Left Ventricular Geometry in Patients with Obstructive Sleep Apnea Coexisting with Treated Systemic Hypertension

Abstract

Background: Left ventricular (LV) hypertrophy is a common consequence of systemic hypertension (SH) and obstructive sleep apnea (OSA). However, little is known about the degree of LV involvement in patients with OSA coexisting with treated SH. Objectives: Our study was designed in order to assess the prevalence of distinct types of LV geometry in treated hypertensive OSA patients. Methods: Patients: 183 patients with treated SH were enrolled to the study. Group 1 consisted of 38 patients with newly-diagnosed OSA and ineffectively treated SH. The remaining 145 patients with effectively treated SH were divided into three groups: group 2 – 70 patients with newly-diagnosed OSA, group 3 – 31 patients with OSA treated with continuous positive airway pressure (CPAP), and group 4 – 44 patients without OSA.Overnight sleep studies and M-mode echocardiography were performed. Results: LV mass index did not differ between the study groups. Mean values of LV end-diastolic diameter (LVED) were 55.4 ± 6.8 mm in group 1 and 53.6 ± 6.9 mm in group 2 and were significantly increased in comparison to subjects treated with CPAP and controls (49.8 ± 6.8 mm and 50.1 ± 64.7 mm, respectively; p = 0.001). LVED correlated positively with the apnea-hypopnea index and desaturation index. LV eccentric hypertrophy was the commonest type of LV geometry in newly-diagnosed OSA patients. Conclusions: The major finding of our study is the predominance of LV eccentric hypertrophy in newly-diagnosed OSA patients. We suggest that a relatively moderate degree of LV involvement in hypertensive OSA patients may depend on the cardioprotective effect of concomitant antihypertensive therapy, ameliorating OSA-dependent neurohumoral abnormalities.