Cox-2 and iNOS are co-expressed in hibernating myocardium with nitrotyrosine suggesting nitric oxide production and peroxynitrite formation. We propose that this is secondary to ischaemia-reperfusion and that the products of these enzymes may have consequences for myocardial contractile function and survival.
A 26 year old woman with a diagnosis of limb girdle muscular dystrophy and peripartum cardiomyopathy underwent orthotopic heart transplantation using standard atrial anastomoses. Recurrent atrial flutter was demonstrated in the absence of histological evidence of cellular rejection. Radiofrequency ablation of the flutter circuit was successfully performed allowing the avoidance of long term antiarrhythmic therapy. Ten weeks following ablation and cessation of amiodarone, presyncopal symptoms were found, associated with daytime and nocturnal sinus pauses of 2.9 seconds and 4.2 seconds, respectively. There was no evidence of AV node conduction impairment. In view of the continued absence of cellular rejection and the evident denervated state of the heart, the pauses reflected significant donor sinus node dysfunction; therefore, an AAIR permanent pacing system was implanted. At the time of pacemaker implantation atrial pacing at 150 beats/ min did not produce significant PR interval prolongation or AV block. This case serves to advise rigorous follow up in such patients to continue to seek evidence of sinus node dysfunction potentially requiring permanent pacemaker implantation. (Heart 1998;79:412-413)
A 38-year-old female with anomalous origin of the left coronary artery (LCA) from pulmonary artery was surgically corrected by tubular reconstruction of the left main coronary artery (LMCA) using the pulmonary artery wall, and this repair was performed under beating heart. Thus, the pulmonary artery was divided above the orifice level and just above the pulmonary valve, and the commissure between nonfacing and left side sinuses was dissected away from the pulmonary artery wall to obtain lateral flaps. The pulmonary artery defect was reconstructed with a roll using an autologous pericardial patch, while the detached commissure was suspended on the pericardial patch. The long tube constructed using pulmonary artery tissue was anastomosed to the anterior aspect of the ascending aorta. These procedures were performed under beating heart simply by clamping the LMCA, since the preoperative myocardial contrast echocardiography confirmed the adequate coronary collateral flow from the right circulation. The postoperative course was uneventful, and a coronary artery angiogram demonstrated a widely patent LMCA. Our experience suggests that, in adult cases, this procedure could be performed without myocardial ischemia simply by clamping the LMCA because of well-developed coronary collateral arteries. The safety of this technique could be confirmed by myocardial contrast echocardiography.
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