Author + information
- Received January 20, 2011
- Revision received November 7, 2011
- Accepted November 10, 2011
- Published online March 1, 2012.
- Mustafa I. Ahmed, MD⁎,
- Ravi V. Desai, MD⁎,
- Krishna K. Gaddam, MD⁎,
- Bharath A. Venkatesh, PhD§,
- Shilpi Agarwal, MS, MD⁎,
- Seidu Inusah, MS†,
- Steven G. Lloyd, MD, PhD⁎,‡,
- Thomas S. Denney Jr, PhD§,
- David Calhoun, MD⁎,
- Louis J. Dell'italia, MD⁎,‡ and
- Himanshu Gupta, MD⁎,‡,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Himanshu Gupta, BDB 101, CVMRI, UAB (Medicine-Cardiovascular Disease), 1530 3rd Avenue South, Birmingham, Alabama 35294-0012
Objectives The goal of this study was to define the mechanism of preserved ejection fraction (EF) despite depressed myocardial strains in hypertension (HTN).
Background Concentric left ventricular (LV) remodeling in HTN may have normal or supranormal EF despite depressed myocardial strains. The reason for such discordance is not clear. The aim of this study was to comprehensively evaluate the LV mechanics in a well-defined HTN population to define underlying reasons for such a paradox.
Methods Sixty-seven patients with resistant HTN and 45 healthy control subjects were studied by cardiac magnetic resonance imaging and tissue tagging with 3-dimensional analysis. Amplitude and directional vector of longitudinal (Ell), circumferential (Ecc), and principal strain for maximal shortening (E3) were computed at basal, mid, and distal LV levels, respectively. LV torsion, defined as the rotation angle of apex relative to base, and LV twist, which accounts for the effects of differential LV remodeling on torsion for comparison among the 2 groups, were also calculated.
Results LV mass index and LV mass/LV end-diastolic volume ratio were significantly higher in the HTN group compared with controls, consistent with concentric LV remodeling. Ell and Ecc were significantly decreased in amplitude with altered directional vector in HTN compared with controls. However, the amplitude of E3 was similar in the 2 groups. Torsion and twist were significantly higher in HTN, which was mainly due to increase in apical rotation. The HTN group demonstrated significantly increased LV wall thickening compared with controls that resulted in greater LVEF in the HTN group compared with controls (70% vs. 65%, p < 0.001, respectively).
Conclusions In compensated LV remodeling secondary to HTN, there is increased LV wall thickening with preserved E3 and increased torsion compared with normal controls. This, therefore, contributes to supranormal LVEF in HTN despite depressed longitudinal and circumferential strains.
Funded by National Institutes of Health grants NIH P50-HL077100 (L.J.D.) and NIH R01-HL104018 (H.G.). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received January 20, 2011.
- Revision received November 7, 2011.
- Accepted November 10, 2011.
- American College of Cardiology Foundation