The effects of left ventricular hypertrophy on the respiratory changes in transmitral Doppler flow patterns of hypertension patients

Background: Left ventricular early diastolic fillings can be reduced by inspiration. However, the effects of left ventricular hypertrophy on such changes have not been studied before. This study was undertaken to investigate whether respiratory changes in transmittal Doppler flow were affected by left ventricular hypertrophy in hypertension patients. Methods: Eighty-three patients (mean age 46 ± 8 years, males) with untreated essential hypertension were included in this study. Transmitral Doppler flow velocity was measured both at end-expiration and end-inspiration. Left ventricular mass was measured by M-mode echocardiography. We divided patients into two groups based on the presence of left ventricular hypertrophy or not. Results: Twenty-one patients were diagnosed to have left ventricular hypertrophy. In patients without left ventricular hypertrophy, the peak early filling velocity decreased significantly (from 74 ± 15 to 71 ± 18 cm s^-1, P = 0.003), the peak atrial velocity increased significantly (from 65 ± 17 to 74 ± 15 cm s^-1, P<0.001) and the early filling to atrial velocity ratio decreased significantly (from 1.2 ± 0.3 to 1.1 ± 0.3, P<0.001) from end-expiration to end-inspiration. In patients with left ventricular hypertrophy, the parameters of transmitral Doppler flow pattern did not change during respiration. Conclusion: Respiratory changes in the transmitral Doppler flow velocity are blunted by left ventricular hypertrophy in hypertension patients. This phenomenon is probably contributed by the increased left ventricular wall stiffness in the left ventricular hypertrophy.