Heart rhythm : the official journal of the Heart Rhythm Society
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The initial experience with left atrial esophageal fistula (LAEF) secondary to atrial fibrillation (AF) ablation procedures revealed a near-universal mortality. A comprehensive description of the principles of LAEF repair in the modern era and its resulting impact on morbidity and mortality are lacking in the literature. ⋯ While improved relative to initial reports, mortality associated with LAEF remains high after corrective intervention. Primary esophageal repair with the placement of tissue between the repaired esophagus and the left atrium may result in lower morbidity and mortality.
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The transient receptor potential melastatin 4 (TRPM4) channel is expressed in the sinoatrial node, but its physiologic roles in this tissue with cardiac pacemaker properties remain unknown. This Ca(2+)-activated nonselective cation channel (NSCCa) induces cell depolarization at negative potentials. It is implicated in burst generation in neurons and participates in induction of ectopic beating in cardiac ventricular preparations submitted to hypoxia/reoxygenation. Accordingly, TRPM4 may participate in action potential (AP) triggering in the sinoatrial node. ⋯ These data showed that TRPM4 modulates beating rate. Pacemaker activity in the sinoatrial node results from the slow diastolic depolarization slope due to the "funny" current, Na/Ca exchange, and a Ca(2+)-activated nonselective cation current, which can be attributable in part to TRPM4 that may act against bradycardia.
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Right cervical vagus nerve stimulation (VNS) provides cardioprotective effects against acute ischemia-reperfusion injury in small animals. However, inconsistent findings have been reported. ⋯ During ischemia-reperfusion injury, both C-VNS and I-VNS provide significant cardioprotective effects compared with I-VNS + atropine. These beneficial effects were abolished by muscarinic blockade, suggesting the importance of muscarinic receptor modulation during VNS. The protective effects of VNS could be due to its protection of mitochondrial function during ischemia-reperfusion.