Isovolumic Acceleration in Predicting Preliminary Phase of Right and Left Ventricular Systolic Dysfunction in Hypertensive Obese Patients

Aims: Isovolumic acceleration assessed with tissue Doppler imaging has been proposed as a preload-independent indicator of left ventricular contractility. We investigated the utility of isovolumic acceleration in the prediction of preclinical right and left ventricular systolic dysfunction in hypertensive and obese subjects.

METHODS
Seventy eight obese (body mass index>30 kg/m2) volunteers were prospectively enrolled. Conventional and tissue Doppler echocardiography was performed on all patients. Myocardial velocities of the left ventricular septal and lateral mitral annulus and lateral tricuspid annulus were obtained. The isovolumic contraction wave was determined as the preceding wave to the systolic wave that begins before the peak of the R wave on ECG. IVA was measured by dividing peak velocity by the time interval from onset of the wave (zero-crossing) during isovolumic contraction to the time at peak velocity of this wave.

RESULTS
There was a positive correlation between waist circumference and left ventricular end systolic (r=0.22 p=0.047) and end-diastolic diameter (r=0.384, r=0.001) and a negative correlation between waist circumference and tricuspid annulus TDI peak systolic velocity (r= -0.311, p=0.006). Although hypertensive and normotensive obese patients had similiar TDI based myocardial velocities, hypertensive obese patients had significantly lower tricuspid annulus isovolumic acceleration (p=0.027), septal isovolumic acceleration (p=0.026), and septal isovolumic contraction myocardial velocity (p=0.018) than normotensive obese subjects.

CONCLUSION
Isovolumic acceleration and isovolumic contraction myocardial velocity analysis may be useful in the diagnosis of subclinical left and right ventricular dysfunction in hypertensive and obese patients.