Left ventricular structural adaptations to obstructive sleep apnea in dilated cardiomyopathy

Area of Science:

• Cardiology
• Sleep Medicine
• Cardiovascular Research

Background:

• Obstructive sleep apnea (OSA) is prevalent in heart failure (HF) patients.
• OSA subjects the left ventricle (LV) to mechanical and adrenergic stress.
• Nonischemic dilated cardiomyopathy (DCM) involves eccentric LV hypertrophy.

Purpose of the Study:

• To investigate the association between OSA and LV hypertrophy in nonischemic DCM.
• To compare LV septal and wall thickness in nonischemic DCM patients with and without OSA.

Main Methods:

• Echocardiography and polysomnography were performed on 47 nonischemic DCM patients.
• Patients were categorized based on the presence or absence of OSA.
• Left ventricular hypertrophy was assessed using wall thickness criteria.

Main Results:

• OSA was present in 45% of the study cohort.
• LV hypertrophy prevalence was significantly higher in OSA patients (47.6% vs. 15.4%, p=0.016).
• Interventricular septal and relative wall thickness were greater in OSA patients; posterior wall thickness did not differ.

Conclusions:

• OSA is associated with increased LV hypertrophy in nonischemic DCM.
• Patients with OSA exhibit altered LV remodeling, with increased septal thickness.
• These changes may result from nocturnal mechanical and adrenergic stimuli from OSA.