Reduced QT variability and increased QT/RR slope in ECG signals of depressed patients with suicidal ideation

Major depressive disorder (MDD) is associated with a number of comorbidities including cardiovascular disease (CVD), with an increased risk of death after myocardial. The aim of this study was to investigate if parameters for ventricular repolarization variability and dynamics in ECG signals are different in MDD patients with/without suicidal ideation and healthy volunteers. Sixty-one ECG recordings (10 minutes) were acquired and analysed from control subjects (44 CONT), 20 MDD subjects with (MDDSI+) and 21 without suicidal ideation [SI] (MDDSI-) for a case-control analysis at a psychiatric clinic in the UAE. The Mini-International Neuropsychiatric Interview (MINI) made diagnoses of MDD and the subscale for was used to evaluate the patients' suicidal intensions [0 to 38]. The subscale for SI consists of 19 items, which was used to evaluate the patients' suicidal intensions [0 to 38]. Then heart rate-corrected QT interval (QTc), QT/RR slope, QT variability (QTV), Median T-wave amplitudes and T-wave variability were estimated. MDD patients with suicidal ideation displayed increased QT/RR slope and reduced QTV, which may reflect abnormal ventricular repolarization liability and lead to higher risk of cardiac arrhythmia and future cardiovascular diseases.