RV dysfunction

Overview
Right ventricular (RV) dysfunction is defined as a state where stroke volume still increases in the presence of increased RV end-diastolic volume. In contrast the RV failure is present when stroke volume cannot increase any further in parallel to increased RV end-diastolic volume.

ACC/AHA criteria
American heart association has proposed the following:

RV dysfunction means the presence of at least 1 of the following:
 * On echocardiography, RV dilation (apical 4-chamber RV diameter divided by LV diameter >0.9) or RV systolic dysfunction
 * On CT, RV dilation (4-chamber RV diameter divided by LV diameter >0.9)
 * Elevation of BNP >90 pg/mL.
 * Elevation of N-terminal pro-BNP >500 pg/mL
 * Electrocardiographic changes (new complete or incomplete right bundle-branch block, anteroseptal ST elevation or depression, or anteroseptal T-wave inversion)

Etiology
Right ventricular (RV) dysfunction occurs directly due to cardiodepressant effects of:
 * Proinflammatory cytokines.
 * Cardiac microthrombi.
 * Ischemia and/or arrhythmias.

Indirect causes of RV dysfunction are:
 * Left ventricular (LV) dysfunction.
 * Afterload increases from endothelial dysfunction.
 * Hypoxic pulmonary vasoconstriction.
 * Pulmonary emboli, and/or pulmonary microthrombi.
 * Pre-load decreases (caused by capillary leak syndrome).
 * Mechanical ventilation contributes to RV dysfunction by negatively affecting pre-load and/or afterload.