Complex railroad track appearance on interval plot for an implantable cardioverter defibrillator shock episode: What is the mechanism?

摘要

An 80-year-old man with a history of ischemic car-diomyopathy with healed anterior myocardial infarction, severe left ventricular systolic dysfunction, sinus node dysfunction, and ventricular tachycardia (VT) received a dual-chamber Medtronic? (Minneapolis, MN, USA) Maximo? II DR ICD model D284DRG in 2008. The patient was on aspirin 100 mg, ramipril 5 mg, atorva-statin 40 mg, amiodarone 200 mg, and carvedilol 25 mg. In February 2013, the patient presented for routine follow-up and during this visit, he reported receiving a single ICD shock 2 weeks before. He did not seek medical attention at that time.