[Relationship between echocardiographic abnormalities and sleep apnea-hypopnea syndrome severity]

Sleep apnea-hypopnea syndrome (SAHS) is a prevalent condition that has well-known cardiovascular repercussions. However, few published echocardiographic studies have investigated the abnormalities present at SAHS diagnosis or their relationship with syndrome severity. Our objective was to evaluate myocardial structural, functional and performance parameters in these patients.

In total, 110 consecutive patients diagnosed with SAHS between June 2005 and 2006 who required treatment with continuous positive airway pressure were divided into two groups according to SAHS severity. Baseline echocardiography was carried out to evaluate structural and functional variables. Findings in the two groups were compared by univariate and multivariate analysis.

The patients' mean age was 54 (13) years, their body mass index was 32 (6), 51% had comorbidities, and 74% were male. Patients with severe SAHS (i.e., apnea-hypopnea index [AHI] > or = 30) smoked and drank alcohol more and had larger neck circumferences. There was no significant difference in any structural parameter between the two groups. Functionally, patients with severe SAHS had shorter aortic (AHI<30 277 [4] ms vs AHIé30 263 [4] ms; P=.02) and pulmonary (AHI < 30 287 +/- 5 ms vs. AHI > or = 30 268 +/- 5 ms; P=.01) ejection times, and a higher Tei index (Left: AHI<30 0.51 [0.01] vs AHIé30 0.57 [0.02] [P=.04]; Right: AHI<30 0.38 [0.02] vs AHIé30 0.49 [0.03] [P=.02]). There were correlations between SAHS severity and the right Tei index, and aortic and pulmonary ejection times (P=.0001, P=.01, and P=.0001, respectively). The pulmonary ejection time was an independent predictor of SAHS severity (odds ratio: 0.98, 95% confidence interval, 0.97-0.99; P=.01).

Myocardial performance is poorer in patients with SAHS. The Tei index and ejection times are all associated with SAHS severity. The pulmonary ejection time is an independent predictor of disease severity.