Assessment of diastolic abnormalities in dilated cardiomyopathy by automated border detection: comparison with conventional doppler parameters

Echocardiographic automated border detection (ABD) is a new technique that displays ventricular volume on-line and provides accurate estimations of derivative left ventricular diastolic indexes, such as peak filling rate (PFR) and time to PFR (TPFR). Only few data compared ABD indexes with other echo Doppler parameters. To determine whether TPFR obtained from ABD presents a correlation with Doppler analysis of transmitral and pulmonary venous flow pattern, we studied 27 dilated cardiomyopathy (DCM) patients (22 males, 5 females, mean age 59 ± 10 years, ejection fraction 24 ± 7%), all in sinus rhythm. From Doppler transmitral curve we calculated: E/A ratio, deceleration time of E and isovolumic retaxation time. Twenty-one out of 27 DCM patients underwent transesophageal echocardiography in order to evaluate diastolic component of pulmonary venous flow. Then, 10/27 DCM patients and 14 normal volunteers were studied using continuous acquisition of ABD signal. A PC equipped with an analog to digital board was used to acquire (300 sample/s) the ABC waveform. An average length of 300 ± 45 beats was used to reduce noise with digital low-pass filter and compute PFR, peak atrial filling rate. In conclusion, 1) a good correlation is present between TPFR measured from ABD and Doppler transmitral and pulmonary venous flow indexes in DCM patients; 2) TPFR index is able to assess left ventricular diastolic abnormalities (from abnormal relaxation to restrictive patterns); 3) direct examination of left ventricular diastolic dynamics with computer assisted ABD echocardiography provides a sensitive technique for the assessment of diastolic dysfunction in DCM patients.