A bioenergetic assessment of mitral regurgitation: A new tool to assess severity?

Mitral regurgitation is frequently classified as mild, moderate or severe based on echocardiography. Patients with mild mitral regurgitation are usually managed medically. We hypothesise that mild mitral regurgitation as assessed volumetrically can in fact be severe when analysed from a bioenergetics point of view. The conservation of energy predicts that any regurgitant volume will require the heart to provide more work energy to support the circulation. Mitral regurgitation involves the left ventricle imparting potential energy, via blood pressure, and kinetic energy, via regurgitant velocity, to the regurgitant blood volume. This implies that regurgitant volume, regurgitant velocity, systolic blood pressure, heart rate, regurgitant orifice area and cardiac output are all important factors. We present limited data to demonstrate our hypothesis. A bioenergetic analysis of mitral regurgitation, may identify patients whose mitral regurgitation, assessed via echocardiography as mild, is actually clinically significant. In addition we identify the importance of blood pressure and heart rate control in patients with mitral regurgitation. The concept that a bit of mitral regurgitation in patients with poor left ventricles is a good thing, as it helps offload the left ventricle is from an engineering point fundamentally flawed.