title: Exercise-induced left bundle branch block and subsequent mechanical left ventricular dyssynchrony--resolved with pharmacological therapy.
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.
authors.affiliation: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. tanakah@med.kobe-u.ac.jp
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Mana
authors.initials: M
authors.lastname: Hiraishi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tsuji
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kaneko
authors.forename: Keiko
authors.initials: K
authors.lastname: Ryo
authors.forename: Kohei
authors.initials: K
authors.lastname: Yamawaki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Kazuko
authors.initials: K
authors.lastname: Norisada
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Kensuke
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kawai
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D001562:Benzimidazoles / Q000627:therapeutic use*; D001713:Biphenyl Compounds; D002037:Bundle-Branch Block / Q000209:etiology* / Q000503:physiopathology; D002227:Carbazoles / Q000627:therapeutic use*; D000077261:Carvedilol; D015444:Exercise; D005080:Exercise Test; D006801:Humans; D008297:Male; D008875:Middle Aged; D011412:Propanolamines / Q000627:therapeutic use*; D013777:Tetrazoles / Q000627:therapeutic use*; D014665:Vasodilator Agents / Q000627:therapeutic use; D018487:Ventricular Dysfunction, Left / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology
chemical_list: D000959:Antihypertensive Agents; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D002227:Carbazoles; D011412:Propanolamines; D013777:Tetrazoles; D014665:Vasodilator Agents; D000077261:Carvedilol; C081643:candesartan