[The variability of the heart rate in patients with a myocardial infarct undergoing systemic fibrinolysis interventions].
Although heart rate variability is a very important prognostic factor in patients with myocardial infarction, the mechanism for the reduction in the vagal cardiac activity is unknown: myocardial infarction can cause local areas of sympathetic or parasympathetic denervation that leads to catecholamine hypersensitivity; the destruction of local ventricular receptors of the autonomic system may alter feedback to the higher centres, impairing autonomic regulation; the mechanical distortion consequent to the infarction can give rise to sympathetic overactivity. Effective thrombolysis in myocardial infarction could reduce myocardial necrosis and, therefore, cause less reduction of vagal activity and/or less sympathetic stimulation. To determine whether systemic thrombolysis has some effect on heart rate variability we studied 40 patients with a first transmural myocardial infarction. Enrollment criteria were very strict: all the patients with conditions potentially influencing heart rate variability were excluded from this study. Between day 15 and day 25 from the infarction patients had an Holter monitoring. A program we developed provided for the automatic identification of R wave, for the calculation of RR interval, and for the recognition of pause, extrasystolic and post-extrasystolic beats, that could be thus excluded from the analysis. Patients were divided in 2 groups: 17 patients treated with thrombolysis and 23 subjects treated traditionally. There were no difference between the 2 groups with regard to the age and cardiac function, except for the less echo score in the fibrinolytic treated group.(ABSTRACT TRUNCATED AT 250 WORDS)
Ferro-Luzzi
M
M
Dipartimento di Scienze Cardiovascolari e Respiratorie, Università degli Studi La Sapienza, Roma.
Penco
M
M
Benedetti
G
G
Romano
S
S
Dagianti
A
A
D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology*; D015912:Thrombolytic Therapy; D013997:Time Factors