Evaluation of subclinical right ventricular dysfunction in obstructive sleep apnea patients using velocity vector...

Area of Science:

• Cardiology
• Sleep Medicine
• Diagnostic Imaging

Background:

• Obstructive sleep apnea (OSA) is increasingly recognized for its systemic effects.
• Subclinical cardiac dysfunction, particularly in the right ventricle (RV), may precede overt symptoms in OSA patients.
• Evaluating RV function is crucial, especially in patients without existing systemic or pulmonary hypertension.

Purpose of the Study:

• To assess subclinical regional RV dysfunction in newly diagnosed OSA patients without hypertension.
• To correlate the severity of OSA with the degree of RV dysfunction.
• To compare the efficacy of velocity vector imaging (VVI) and tissue Doppler imaging (TDI) in detecting RV abnormalities.

Main Methods:

• Recruited 27 OSA patients and 26 healthy controls.
• Utilized 24-h ambulatory blood pressure monitoring for all participants.
• Employed VVI for RV free wall strain and strain rate (SR) analysis, and TDI for myocardial velocities and isovolumic acceleration (IVA).

Main Results:

• OSA patients exhibited significantly impaired VVI-derived RV systolic velocities, strain, and SR (P<0.0001).
• RV isovolumic acceleration (IVA) was the sole significantly impaired TDI parameter (P<0.0001).
• RV IVA, mid free wall strain, and SR showed strong correlations with the apnea-hypopnea index (AHI).

Conclusions:

• Subclinical RV dysfunction is prevalent in OSA patients, even with normal systemic and pulmonary artery pressures.
• TDI-derived RV IVA and VVI-derived RV deformation effectively quantify RV function abnormalities in OSA.
• These imaging techniques can identify and assess RV dysfunction in OSA patients.