QUANTITATIVE ASSESSMENT OF RIGHT VENTRICULAR REGIONAL WALL MOTION IN HUMAN HEART

Abstract

BACKGROUND: The importance of right ventricular (RV) dysfunction is increasingly recognized in multiple cardiopulmonary diseases such as pulmonary arterial hypertension, congestive heart failure and myocardial infarction. However, the assessment of RV function remains limited and challenging due to it’s complexity of geometry and the mechanical interaction with left ventricle (LV).

MATERIAL AND METHOD: 9 subjects who underwent magnetic resonance imaging (MRI) scans were recruited for this study. 4 subjects are healthy normal volunteers (female/male=1/3, aging from 16 to 29 years old) without any major medical problem while the other 5 are patients with right ventricular (RV) dysfunction (female/male=2/3, aging from 14 to 60 years old). The contours of right ventricles were drawn using CMRtools during cardiac cycle. A MATLAB algorithm was developed to calculate the displacements values during the cardiac cycle to access the wall motion of RV.

RESULTS: The algorithm for automatic quantitative assessment of RV wall motion in terms of displacement was developed. There were distinct differences in regional wall displacement in patients with RV dysfunction (PRV) compared to normal healthy volunteers (NRV). The right ventricular shape was elongated, cresentic and trapezoidal in NRV. However, for PRV, cross-sectional area was significantly larger and they are highly dilated or round compared to normal subjects. It was also observed that displacement waveform for PRV have more variations/multiple high peaks compared to NRV. Maximal displacement was much lower in PRV compared to NRV, in particular at basal regions (0.21±0.06 mm in PRV versus 0.38±0.07 mm in NRV).

CONCLUSION: The Matlab-based algorithm for automatic quantitative assessment of right ventricular regional wall motion has been developed. There were distinctive differences in wall motion in patients with RV dysfunction compared to normal subjects. This new approach may facilitate the heart disease diagnostic and management. It was also useful to evaluate the effectiveness of therapeutic intervention in patient with severe right ventricular failure.