Variabilidade da frequência cardíaca em pacientes com Distrofia Miotônica tipo 1

Abstract

and in the sinoatrial node associated to myocyte hypertrophy 7 . Patients with greater skeletal muscle impairment are older and experience heart problems more frequently 8 .The autonomic nervous system plays a crucial role in heart rate (HR) modulation. A decrease in its variability is a predictor of morbidity and mortality 9,10 . Earlier research found that healthy women showed greater vagal dominance over HR, which seems to account for their enhanced cardioprotection compared to men, although these differences decrease with age 11. The study of heart rate variability (HRV) has therefore been proposed as a simple, inexpensive and non-invasive method that provides information on neurocardial integrity. A number of investigations on the overall function of the autonomic nervous system in patients with MD show that the presence of autonomic neuropathy is highly unlikely 1,12,13 . However, studies on autonomic modulation of HR in patients with MD have obtained conflicting results [14][15][16][17][18] . The present study aimed to evaluate the possible differences in autonomic modulation of HR between the sexes for patients with MD and healthy individuals in different body positions and the influence of interaction between sex and disease on autonomic modulation of HR in different body positions. IntroductionMyotonic dystrophy (MD) is the most frequent form of muscular dystrophy in adults 1,2 . Clinical manifestations of MD are myotony, muscle weakness, cardiac abnormalities, cataracts, endocrine and digestive tract disturbances; sleep disorders and baldness 3-5 . Heart problems experienced by patients with MD are well known 1,6 . Most patients are asymptomatic; however, alterations in cardiac physiology are common, as observed in electrocardiograms 6 . Clinical manifestations include conduction delay, rhythm disturbances and myocardial disease. Electrocardiographic disorder indicates abnormalities in intraventricular and atrioventricular conduction, atrial fibrillation and ventricular arrhythmias. Histopathology data show fibrosis in the conduction system Abstract Background: Cardiac involvement is common in myotonic dystrophy (MD) patients. Heart rate variability (HRV) is a simple and reliable technique that can be useful for studying the influence of the autonomic nervous system on the heart.

Autonomic regulation in muscular dystrophy

“…Fregonezi et al (2012) found influence of gender and disease on HRV in DM1 patients and healthy individuals in different body positions (sitting and supine). HRV was done during short time periods in sitting and supine positions in addition to analyse the magnitude of gender influence.…”

Influência Da Atividade Física Na Modulação Autonômica Cardíaca

“…High HRV values represent a good adaptation and characterize a healthy person, while their decrease indicates an abnormal adaptation of the autonomous nervous system, and are associated with morbidity and mortality, being also linked to the onset or worsening of heart diseases 1,4,5 .…”

Analysis of the Autonomic Regulation in a Case of Facioscapulohumeral Muscular Dystrophy after Ken Ware Treatment

“…When distinguishing the case of the myotonic dystrophy (DM) in the myotonic dystrophy type 1 (DM1) and type 2 (DM2) with different clinical phenotypes, we find that in such conditions we have indication of ANS in-volvement such as heart rhythm conduction disturbances, orthostatic hypotension, disorders of sweating, abnormal gut movements, and dysfunction of genitourinary apparatus as studied in particular from [14]. Very important results may be found in [10] [15]- [26].…”