AUTOMATIC BORDER DETECTION TO ASSESS RIGHT-VENTRICULAR FUNCTION FOLLOWING SURGICAL-TREATMENT OF THROMBOEMBOLIC PULMONARY-HYPERTENSION

Automatic border detection (ABD) has been developed as a potentially u seful means for evaluating ventricular function on line in an automati c fashion. Its success with tracking left ventricular function is esta blished but little is known about its ability to assess right ventricu lar (RV) function. Accordingly, 20 patients with severe pulmonary hype rtension due to chronic thromboembolic disease underwent standard two- dimensional echocardiography and imaging with ABD before and after pul monary thromboendarterectomy to correct pulmonary hypertension. ABD-de rived results were compared to manually planimetered RV areas calculat ed from the apical four-chamber view. Doppler tricuspid regurgitant ve locity fell significantly with surgery from 4.4 +/- 0.6 to 2.9 +/- 0.7 m/sec (P < 0.001). The mean values for RV areas derived by manual pla nimetry and ABD were similar, as was fractional area shortening, which improved significantly with surgery (manual 0.24 +/- 0.01 preoperativ e us 0.31 +/- 0.11 postoperative, P < 0.05; and ABD 0.19 +/- 0.05 preo perative us 0.32 +/- 0.15 postoperative, P < 0.001). There was, howeve r very little correlation between the individual values for ABD versus manually derived RV areas and fractional area shortening, with the be st correlation being the RV end-diastolic areas after surgery (gamma = 0.684x + 7.9, r = 0.564, P = 0.01). These results demonstrate that bo th manually planimetered RV areas and those determined by ABD can adeq uately follow changes in ventricular function over time. However varia bility within each technique may prevent direct comparison of the abso lute values of the two techniques.