Right Ventricular Function in Obstructive Sleep Apnea

Many risk factors for OSA, such as male gender, obesity, and increasing age are the same as for cardiovascular diseases. This fact makes it more difficult to establish a causal relationship between OSA and cardiovascular diseases. The relationship between OSA and right ventricular (RV) function is controversial. RV dysfunction may be a result of chronic intermittent hypoxia and hypercapnia during apneic episodes. It may also occur secondary to left ventricular dysfunction as a result of increased afterload and sympathetic activity which causes secondary hypertension. As systemic hypertension is one of the most accompanying and contributing factors in OSA along with obesity, we tried to compare the effects of newly diagnosed OSA on RV function with an age and body mass index- matched control group.

Inclusion criteria

For OSA patients (group1)

• Apnea Hypopnea Index equal or more than 15
• Epworth sleepiness scale equal or more than 10
• No previous treatment for OSA

Exclusion criteria

• Age < 18 years
• Known hypertension, or 24-hour mean blood pressure of 135 and/or 85 mmHg or more
• Mean pulmonary artery pressure > 25 mmHg
• Diabetes mellitus
• Left ventricular ejection fraction < 60%
• Moderate to severe valvular disease
• Cardiomyopathy
• Renal failure
• Coronary artery disease
• Obstructive or restrictive lung disease demonstrated on pulmonary function test
• Connective-tissue or chronic thromboembolic disease
• Pericardial disease
• Cancer and/or other important comorbidities with an expected survival < 2 years
• Suboptimal echocardiographic images for measurements