Arrhythmogenes Risiko bei Patientinnen mit Anorexia nervosa unter besonderer Berücksichtigung des QTc-Intervalls
Walter, Christiane Emmy Elisabeth
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Prolongation of QTc-interval and triggered cardiac arrhythmia has been thought to be one reason of the elevated mortality in anorexia nervosa (AN). Previous studies measured only small samples and almost solely used Bazett’s formula. Prevalence of QTc-prolongation and arrhythmic risk remains controversial. In this study data of 100 female inpatients diagnosed with AN were analyzed in sample 1; in sample 2 23 inpatients and 23 controls were analyzed. Patients with pre-existing cardiac illness or intake of QT-prolonging drugs were excluded. The predicted values matched for sex, age and heart rate (HR) of the algorithm available on http://biostat.mc.vanderbilt.edu/wiki/Main/ECGPred were used as reference data. BMI for control data was set as 21 kg/m2. Bazett’s, Framingham’s, Fridericia’s and Hodges’ formula were used for HR-correction and compared to each other. The used correction formulae caused significantly dissimilar results. The lowest correlation with HR was found in Hodges’ correction. The mean QT and QTc-intervals in sample 1 were within normal limits. Compared to the predicted normal values, the mean QTc-interval of Bazett’s formula was significantly shorter. Results of Fridericia’s and Hodges’ formula were significantly longer and those of Framingham’s formula were not significantly different from the normal sample. However, if considered individually, QT- and QTc-intervals are significantly more frequently above the 95 % normal range than expected. However, only 1 % - 3 % of QTc-intervals are longer than 0.500 sec. Sample 2 showed significantly shorter QTc-intervals (within normal limits) than sample 1, while HR was similar. 24-h-ECGs findings showed significantly more periods of bradycardia and pauses in AN than in the controls. VPB appeared sporadic in both groups. While no formula is ideal, Hodges’ one showed best results. The mean QT- and QTc-intervals are within normal range, although some are prolonged. An elevated arrhythmic risk cannot be deduced.
Subject HeadingsArrhythmie [GND]
Anorexia nervosa; In adolescence [MeSH]
Arrhythmias, cardiac [MeSH]