Steep left ventricle to aortic root angle and hypertrophic obstructive cardiomyopathy: study of a novel association using three-dimensional multimodality imaging
- D H Kwon1,
- N G Smedira1,
- Z B Popovic1,
- B W Lytle1,
- R M Setser2,
- M Thamilarasan1,
- P Schoenhagen1,2,
- S D Flamm1,2,
- H M Lever1,
- M Y Desai1,2
- 1Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA
- 2Imaging Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Correspondence to Dr M Y Desai, Department of Cardiovascular Medicine, Heart and Vascular Institute, Desk J1-5, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA; desaim2{at}ccf.org
- Accepted 28 April 2009
- Published Online First 22 June 2009
Abstract
Background: Patients with hypertrophic cardiomyopathy (HCM) exhibit a difference in left ventricular outflow tract (LVOT) obstruction, independently of basal septal thickness (BST). Some patients with HCM have a steeper left ventricle to aortic root angle than controls.
Objective: To test the predictors of the LV-aortic root angle and the association between LV-aortic root angle and LVOT obstruction using three-dimensional imaging.
Patients: 153 consecutive patients with HCM (mean (SD) age 46 (14) years, 68% men) and 62 patients with hypertensive heart disease of the elderly (all >65 years of age, 73 (6) years, 34% men) who underwent whole-heart three-dimensional cardiac magnetic resonance (CMR) angiography (1.5 T) and Doppler echocardiography. Forty-two controls (age 43 (11) years, 38% men) who underwent contrast-enhanced multidetector computed tomography and were free of cardiovascular pathology were also studied.
Main outcomes: LV-aortic root angle, BST and maximal non-exercise LVOT gradient were measured in patients with HCM and in hypertensive-elderly patients. Additionally, LV-aortic root angle and BST were measured in controls.
Results: The mean (SD) LV-aortic root angle was significantly different (p<0.001) in the three groups: HCM (134 (10)°), hypertensive-elderly (128 (10)°), control (140 (7)°). There was an inverse correlation between age and LV-aortic root angle in the three groups (all p<0.001): HCM (r = −0.56), hypertensive-elderly (r = −0.35), control (r = −0.48). On univariate analysis, in the HCM group, LV-aortic root angle (β = −0.34, p<0.001), age (β = 0.23, p = 0.01) and end-systolic volume index (β = −0.20, p = 0.02), but not BST (β = 0.02, p = 0.8), were associated with LVOT gradient. On multivariate analysis, only LV-aortic root angle was associated with LVOT gradient.
Conclusions: Patients with HCM have a steeper LV-aortic root angle than controls. In patients with HCM, a steeper LV-aortic root angle predicts dynamic LVOT obstruction, independently of BST.
Footnotes
-
See Editorial, page 1725
-
Competing interests None declared.
-
Ethics approval Approved by the Cleveland Clinic IRB.
-
Provenance and Peer review Not commissioned; externally peer reviewed.
