Dispersion of ventricular repolarization as diagnostic tool in the assessment of autonomic function in Parkinson’s disease
Hýzýr ULVÝ, M.D., Dilcan KOTAN, M.D.     
Atatürk University, Medical Faculty, Department of Neurology, Erzurum,Turkey Batman Goverment Hospýtal, Department of Neurology, Batman,Turkey

Purpose: The aim of our study was to evaluate possible autonomic nervous system (ANS) dysfunction in patients with Parkinson’s disease (PD), and its correlation with score of Hoehn and Yahr Scale (SHYS).

Methods: We studied 21 patients with PD; the mean age was 63.56±17.92 years (yrs) (range 30 yrs to 70 yrs; 8 female and 13 male) and 59 age-matched healthy subjects (control), the mean age was 61.64±11.21 years (yrs) (range 33 yrs to 87yrs; 31 female and 28 male). In all persons 12 leads ECG were recorded at a speed of 50 mm/s. Ventricülar repolarization parameters (QT, QTc, JT, and JTc) and ventricülar repolarization dispersion (d) parameters (QT-d, QTc-d, JT-d, JTc-d were detected. QT and JT intervals were measured from the beginning and from the end of the QRS complex, respectively, to the end of T wave to baseline while excluding the U wave. Using Bazett formula, these intervals were corrected for heart rate. Repolarization dispersion parameters were calculated the difference between minimal and maximal values of QT, JT, QTc, and JTc among 12 leads. Mean QT-d, QTc-d, JTd, JTc-d in PD were significantly longer than that of th e normal subjects (p<0.05). No correlation was observed between SHYS and ventricüler repolarization dispersion parameters.

Conclusion: Dispersion of repolarization, the difference in repolarization duration among several electrocardiographic leads, has been proposed measure of repolarization heterogeneity, and increased dispersion has been found to be assosiated with ANS. We conclude that ventricüler repolarization dispersion parameters evaluation are helpful and cheap method in the assessment of autonomic function in PD.