Ehud Chorin1, Aviram Hochstadt1, Sami Viskin2, Uri Rozovski3, Ofer Havakuk1, Adrian Baranchuk4, Andres Enriquez4, Boris Strasberg3, Milton E Guevara-Valdivia5, Manlio F Márquez6, Héctor González-Pacheco6, Can Hasdemir7, Raphael Rosso1. 1. Tel-Aviv Sourasky Medical Center, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel. 2. Tel-Aviv Sourasky Medical Center, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel. Electronic address: samiviskin@gmail.com. 3. Rabin Medical Center, Petah-Tikva, Sackler School of Medicine, Tel Aviv University, Tel-Aviv, Israel. 4. Kingston General Hospital and Queen's University, Kingston, Ontario, Canada. 5. UMAE Hospital de Especialidades Dr. Antonio Fraga Mouret, CMN La Raza IMSS, Mexico City, Mexico. 6. Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico. 7. Ege University School of Medicine, Izmir, Turkey.
Abstract
BACKGROUND: Female gender increases the risk of torsades de pointes (TdP) in the long QT syndrome, and this increased risk is assumed to be due to their longer QT interval. OBJECTIVE: The purpose of this study was to study the interplay between gender, duration of the QT interval, and risk of TdP during AV block. METHODS: We studied 250 patients (48% women) with AV block. QT interval was measured at the time of most severe bradycardia. We then constructed different receiver operating characteristic curves for the QTc of males and females for predicting TdP. RESULTS: As expected, patients with TdP had longer QTc intervals than did patients with uncomplicated AV block (564 ± 81 ms vs 422 ± 62 ms, P < .001). This correlation between longer QTc and higher risk of TdP was true for both genders. However, the QT of females with TdP was shorter than the respective value for males with TdP. Despite similar severity of bradycardia, the QT was shorter for females (QT 672 ± 88 ms vs 727 ± 57 ms for females with TdP vs males with TdP, P = .022). The QTc/TdP risk curve for females was shifted to the left in comparison to the pertinent graph for males. Female gender was an independent predictor of TdP. CONCLUSION: Women are at increased risk for developing TdP during AV block, but this increased risk is independent of their longer QT interval. Females develop TdP with QT intervals that are not necessarily arrhythmogenic for males.
BACKGROUND: Female gender increases the risk of torsades de pointes (TdP) in the long QT syndrome, and this increased risk is assumed to be due to their longer QT interval. OBJECTIVE: The purpose of this study was to study the interplay between gender, duration of the QT interval, and risk of TdP during AV block. METHODS: We studied 250 patients (48% women) with AV block. QT interval was measured at the time of most severe bradycardia. We then constructed different receiver operating characteristic curves for the QTc of males and females for predicting TdP. RESULTS: As expected, patients with TdP had longer QTc intervals than did patients with uncomplicated AV block (564 ± 81 ms vs 422 ± 62 ms, P < .001). This correlation between longer QTc and higher risk of TdP was true for both genders. However, the QT of females with TdP was shorter than the respective value for males with TdP. Despite similar severity of bradycardia, the QT was shorter for females (QT 672 ± 88 ms vs 727 ± 57 ms for females with TdP vs males with TdP, P = .022). The QTc/TdP risk curve for females was shifted to the left in comparison to the pertinent graph for males. Female gender was an independent predictor of TdP. CONCLUSION:Women are at increased risk for developing TdP during AV block, but this increased risk is independent of their longer QT interval. Females develop TdP with QT intervals that are not necessarily arrhythmogenic for males.
Authors: Katerina Hnatkova; Martina Šišáková; Peter Smetana; Ondřej Toman; Katharina M Huster; Tomáš Novotný; Georg Schmidt; Marek Malik Journal: Int J Cardiol Date: 2019-10-07 Impact factor: 4.164