Repolarization changes induced by mental stress in normal subjects and patients with coronary artery disease: effect of nitroglycerine

Neurovisceral interactions within the brain-heart axis as the basis of neurocardiology

The use of a systematic approach to the study of the etiology of a certain pathology makes it possible to improve the understanding of its pathogenesis, as well as to develop more effective diagnostic and therapeutic approaches, including improving the prediction of its risk. Within this review, we will consider such an area of interdisciplinary research as neurocardiology, which studies the brain-heart axis. Examples of cardiovascular diseases associated with organic and functional disorders of this axis will be considered, as well as the prospects for research in this area and their translational significance for clinical medicine.

Electrocardiographic signs of autonomic imbalance in medicated patients with first-episode schizophrenia spectrum disorders – relations to first treatment discontinuation and five-year remission status

Purpose

To explore measures in electrocardiograms (ECG) influenced by autonomic balance in early schizophrenia spectrum disorders and to examine their relation to subsequent first antipsychotic pharmacotherapy discontinuation and five-year remission status.

Subjects and methods

Twelve-lead ECGs were recorded at baseline in 58 patients with first-episode schizophrenia spectrum disorders and in 47 healthy controls of similar age. Selected ECG variables included heart rate and measures of repolarization. Pharmacotherapy data were extracted from medical records. At a five-year follow-up the patients were interviewed and assessed with the Positive and Negative Syndrome Scale.

Results

Patients had higher heart rate and a different ST-T pattern than the controls. High T-wave amplitudes in the leads aVF and V5 and ST-elevations in V5 were associated both with higher risk of an earlier discontinuation of first antipsychotic pharmacotherapy and with non-remission five years later.

Discussion and conclusion

In this longitudinal cohort study, simple ECG measures influenced by autonomic balance in the early phase of schizophrenia spectrum disorders contained prognostic information. As this is the first report of this association and is based on a relatively small sample, the results should be interpreted with caution.

Effect of mental challenge induced by movie clips on action potential duration in normal human subjects independent of heart rate

BACKGROUND

Mental stress and emotion have long been associated with ventricular arrhythmias and sudden death in animal models and humans. The effect of mental challenge on ventricular action potential duration (APD) in conscious healthy humans has not been reported.

METHODS AND RESULTS

Activation recovery intervals measured from unipolar electrograms as a surrogate for APD (n=19) were recorded from right and left ventricular endocardium during steady-state pacing, whilst subjects watched an emotionally charged film clip. To assess the possible modulating role of altered respiration on APD, the subjects then repeated the same breathing pattern they had during the stress, but without the movie clip. Hemodynamic parameters (mean, systolic, and diastolic blood pressure, and rate of pressure increase) and respiration rate increased during the stressful part of the film clip (P=0.001). APD decreased during the stressful parts of the film clip, for example, for global right ventricular activation recovery interval at end of film clip 193.8 ms (SD, 14) versus 198.0 ms (SD, 13) during the matched breathing control (end film left ventricle 199.8 ms [SD, 16] versus control 201.6 ms [SD, 15]; P=0.004). Respiration rate increased during the stressful part of the film clip (by 2 breaths per minute) and was well matched in the respective control period without any hemodynamic or activation recovery interval changes.

CONCLUSIONS

Our results document for the first time direct recordings of the effect of a mental challenge protocol on ventricular APD in conscious humans. The effect of mental challenge on APD was not secondary to emotionally induced altered respiration or heart rate.

Cardiac repolarization instability during psychological stress in patients with ventricular arrhythmias

INTRODUCTION

Changes in the autonomic nervous system activity are a major trigger of life-threatening ventricular tachyarrhythmias (VTAs). Mental arithmetic, a condition administered in a laboratory setting, can provide insight into the autonomic nervous system activity effects on cardiac physiology. We examined the responses of cardiac repolarization to laboratory-induced psychological stressors in patients with implantable cardioverter-defibrillators (ICDs) with the objective of identifying the indices that differentiate patients with and without subsequent VTA in follow-up.

METHODS

Continuous electrocardiographic signals were recorded using 3 standard bipolar (Holter) leads in 56 patients (age, 63.6 ± 11.9; female, 12%; left ventricular ejection fraction, 32.3 ± 11) with ICDs during mental arithmetic. The patients were separated into those with subsequent VTA during 3 to 4 years of follow-up (group 1: n = 9) and those without VTA (group 2: n = 47). Changes in repolarization (QT interval, mean T wave amplitude [Tamp], and T wave area) were analyzed during 5 minutes at baseline, stress, and recovery. The temporal instability of Tamp and T wave area was examined using the range (Δ) and variance (σ(2)) of beat-to-beat variations of the corresponding parameters.

RESULTS

There were no significant differences in heart rate between the 2 groups at baseline (61 vs 63 beats per minute, P = .97), stress (64 vs 65 beats per minute, P = .40), and recovery (62 vs 61 beats per minute, P = .88). However, during mental stress and poststress recovery, ΔTamp was almost 2-fold greater in group 1 compared with group 2 (111 [57-203] vs 68 [44-94] μV, P = .04, respectively). Changes in QT intervals were also greater in group 1 compared with group 2 (P = .02).

CONCLUSION

Among patients with ICDs, changes of Tamp after psychological stress were greater in those with subsequent arrhythmic events. This might signal proarrhythmic repolarization response and help identify patients who would benefit the most from ICD implantation and proactive management.