Published in:
Open Access
01-12-2011 | Case report
Exercise-induced left bundle branch block and subsequent mechanical left ventricular dyssynchrony -resolved with pharmacological therapy
Authors:
Hidekazu Tanaka, Mana Hiraishi, Tatsuya Miyoshi, Takayuki Tsuji, Akihiro Kaneko, Keiko Ryo, Kohei Yamawaki, Yuko Fukuda, Kazuko Norisada, Kazuhiro Tatsumi, Kensuke Matsumoto, Hiroya Kawai, Ken-ichi Hirata
Published in:
Cardiovascular Ultrasound
|
Issue 1/2011
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Abstract
A 53-year-old man with depressed ejection fraction (EF) of 35% and QRS width of 88 ms at rest was admitted to our institution with a complaint of exertional chest discomfort and dyspnea. During treadmill exercise, left bundle-branch block (LBBB) with a QRS width of 152 ms occurred at a heart rate of 100 bpm. During LBBB, the patient showed significant mechanical dyssynchrony as evidenced by a two-dimensional speckle tracking radial strain of 260 ms (≥130 ms), defined as the time difference between anterior-septum and posterior wall. Five-month after carvedilol and candesartan administration, EF had improved to 49% and LBBB did not occur until a heart rate of 126 bpm was attained during treadmill exercise. It appears that pharmacological therapy may be useful for patients with heart failure and exercise-induced LBBB.