Invited Speaker

New Concepts in the Non Invasive Evaluation of Remodeling of the Right Ventricle in Pulmonary Arterial Hypertension: Future Targets for Drug Evaluation
Rio Aguilar Torres
USA

The serial evaluation of the right ventricular function in pulmonary hypertension is mandatory, since most deaths are secondary to its failure. The majority of the proposed methods of echocardiographic assessment of right ventricular function are based on volumetric approximations of the right ventricle. However, such approaches have intrinsic limitations, first since volume related measures such as ejection fraction are load dependent, second because of the complex geometry of the right ventricle . The issue of right ventricular geometry is usually overcome using the so called geometry independent parameters such as tricuspid annular velocity and TAPSE and three dimensional echocardiography. Nevertheless assessments based on tricuspid annular excursion have important inherent limitations as independent measurements of right ventricular pumping function. However, is it really necessary to analyse right ventricular volumes in order to calculate a variable so dependent on post load such as ejection fraction, particularly in a clinical setting where afterload is so important, such as pulmonary hypertension? It appears that the Echo Doppler technology will be more logically applied to the study of functional aspects unable to be quantified by other imaging techniques.

Another promising tool for right ventricular assessment is tissue doppler imaging techniques, but at present, data are relatively scarce and variability of results are still too high to rely only in this method for right ventricular function analysis in pulmonary hypertension . However some studies have already reported normal range of mechanical variables in Doppler imaging studies, have shown evidence of interventricular dyssynchrony in pulmonary hypertension and have related these variables to serum levels of brain natriuretic peptide. In addition even some variables, such as apical strain rate, have been correlated with pulmonary artery pressures .