Contrast echocardiography of the left ventricle an independent predictor of pulmonary artery pressure?

To test the hypothesis that left heart opacification is dependent on pulmonary artery pressure, we analyzed consecutively 12 patients with normal and 8 patients with abnormal pulmonary artery pressure with a new lung capillary stable echo contrast agent. Patients underwent contrast echocardiographic examination within 6 hours before right and left heart catheterization with 200 mg/ml and 400 mg/ml SHU 508A intravenously. The mean pulmonary artery pressure was 15.4 mmHg in the patients with normal pulmonary artery pressures and 46.4 mmHg in the patients with pulmonary hypertension (p < 0.000). Echocardiograms were video-intensitometrically analyzed for intensity maximum (MAX), half-time of video-intensity decay (T1/2), area under the intensity curve (AUC) in the right and left ventricle and transit time from left to right heart (TT). Patients with normal pulmonary artery pressure showed sufficient left heart opacification, in the left ventricle MAX was 37 +/- 15 IU, AUC measured 653 +/- 463 IUxs and T1/2 was 4.4 +/- 2.6 s, while patients with elevated pulmonary artery pressure showed no significant left heart opacification. In the left ventricle MAX was 8 +/- 10 IU (p = 0.006), AUC measured 66 +/- 108 (p = 0.003) and T1/2 was 2.0 +/- 2.0 s (p = 0.041). TT was significantly increased in patients with elevated pulmonary artery pressure (11.8 +/- 4.6 s versus 6.5 +/- 2.8 s in patients with normal pulmonary artery pressure, p = 0.005). Thus, elevated pulmonary pressure has a significant impact on left heart opacification, which may be used for diagnostic purposes.