Ventricular Fibrillation During Swimming in a Patient With Long-QT Syndrome
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 ventricular 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.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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