Left Ventricle Energy Loss In Normo- And Hypertensive Subjects

Background Vector flow mapping is a novel echocardiographic technique that enables the visualization of the intraventricular flow. We aimed to evaluate and compare the index of hemodynamic dissipative energy loss in patients with hypertension and the ones with normotensive, unaffected control subjects. Methods & Results Transthoracic echocardiography was performed in eighty-nine hypertensive patients with preserved left ventricular ejection fraction, fifty-one hypertensive patients with left ventricular hypertrophy (LVH group) and thirty-eight hypertensive patients without LVH (non-LVH group). Forty-two healthy volunteers were enrolled as the control group. The stored images were analyzed to calculate the energy loss. The average energy loss of diastole in the LVH group was significantly increased (controls vs. non-LVH vs. LVH: 7.07 +/- 0.91 vs. 12.44 +/- 3.14 vs. 16.29 +/- 3.17 J/s per m(3)). Compared with the control group, the energy loss was significantly increased in the LVH group during the different periods in diastole. The energy loss in the non-LVH group was the greatest among the three groups during the atrial contraction period. Conclusions Energy loss provides a promising method for evaluating the energy efficiency in the left ventricle and may be a new indicator of left ventricular cardiac dysfunction.