Sleep Apnea and Heart Failure

The new researches and the basic clinical practice statistics reveal the fact that the link between sleep apnea and heart failure. Heart failure is a condition in which the heart is unable to perform the pumping function and provide adequate circulation. The development of cardiac failure leads to insufficient supply of oxygen to the heart muscle, with the increased demand for it, and also leads to metabolic disturbances in muscle.

Obstructive sleep apnea is characterized by recurrent episodes of sleep during the pauses in breathing, followed by the next revival. Periodic pause (apnea) or reduction (hypopnea) of the respiratory flow is accompanied by a drop in the oxyhemoglobin content, which, entails damage to the myocardium.

Each time a forced awakening (even for a short time) the heart rate raises, blood pressure rises, and the heart has to work harder in order to cope up with hypoxic conditions. An episode of pause in breathing stimulates the activity of the sympathetic nervous system, while in the blood increases the level of adrenaline, which causes the tachycardia and increased myocardial oxygen demand.

It is the interruption of breathing in patients with sleep apnea and associated with him, sympathetic tonic and hypoxia increase the risk of heart failure. Congestive heart failure in patients with obstructive sleep apnea syndrome tends to progression. The main factor for the adverse effects of this syndrome is considered to be at a significant increase in negative intra thoracic pressure during inspiration, which causes an increase in preload on the heart.

The right ventricle during periods of apnea expands and becomes full of blood, and it disrupts the function of the left ventricle, making it difficult to fill with blood during diastole. Therefore, during apnea appear symptoms of heart failure – cardiac output may decrease considerably.

Slowing of the heart rate causes an increase in after load on the heart. As a result of activation of neurohumoral systems, increasing preload and after load in hypoxic conditions, changes in the myocardium that contributes to the progression of heart failure.

Heart failure is accompanied by marked changes in the ECG as a coronary segment depression ST, which is recorded on the background of episodes of apnea and tachycardia. Episodes of myocardial ischemia are observed mainly in the phase of rapid eye movements – this is the peak time of apnea and hypoxemia.

About 40% of people with heart failure have breathing problems associated with sleep. In this regard, there is a need for timely diagnosis and treatment of the underlying disease – obstructive sleep apnea syndrome. This is important for the prevention of cardiac insufficiency, progression EEI improve the quality of life of the patient.

Detailed analysis of the disturbance that occur during sleep, is carried out using polysomnography, which involves simultaneous registration of EEG, EOG (electroculography), EMG, respiratory flow of blood oxygen saturation.

Early treatment of respiratory disorders during sleep can greatly reduce the chance of developing cardiovascular disease. The only effective method of treatment for these disorders is breathing CPAP therapy or weight loss if the patient is obese. Most patients who are undergoing bariatric surgery will also need an outpatient sleep study before they can be cleared for surgery and undergo anesthesia.