Objective The aims of our study are to describe the time intervals between the end of transmitral flow A velocity and onset of QRS on the ECG, stroke volume of left atrium at end of T wave and onset of P wave on the ECG in normal subjects, and examine the effect of age on these parameters.
Methods Total of 138 normal healthy adults (22–78 years old) were enrolled. The transmitral flow E and A wave were recorded by Doppler echocardiography. The time intervals from the end of transmitral flow A velocity to the onset of QRS on the ECG, diameters of mitral annulus at the end of T wave and the onset of P wave on the ECG, VTI of the mitral valve E and A were measured. We calculated the SV of mitral valve E and A as formulas: SV=0.785*diameter of mitral 2*VTI.
Results Showed in table 1.
Conclusions SV-A increased and the time intervals between the end of A wave to the onset of QRS decreased reflected the deterioration of left atrial conduit function and increased pump function due to reduced left ventricular diastolic function with age.