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Background: The purposes of this study were to identify nocturnal patterns of heart rate (HR) in depressed and nondepressed patients after an acute myocardial infarction (MI) and to determine which patterns, if any, are associated with all-cause mortality or recurrent infarction., Methods: Functional data analysis and model-based clustering methods were used to identify nocturnal HR patterns in 245 depressed and 247 nondepressed patients with a recent MI. All-cause mortality and recurrent infarctions were ascertained over a median follow-up of 24 months., Results: Three HR activity patterns were identified. In the first, HR gradually declined during the nighttime and increased the next morning. The second pattern was similar, but with a higher overall HR during the recording interval. The third showed almost no decrease in HR at night (ie, "nondipping"). All-cause mortality was higher among patients with pattern 3 than pattern 1 (P = .007), and the combined end point of recurrent MI or all-cause mortality was higher in pattern 3 than pattern 2 (P = .05). Patterns 2 and 3 were more common in the depressed than in the nondepressed patients., Conclusions: The nondipping nocturnal HR independently predicts all-cause mortality and recurrent MI. Future studies should examine the underlying causes of nondipping nocturnal HR and its association with depression and investigate the effects of treatment on survival., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Objectives: To determine if: 1) depressed patients with a recent acute myocardial infarction (AMI) have higher nighttime heart rate (HR) than nondepressed patients, and 2) elevated nighttime HR is associated with decreased survival post AMI. Depression is a risk factor for mortality post AMI. It is also associated with sleep disturbances and with elevated HR, which may be more pronounced at night. Resting and 24-hour HR have been found to predict mortality in patient and community samples., Methods: Ambulatory electrocardiographic data were obtained from 333 depressed patients and 383 nondepressed patients with recent AMI. They were followed for up to 30 months (median = 24 months)., Results: Depressed patients had higher nighttime HR (70.7 +/- 0.7 versus 67.7 +/- 0.6 beats per minute (bpm); p = .001), and daytime HR (76.4 +/- 0.7 versus 74.2 +/- 0.6 bpm; p = .02) than nondepressed patients, even after adjusting for potential confounds. Depression (hazard ratio (Haz R) = 2.19; p = .02) and nighttime HR (Haz R = 1.03; p = .004), but not daytime HR, predicted survival after adjusting for other major predictors and for each other. The interaction between nighttime HR and depression on survival approached, but did not achieve, significance (p = .08)., Conclusions: Mean day and nighttime HR values are higher in depressed patients than in nondepressed patients post AMI. Depression and elevated nighttime HR, but not daytime HR, are independent predictors of survival in these patients. Although depressed patients have a higher nighttime HR than nondepressed patients, nighttime HR predicts mortality in both depressed and nondepressed patients.

Background: Depression is associated with an increased risk for mortality after acute myocardial infarction (MI). The purpose of this study was to determine whether low heart rate variability (HRV) mediates the effect of depression on mortality., Methods: Twenty-four-hour ambulatory electrocardiograms were obtained from 311 depressed patients with a recent acute MI who were enrolled in the Enhancing Recovery in Coronary Heart Disease (ENRICHD) clinical trial and from 367 nondepressed patients who met the ENRICHD medical inclusion criteria. Standard HRV indexes were extracted from the recordings., Results: The log of very low-frequency (LnVLF) power, an index of HRV derived from power spectral analysis of the electrocardiogram signal (0.0033-0.04 Hz [in milliseconds squared]), was lower in the depressed than in the nondepressed patients (P<.001). There were 47 deaths (6.1%) during a 30-month follow-up. After adjusting for potential confounders, the depressed patients remained at higher risk for all-cause mortality compared with the nondepressed patients (hazard ratio, 2.8; 95% confidence interval [CI], 1.4-5.4; P<.003). When LnVLF power was entered into the model, the hazard ratio for depression dropped to 2.1 (95% CI, 1.1-4.2; P = .03). The proportion of the risk for depression attributable to LnVLF power was 0.27 (95% CI, 0.23-0.31; P<.001)., Conclusions: Low HRV partially mediates the effect of depression on survival after acute MI. This finding helps to clarify the physiological mechanisms underlying depression's role as a risk factor for mortality in patients with coronary heart disease. It also raises the possibility that treatments that improve both depression and HRV might also improve survival in these patients.

The responses to the Japanese edition of the Jenkins Activity Survey (JAS) (Form C) were analyzed in 1682 male employees of a Japanese enterprise to investigate the characteristics of the Type A behavior pattern (TABP) in Japan. When the occupational level was controlled, the mean values of the Type A score were found to be quite similar to those of the Western Collaborative Group Study (WCGS), although those of factor H scores were considerably lower than those of the WCGS. Additionally, the results of a factor analysis conducted on the responses to JAS questions showed that the factor structure of the responses was basically equal to that found in the WCGS. In contrast to factor J of the WCGS, however, Japanese factor J did not comprise the items which signaled rises in positions or incomes in recent years. The results of this study indicate that the JAS is able to measure the TABP in Japan, at least concerning its three component factors. Furthermore, they suggest that the TAPB is not necessarily reinforced in Japanese occupational environments.