The pauses in breathing during sleep, observed in obstructive sleep apnea syndrome (OSAS), are the cause of cardiac arrhythmias. In a patient whose breathing periodically stops during sleep against the background of snoring, episodes of sinus bradycardia, sinus tachycardia, atrioventricular blockades, ventricular and atrial extrasystoles are often detected. Changes in the frequency and nature of the rhythm can persist only during the night or be present around the clock, constantly.
Cardiac arrhythmias with rapid changes in heart rate are very common in sleep apnea. They cause serious disturbances in the work of the heart, and this has a bad effect on the blood supply to all organs and tissues. Such arrhythmias are life threatening.
The most common variant of cardiac arrhythmias in obstructive sleep apnea syndrome is severe sinus bradycardia. This type of arrhythmia occurs in 68% of patients with OSA and is characterized by a decrease in heart rate to 30-50 beats per minute. As a rule, bradycardia occurs during respiratory arrest. Since these stops can develop up to hundreds of times per night, the corresponding number of times the patient has rhythm disturbances.
When, after stopping, a person begins to breathe again, his heart rate increases, and episodes of tachycardia are recorded. The heart, which was beating slowly before, begins to work faster. The pulse reaches 100-150 beats per minute! (norm 60-80) At this moment, a large load suddenly falls on the heart, it “overworks”, it gradually wears out. If a person with sleep apnea simultaneously has coronary heart disease (and this is a very common combination), at the moments of respiratory arrest and the appearance of arrhythmias, he may experience attacks of nocturnal angina pectoris.
The pronounced fluctuations in heart rate from very slow to very fast are so significant that doctors take this indicator into account as an important criterion for the presence of obstructive sleep apnea syndrome.
The second type of cardiac arrhythmias recorded in obstructive sleep apnea is atrioventricular blockade, more often II and III degrees (that is, severe). With this type of cardiac arrhythmias, there is a slowdown in the conduction of an electrical impulse from the atria to the ventricles. With atrioventricular blockade of the II degree, not every impulse reaches the ventricles, the heart contracts rarely and often irregularly. Atrioventricular blockade of the III degree is characterized by the complete absence of impulses from the atria to the ventricles. The chambers of the heart work inconsistently , the atria and ventricles function on their own, the blood begins to be pumped with difficulty by the heart. Atrioventricular blockade of the III degree can cause severe life-threatening consequences.
It has been found that the incidence of obstructive sleep apnea syndrome in patients who have previously had a pacemaker implanted for similar bradyarrhythmias is 59%. This fact confirms the role of sleep apnea syndrome in the development of serious cardiac arrhythmias.
Among the rhythm disturbances associated with obstructive sleep apnea, also include ventricular and atrial extrasystoles, which are recorded at the end of respiratory arrest against the background of an accelerated heart rate.
Patients with sleep apnea have an increased risk of atrial fibrillation (atrial fibrillation). This cardiac arrhythmia doubles the overall mortality of patients . The degree of nocturnal desaturation (oxygen starvation during sleep) has been proven to be the cause of recurrent atrial fibrillation in the absence of treatment, even if these patients previously underwent successful cardioversion (that is, if their heart rhythm was previously restored to normal).
The above facts dictate the need for a comprehensive examination of patients with cardiac arrhythmias for sleep apnea in order to select the correct therapeutic tactics. Such at the moment is CPAP – therapy.
At present, improved Prisma Line CPAP devices from the new line of Weinmann , Germany have been developed. Their use allows the most effective and comfortable treatment of the entire spectrum of respiratory disorders in patients with obstructive sleep apnea syndrome.