A 23-year-old female with Ebstein's anomaly of tricuspid valve underwent one and half ventricular repair with tricuspid valve annuloplasty, atrial septal defect closure and cavopulmonary anastamosis of right superior venacava to the right pulmonary artery. She also needed dual chamber pacing for symptomatic bradycardia secondary to sinus nodal and atrioventricular nodal disease. There was no pre-excitation or tachyarrhythmias. Left atrial and left ventricular epicardial leads were connected to a pulse generator that was implanted in epigastric subcutaneous pocket. There was synchronous atrioventricular pacing with acceptable pacing thresholds during the time of implantation. Three months later, new onset symptomatic diaphragmatic pacing was observed from atrial lead. So the pacemaker was reprogrammed to pace ventricle alone. After another two months, diaphragmatic pacing was observed from ventricular lead too. The threshold voltage for ventricular capture was more than that of the diaphragm. The reasons for delayed onset diaphragmatic pacing through both leads almost five months after the epicardial lead placement and pacemaker implantation was not understood. Her symptoms related to bradycardia warranted permanent dual chamber pacing. Since extensive dissections will be needed through the previous surgical scars and adhesions in midline sternotomy and left thoracotomy, a second epicardial lead repositioning was not considered. A minimal incision right anterolateral thoracotomy was made and two introducer sheaths were inserted through two pursestring sutures placed on the right atrial free wall.() Two screw-in endocardial leads were inserted through the sheaths under transesophageal echocardiographic guidance into the right atrial appendage tip and right ventricular apex to achieve atrioventricular pacing. On a follow up of nine months, the patient was asymptomatic, pacing was synchronous and chest X-ray showed both the new and old leads. ()
A 76-year-old man with history of ischemic cardiomyopathy and paroxysmal atrial fibrillation who underwent a Dual-Chamber Medtronic Implantable Cardioverter-Defibrillator (ICD) placement 6 years earlier in an outside facility presented to the emergency room with worsening shortness of breath. Initial workup in the emergency room revealed acute on chronic combined congestive heart failure. An AP chest X-ray film was interpreted by the radiologist as cardiomegaly with pulmonary vascular congestion and satisfactory ICD lead position (Figure ). No lateral view was obtained at the time.\nBedside Echo showed severely reduced left ventricular systolic function with dilated right ventricle and moderate-to-severe pulmonary hypertension. Surprisingly, the ICD lead was clearly going from the left atrium through the mitral valve to the left ventricular cavity (Figures , , and ). A lateral chest X-ray view revealed that the ICD shock lead tip is directed posteriorly, indicating its presence in the left ventricular cavity (Figure ). A transesophageal echocardiogram showed the ICD lead went from the superior vena cava to the right atrium, crossing through a small sinus venous atrial septal defect to the left atrium, and into the left ventricular cavity via the mitral valve. Luckily, the patient was on chronic anticoagulant because of chronic atrial fibrillation, so no thromboembolic complications were reported. Interestingly enough, the patient had two prior trans-thoracic echocardiograms that were interpreted by the same cardiologist without mention of abnormal ICD lead placement. Furthermore, prior ICD interrogation reports from his primary cardiologist showed chronically elevated shock lead impedance but pacing threshold and sensing were good. No therapy was needed since device implantation.\nBecause extraction of a chronically implanted ICD lead carries a high risk of major cardiovascular complications (2%-4%) including vascular injury, cardiac perforation resulting in cardiac tamponade, and occasionally thromboembolic complications or even death, and because the patient was chronically anticoagulated, the decision is made to continue conservative management.