Sleep Apnea May Trigger Abnormal Heart Rhythms

A new study suggests that episodes of obstructive sleep apnea may trigger two types of “cardiac arrhythmias,” which are abnormal heart rhythms.

The study involved 2,816 people. Their sleep was evaluated during an overnight sleep study.

The sleep study results were examined for two types of abnormal heart rhythms: ventricular tachycardia and atrial fibrillation – or AF.

Results show that the overall rate of arrhythmias was low; 62 abnormal heart rhythms occurred in 57 people.

But the relative risk of an abnormal heart rhythm was much higher after a breathing disturbance; people were nearly 18 times more likely to have an arrhythmia after a breathing pause than after normal breathing.

“Do these events act as a trigger for cardiac abnormalities?" study co-author Dr. Susan Redline said to HealthDay News. “We established that there is a close temporal relationship.”

The study also found that abnormal heart rhythms occurred even when OSA was less severe.

“Most of the arrhythmias occurred in people with mild-to-moderate sleep apnea," said Redline.

AF is the most common type of serious arrhythmia; long-term AF can lead to stroke and heart failure. AF is a very fast and irregular contraction of the atria.

The atria are the two upper chambers of the heart. They collect blood as it comes into the heart.

Ventricular tachycardia is a fast, regular beating of the ventricles. These are the two lower heart chambers. They pump blood out of the heart to the lungs and other parts of the body. Ventricular arrhythmias can be very dangerous.

In June the Sleep Education Blog reported on the link between sleep apnea and abnormal heart rhythms in older men.

Find out more about cardiac arrhythmias on the NHLBI Web site. Get help for sleep apnea at an AASM-accredited sleep center near you.