Description of the resting electrocardiogram in a series of patients with myasthenia gravis
Asensio, E.; Gómez, M.Ãa.; Narváez, R.é; Castillo, L.; Oseguera, J.; Dorantes, J.; Orea, A.; Hernández, P.; Rebollar, V.ón.
Revista de Investigacion Clinica; Organo del Hospital de Enfermedades de la Nutricion 55(3): 270-275
2003
ISSN/ISBN: 0034-8376 PMID: 14515671 Document Number: 555637
Myasthenia gravis (MG) is a disease characterized by the presence of acetylcholine receptor-directed autoantibodies. Functional cardiac disorders are the most common since there is no neuro-muscular plate in the heart. Autonomic nervous system is involved in MG, but the cardiac manifestations of such an involvement remain unclear. Previous EKG studies in patients with MG show heterogeneous results. A retrospective, descriptive and observational study was performed to know the main electrocardiographic characteristics and some autonomic nervous function in a series of patients with MG. One-hundred seventeen patients with EKG were analyzed. Twenty-eight were 47.9 +/- 20 years-old males, and 89 were women of 35.2 +/- 7.7 years (p = 0.001). 49 (41.9%) EKG had no changes, while 68 (58.1%) did. The main QT dispersion was 35.5 +/- 18.4 ms among those with some anomaly (p = 0.27). In 54 (78.3%) patients with an abnormal EKG there was T wave alternans, which was also present in 35 (71.4%) (p = 0.32) patients with normal EKG. MG is frequently associated to unspecific EKG changes. Dynamic electrocardiography allows a precise evaluation of the kind of cardiac involvement derived from MG, specifically the one related to the autonomic function, that is apparently affected in both the sympathetic and parasympathetic arms.