Small Heart With Low Cardiac Output for Orthostatic Intolerance in Patients With Chronic Fatigue Syndrome

Abstract

Background: The etiology of chronic fatigue syndrome (CFS) is unknown. Orthostatic intolerance (OI) is common in CFS patients. Recently, small heart with low cardiac output has been postulated to be related to the genesis of both CFS and OI. Hypothesis: Small heart is associated with OI in patients with CFS. Methods: Study CFS patients were divided into groups of 26 (57%) CFSOI(+) and 20 (43%) CFSOI(−) according to the presence or absence of OI. In addition, 11 OI patients and 27 age-and sex-matched control subjects were studied. Left ventricular (LV) dimensions and function were determined echocardiographically. Results:The mean values of cardiothoracic ratio, systemic systolic and diastolic pressures, LV end-diastolic dimension, LV end-systolic dimension, stroke volume index, cardiac index, and LV mass index were all significantly smaller in CFSOI(+) patients than in CFSOI(−) patients and healthy controls, and also in OI patients than in controls. A smaller LV end-diastolic dimension (<40 mm) was significantly (P < 0.05) more prevalently noted in CFSOI(+) (54%) and OI (45%) than in CFSOI(−) (5%) and controls (4%). A lower cardiac index (<2 L/min/mm 2 ) was more prevalent in CFSOI(+) (65%) than in CFSOI(−) (5%, P < 0.01), OI (27%), and controls (11%, P < 0.01). Conclusions: A small size of LV with low cardiac output was noted in OI, and its degree was more pronounced in CFSOI(+). A small heart appears to be related to the genesis of OI and CFS via both cerebral and systemic hypoperfusion. CFSOI(+) seems to constitute a well-defined and predominant subgroup of CFS.

Small Heart as a Constitutive Factor Predisposing to Chronic Fatigue Syndrome

“…60 CFS with OI seems to constitute a well-defined and predominant subgroup of CFS. Small heart with reduced cardiac performance due to decreased preload may be an important target for the treatment of CFS.…”

Chronic fatigue syndrome in 57-year-old woman

“…According to the literature, when compared to the controls, many CFS patients are characterized by orthostatic disorders and lower blood pressure, both possibly resulting from the abnormal functioning of ANS. Howev-er, to date, this phenomenon has not been fully elucidated [5,[7][8][9][10]. Using the Task Force Monitor might allow us to develop objective tools to diagnose CFS and perhaps allow us to diagnose it earlier.…”

Multiscale analysis of heart rate variability in non-stationary environments

“…Recent small-sample studies about possible cardiac irregularities (Naschitz et al, 2006; Boneva et al, 2007; Burton et al, 2009; Hurwitz et al, 2009; Hollingsworth et al, 2011; Miwa and Fujita, 2011; Newton et al, 2011; Rahman et al, 2011; Beaumont et al, 2012) have motivated us to carefully examine whether HRV in persons with CFS may be substantially different from that in healthy controls. Given that previous studies have already tried to quantify the difference between the HRV of healthy control and CFS subjects using standard HRV metrics that assume stationarity, we have chosen two completely different multiscale methods, AFA and SDLE, that do not assume stationarity to analyze HRV, and used them on data from healthy control and CFS subjects in a highly non-stationary environment.…”

“…While no known biomarker for CFS has been identified to date, recent small-sample studies have suggested certain cardiac irregularities, such as low nocturnal HRV (Boneva et al, 2007; Burton et al, 2009; Rahman et al, 2011), small left ventricle and orthostatic intolerance (Miwa and Fujita, 2011), short QT interval (Naschitz et al, 2006), and low blood volume and diminished cardiac function (Hurwitz et al, 2009; Hollingsworth et al, 2011), are associated with CFS. It is not known if the cardiac irregularities are themselves a cause of the symptoms of CFS or if they are symptoms of the autonomic dysfunction and other systemic breakdowns which are more directly causative.…”