Determination of right ventricular dysfunction using the speckle tracking echocardiography method in patients with obstructive sleep apnea

BACKGROUND: The speckle tracking echocardiography (STE) method shows the presence of right ventricular (RV) dysfunction before the advent of RV failure and pulmonary hypertension in patients with cardiopulmonary disease. We aimed to assess subclinical RV dysfunction in obstructive sleep apnea (OSA) using the STE method. METHOD: Twenty-one healthy individuals and 58 OSA patients were included. According to severity as determined by the apnea-hypopnea index (AHI), OSA patients were examined in three groups: mild, moderate and severe. RV free wall was used in STE examination. RESULTS: Right ventricle strain (ST %) and systolic strain rate (STR-S 1/s) were decreasing along with the disease severity (ST - healthy: -34.05 ± -4.29; mild: -31.4 ± -5.37; moderate: -22.75 ± -4.89; severe: -20.89 ± -5.59; p < 0.003; STR-S - healthy: -2.93 ± -0.64; mild: -2.85 ± -0.73; moderate: -2.06 ± -0.43; severe: -1.43 ± -0.33; p < 0.03). Correlated with the disease severity, the RV early diastolic strain rate (STR-E) was decreasing and the late diastolic strain rate was increasing (STR-E - healthy: 2.38 ± 0.63; mild: 2.32 ± 0.84; moderate: 1.66 ± 0.55; severe: 1 ± 0.54; p < 0.003; STR-A - healthy: 2.25 ± 0.33; mild: 2.32 ± 0.54; moderate: 2.79 ± 0.66; severe: 3.29 ± 0.54; p < 0.03). The STR-E/A ratio was found to be in a decreasing trend along with the disease severity (healthy: 1.08 ± 0.34; mild: 1.06 ± 0.46; moderate: 0.62 ± 0.22; severe: 0.34 ± 0.23; p < 0.03). CONCLUSIONS: Subclinical RV dysfunction can be established in OSA patients even in the absence of pulmonary hypertension and pathologies which could have adverse effects on RV functions. In addition to the methods of conventional, Doppler and tissue Doppler echocardiography, using the STE method can determine RV dysfunction in the subclinical phase.