Aims: It remains to be proven whether left ventricular (LV) peak systolic velocity indices (peak systolic annulus tissue velocities, ejection velocity, and strain rate) are more closely related to contraction than LV end-systolic echocardiographic indices (ejection fraction, fractional shortening, systolic annulus displacement, global strain, and ejection velocity time integral). The study aimed to compare the ability of different echocardiographic methods in detecting contraction changes of the LV.
Methods and results: Thirty-three healthy volunteers (20-32 years) were examined by echocardiography at rest, during 10 μg/kg/min dobutamine (n = 20), and after injection of 15 mg metoprolol (n = 20). The effects of dobutamine and metoprolol on peak systolic velocity indices and end-systolic indices were compared. The relative increase from rest to dobutamine stress and the relative decrease after injection of metoprolol were 62 and -15% for peak systolic annulus tissue velocity, 60 and -11% for LV outflow tract (LVOT) peak velocity, 56 and -11% for peak systolic strain rate, 25 and 1% for ejection fraction, 30 and -1% for systolic mitral annulus displacement, 30 and -5% for LVOT velocity time integral, and 21 and -3% for global strain, respectively. The changes of the peak systolic indices were significantly higher (all P < 0.05) than the changes of the end-systolic indices.
Conclusion: Peak systolic velocity indices (mitral annulus tissue velocities, ejection velocities, and strain rate) exhibited greater variation than end-systolic indices during inotropic alterations from which it is assumed that they better reflected LV contraction.