Understanding Right Heart Flow: Implications for Interatrial Shunt Device Therapy in Heart Failure.

Elevation in left atrial pressure with subsequent pulmonary congestion is central to the pathology of heart failure. Interatrial shunts have emerged as a potential therapeutic strategy in patients with heart failure, especially those with diastolic dysfunction. These devices decrease left atrial pressure by shunting blood into the right atrium. Normal right heart flow is characterized by a predominant vortex formation in the right atrium, which then enters the right ventricle as a direct flow that preserves kinetic energy and right ventricular work efficiency. Examining the abnormal right heart blood flow patterns in naturally occurring interatrial shunts using 4-dimensional flow magnetic resonance imaging can improve our understanding of the effects of various interatrial shunt devices currently being investigated for heart failure management.