Link Exists Between Sleep Apnea and Cardiac Disease

 

OSA has been linked to the risk of heart failure, hypertension, type 2 diabetes, elevated blood pressure, atrial fibrillation and stroke.

It’s been shown that there is nearly a 60 percent greater risk of developing heart failure in middle-aged men with severe sleep apnea and twice the increased risk of those with severe OSA suffering a stroke. As many as 4 in 10 of those with high blood pressure also have OSA. Studies have also shown that this risk is reduced to normal levels when those patients with sleep apnea are treated with PAP therapy.

Sleep apnea is defined as a common sleep-related breathing disorder characterized by regular episodes of reduced inspiratory airflow due to upper airway obstruction during sleep. OSA is associated with a significant increase in sympathetic activity during sleep, influencing heart rate and blood pressure.

It’s the connection between OSA, cardiac disease, and the benefit of the most common treatment for the sleep disorder (the use of the PAP therapy) in reducing it that makes it so important for primary care physicians and cardiologists to screen patients with cardiac disease for suspected OSA. According to the National Healthy Sleep Awareness Project, this begins by determining whether patients demonstrate any of these five warning signs and risk factors for OSA:

Snoring

Choking or gasping during sleep

Fatigue or daytime sleepiness

Obesity (with a BMI of 30 or higher)

High blood pressure

Since most patients may not necessarily be forthcoming about their sleep problems, believing it is normal to feel tired, doctors need to proactively raise the issue. As a means to this end, physicians should consider offering patients this five- question questionnaire provided by the National Sleep Foundation. If there is a concern that a patient has one or more of these risk factors, a sleep evaluation should be recommended to investigate whether there is a sleep disorder.

 

SLEEP STUDY

A sleep study, or polysomnogram, is a noninvasive, pain-free procedure that equires the patient staying overnight in a sleep center (although a home study is also possible). During the study, brain wave activity, eye movements, muscle tone, heart rhythm and breathing are monitored. Are they struggling to breathe? Have they stopped breathing at certain times? What is their oxygen status? All of this helps determine if the patient’s airway is being obstructed while asleep. The patient’s sleep position is also observed, as sleep apnea tends to be worse when the patient lays supine.

After recording a full night’s sleep, the technologist tabulates the data and presents it to a physician for interpretation. Should it be determined that the patient has sleep apnea, a titration study will be conducted to find the right amount of air pressure needed to prevent the patient’s upper airway from becoming blocked and eliminate breathing pauses in their sleep. As with the earlier polysomnogram, sensors are again attached to the patient’s body to monitor their sleep, as they are fitted with a nasal mask that is connected by a hose to a small electric unit. The fitting process is an important first step in the PAP titration. At certain intervals throughout the night, the technologist will remotely change the air pressure received through the mask. Pressure starts at a very low level and gradually increases as needed to eliminate any apneic events. The study is completed the next morning. Other treatments, if deemed necessary, may also be explored.

At-risk populations, those with a preponderance of cardiac comorbidities like hypertension, atrial fibrillation, diabetes, heart failure, hypertension, high BMI and stroke, such as found throughout the Bronx, are in particular need of OSA screening. As one cardiologist said, not screening for sleep apnea is akin to an auto mechanic fixing three tires on a car and never checking the fourth but simply hoping for the best.

For more information on the Center for Sleep Medicine at SBH call 718-960-3730