[Dynamic online quantification of left ventricular function by automated boundary detection: validation of a new echocardiography method].
A recently developed ultrasonic integrated backscatter imaging system allows automated border detection (ABD) of the blood-tissue interface in real time and provides instantaneous measurement of left ventricle cavity area in a beat-to-beat fashion. Three validations of this new system have been performed. 1) In 70 subjects (38 normal volunteers and 32 patients) the on-line ABD-derived areas (end-diastole, -systole = EDA, ESA) and the resulting fractional area change (FAC) of the left ventricle (apical four-chamber view) were compared with the off-line areas and FAC traced manually. All correlations were close (EDA r = 0.97, ESA r = 0.98, FAC r = 0.92; p < 0.0001). 2) In 36 patients with mitral regurgitation (MR), ABD-FAC was compared to the Doppler-derived systolic rate of pressure rise (RPR) which corresponds to systolic dP/dt, as simultaneous studies with high-fidelity pressure measurements have shown. Linear regression analysis yielded a significant correlation with r = 0.91; p < 0.0001. 3) In 26 patients undergoing routine heart catheterization, ABD-echo was performed on the same day. ABD-derived areas (end-diastole, -systole) and FAC (apical two- and four-chamber view) were compared to the corresponding angiographic data derived from biplane projection in 30 degrees RAO and 60 degrees LAO. Linear regression analysis yielded significant values for all correlations (EDA r = 0.88, ESA r = 0.95, FAC 0.90; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)