Sleep-disordered breathing can have an impact on heart health. A study based upon measurements in a sleep lab shows clear relationships between certain types of breathing abnormalities and specific heart rhythm problems.
Sleep apnea, where the patient stops breathing many times in the night, is a common problem which can increase the risk of heart disease. But there are many types of sleep apnea and they can only be diagnosed by polysomnography, which measures breathing patterns during sleep. This approach can link breathing problems more firmly with heart problems and help better diagnosis and treatment.
Researchers at Case Western University School of Medicine studied nearly 3,000 men who underwent polysomnography. The number of times they ceased breathing or did shallow breathing was recorded, along with oxygen levels in the blood. Heart arrhythmias were also recorded.
Having more episodes of paused or shallow breathing was linked to arrhythmias involving either the upper chambers, the atria, or the lower chambers, known as the ventricles. Obstructive sleep apnea, the most common type of sleep-disordered breathing, was linked most often with ventricular arrhythmias. But central sleep apnea, which is linked to malfunctioning in brain signals controlling breathing, is more likely to be linked to arrhythmias involving the atria. The more severe the breathing problem, the bigger the effect on the heart.
The researchers think that hypoxia – or lowered levels of oxygen in the blood – may be a factor linking sleep-disordered breathing and heart problems. Another factor could be the impact of disordered breathing on the nervous system. Sleep-disordered breathing requires careful diagnosis and treatment to reduce the impact on long-term heart health.