Cardiovascular Ultrasound (Feb 2011)

Exercise-induced left bundle branch block and subsequent mechanical left ventricular dyssynchrony -resolved with pharmacological therapy

  • Tatsumi Kazuhiro,
  • Norisada Kazuko,
  • Fukuda Yuko,
  • Yamawaki Kohei,
  • Ryo Keiko,
  • Kaneko Akihiro,
  • Tsuji Takayuki,
  • Miyoshi Tatsuya,
  • Hiraishi Mana,
  • Tanaka Hidekazu,
  • Matsumoto Kensuke,
  • Kawai Hiroya,
  • Hirata Ken-ichi

DOI
https://doi.org/10.1186/1476-7120-9-4
Journal volume & issue
Vol. 9, no. 1
p. 4

Abstract

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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.