Anterior ST-elevation myocardial infarction after Excimer laser extraction of defibrillator leads

Abstract

SummaryWe describe a case of a so far unknown complication after failed extraction of defibrillator leads. Perforation of the LIMA bypass caused by Excimer laser created an arterio-venous fistula from the proximal bypass to the superior subclavian vein and occlusion of the distal LIMA bypass with consecutive anterior ST-elevation myocardial infarction.Key words: Excimer laser extraction; defibrillator leads; myocardial infarction; arterio-venous fistula; aortocoronary bypass Case reportA 60-year-old woman was admitted to our hospital for replacement of broken defibrillator leads. The patient was known to have ischemic heart disease since a medically treated inferior myocardial infarction in 1985. In early 1996, coronary bypass surgery was performed with implantation of a LIMA to LAD and RIMA to RCA graft. A single chamber defibrillator was implanted at the left pectoral region in late 1996 for non-sustained ventricular tachycardia and persistent low left ventricular ejection fraction. In 1998, an isolation defect of the defibrillator leads was diagnosed and new leads were implanted. The original lead could not be removed and was left in place. In 2007, a coronary angiogram documented open LIMA to LAD and RIMA to RCA grafts. Native LAD and RCA were both chronically proximally occluded.After repeated inadequate shock deliveries occurred in late 2010 because of electrical artefacts produced by the patient's arm movement, defibrillator lead malfunction was diagnosed and the patient was sent for lead replacement. The Excimer laser extraction technique was attempted on both right ventricular leads, but the cleaning guide wire could not be advanced more than 20 cm and both leads could not be removed. Finally, a third ventricular lead and a new single chamber ICD were implanted through the right subclavian vein. During the procedure, a short fall in blood pressure was noticed and successfully treated with a single bolus of 250 ml of pure saline. After extubation, the patient instantaneously complained about severe chest pain and ECG showed new ST segment elevation of the anterior wall. An immediately performed angiogram showed arteriovenous fistula between the proximal LIMA bypass and the superior subclavian vein and occlusion of the distal LIMA bypass ( fig. 1). Due to the anatomical proximity, the laser had probably perforated the vein, "cutted" the LIMA-graft and created a connection between LIMA and the left subclavian vein. Several attempts to reopen the distal LIMA bypass percutaneously were unsuccessful. Finally, the arterio-venous fistula was coiled with a 4×6 mm Amplatzer ® vascular plug to prevent persistent left to right shunt and consecutive volume overload ( fig. 2). An intra-aortic balloon pump was placed and used for 24 hours after the procedure. Thereafter the patient remained haemodynamically stable. Repetitive blood samples showed a relevant CK peak of 2993 U/l on day two after the LIMA occlusion and a decline of left ventricular ejection fraction measured in echocardiography from 38% pre-operatively t...