Cardiovascular Dysfunction with Low Cardiac Output Due to a Small Heart in Patients with Chronic Fatigue Syndrome

Abstract

Little attention has been paid to possible cardiovascular involvement in patients with chronic fatigue syndrome (CFS), although many of their symptoms and signs suggest cardiovascular dysfunction. Possible cardiovascular symptoms and cardiac function were investigated in CFS patients. Cardiovascular symptoms were intensively investigated and cardiac function was evaluated echocardiographically. Fifty-three patients (23 men and 30 women, mean age: 31+/-7 years) with CFS under 50 years were studied. Slender build (body mass index <20 kg/m(2)) was common (47%). Possible cardiovascular symptoms including shortness of breath (32%), dyspnea on effort (28%), rapid heartbeat (38%), chest pain (43%), fainting (43%), orthostatic dizziness (45%) and coldness of feet (42%), were all frequent complaints. Hypotension (28%) was occasionally noted. Electrocardiograms frequently revealed right axis deviation (21%) and severe sinus arrhythmia (34%) suggesting accentuated parasympathetic nervous activity. Small heart shadow (cardiothoracic ratio <or=42%) was noted on the chest roentgenogram in 32 patients (60%). Echocardiographic examination demonstrated low cardiac indexes (<2 L/min/m(2)) with low stroke volume indexes (<30 mL/m(2)) due to a small left ventricular chamber in 19 (36%, p<0.05 vs. 8% in 36 controls). None had reduced left ventricular ejection fraction. Cardiovascular symptoms are common in CFS patients. Cardiac dysfunction with low cardiac output due to small left ventricular chamber may contribute to the development of chronic fatigue as a constitutional factor in a considerable number of CFS patients.