Japanese researchers had previously discovered that “small heart” with low cardiac output is prevalent in CFS patients. Colleagues had also reported that patients with postural orthostatic tachycardia, which is often noted in patients with chronic OI (Orthostatic Intolerance), have small hearts coupled with reduced blood volume compared with healthy controls, as determined by magnetic resonance imaging and blood volume measurements.
In the present study, left ventricular (LV) size and function were evaluated echocardiographically in CFS patients with and without OI, and also in OI patients without CFS, to clarify the differences in cardiac size and function among these patients and healthy controls.
They concluded that a small size of LV with reduced cardiac function is common in patients with OI and its degree appears to be more pronounced in CFS patients with OI. Chronic fatigue syndrome with OI seems to constitute a well-defined and predominant subgroup of CFS. Small heart with impaired cardiac performance due to decreased preload appears to be an important target for the treatment of CFS and OI.
