QT interval and QT dispersion in multiple system atrophy (Shy-Drager syndrome)

Abstract

To evaluate the influence of autonomic function on the QT interval and QT dispersion, 18 patients (10 males and 8 females; mean age 61 +/- 9 years) with multiple system atrophy (MSA, Shy-Drager syndrome) were studied. Cardiovascular tests were performed to assess the degree of autonomic dysfunction. The QT interval, corrected QT (QTc), QT dispersion (QTd), corrected and adjusted QTd were calculated from a standard 12-lead electrocardiogram. Fifteen healthy subjects matched for sex and age were studied as controls. Nine MSA patients showed severe autonomic dysfunction with orthostatic hypotension. In the remaining patients definite autonomic impairment was found. No statistically significant difference was found in QTd and only a trend towards higher values of maximal QTc was found in patients compared with controls. QTc prolongation, defined as greater than the mean +/- 2 SD of the controls, was detected only in three out of the 18 MSA patients (17%). No correlation was found between the severity of autonomic impairment and repolarization parameters. Our data suggest that chronic autonomic impairment in patients with MSA does not significantly affect ventricular repolarization and ventricular dispersion.

QT dispersion in patients with arrhythmogenic right ventricular dysplasia

“…It has been proposed by several authors that the autonomic nervous system has an effect on dispersion of repolarization [32][33][34][35][36][37] . Normal QT dispersion has been found in patients with primary autonomic failure [38,39] , but in a study in diabetic patients with autonomic dysfunction the QT dispersion was increased [34] . This apparent discrepancy may be due to the fact that primary autonomic failure mainly involves the sympathetic nervous system, whereas diabetics also invariably have defects of the vagal innervation of the heart [40] .…”

Age and Gender Differences in Cardiovascular Autonomic Failure in the Transgenic PLP-syn Mouse, a Model of Multiple System Atrophy

“…Data on QT and QTc intervals in patients with MSA are contentious. Indeed, Frongillo et al ( 41 ) found that only 3 out of 18 MSA patients (~17%) had a prolonged QTc interval suggesting that patients with MSA did not exhibit any significant change in ventricular repolarization and dispersion. On the other hand, Deguchi et al ( 12 ) depicted in 22 MSA patients a prolonged QTc interval compared with healthy controls.…”