Nova abordagem técnica para papilopexia cruzada em operação de substituição valvar mitral: resultados imediatos

Introduction: The maze procedure for primary atrial fibrillation treatment, initially proposed by Cox, is somewhat complex, and it increases the morbidity risk compared to isolated mitral valve surgery. Objective: To describe the surgical technique, the concepts of electrophysiology adopted and the preliminary results of a new surgical and electrophysiological approach, including specific atrial circuit blocking as defined by Frame and optimization of the surgical tactic for atrial fibrillation treatment. Method: Eight patients with chronic atrial fibrillation and mitral valve dysfunction, associated in one case with tricuspid valve regurgitation were operated on. The following modifications of the classic Cox procedure were employed: 1-Exclusion of the left atrium appendage by an internal suture closing its left atrial ostium; 2-Exclusion of the right atrium appendage by a purse-string suture used for fixation of the superior vena cava draining cannula; 3-Single atrial incision; 4-Trans-endocardium electrocauterization in the left atrium wall around all pulmonary vein ostia; 5-Substitution of the incisions and sutures in the left atrium by trans-endocardium electrocauterization. Results: The cardiopulmonary bypass time varied from 64 to 133 min (mean 107.5 min) and the cardioplegic time from 40 to 105 min. (mean 76.7 min). At the end of the surgery all patients were in regular atrial rhythm. The postoperative period was uneventful with all patients discharged from hospital showing regular atrial rhythm, without definitive pacemaker implantation. In the six-month postoperative follow up after surgery, six patients were in regular atrial rhythm (75%) with preserved atrial contractions, and two (25%) with clinically controlled atrial fibrillation (NYHA II). Also there were no embolic complications nor thrombotic evidence in the Doppler echocardiography control. Conclusion: It is concluded in this initial series of cases that the electrophysiological approach and the surgical technique employed improved the surgical treatment of the atrial fibrillation making correction of mitral and tricuspid valve injuries possible without additional morbidity.

Efeitos da N-acetilcisteína no precondicionamento isquêmico: estudo em corações isolados de ratosEffects of n-acetylcysteine on ischemic preconditioning. Study in isolated rat hearts Abstract Objective: The aim of this study is to assess if NAcetylcysteine (NAC) changes the Ischemic Preconditioning (IP) in isolated rat hearts using only one cycle of IP.Methods: Heart Rate (HR), Coronary Flow (CF) and Myocardial Contractility (dP/dt) were registered in 30 Wistar rat's hearts. After anesthesia the hearts were removed and perfused with Krebes-Hensleit equilibrated solution with 95% of O 2 and 5% of CO 2 according Langendorff's method. GI: Control (n=6); GII: 20 min. ischemia (n=6); GIII: IP (n=6); GIV 50 ìg/ml/min NAC before IP (n =6); GV: 100 ìg/ ml/min NAC before IP (n=6). Parameters were measured after 15 min. of stabilization (T 0) and T3, T5, T10, T15, T20, T25 and T30 min. after reperfusion. Statistical significance was considered when P<0.05.Results: There were changes on HR comparing GI with GII at T20 and T25 and comparing GI with GIII, GIV with GV at T10 and T20 (P<0.05). CF was different comparing GI with GII at T3 and T5, GI with GIV at T10 and GI with GV at T10 and T25 (P<0.05). Myocardial Contractility was similar comparing GIII with GI and GV. GIII had higher dP/dt than GIV but without statistical difference (P>0.05). dP/dt was higher in GV than GIV but with statistically significant difference only at T30.Conclusion: dP/dt was better in preconditioned hearts and was changed if using NAC in GIV. The use of NAC didn't change the effects of preconditioning on myocardial contractility in GV. Descriptors 24OLIVEIRA, DM ET AL -Effects of n-acetylcysteine on ischemic preconditioning. Study in isolated rat hearts Bras Cir Cardiovasc 2009; 24(1): 23-30 Rev INTRODUCTIONMyocardial protection during heart surgery has been the focus of basic and clinical research in the last 50 years [1]. In 1955, Lewis was the first to perform in human intracardiac surgery using hypothermia. Melrose proposed the use of cardiac arrest using an infusion of potassium in the ascending aorta. Since then, numerous tactics and techniques of myocardial protection have been developed.Murry et al.[2] described the mechanism of ischemic preconditioning (IP) by showing that short episodes of ischemia and reperfusion before a prolonged ischemic event would reduce the size of infarction and improved cardiac function. In experimental studies, this mechanism is considered the most powerful natural way of cardioprotection [3]. Studies with IP in heart surgery have shown conflicting results, but the majority confirmed that the IP is an effective adjunct in myocardial protection [3][4][5].Clinical studies in cardiology and heart surgery showed tendency to cardioprotection by using adenosine, but the effects are not as obvious as those observed in experimental researches [3,4]. Morris and Yellon [6] emphasized the existence of a threshold of stimulation, with the need of activation not only of adenosine receptors, but also of bradykinin and ...

RBCCV 44205-769 Nova abordagem técnica para papilopexia cruzada em operação de substituição valvar mitral: resultados imediatosNew technical approach for crossed papillopexy in mitral valve replacement surgery: short term results Abstract Objective: To present the crossed papillopexy technique and its initial results in the preservation of papillary muscles in mitral valve replacement and ventricular remodeling surgeries for heart failure (CHF).Method: Ten patients, 70% male, with ages between 15 and 75 years old (mean 44.4 ± ± ± ± ± 18.7 years old), suffering from rheumatic mitral valve disease (50%), mitral valve prolapse (10%) or dilated cardiomyopathy (40%), were studied. After opening the left atrium and adequate exposure of the mitral valve, the anterior leaflet already free of its annulus fixation was centrally divided and each half, with its cordae tendineae complex fixed to the commissure on the opposite side. Following this, mechanical (seven cases) or biological (three cases) prostheses were implanted using single sutures in the valve annuli, with reduction of the mitral valve annulus for better ventricular remodeling in CHF cases.Results: All patients were discharged from hospital in good clinical conditions. Additionally all presented with great improvement in the cardiac performance at the end of the first month of follow-up, with significant reductions in the left ventricular and left atrium systolic diameters (p<0.05) and mean increases in the left ventricle ejection fraction of from 46.7 to 56.4 % (p<0.05).Conclusion: The crossed papillopexy technique in valve replacement surgeries for mitral valve lesions and CHF presented significant increases in the left ventricular function and improvement of ventricular remodeling in the studied postoperative period. Descriptors: Mitral valve, surgery. Papillary muscles, surgery. Heart valve prosthesis. Resumo Objetivo: Apresentar a técnica de papilopexia cruzada e seus resultados iniciais na preservação dos músculos papilares em operações de substituição valvar mitral e remodelamentoDescritores: Valva mitral, cirurgia. Músculos papilares, cirurgia. Prótese das valvas cardíacas.

Doença da discinesia miocárdica de estresseMyocardium stress diskinesia disease 379 GOMES, OM ET AL -Myocardium stress diskinesia disease