Very often as part of the work up for atrial fibrillation, patients are referred for sleep studies to determine if there is coexistent sleep apnea. This seems like a big jump from snoring and making noise breathing at night to having an irregular heartbeat. However, the two are closely related.
Let’s take a look at some basic physiology of snoring. Snoring occurs because as the person is breathing in, the airway is blocked in the back of the throat, behind the palate, and behind the tongue. If airflow is cut off, three things happen:
Oxygen can drop because the person is not breathing
The person wakes up, leading to sleep deprivation the following day
There is an outpouring of stress hormones, namely adrenaline, as a response to choking in one’s sleep. Adrenaline makes the heart beat faster.
Now let’s look at some basic physiology of the heart. The heart has a natural pacemaker in the right atrium. Electrical impulse travels across the atrium down to the lower chambers of the heart. Everyone remembers that the heart has four chambers. The smaller chambers on the right side are responsible to pump blood to the lungs. Blood is returned to the larger chambers on the left side to pump blood to the whole body. The chambers on the right side have to be smaller because if the pressure were too high, blood would fly out of the lungs. Most importantly, the heart loves oxygen, it beats all the time and consumes a lot of oxygen. If the heart stops, it leads to major problems.
Let’s put it all together. During episodes of sleep apnea, the oxygen level drops and puts a major strain on the heart and it has to work extra hard. This leads to remodeling of the heart where the chambers become thicker and bigger in order to pump extra hard. If the walls of the right atrium, where the natural pacemaker is, become stretched, you can imagine how the wiring is going to be disrupted. It would be as if the walls in your house were stretched, tearing and shorting out the wires. Additionally, as previously noted, there are large quantities of adrenaline being produced, whipping the heart and making it beat faster. The net result of all of these things is that the heart deteriorates into a rapid irregular, rhythm — atrial fibrillation.
Sleep apnea is a major cause of atrial fibrillation. Studies have demonstrated that patients with sleep apnea have four times the risk of having atrial fibrillation as patients without sleep apnea. In coronary artery bypass patients, the rate of post-operative atrial fibrillation was significantly higher among patients with sleep apnea.
There are many ways to treat atrial fibrillation, such as medication, cardioversion, cardiac ablation, and pacemakers. Patients with atrial fibrillation and sleep apnea generally respond poorly to pharmacologic or non-pharmacologic therapy (cardioversion or ablation), with a high rate of recurrence. Hence if the sleep apnea is not treated, the atrial fibrillation will also not be able to be treated. If you have atrial fibrillation or other cardiac arrhythmias, it is considered standard of care to pursue an investigation of sleep apnea, and the sleep apnea should be treated.
For more information, join me October 26, at 6:00 p.m. for a free education session about sleep issues and heart health at Raritan Bay Medical Center-Old Bridge. Registration is required, call 1-800-DOCTORS.
Board certified Pulmonologist and Sleep Medicine Specialist Dr. Andrew Freedman is affiliated with Hackensack Meridian Health Raritan Bay Medical Center-Old Bridge’s Center for Sleep Medicine. The state-of-the-art diagnostic center provides the highest quality care for adults and children under the direction of board certified sleep physicians. Dr. Freedman’s office is located at 465 Cranbury Rd., East Brunswick, NJ. To make an appointment, call 732-360-4255.
With locations in Perth Amboy and Old Bridge, New Jersey, Raritan Bay Medical Center delivers critical world-class healthcare services care to Monmouth and Middlesex County residents. As providers of first-class healthcare in the areas of stroke, cardiology, cancer, physical rehabilitation, pulmonary rehabilitation, pediatric medicine, Raritan Bay Medical Center continues to stay on the forefront of medicine.
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