More on heart rate variability in obstructive sleep apnea: confusion on a higher level or first step to unravel the cardiovascular mystery of the sleep apnea patient?

Lacunar stroke and heart rate variability during sleep

OBJECTIVE

Autonomic instability during sleep can influence the risk of cerebrovascular diseases. In this study, we performed a polygraphy to evaluate, heart rate variability (HRV) in a group of patients with lacunar stroke that is a condition at high risk of recurrence.

METHODS

Twenty-one lacunar stroke patients were enrolled one month after stroke occurrence. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). The presence of common sleep disorders and autonomic changes during the night was investigated by a polygraphy monitoring. Results were compared with those obtained in a group of 21 healthy subjects.

RESULTS

Patients and controls were similar for age, sex distribution and main cardiovascular risk factors with the exception of the body mass index. Significant differences were detected for all polysomnographic (PSG) parameters and for the PSQI score. By considering HRV values, patients with pathologic values (12 patients, HRV>2) showed significantly higher values in BMI (31 ± 2.9 vs. 26.6 ± 3.6, p = 0.006) and PSQI scores (7.9 ± 2.6 vs. 4.2 ± 1.9) with respect to patients with normal HRV values (nine patients, HRV≤2).

CONCLUSIONS

The results of this study suggest that the prevalence of nocturnal autonomic dysfunction is high in lacunar stroke patients even in the absence of the commonest sleep-related disorders. An abnormal HRV may contribute to increase the risk of stroke recurrence. Based on our results, the indication to polygraphy in patients with lacunar stroke should be carefully considered.