Depression but not anxiety influences the autonomic control of heart rate after myocardial infarction.
OBJECTIVE
It has been previously hypothesized that the adverse outcome observed in depressed patients after myocardial infarction might be due to an imbalance in autonomic nervous system activity. The aim of this study was to define the role of depressive and anxious symptoms in influencing autonomic control of heart rate after myocardial infarction.


RESULTS
The SD of RR intervals, baroreflex sensitivity, and depression and anxiety (Zung's scales) were assessed before discharge in 103 patients with acute myocardial infarction; 32 were found to be depressed. Among the patients who were not taking beta-blockers, those with depression had significantly lower SDs of RR intervals and baroreflex sensitivity than did those without depression (96.3 +/- 22.2 ms vs 119.5 +/- 37.7 ms, P =.016; 8.6 +/- 6.2 ms vs 11.8 +/- 6.5 ms/mm Hg, P =.01, respectively). No differences were found when anxiety was considered or when beta-blockers were given. Among the patients not taking beta-blockers, there was a significant correlation between depression levels and both the SD of RR intervals (r = -0.47) and baroreflex sensitivity (r = -0.40).


CONCLUSIONS
In patients with myocardial infarction, depression but not anxiety negatively influences autonomic control of heart rate. Beta-blockers modify these influences.
Pitzalis
M V
MV
Institute of Cardiology, University of Bari, Bari, Italy. mariavittoria.pitzalis@cardio.uniba.it
Iacoviello
M
M
Todarello
O
O
Fioretti
A
A
Guida
P
P
Massari
F
F
Mastropasqua
F
F
Russo
G D
GD
Rizzon
P
P
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D001007:Anxiety / Q000209:etiology / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology; D002940:Circadian Rhythm; D003863:Depression / Q000209:etiology / Q000503:physiopathology*; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D011379:Prognosis; D012189:Retrospective Studies
D000319:Adrenergic beta-Antagonists