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

• 2012, Small Heart as a Constitutive Factor Predisposing to Chronic Fatigue Syndrome - (Full text)
• 2011, Small Heart With Low Cardiac Output for Orthostatic Intolerance in Patients With Chronic Fatigue Syndrome - (Full text)
• 2009, Cardiovascular dysfunction with low cardiac output due to a small heart in patients with chronic fatigue syndrome - (Full text)
• 2008, Small Heart Syndrome in Patients with Chronic Fatigue Syndrome - (Abstract)

Learn more

• 2012, Small Heart as a Constitutive Factor Predisposing to Chronic fatigue Syndrome (book chapter)

See also

• Cardiac problems in ME/CFS
• Cardiovasular system
• Kunihisa Miwa

orthostatic intolerance (OI) - The development of symptoms when standing upright, where symptoms are relieved upon reclining. Patients with orthostatic intolerance have trouble remaining upright for more than a few seconds or a few minutes, depending upon severity. In severe orthostatic intolerance, patients may not be able to sit upright in bed. Orthostatic intolerance is often a sign of dysautonomia. There are different types of orthostatic intolerance, including postural orthostatic tachycardia syndrome (POTS).