Doppler echocardiographic study of left ventricular diastole in non-anaesthetized healthy cats.

The current study: (1) describes the Doppler technique for the assessment of diastolic function in feline patients; (2) reports normal Doppler diastolic values; and (3) determines the effect of ageing on these parameters. Doppler echocardiography was performed on 20 non-anaesthetized healthy cats. Each diastolic parameter was correlated with age, body weight, body surface area and R-R interval. To assess the isovolumetric relaxation phase of diastole, isovolumetric relaxation time was measured. To assess the filling phase of diastole, we measured peak flow velocities of the E and A waves, diastolic filling time, acceleration and deceleration time of the E wave and the E/A ratio of transmitral flow, peak flow velocity of the S, D and the A retrograde waves, as well as the S/D ratio and the systolic fraction of pulmonary venous flow. We found a significant correlation between age and peak flow velocity of the A wave, normalized peak flow velocity of the A wave, the E/A ratio, the acceleration time of the E wave, the diastolic filling time, the velocity time integral of the E wave, the peak flow velocity of the S wave and the systolic fraction. It was concluded that Doppler echocardiographic analysis of diastole is possible in the cat and that age has most effect on filling parameters.