Enhanced inotropic response to dobutamine in strength-trained subjects with left ventricular hypertrophy

Oscar E. Suman, Deborah Hasten, Michael J. Turner, Morton R. Rinder, Robert J. Spina, Ali A. Ehsani

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

To determine whether strength-trained individuals with physiological concentric left ventricular (LV) hypertrophy exhibit enhanced inotropic responses to catecholamines, we studied 11 bodybuilders, aged 33.0 ± 2 (SE) yr old, and 10 sedentary healthy subjects, aged 31.3 ± 2.4 yr old, at baseline and during infusion of incremental doses of dobutamine after atropine. The bodybuilders had larger LV mass, posterior wall and septal wall thicknesses, and wall thickness-to-radius ratio, assessed with two- dimensional echocardiography, than did the sedentary subjects. There was a significant correlation between LV mass and lean body mass irrespective of training status. Baseline LV fractional shortening was similar in the two groups. There was a greater inotropic response to dobutamine in the strength- trained individuals, as evidenced by a steeper slope of the fractional shortening-end-systolic wall stress relationship with a higher y-axis intercept and by a shallower end-systolic wall stress-end systolic diameter relationship without changes in end-diastolic diameter. The heart rate response to dobutamine was attenuated in the strength-trained athletes. There was a significant correlation (r = 0.604, P < 0.05) between the inotropic sensitivity to dobutamine and LV mass normalized for lean body mass in the bodybuilders. The data suggest that concentric LV physiological hypertrophy in the resistance-trained individuals is associated with enhanced inotropic but not chronotropic responses to catecholamines.

Original languageEnglish
Pages (from-to)534-539
Number of pages6
JournalJournal of Applied Physiology
Volume88
Issue number2
DOIs
StatePublished - Feb 2000

Keywords

  • Cardiac function
  • Inotropic sensitivity
  • Physiological cardiac concentric hypertrophy

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