Left Ventricular Changes Seen in Obstructive Sleep Apnea
(HealthDay News) – Patients with obstructive sleep apnea (OSA) have structural and functional changes in left ventricular (LV) function similar to those seen in patients with hypertension, which are resolved following continuous positive airway pressure (CPAP) therapy.
Mehmood Butt, MRCP, from City Hospital in Birmingham, UK, and colleagues assessed LV function using two-dimensional echocardiography, three-dimensional echocardiography (3DE), and tissue Doppler imaging in 40 patients with moderate-to-severe OSA, 40 patients with hypertension (without OSA), and 40 healthy controls. Individuals with OSA were treated with CPAP for a mean of 26 weeks, after which they underwent repeat echocardiographic assessment.
The investigators found that, compared with healthy participants, those with OSA and hypertension had significantly greater posterior wall thickness and LV mass index, reduced mitral annular systolic velocity (S), and impaired diastolic function. The mean left atrial volume index was significantly greater in OSA and hypertensive participants versus healthy controls, as seen on 3DE. CPAP therapy resulted in significant changes, including reduced posterior wall thickness and improvements in LV ejection fraction, S velocity, and parameters of LV diastolic impairment.
"Moderate to severe OSA causes structural and functional changes in LV function on echocardiography comparable to that seen in hypertension, with both acute and chronic LV diastolic dysfunction parameters impaired," the authors write. "This may imply that OSA could be crucial in development of LV diastolic dysfunction which may lead to heart failure and increased mortality if left untreated."
Funding for the Sonovue® contrast used in the study was provided by Bracco Research SA.