Depression after Heart Attack is Predictor of Death
After accounting for a number of potential factors that might influence the results, depressed patients had higher nighttime heart rate (70.7 versus 67.7 beats per minute) and daytime heart rate (76.4 versus 74.2 beats per minute) than non-depressed patients.
Overall, 33 depressed patients (9.9 percent) and 14 non-depressed patients (3.7 percent) died during follow-up. Twenty-four of the deaths among the depressed patients (73 percent) and 10 of the deaths among the non-depressed patients (71 percent) were classified as likely due to cardiovascular causes.
Carney and colleagues also report that nondepressed patients with low heart rate had the best survival, and depressed patients with high heart rate had the worst.
After adjusting for other major predictors and for each other, depression and a high nighttime, but not daytime, heart rate independently increased the risk of death in these post-heart attack patients.
According to the investigators, disturbed sleep, which is frequently reported in patients with depression, may help explain the association of nighttime elevated heart rate with mortality.
There is evidence that arousals from sleep that are associated with increased heart rate may provoke events related to ischemia (restriction of the blood supply and thus oxygen to the tissues) and abnormal heart rhythms in patients with heart disease.
For information about missed or misdiagnosed heart attacks, see the Pennsylvania medical malpractice attorneys.