Right ventricular failure: physiology and assessment.

Right ventricular function can be altered in several disease states involving lungs and heart. Severe right ventricular dysfunction is a major determinant of outcome in such situations, and may strongly influence clinical management. The complex geometry of the right ventricle and the different physiology with respect to the left ventricle make the right ventricular failure difficult to define and assess. The response to increased afterload is the main determinant of right ventricle physiology in pathologic conditions. This consists of right ventricular hypertrophy and enlargement, with reduced coronary blood flow to the right ventricular wall, dilation of tricuspid annulus and displacement of interventricular septum. This latter change involves the left ventricular diastolic function, which is reduced by leftward septal shifting. In right ventricle myocardial ischemia and infarction the primum movens of altered right ventricular function is not an increase in afterload, but the ischemic involvement of the right ventricle, more often in the setting of an inferior acute myocardial infarction. The assessment of right ventricular failure is based on thermodilution by pulmonary artery catheter, contrast and radionuclide ventriculography, echocardiography, and magnetic resonance. Among these techniques, thermodilution and echocardiography play a relevant role in clinical scenarios, being readily available and feasible bedside.