A diagnostic cycle test for McArdle's disease

• Published in: Annals of neurology Vol. 54; no. 4; pp. 539 - 542
• Main Authors: Vissing, John, Haller, Ronald G.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2003; Willey-Liss
• Subjects: Biological and medical sciences; Carbohydrates (enzymatic deficiencies). Glycogenosis; Case-Control Studies; Errors of metabolism; Exercise - physiology; Exercise Test; Exercise Therapy; Female; Glycogen Storage Disease Type V - diagnosis; Glycogen Storage Disease Type V - physiopathology; Heart Rate - physiology; Humans; Male; Medical sciences; Metabolic diseases; Metabolism, Inborn Errors - diagnosis; Metabolism, Inborn Errors - physiopathology; Predictive Value of Tests; Reproducibility of Results; Time Factors; Physical exercise; Human; Glycogenosis V Mac Ardle; Healthy subject; Cardiovascular disease; Metabolic diseases; Metabolism; Enzymopathy; Genetic disease; Workload; Heart rate; Heart disease; Carbohydrate; Diagnosis
• ISSN: 0364-5134; 1531-8249
• DOI: 10.1002/ana.10725

We investigated whether the second wind phenomenon (ie, a decrease in heart rate and perceived exertion during exercise) is pathognomonic for McArdle's disease. Twenty‐four patients with McArdle's disease, 17 healthy subjects, and 25 patients with other inborn errors of muscle metabolism cycled a constant workload for 15 minutes. In McArdle's disease patients, heart rate consistently decreased by 35 ± 3 beats per minute from the 7th to the 15th minute of exercise, whereas heart rate increased progressively with exercise in all 42 control subjects. The findings indicate that cycling at a moderate, constant workload provides a specific, sensitive, and simple diagnostic test for McArdle's disease. Ann Neurol 2003;54:539‐542