[Catheter ablation of tachycardia of the outlet right ventricle using radiofrequency as power source]. / Ablação por cateter de taquicardia de via de saída de ventrículo direito utilizando radiofreqüência como fonte de energia.

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.

[Catheter ablation in patients with refractory cardiac arrhythmias with radiofrequency techniques]. / Ablação por cateter em pacientes com arritmias cardíacas refratárias utilizando técnicas de radiofreqüência.

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.

[Analysis of the junctional rhythm characteristics in patients with nodal reentry tachycardia treated with slow pathway radiofrequency ablation]. / Análise das características do ritmo juncional em pacientes com taquicardia por reentrada nodal submetidos a ablação da via lenta por radiofreqüência.

PURPOSE: To study the quantitative and qualitative aspects of junctional rhythm (JR) during radiofrequency (RF) catheter ablation of slow pathway in atrioventricular nodal reentrant tachycardia. METHODS: Twenty five patients, 5 males, ages ranging from 15 to 76 years, with recurrent atrioventricular nodal reentrant tachycardia, underwent to RF catheter ablation of slow pathway. During RF applications (40V, duration 60s) electrocardiographic was continuously recorded. The recordings were posteriorly used to study the presence and characteristics of JR (number of episodes, frequency and time of onset) at the effective and ineffective RF sessions. All variables were expressed as median and mean +/- SD. Univariate analysis of the effects of each variable on success or failure of ablation were performed using x2 test. A p value < 0.05 was considered significant. RESULTS: One hundred forty nine RF sessions were performed, 25 effective and 124 ineffective (mean per patient 6, range 1 to 22). JR was present in 18 of 25 effective and 44 of 124 ineffective sessions (p < 0.05). Mean time of appearance was 12s, occurring later this time in 9 of 18 effective and in 10 of 44 ineffective sessions (p < 0.05). Mean number of episodes was 3, occurring higher number in 7 of 18 effective and in 4 of 44 ineffective sessions (p < 0.05). Median of frequency of JR was 100bpm; 11 of 18 effective and 15 of 44 ineffective sessions presented higher frequencies (p < 0.05). CONCLUSION: JR during slow pathway ablation is a sensitive marker of ablation success. JR predictor of success has higher number of episodes, higher frequency and later time of appearance than that one of ineffective sessions.

[Cardiorespiratory response during exercise in heart transplant recipients. Comparative ergoespirometric analysis with normal health subjects]. / Respostas cardiorrespiratórias durante exercício em portadores de transplante cardíaco. Análise ergoespirométrica comparativa com indivíduos normais.

PURPOSE: To evaluate the cardiorespiratory response of heart transplant (HT) recipients. METHODS: Nine HT recipients (GI) underwent ergospirometric tests and were compared to 9 apparently healthy, sedentary subjects with similar sex, age, weight and height (GII). All were male patients aging 48 +/- 12 years, in functional class I (NYHA) an average of 23 +/- 21 months after HT. They were receiving cyclosporin, azathioprine, prednisone, dipyridamole and antihypertensive drugs. The tests were symptom-limited and they were interrupted due to exhaustion. RESULTS: During peak exercise, GI had a significantly lower physical performance related to lower VO2, VE, VEO2, HR, endurance time and work load. At the anaerobic threshold, VO2, endurance time and work load levels were also significantly lower in GI. The physical performance was similar between the groups in the 40W load. CONCLUSION: The cardiorespiratory performance in GI was significantly lower at peak exercise and similar to GII in the 40W load, showing the HT benefits cardiac patients during usual activities.

[Percutaneous retrieval of intravascular foreign bodies]. / Retirada percutânea de corpos estranhos intravasculares.

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.