Heart rate variability and hypercapnia in Duchenne muscular dystrophy.
OBJECTIVE
To investigate the relationship between heart rate variability and hypercapnia.


METHODS
We measured the coefficient of variation of R-R interval (CVrr) and arterial blood gas pressures in 73 patients with Duchenne muscular dystrophy.


RESULTS
CVrr was negatively correlated with arterial partial pressure of carbon dioxide (PaCO(2)). In patients whose CVrr was larger than 5%, 84% of them had no hypercapnia while the other 16% had hypercapnia (PaCO(2) >45 mmHg). In contrast, 27% of those with CVrr smaller than 3% had no hypercapnia, 73% had hypercapnia and 47% had severe hypercapnia (PaCO(2) >50 mmHg).


CONCLUSIONS
We first showed that CVrr was negatively correlated with PaCO(2), and propose that abnormally low CVrr indicates respiratory insufficiency in patients with Duchenne muscular dystrophy.
Mochizuki
Hitoshi
H
Department of Neurology, Higashi-Saitama National Hospital, Hasuda. mochizuki-h@umin.ac.jp
Okahashi
Satomi
S
Ugawa
Yoshikazu
Y
Tamura
Takuhisa
T
Suzuki
Mikiya
M
Miyatake
Satoko
S
Shigeyama
Toshiki
T
Ogata
Katsuhisa
K
Kawai
Mitsuru
M
D000293:Adolescent; D000328:Adult; D002648:Child; D004562:Electrocardiography / Q000379:methods / Q000592:standards; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006935:Hypercapnia / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D055815:Young Adult