Assessment of left ventricular energy loss in patients with mild coronary artery stenosis by using vector flow mapping combined with exercise stress echocardiography

Abstract

Objectives To evaluate the left ventricular energy loss (EL), energy loss reserve (EL‐r), and energy loss reserve rate in patients with mild coronary artery stenosis by using vector flow mapping (VFM) combined with exercise stress echocardiography. Methods A total of 34 patients (case group) with mild coronary artery stenosis and 36 sex and age matched patients (control group) without coronary artery stenosis according to coronary angiogram were prospectively enrolled. The total energy loss (ELt), basal segment energy loss (ELb), middle segment energy loss (ELm), apical segment energy loss (ELa), energy loss reserve (EL‐r), and energy loss reserve rate were recorded in the isovolumic systolic period (S1), rapid ejection period (S2), slow ejection period (S3), isovolumic diastolic period (D1), rapid filling period (D2), slow filling period (D3), and atrial contraction period (D4). Results Compared with the control group, some of the EL in the resting case group were higher; some of the EL in the case group were lower after exercise, and those during D1 ELb and D3 ELb were higher. Compared with the resting state, the total EL and the EL within the time segment in the control group were higher after exercise, except during D2 ELb. In the case group, except for during D1 ELt, ELb and D2 ELb, the total and segmental EL of each phase was mostly higher after exercise (p < .05). Compared with the control group, most of the EL‐r and EL reserve rates in the case group were lower (p < .05). Conclusion The EL, EL‐r, and energy loss reserve rate have a certain value in the evaluation of cardiac function in patients with mild coronary artery stenosis.

Evaluation of left ventricular flow field changes after stress in patients with nonobstructive coronary artery disease using ultrasonic flow vector imaging

“…Eddy currents are an effective form of natural energy storage. Eddy currents may increase the shear stress at the ventricular wall, but they can maintain the blood flow stability and reduce energy loss ( 17 ). Previous studies confirmed that evaluating eddy current models has great clinical significance for better understanding the left ventricular function ( 18 – 21 ).…”