Bepridil produces prominent bradycardia-dependent QT prolongation in patients with structural heart disease
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Updated: Jul 14, 2026

Electrocardiogram Recordings in Anesthetized Mice using Lead II
Published on: June 20, 2020
Tsuneaki Sadanaga1, Satoshi Ogawa
1Division of Cardiology, Yatsushiro General Hospital, Yatsushiro, Japan. kamefu@rb3.so-net.ne.jp <kamefu@rb3.so-net.ne.jp>
Abstract:
The aim of the present study is to elucidate the effect of bepridil on heart rate-dependent QT prolongation in patients with or without structural heart disease. QT intervals and the preceding R-R intervals were randomly measured by 24-hour Holter electrocardiogram in 29 patients with symptomatic arrhythmias. The slope of the regression curve was used as a marker of bradycardia-dependent QT prolongation. The slope was not different in patients without structural heart disease (0.34 +/- 0.10) as compared with the apparently normal control subjects (0.32 +/- 0.057, n = 29), whereas it was larger than that in patients with structural heart disease (0.57 +/- 0.17; P < .01). Steep slopes (>0.43) were observed in 11 of the 14 patients with structural heart disease, whereas they were observed only in 1 patient without structural heart disease (P < .01). In conclusion, we need to pay attention to bradycardia-dependent QT prolongation by bepridil, especially when dealing with structural heart disease.
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