Objectives: Impaired cardiac function has been confirmed in patients with chronic fatigue syndrome (CFS).
Magnetic resonance cardiac tagging [aka electromechanical heart mapping] is a novel technique that assesses myocardial wall function in vivo.
We hypothesized that CFS patients may have impaired development and release of myocardial torsion and strain. [Note: The heart not only contracts but rotates as it pumps.]
Methods: Cardiac morphology and function was assessed using magnetic resonance imaging and cardiac tagging methodology in 12 CFS (Fukuda) and 10 matched controls.
Results: Compared to controls the CFS group had substantially reduced LV [left ventricular] mass (reduced by 23%), end diastolic volume (30%), stroke volume (29%), and cardiac output (25%).
Residual torsion at 150% of the end-systolic time was found to be significantly higher in the CFS patients (5.3±1.6o) compared to the control group (1.7±0.7o, p=0.0001).
End diastolic volume index correlated negatively with both torsion to endocardial strain ratio (TSR) (r =-0.65, p=0.02) and the residual torsion at 150% end systolic time (r=-0.76, p=0.004), so decreased end diastolic volume is associated with raised TSR and torsion persisting longer into diastole. Reduced end diastolic volume index also correlated significantly with increased radial thickening (r=-0.65, p=0.03) and impaired diastolic function represented by the ratio of early to late ventricular filling velocity (E/A ratio, r=0.71, p=0.009) and early filling percentage (r=0.73, p=0.008).
Conclusion: CFS patients have markedly reduced cardiac mass and blood pool volumes, particularly end diastolic volume: this results in significant impairments in stroke volume and cardiac output compared to controls. The CFS group appeared to have a delay in the release of torsion.
Source: Journal of Internal Medicine, Jul 27, 2011. DOI: 10.1111/j.1365-2796.2011.02429.x. Hollingsworth KG, Hodgson T, Macgowan GA, Blamire AM, Newton JL. Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, and Institute for Ageing and Health, Campus for Ageing and Vitality, and Institute of Human Genetics, Newcastle University; Department of Cardiology, Freeman Hospital, Newcastle upon Tyne, UK. [Email: firstname.lastname@example.org]