Heart rate variability as an index of sympathovagal interaction after acute myocardial infarction.
Am J Cardiol
; 60(16): 1239-45, 1987 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-3687775
By analysis of spectral components of heart rate variability, sympathovagal interaction was assessed in patients after acute myocardial infarction (AMI). At 2 weeks after AMI (n = 70), the low-frequency component was significantly greater (69 +/- 2 vs 53 +/- 3 normalized units [NU], p less than 0.05) and the high-frequency component was significantly smaller (17 +/- 1 vs 35 +/- 3 NU) than in 26 age-matched control subjects. This difference was likely to reflect an alteration of sympathovagal regulatory outflows with a predominance of sympathetic activity. At 6 (n = 33) and 12 (n = 29) months after AMI, a progressive decrease in the low- (62 +/- 2 and 54 +/- 3 NU) and an increase in the high-frequency (23 +/- 2 and 30 +/- 2 NU) spectral components was observed, which suggested a normalization of sympathovagal interaction. An increase in sympathetic efferent activity induced by tilt did not further modify the low-frequency spectral component (78 +/- 3 vs 74 +/- 3 NU) in a subgroup of 24 patients at 2 weeks after AMI. Instead, 1 year after AMI, this maneuver was accompanied by an increase in the low-frequency component (77 +/- 3 vs 53 +/- 3 NU, p less than 0.05) of a magnitude similar to the one observed in control subjects (78 +/- 3 vs 53 +/- 3 NU). These data indicate that the sympathetic predominance that is detectable 2 weeks after AMI is followed by recovery of vagal tone and a normalization of sympathovagal interaction, not only during resting conditions, but also in response to a sympathetic stimulus.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Sistema Nervioso Simpático
/
Nervio Vago
/
Frecuencia Cardíaca
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Infarto del Miocardio
Límite:
Adult
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Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Am J Cardiol
Año:
1987
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Estados Unidos