The impact of isometric handgrip testing on left ventricular twist mechanics

Rory B. Weiner, Arthur E. Weyman, Jonathan H. Kim, Thomas J. Wang, Michael H. Picard, Aaron L. Baggish

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

Left ventricular (LV) rotation occurs due to contraction of obliquely oriented myocardial fibres. Left ventricular twist (LVT) results from rotation of the apex and base in opposite directions. Although LVT is altered in various cardiac diseases, physiological factors that affect LVT remain incompletely understood. Isometric handgrip testing (IHGT), a well-established laboratory-based technique to increase LV afterload, was performed for 3 min at 40% maximum force generation in healthy human subjects (n= 18, mean age 29.7 ± 2.7 years). Speckle-tracking echocardiography was used to measure LV volumes, LV apical and basal rotation, peak systolic LVT and peak early diastolic untwisting rate (UTR) at rest and at peak IHGT. IHGT led to significant increase in systemic blood pressure (systolic, 120.6 ± 9.7 vs. 155.6 ± 14.5 mmHg, P < 0.001; diastolic, 67.5 ± 6.4 vs. 94.1 ± 21.1 mmHg, P < 0.001) and LV end-systolic volume (44.2 ± 7.8 vs. 50.5 ± 10.8 ml, P= 0.005), as well as a significant increase in heart rate (62.8 ± 11.7 vs. 84.7 ± 13.8 beats min -1; P < 0.001). IHGT produced a significant acute reduction in LV stroke volume (63.9 ± 12.0 vs. 49.4 ± 7.8 ml, P < 0.001). In this setting, there was a significant decrease in peak systolic apical rotation (11.9 ± 3.0 vs. 8.6 ± 2.2 deg, P < 0.001) and a resultant 25% decrease in peak systolic LVT (16.6 ± 2.8 vs. 12.5 ± 2.8 deg, P < 0.001). The magnitude of peak early diastolic UTR did not change (-114.5 ± 26.4 vs. -110.6 ± 39.8 deg s -1, P= 0.71). Peak systolic apical rotation and LVT decrease during IHGT in healthy humans. This impairment of LV twist mechanics may in part underlie the LV dysfunction that can occur in the clinical context of acute increase in afterload.

Original languageEnglish (US)
Pages (from-to)5141-5150
Number of pages10
JournalJournal of Physiology
Volume590
Issue number20
DOIs
StatePublished - Oct 1 2012
Externally publishedYes

ASJC Scopus subject areas

  • Physiology

Fingerprint Dive into the research topics of 'The impact of isometric handgrip testing on left ventricular twist mechanics'. Together they form a unique fingerprint.

  • Cite this

    Weiner, R. B., Weyman, A. E., Kim, J. H., Wang, T. J., Picard, M. H., & Baggish, A. L. (2012). The impact of isometric handgrip testing on left ventricular twist mechanics. Journal of Physiology, 590(20), 5141-5150. https://doi.org/10.1113/jphysiol.2012.236166