Antonio Carlos Pereira Barreto

SURGICAL TREATMENT OF ENDOMYOCARDIAL FIBROSIS : A NEW APPROACH

Endomyocardial fibrosis has been treated surgically for many years. For complete removal of fibrosis from both ventricles by the classic technique, each atrioventricular (AV) valve was removed and replaced with a prosthesis. Relapse of endomyocardial fibrosis has not been observed after surgical correction. Reoperations have been carried out because of complications of valve prostheses. A new surgical technique for removal of ventricular fibrous tissue with preservation of the mitral and tricuspid valves was used in nine consecutive patients with endomyocardial fibrosis. Initial results show a reduction of pulmonary hypertension, mean right and left atrial pressures and end-diastolic pressures in both ventricles. Tricuspid annuloplasty was performed in seven patients and mitral annuloplasty in five. No valve prosthesis was used. There was no death and New York Heart Association functional class improved from class III or IV in the preoperative period to class I or II in the postoperative period. These data suggest that resection of endocardial fibrous tissue can be indicated early in the clinical course and performed with preservation of the AV valves.

Hemodynamic study during upright isotonic exercise before and six months after dynamic cardiomyoplasty for idiopathic dilated cardiomyopathy or Chagas' disease

Abstract Dynamic cardiomyoplasty is a new surgical procedure proposed for treatment of patients with congestive heart failure. 1 Recently, studies have shown improvement in functional class in selected patients after surgery. 2 The hemodynamic effects of cardiomyoplasty during exercise have not been documented. We report hemodynamic results in 3 patients during treadmill upright exercise before and after dynamic cardiomyoplasty.

Aneurysm of the left atrial appendage

We present the case of a 33-year-old woman with atrial tachyarrhythmias and chest pain. The transthoracic echocardiography demonstrated an intrapericardial liquid mass confirmed as an aneurysm of the left atrial appendage by a nuclear magnetic imaging study. Aneurysmectomy was performed with the assistance of cardiopulmonary bypass with a bilateral submammary skin incision and subsequent median sternotomy. The patient had an uneventful postoperative course. We suggest aneurysmectomy aided by cardiopulmonary bypass as a safer method of treatment for this rare cardiac anomaly.

Peak Oxygen Consumption and Resting Left Ventricular Ejection Fraction Changes After Cardiomyoplasty at 6-Month Follow-up

BACKGROUND The effects of cardiomyoplasty on cardiopulmonary exercise test characteristics are not fully known. METHODS AND RESULTS We determined in 19 patients who underwent cardiomyoplasty for treatment of refractory heart failure (New York Heart Association [NYHA] functional class III) before (pre) and at 6-month follow-up (post) maximum oxygen consumption (peak VO2), NYHA functional class, and resting left ventricular ejection fraction (LVEF) (MUGA). We analyzed the results according to pre peak VO2 < or > 14 mL/kg per minute and the correlation between the changes in absolute values of LVEF and peak VO2. Pre- and post-peak VO2 values were 15.9 +/- 4.4 and 18.6 +/- 6.4 mL/kg per minute, respectively (P = .059). In the subgroup with pre-peak VO2 < 14 mL/kg per minute, the peak VO2 increased from 11.1 +/- 1.9 to 16.4 +/- 6.2 mL/kg per minute (P = .02). The subgroup with peak VO2 > 14 mL/kg per minute showed pre- and post-peak VO2 of 19.2 +/- 2.6 and of 20.1 +/- 7 mL/kg per minute, respectively (P = .06). The pre-total exercise time of the entire group increased from 688.4 +/- 222.1 to 833.7 +/- 241.6 seconds (P < .04). For the subgroup with preoperative peak VO2 < 14 mL/kg per minute, exercise time improved from 585 +/- 76.9 to 825 +/- 186.3 seconds (P < .01). In the subgroup with preoperative VO2 > 14 mL/kg per minute, the preexercise and postexercise time was 763.6 +/- 264.4 and 840 +/- 282 seconds, respectively (P = .4). Pre-LVEF increased from 20.6 +/- 3.3% to 24.2 +/- 7.8% at 6 months of follow-up (P = .02). At 6 months of follow-up, 9 patients were in NYHA functional class I and 10 were in class II. There was no correlation between LVEF values and absolute values of peak VO2 before (r = .123, P = .6) and after (r = .27, P = .2) cardiomyoplasty. A weak correlation was observed between the changes in absolute values of peak VO2 and LVEF from the preoperative to the postoperative period (r = .48, P = .048). CONCLUSIONS Cardiomyoplasty is a useful method for improving NYHA functional class and LVEF in patients with heart failure. Peak VO2 < 14 mL/kg per minute before cardiomyoplasty may be a selection criterion with which to determine improved exercise capacity after surgery. The effects of cardiomyoplasty on LVEF appear to be partially associated with maximum exercise capacity changes.

Clinical Predictors of Prognosis in Severe Aortic Stenosis in Unoperated Patients >75 Years of Age

In elderly patients with severe aortic stenosis, clinical evaluation can dictate decision making. Asymptomatic patients in normal sinus rhythm, without left atrial enlargement and without bundle branch block, can be safely followed clinically, regardless of echocardiographic findings.

Management of aortic insufficiency in chronic aortic dissection.

From January 1980 to December 1988, 44 patients with chronic aortic dissection and aortic insufficiency underwent operation. This group of patients was analyzed to evaluate the outcome of those in whom the aortic valve was preserved compared with those having valve replacement. The overall preoperative characteristics of the two groups were similar except for the incidence of Marfans syndrome. Valve replacement was the elected procedure in patients with valve degeneration or annuloaortic ectasia. In patients with leaflet prolapse with or without an enlarged annulus, a plastic procedure was used. In 48% of the patients, it was possible to preserve the valve. There were five hospital deaths (11%): three were due to low-output syndrome, one was due to bleeding, and one was due to neurological complications. There were two late deaths (5%). Follow-up of the 37 surviving patients ranged from 2 to 108 months (mean follow-up, 18 months). Seventy-eight percent of the survivors were in functional class I and the others were in class II. Two patients in whom the aortic valve was preserved had mild aortic insufficiency. Three patients with bioprostheses underwent reoperation because of prosthetic valve dysfunction. One patient who had aortoplasty and an aortic valve plastic procedure was seen with redissection and aortic insufficiency after 60 months and was reoperated on using the Bentall technique. The actuarial survival curves showed that patients who underwent valvoplasty had higher, but not significantly higher, survival rates than the valve replacement patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle electrical stimulation improves neurovascular control and exercise tolerance in hospitalised advanced heart failure patients

Background We investigated the effects of muscle functional electrical stimulation on muscle sympathetic nerve activity and muscle blood flow, and, in addition, exercise tolerance in hospitalised patients for stabilisation of heart failure. Methods Thirty patients hospitalised for treatment of decompensated heart failure, class IV New York Heart Association and ejection fraction ≤ 30% were consecutively randomly assigned into two groups: functional electrical stimulation (n = 15; 54 ± 2 years) and control (n = 15; 49 ± 2 years). Muscle sympathetic nerve activity was directly recorded via microneurography and blood flow by venous occlusion plethysmography. Heart rate and blood pressure were evaluated on a beat-to-beat basis (Finometer), exercise tolerance by 6-minute walk test, quadriceps muscle strength by a dynamometer and quality of life by Minnesota questionnaire. Functional electrical stimulation consisted of stimulating the lower limbs at 10 Hz frequency, 150 ms pulse width and 70 mA intensity for 60 minutes/day for 8–10 consecutive days. The control group underwent electrical stimulation at an intensity of < 20 mA. Results Baseline characteristics were similar between groups, except age that was higher and C-reactive protein and forearm blood flow that were smaller in the functional electrical stimulation group. Functional electrical stimulation significantly decreased muscle sympathetic nerve activity and increased muscle blood flow and muscle strength. No changes were found in the control group. Walking distance and quality of life increased in both groups. However, these changes were greater in the functional electrical stimulation group. Conclusion Functional electrical stimulation improves muscle sympathetic nerve activity and vasoconstriction and increases exercise tolerance, muscle strength and quality of life in hospitalised heart failure patients. These findings suggest that functional electrical stimulation may be useful to hospitalised patients with decompensated chronic heart failure.

Fibroma cardíaco mimetizando cardiomiopatia hipertrófica

A 33 year-old woman was seen, for the first time, ten years ago, for evaluation of a recurrent chest pain, dyspnea and arrhythmia. She was submitted to echocardiographic studies and a cardiac catheterization. The diagnoses was endomyocardial fibrosis at first, and hypertrophic cardiomyopathy after. Despite treatment with propranolol and quinidine, the episodes of dyspnea and tachyarrhythmias became more frequent and severe, and the patient was guided to our Service. Cardiac re-catheterization, echocardiographic and computed tomography studies identified in traumural cardiac fibroma and the patient was referred for surgical treatment. The cardiac fibroma was successfully resected on extracorporeal bypass and with cardioplegic arrest of the heart. Repair of the heart was accomplished with a patch placed to close the left ventricular cavity. The postoperative course was uncomplicated, and she remains assymptomatic two years later. We have emphazied tha this tumor often produces clinically obscure disease, simulating particularly the left ventricle hypertrophic cardiomiopathy.

Perspectivas da cardiomioplastia no tratamento das cardiomiopatias

A utilizacao de enxertos musculares esqueleticos, estimulados sincronamente ao coracao, para substituir ou envolver o miocardio, tem sido apontada como uma nova alternativa no tratamento das cardiomiopatias terminais. No Instituto do Coracao, 5 pacientes portadores de cardiomiopatia dilatada, com sintomas de insuficiencia cardiaca congestiva, refratarios a terapeutica medicamentosa, foram submetidos a cardiomioplastia, no periodo de maio a dezembro de 1988. Em 1 dos casos, a etiologia era chagasica e, nos demais, idiopatica. A operacao constou do envolvimento dos ventriculos direito e esquerdo pelo musculo grande dorsal esquerdo e do implante do sistema de estimulacao muscular. Nao houve obitos, no periodo pos-operatorio imediato e, em 1 dos casos, ocorreu perda da resposta contratil do enxerto muscular, tendo o paciente falecido por insuficiencia miocardica, 2 meses apos a operacao. Os outros 4 pacientes foram seguidos por 4 a 9 meses, sendo constatada melhora do quadro clinico e do desempenho fisico, associada a menor necessidade de medicamentos, em relacao ao pre-operatorio. A angiografia radioisotopica demonstrou aumento da fracao de ejecao do ventriculo esquerdo, com estimulacao do grande dorsal em 43 ± 3% e a avaliacao hemodinâmica documentou elevacao do trabalho sistolico daquela câmara, associada a queda da pressao capilar pulmonar, apos a cardiomioplastia. Por outro lado, foi tam jem observada diminuicao da capacidade vital em 15 ± 4%, nao sendo identificada, contudo, qualquer limitacao clinica decorrente desse fato. Em conclusao, a cardiomioplastia pode aumentar a contratil idade das câmaras ventriculares em pacientes com cardiomiopatia dilatada, facilitando o controle do quadro congestivo. Este estudo sugere, ainda, que essa tecnica pode ser realizada com baixa mortalidade imediata e que a morbidade do procedimento parece estar restrita a possibilidade de perda do enxerto e as alteracoes da funcao pulmonar decorrentes da presenca do grande dorsal no interior do torax.

Fatores de risco na cirurgia das dissecções da aorta ascendente e arco aórtico

The surgical experience in the treatment of 72 patients with proximal aortic dissections was analized to identify the determinants of high operative risk. Thirty-seven patients were operated upon in the acute stage and the dissection was restrict to ascending aorta in 9. The most common surgical procedure was the interposition of Dacron graft in the ascending aorta associated to obliteration of false lumen. The aortic arch was approached only in 5 patients. The overall operative mortality was 27.7% and patients with acute dissections had mortality rate of 43.5%. There was a direct relationship between the causes of death and preoperative complications in 45% of these cases. The following factors were considered predictors of high operative risk: previous neurologic compromise, cardiac tamponade, persistent shock, acute myocardial ischemia and renal dysfunction. Involvement of innominate or carotid arteries by dissection, presence of intimal tear in aortic arch, mesenteric ischemia and only in the acute cases, moderate or severe aortic valve incompetence were also correlated with a higher operative mortality. In conclusion, the operative risk of the treatment of proximal aortic dissection has a relationship with preoperative clinical condition. Better results in the acute stage could be improved by early diagnosis and adequate medical therapy during investigation period.