Heart rate variability in patients with sleep-related breathing disorders.
The increased mortality among patients with obstructive sleep apnea syndrome has been explained in part by the increased incidence of arterial and pulmonary hypertension. A decreased heart rate variability (HRV) has been shown to be associated with an increased mortality as well. We investigated 53 patients, admitted to the hospital for chest pain for sleep-related breathing disorders (SRBD) with an ambulatory screening device (MESAM-IV). HRV was recorded simultaneously. All patients received coronary artery catheterization and 36 had significant coronary artery disease (CAD; 67.9%). Standard time domain parameters were compared by a 4-way Anova for patients with an oxygen desaturation index of more and less than 5/hour and the factors CAD, diabetes and beta-blocker use. The percentage of differences between RR intervals that differ more than 50 ms (pNN > 50: 9.0 +/- 11.1 vs. 19.2 +/- 22.2%: p < 0.05) as well as the root mean square of these differences (38.0 +/- 29.0 vs. 59.2 +/- 51.5 ms; p < 0.05) were significantly decreased in patients with SRBD. In an hourly breakdown the number of desaturations was not correlated with a change in HRV. Mean oxygen saturation was significantly decreased in patients with SRBD (95.2 +/- 1.8 vs. 96.2 +/- 1.42%, p < 0.05), and positively correlated with the pNN > 50 (r = 0.34, p < 0.01). This correlation might suggest a more profound pathophysiological interaction between HRV and SRBD than short-term vagal activation alone. The results favor HRV for inclusion in future risk stratification models in patients with sleep apnea syndrome.
Department of Internal Medicine, University of Bonn, Germany.
T
T
Bauer
S
S
Ewig
H
H
Schäfer
E
E
Jelen
H
H
Omran
B
B
Lüderitz
D006328:Cardiac Catheterization; D002637:Chest Pain / Q000209:etiology; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000401:mortality / Q000503:physiopathology*
D010100:Oxygen