AIMS: Syncope in patients with the long QT syndrome is commonly attributed to a ventricular arrhythmia (torsades de pointes). The susceptibility of patients with the long QT syndrome (LQTS) to neurally mediated syncope is currently unknown. METHODS AND RESULTS: Head-up tilt table testing (70 degrees) was performed in six patients with the long QT syndrome and a history of syncope. All patients had syncope with a mixed response. The RR interval was significantly decreased 2 min before the onset of syncope (980 +/- 125 ms vs 630 +/- 91 ms, P=0.003), and significantly increased during syncope (983.17 +/- 224.71; P=0.006). Non-significant changes in QT intervals were observed. Baseline QT was 513 +/- 86 ms and decreased to 450 +/- 59 ms 2 min before the onset of syncope (P=0.11). Although not statistically significant, QT intervals during syncope were longer than at 2 min before syncope (485 +/- 85 ms vs 450 +/- 59 ms; P=0.29). CONCLUSION: Our results suggest that patients with the LQTS are susceptible to neurally mediated syncope. Whether this susceptibility differs from control populations remains unresolved. From a clinical standpoint, neurocardiogenic syncope should be considered a diagnostic alternative in patients with LQTS.
AIMS: Syncope in patients with the long QT syndrome is commonly attributed to a ventricular arrhythmia (torsades de pointes). The susceptibility of patients with the long QT syndrome (LQTS) to neurally mediated syncope is currently unknown. METHODS AND RESULTS: Head-up tilt table testing (70 degrees) was performed in six patients with the long QT syndrome and a history of syncope. All patients had syncope with a mixed response. The RR interval was significantly decreased 2 min before the onset of syncope (980 +/- 125 ms vs 630 +/- 91 ms, P=0.003), and significantly increased during syncope (983.17 +/- 224.71; P=0.006). Non-significant changes in QT intervals were observed. Baseline QT was 513 +/- 86 ms and decreased to 450 +/- 59 ms 2 min before the onset of syncope (P=0.11). Although not statistically significant, QT intervals during syncope were longer than at 2 min before syncope (485 +/- 85 ms vs 450 +/- 59 ms; P=0.29). CONCLUSION: Our results suggest that patients with the LQTS are susceptible to neurally mediated syncope. Whether this susceptibility differs from control populations remains unresolved. From a clinical standpoint, neurocardiogenic syncope should be considered a diagnostic alternative in patients with LQTS.
Authors: Ewelina Kolarczyk; Grażyna Markiewicz-Łoskot; Lesław Szydłowski Journal: Int J Environ Res Public Health Date: 2020-03-15 Impact factor: 3.390
Authors: Grażyna Markiewicz-Łoskot; Ewelina Kolarczyk; Bogusław Mazurek; Marianna Łoskot; Lesław Szydłowski Journal: Int J Environ Res Public Health Date: 2020-09-04 Impact factor: 3.390