Electrophysiology of The Heart: A Contrast Between Second Generation Antipsychotics

Volume 3 - Issue 4

Saeed Shoja Shafti* and Parisa Fallah Jahromi

Received:August 05, 2019;   Published:August 12, 2019

DOI: 10.32474/PRJFGS.2019.03.000170

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Abstract

Introduction: Extension of the Q-Tc interval is usually accepted as a proxy indicator for the ability of a medication to cause ‘Torsade de Pointes’ (TdP). In the current study, safety of olanzapine against risperidone was compared amongst a cluster of schizophrenic patients, to see the incidence of the electrocardiographic variations that can be induced by those newer antipsychotics.

Method: Two hundred and sixty-eight female schizophrenic patients had been divided into one of the parallel groups, to take part in an open-label investigation for random assignment to olanzapine or risperidone. Typical twelve-lead surface EKG had been taken from each one of patients at starting point, before initiation of management, and at the end of treatment, before discharge from hospital. The parameters that had been measured involved: ‘heart rate’ (HR), ‘P-R interval’, ‘QRS interval’, ‘Q-T interval’ (corrected = Q-Tc), ‘Ventricular Activation Time’ (VAT), ‘ST segment’, ‘T wave’, Axis of QRS, and finally inter-ventricular conduction pattern.

Results: 37.83% of cases in the olanzapine group and 30% of them in the risperidone group displayed some Q-Tc variations. 13.51% and 24.32% of the patients in the olanzapine group exhibited extension and shortening of the Q-Tc, separately. But, the changed cases in the risperidone group exposed merely continuation of Q-Tc. ‘Comparison of means’ revealed a substantial increase in Q-Tc by risperidone (p < 0.02). Similarly, ‘Comparison of proportions’, presented meaningfully more cases with shortening of QT-c in comparison with cases with its prolongation in the olanzapine group (p<0.01). No important modifications with regard to other parameters were obvious. ‘Post-hoc’ power analysis revealed an acceptable power of 0.88 as regards this assessment.

Conclusion: Both of olanzapine and risperidone had analogous possibility for generation of Q-Tc alterations, whereas production of more variations in ECG was more discernible by olanzapine, in comparison with risperidone. Moreover, shortening of Q-Tc was limited to olanzapine.

Keywords: Electrocardiography; Second Generation Antipsychotics; Olanzapine; Risperidone; Q-Tc

Abstract| Introduction| Method| Statistical Analysis| Results| Discussion| Conclusion| References|