Ventricular Fibrillation During Swimming in a Patient With Long-QT Syndrome

P. Ott
2002 Circulation  
A 32-year-old woman was diagnosed with long-QT syndrome in 1997. One year later, a single-chamber implantable cardioverter-defibrillator (ICD) was implanted after multiple episodes of syncope. She has had no syncope or ICD discharge during the last 19 months. She passed out while swimming. She was pulled from the water semiconscious by her 13-year-old daughter and did not remember receiving an ICD shock. A 12-lead ECG showed a QT interval of 600 ms (Figure 1 ). The ICD interrogation revealed
more » ... tricular fibrillation followed by correct arrhythmia detection and successful termination by defibrillation through the device (Figure 2 ). This occurred at the time she was swimming. Swimming appears to be a specific trigger of arrhythmias in long-QT 1 syndrome. Why swimming has such a specific correlation with the long-QT 1 syndrome is unclear. It is tempting, however, to speculate that this activity may provide particularly intense sympathetic stimulation due to physical exertion, possibly combined with fear. Figure 2 . Displayed are the ventricular electrograms (recorded from the shock electrode) from the episode during swimming (25 mm/s). The onset of ventricular fibrillation appears to be preceded by premature ventricular beats and a brief run of ventricular tachycardia. 522 Circulation
doi:10.1161/01.cir.0000018643.56813.8c pmid:12135956 fatcat:zkzwuyekvvcfnh2txqe6wgnbki