Vol. 1 Núm. e00002 (2016): Discriminative value of cardiopulmonary progressive exercise test in mitochondrial myopathy and chronic fatigue syndrome
Autores: Miriam Estébanez Muñoz1*, Francisco García2, Francisco Javier Arpa Gutiérrez3, Patricia Martinez3, Jorge F. Gómez Cerezo4, Alberto M. Borobia Pérez5, Blas Rojo Moreno-Arrones6, Franciso J. Barbado Hernández1
OBJECTIVE: To determine the diagnostic accuracy of the cardiopulmonary exercise testing to discriminate between mitochondrial myopathy (MM) and chronic fatigue syndrome (CFS).
METHODS: Nineteen CFS and 27 MM patients (18-65 years) were consecutively recruited from subjects sent to a neurology consultation by exercise intolerance. 18 healthy subjects were recruited as control group. A baseline spirometry and a symptom-limited incremental cycle exercise test were conducted in all subjects. Cardiovascular response was mainly assessed by the peak heart rate (HR) and the HR slope. Biomechanical efficiency was assessed by the total work oxygen cost (ΔV´O2/ΔW) during exercise and recovery.
RESULTS: Patients with MM or CFS showed a limited exercise tolerance, demonstrated by a lower peak oxygen uptake and peak work rate than control subjects. CFS patients had a higher HR slope (9.6±3.1 vs. 7.2±2.1 1/ml/Kg, p=0.02) and a lower work ΔV´O2/ΔW (12.1±2.9 vs. 16.0±3.9 ml/min/w, p<0.001) than MM patients. The area under the ROC curves of the HR slope and work ΔV´O2/ΔW to discriminate between CFS and MM were 0.72 (CI95%:0.56-0.87) and 0.79 (CI95%:0.65-0.92), respectively.
CONCLUSION: As response parameters to cardiopulmonary exercise testing, HR slope and work ΔV´O2/ΔW have shown to be useful in discriminating between CFS and MM.