Small heart syndrome

Small heart syndrome is associated with a small heart shadow on a chest X-ray or magnetic resonance imaging. It was first proposed in 1944 as "neurocirculatory asthenia." Current studies show that small heart syndrome is associated with a smaller left ventricular chamber size and diminished cardiac stroke volume.

Small heart syndrome is characterized with weakness or fatigue even after ordinary exertion, heart palpitation, dyspnea, and fainting. Miwa and Fujita have shown that it is signiﬁcantly more prevalent in ME/CFS patient (61%) compared to a control group (24%).

Notable studies

 * 2011, Small Heart With Low Cardiac Output for Orthostatic Intolerance in Patients With Chronic Fatigue Syndrome
 * 2008, Small Heart Syndrome in Patients with Chronic Fatigue Syndrome