Researchers taking part in the Sleep Heart Health Study reported that patients with severe sleep apnea are two to four times more likely to experience complex, abnormal heart rhythms while sleeping than individuals without the problem. The researchers reported that individuals with sleep-disordered breathing had four times the odds of atrial fibrillation and three times the odds of nonsustained ventricular tachycardia. Atrial fibrillation consists of very rapid contractions of the atria (the upper chambers of the heart), leading the ventricles (the lower chambers of the heart) to beat irregularly. This results in decreased heart output and potential for clot formation. Tachycardia is defined by abnormally rapid heartbeats—over 100 beats per minute in an adult. Similar findings were reported by researchers from St. Louis University who studied 134 patients with coronary heart disease who hadn’t been diagnosed with a sleep disorder. In the patients who had a type of an irregular heartbeat called ventricular premature contraction, more than 40% also had severe sleep apnea—and didn’t realize it. The real worry is that benign arrhythmia can be a harbinger of a much more serious—and lethal—heart rhythm disorder. While most people with the mild version of arrhythmia will be just fine, in some people it’s possible it can worsen during the night and lead to sudden death. The researchers reported that sleep apnea seemed to exacerbate ventricular premature contraction, especially during the dream stage, or REM, of sleep. That’s because there’s less oxygen being pumped through the body in REM than in other stages of sleep, and this can bring on arrhythmia. The brain is less alert, which is why people don’t simply wake up to solve the problem. |
