Psychological Distress and Arrhythmia: Risk Prediction and Potential Modifiers

The connection between the heart and the brain has long been anecdotally recognized but has systematically been studied only relatively recently. Cardiac arrhythmias, especially ventricular arrhythmias that can lead to sudden cardiac death, remain a major public health concern and there is mounting evidence that psychological distress plays a critical role both as a predictor of high-risk cardiac substrate and as an inciting trigger. The transient, unpredictable nature of emotions and cardiac arrhythmias has made their study challenging, but evolving technologies in monitoring and imaging along with larger epidemiological data sets have encouraged more sophisticated studies examining this relationship. Here we review the research on psychological distress including anger, depression and anxiety on cardiac arrhythmias, insights into proposed mechanisms, and potential avenues for future research

Antipsychotic medications and sudden cardiac arrest: More than meets the eye?

Sudden cardiac arrest (SCA) remains an important public health problem and is stubbornly difficult to predict or prevent. A growing literature has emerged studying psychiatric conditions, such as depression and schizophrenia, and risk of arrhythmia and SCA.1–3 This field is challenging from an epidemiologic perspective, partly because of the rarity of SCA events in the general population without known heart disease and the potential confounding factors that may influence findings.4 For instance, there is increased recognition that treatments for mental illness may themselves raise cardiac risk

Don't worry, be happy: positive affect and reduced 10-year incident coronary heart disease: The Canadian Nova Scotia Health Survey

AIMS: Positive affect is believed to predict cardiovascular health independent of negative affect. We examined whether higher levels of positive affect are associated with a lower risk of coronary heart disease (CHD) in a large prospective study with 10 years of follow-up. METHODS AND RESULTS: We examined the association between positive affect and cardiovascular events in 1739 adults (862 men and 877 women) in the 1995 Nova Scotia Health Survey. Trained nurses conducted Type A Structured Interviews, and coders rated the degree of outwardly displayed positive affect on a five-point scale. To test that positive affect predicts incident CHD when controlling for depressive symptoms and other negative affects, we used as covariates: Center for Epidemiological Studies Depressive symptoms Scale, the Cook Medley Hostility scale, and the Spielberger Trait Anxiety Inventory. There were 145 (8.3%) acute non-fatal or fatal ischaemic heart disease events during the 14 916 person-years of observation. In a proportional hazards model controlling for age, sex, and cardiovascular risk factors, positive affect predicted CHD (adjusted HR, 0.78; 95% CI 0.63-0.96 per point; P = 0.02), the covariate depressive symptoms continued to predict CHD as had been published previously in the same patients (HR, 1.04; 95% CI 1.01-1.07 per point; P = 0.004) and hostility and anxiety did not (both P > 0.05). CONCLUSION: In this large, population-based study, increased positive affect was protective against 10-year incident CHD, suggesting that preventive strategies may be enhanced not only by reducing depressive symptoms but also by increasing positive affect

Ibutilide Increases the Variability and Complexity of Atrial Fibrillation Electrograms: Antiarrhythmic Insights Using Signal Analyses

Introduction Intravenous ibutilide is used to convert atrial fibrillation (AF) to sinus rhythm (SR) due to its Class III antiarrhythmic mechanisms. However, the effects of ibutilide on local electrograms (EGMs) during AF have not been elucidated. Methods and Results We used EGM analysis techniques to characterize how ibutilide administration changes the frequency, morphology, and repeatability of AF EGM signals, thereby providing insight into ibutilide's antiarrhythmic mechanism of action. AF recordings were collected from 21 patients with AF, both before and after ibutilide administration. The effects of ibutilide on the following AF EGM parameters were assessed: (1) dominant frequency (DF), (2) variations in EGM amplitude and overall morphology, (3) repetition of EGM patterns, and (4) complexity of the AF frequency spectra. When comparing pre- versus post-ibutilide administration EGMs, DF decreased from 5.45 Hz to 4.02 Hz (P < 0.0001). There was an increase in the variability of both AF EGM amplitudes (P = 0.003) and overall AF EGM morphologies (P = 0.003). AF EGM pattern repetitiveness decreased (P = 0.01), and the AF frequency spectral profile manifested greater complexity (P = 0.02). Conclusions Novel EGM signal analysis techniques reveal that ibutilide administration causes increased complexity in the atrial electrical activation pattern with decreasing rate. These findings may be explained by the progressive destabilization of higher frequency, more homogeneous primary drivers of AF over the course of ibutilide administration, and/or less uniform propagation of atrial activation, until AF maintenance becomes more difficult and either transforms to atrial tachycardia or terminates to SR

Exposure to tricyclic antidepressants is associated with an increased risk of incident CHD events in a population-based study

Purpose The purpose of this study was to assess the association between antidepressant use and incident coronary heart disease (CHD) events in a sample of individuals without known baseline heart disease. Participants and methods We studied a group of 970 randomly selected community-dwelling adults in the 1995 Nova Scotia Health Survey, who were followed for up to 10 years. Antidepressant usage was classified according to class. Primary outcomes were acute coronary syndrome hospitalizations or cardiac death, determined by centralized, standardized ratings. Results During a follow-up period of 10 years, there were 147 incident CHD events (139 acute coronary syndromes and 8 cardiac deaths) during the 8129 person-years of observation (incidence rate=18.1 events/1000 person-years). In a model controlling for age, sex, Framingham risk score, time to last annual exam, aspirin exposure, and depressive symptoms, an increased risk of CHD events was associated with tricyclic antidepressant exposure (adjusted hazard ratio, 2.10; 95% confidence interval, 1.09–4.06; p =0.027). Conclusion In this prospective population-based study, exposure to tricyclic antidepressants was associated with higher risk of first CHD events

Global Psychological Distress and Risk of Atrial Fibrillation Among Women: The Women's Health Study

Background Symptoms of psychological distress and depression have been associated with risk of ventricular arrhythmias and sudden cardiac death. Their relationship with atrial arrhythmias, however, is less well studied. Methods and Results We sought to assess the long-term relations between psychological distress and risk of atrial fibrillation (AF) in the Women's Health Study of female health professionals. We measured psychological symptoms with the Mental Health Inventory-5. Incident AF was assessed annually and verified through medical records. Among 30 746 women without history of cardiovascular disease or AF, 771 cases of AF occurred during a median follow-up of 125 months (interquartile range, 117–130 months). Global psychological distress was not associated with AF risk in age-stratified (P=0.61 for linear trend) or multivariable proportional-hazards models that included antidepressant use (P=0.34). A proxy measure for depression, consisting of Mental Health Inventory-5 score <53, antidepressant use, or both, was also not associated with AF risk in multivariable models (hazard ratio=0.99; 95% confidence interval, 0.78–1.25; P=0.93). In post hoc analyses of individual symptoms from the Mental Health Inventory-5, positive affect, “feeling happy some/a good bit of the time,” was associated with reduced risk of AF (hazard ratio=0.69; 95% confidence interval, 0.49–0.99; P=0.04); other depressive and anxious symptoms were not. Conclusions In this prospective study of women without known cardiovascular disease, global psychological distress and specific depressive symptoms were unrelated to AF risk

Relationship between premature ventricular complexes and depressive symptoms in non-ST-elevation acute coronary syndrome

Aims: Depression is a recognized risk marker for mortality among acute coronary syndrome (ACS) patients. We hypothesized that ventricular arrhythmia detected by inpatient telemetry monitoring is more frequent among ACS patients with elevated depressive symptoms compared to those without depressive symptoms. Methods and results: We analysed data from patients enrolled in a prospective observational study of depression in ACS. Telemetry recordings during the index admission (average recording 21.3±3.0 hours) were analysed for frequent premature ventricular complexes (PVCs), defined as ≥10 per hour. The self-report Beck Depression Inventory (BDI) was used to assess depressive symptoms. Among 200 ACS patients, frequent PVCs were observed in 29% of patients with moderate depressive symptoms (BDI ≥10), 27% of those with mild symptoms (BDI 5–9), and only 11% of those with no/minimal symptoms (p=0.02). Log-transformed PVCs per hour were associated with depressive symptom category (p=0.008). In a multivariable logistic regression model that included age, gender, left ventricular ejection fraction, cardiovascular risk score, heart rate, and QT interval, mild symptoms (OR 3.02, 95% 0.97–9.43, p=0.058) and moderate-severe symptoms (OR 3.94, 95% CI 1.27–12.22, p=0.018) were associated with frequent PVCs. Conclusions: In this sample of ACS patients, depressive symptoms were independently associated with frequent PVCs during inpatient telemetry monitoring

Improved frequency resolution for characterization of complex fractionated atrial electrograms

Background: The dominant frequency of the Fourier power spectrum is useful to analyze complex fractionated atrial electrograms (CFAE), but spectral resolution is limited and uniform from DC to the Nyquist frequency. Herein the spectral resolution of a recently described and relatively new spectral estimation technique is compared to the Fourier radix-2 implementation. Methods: In 10 paroxysmal and 10 persistent atrial fibrillation patients, 216 CFAE were acquired from the pulmonary vein ostia and left atrial free wall (977 Hz sampling rate, 8192 sample points, 8.4 s duration). With these parameter values, in the physiologic range of 3–10 Hz, two frequency components can theoretically be resolved at 0.24 Hz using Fourier analysis and at 0.10 Hz on average using the new technique. For testing, two closely-spaced periodic components were synthesized from two different CFAE recordings, and combined with two other CFAE recordings magnified 2×, that served as interference signals. The ability to resolve synthesized frequency components in the range 3–4 Hz, 4–5 Hz, …, 9–10 Hz was determined for 15 trials each (105 total). Results: With the added interference, frequency resolution averaged 0.29 ± 0.22 Hz for Fourier versus 0.16 ± 0.10 Hz for the new method (p < 0.001). The misalignment error of spectral peaks versus actual values was ±0.023 Hz for Fourier and ±0.009 Hz for the new method (p < 0.001). One or both synthesized peaks were lost in the noise floor 13/105 times using Fourier versus 4/105 times using the new method. Conclusions: Within the physiologically relevant frequency range for characterization of CFAE, the new method has approximately twice the spectral resolution of Fourier analysis, there is less error in estimating frequencies, and peaks appear more readily above the noise floor. Theoretically, when interference is not present, to resolve frequency components separated by 0.10 Hz using Fourier analysis would require an 18.2 s sequence duration, versus 8.4 s with the new method

Depressive Symptoms and All-Cause Mortality in Unstable Angina Pectoris (from the Coronary Psychosocial Evaluation Studies [COPES])

Although depression is clearly associated with increased mortality after acute myocardial infarction, there is a paucity of data examining the impact of depression on patients with unstable angina (UA). We analyzed the relation between depressive symptoms and all-cause mortality in patients with UA who were enrolled in a prospective multicenter study of depression and acute coronary syndrome (ACS). Depressive symptoms were measured with the Beck Depression Inventory (BDI) within 1 week of the ACS event, and patients were selected for a BDI score 0 to 4 or ≥10. Our sample included 209 patients with UA, with 104 (50%) having a BDI score ≥10. Proportional hazards analyses adjusted for variables including left ventricular ejection fraction, Global Registry of Acute Coronary Events risk score, and Charlson co-morbidity index. In multivariable analyses, a BDI score ≥10 was associated with increased risk of 42-month all-cause mortality (hazard ratio 2.04, 95% confidence interval 1.20 to 3.46, p = 0.008) compared to a BDI score 0 to 4. In conclusion, our results confirm and extend previous evidence linking depression to worse outcomes in UA and suggest that interventions that address depression may be worth examining across the spectrum of risk in ACS

Depression and Risk of Sudden Cardiac Death and Coronary Heart Disease in Women Results From the Nurses' Health Study

ObjectivesWe assessed the association between depression and sudden cardiac death (SCD) and cardiac events among individuals without baseline coronary heart disease (CHD).BackgroundDepression is a risk factor for cardiac events and mortality among those with CHD, possibly from arrhythmia.MethodsWe studied depressive symptoms and a proxy variable for clinical depression consisting of severe symptoms and/or antidepressant medication use and their relationship to cardiac events in the Nurses' Health Study. Questionnaires in 1992, 1996, and 2000 assessed symptoms with the Mental Health Index (MHI-5), and antidepressant use was assessed in 1996 and 2000. Primary end points included SCD, fatal CHD, and nonfatal myocardial infarction.ResultsAmong 63,469 women without prior CHD/stroke in 1992, 7.9% had MHI-5 scores <53, previously found to predict clinical depression. Depressive symptoms were associated with CHD events, and the relationship was strongest for fatal CHD, where the association remained significant even after controlling for CHD risk factors (hazard ratio [HR]: 1.49; 95% confidence interval [CI]: 1.11 to 2.00 for MHI-5 score <53). In models from 1996 onward, our proxy variable for clinical depression was most associated with SCD in multivariable models (HR: 2.33, 95% CI: 1.47 to 3.70), and this risk was primarily due to a specific relationship between antidepressant use and SCD (HR: 3.34, 95% CI: 2.03 to 5.50).ConclusionsIn this cohort of women without baseline CHD, depressive symptoms were associated with fatal CHD, and a measure of clinical depression including antidepressant use was specifically associated with SCD. Although antidepressant use might be a marker of worse depression, its specific association with SCD merits further study