Impaired right ventricular myocardial perfusion and right ventricular dysfunction in patients with pulmonary arterial hypertension: a study of contrast echocardiography and strain imaging

Background: Little is known about right ventricular (RV) dysfunction in patient with pulmonary arterial hypertension (PAH). Recently, RV ischemia has been reported to be a contributory factor in the development of RV dysfunction. The aim of this study is to evaluate RV myocardial perfusion and assess its relationship with RV dysfunction. Methods: This prospective study consisted of 10 consecutive patients (7 female, 51±17 years) with PAH (6 idiopathic PAH (IPAH), and 4 chronic thromboembolic pulmonary hypertension (CTEPH)), and 6 healthy controls (3 females, 37±6 years). Quantitative myocardial contrast echocardiography (MCE) was performed using Philips iE33 imaging system with an S5-1 probe. We depicted the apical four chamber view. A solution of Levovist (300mg/ml) was inravenously administered at a rate of 3ml/min with a volumetric pump. End-systolic images were obtained every four heart beats. The MCE images were analyzed off-line using VoluMap-445 system. The RV myocardium was divided into six segments, at each myocardial segment, calibrated contrast intensity (CI) was determined as the difference (dB) between the mean myocardial CI and cavity CI. 2D speckle tracking echocardiographic study was also performed using Vivid E9 ultrasound system. Results: Among 96 RV myocardial segments, quantitative CI analysis was possible in 86 segments (90%). RV fractional area change was 46% (healthy), 34% (CTEPH) and 25% (IPAH). Mean calibrated CI of RV free wall was -13.4dB, -19.3dB and -22.8dB, respectively (p=0.01). We found good inverse correlation between calibrated CI and longitudinal strain of RV free wall (r=-0.5, p=0.0013). ![Figure][1] Conclusion: Quantitative MCE revealed patients with PAH have impaired RV myocardial perfusion, and this correlated well with the RV longitudinal myocardial dysfunction. [1]: pending:yes