Everyone knows that the heart is a muscle that keeps the body moving and alive. When it is healthy and working properly, the heart is strong and does its job without much attention paid to it at all. On the other hand, a not-so-healthy heart can be to blame for a vast array of health problems. With heart disease as the leading cause of the death of Americans today, and stroke following closely as one of the leading causes of death as well as disability, it is vitally important that we pay attention to heart health.
One condition that is linked to the health of the heart is sleep apnea. This is a sleep disorder in which the body does not breathe as often as it should due to either airway blockage (Obstructive Sleep Apnea—OSA) or brain malfunction (Central Sleep Apnea—CSA). When the body does not breathe as it should during sleep, a lack of oxygen and increase in carbon dioxide begin to affect the health.
Other problems and symptoms related to sleep apnea include:
- Loud snoring
- Forgetfulness, irritability, mood changes, poor work performance
- Fatigue and sleepiness (even during activity)
- High blood pressure
- Dry or sore throat
- Inability to go to sleep or stay asleep
- Headaches and migraines
- Thyroid problems
- Atrial fibrillation (AFib)
- Obesity and weight gain
- Heart disease or heart failure
How Sleep Apnea Affects the Heart
One of the main jobs of the heart is to carry oxygen throughout the blood vessels to the body, and then carry the carbon dioxide (waste) back out of the breathing passages. When breathing happens properly during sleep, the heart continues to beat at a slow, resting rate. In fact, during sleep, the heart should beat 10%-20% less actively than during wakefulness, allowing the heart to receive some “down-time” during sleep as well.
When breathing is interrupted and reduces the amount of oxygen available to the bloodstream, the heart rate tends to drop initially. Then, the brain sends a message to the heart that it needs more oxygen through the release of epinephrine, a stress hormone. This startles the body awake and the heart responds by speeding up and beating faster, trying to get more oxygen to the brain and body. Most people with sleep apnea have 10%-20% more heart activity during sleep, which is the opposite of a healthy person.
The regular occurrence of the startle reflex and increased heart rate result in what is known as hypertension, or high blood pressure. People who have low levels of oxygen at night due to sleep apnea tend to continue with the high blood pressure during the day, creating a chronic condition. Over time, people who have obstructive sleep apnea (OSA) are exposed to unhealthy stimuli to the heart that could cause damage or contribute to problems related to the circulatory system.
Some researchers have estimated that people who live with untreated sleep apnea may increase their risk of death by heart disease by up to five times what it would be otherwise. One study performed by the National Sleep Foundation discovered that men with severe obstructive sleep apnea (OSA) were almost 60% more likely to develop congestive heart failure (not pre-existing) than men who did not have sleep apnea. In addition, this study showed that men between the ages of 40 and 70 with severe sleep apnea were almost 70% more likely to develop heart disease than those men with milder forms of sleep apnea.
Sleep Apnea and Atrial Fibrillation (AFib)
People who have obstructive sleep apnea and high blood pressure experience strain on the heart as time passes. The walls of the heart may tend to thicken as the muscle needs to work harder over time. This can cause the structure of the heart to change, becoming less flexible and stiffer, with more muscle cells growing. All of these things can reduce the ability for the heart to function appropriately, often cause arrhythmias including Atrial Fibrillation.
Atrial Fibrillation (AFib) is another condition that has been found to have a clear connection to the presence of sleep apnea. While a healthy heart is expected to beat strongly and with regular rhythms, hearts that has AFib experience a fluttering or arrhythmia of heart beating. This means the heart is sort of stuttering and does not pump the blood out to and in from the body as it should. AFib can be the lead-in to various types of heart disease and stroke, which can ultimately lead to heart failure and premature death.
Central Sleep Apnea and Heart Failure
Rather than being caused by a physical obstruction of breathing the way that the more common obstructive sleep apnea (OSA) is, central sleep apnea (CSA) is a less common condition where the brain does not send the appropriate signals to trigger the body to breathe. CSA is not as well-understood as OSA, and may be linked to various neurological conditions such as brain infection or injury, or the use of narcotics.
A link between CSA and heart problems remains, but it tends to be more of a mystery to medical experts. Whereas OSA is likely a cause of heart failure, CSA could possibly be a consequence of heart failure. In the case of CSA, heart congestion can cause the body to hyperventilate, stimulate heart receptors, lead to the activation of the nervous system, and ultimately resulting in breathing problems during sleep.
Sleep Apnea Treatments
Heart experts have found that sleep apnea occurs in around half of patients who have heart failure, which is a disease with a very high mortality rate. The good news is that people who are treated for sleep apnea in conjunction with heart problems (such as high blood pressure) typically find significantly improved health as their bodies fall into healthy rhythms of sleep and heart function again.
CPAP (Continuous Positive Airway Pressure) machines are the most common treatment for obstructive sleep apnea, allowing the patient to sleep without breathing episodes. It has been found that people with have both heart failure and sleep apnea can benefit significantly from treatment with a CPAP machine.
Depending on the cause for sleep apnea, other treatment options that are healthy for both conditions include losing weight, quitting smoking, better exercise, cutting back on alcoholic drinks, and living a generally better lifestyle overall.
Because of the strong association between sleep apnea and heart failure, it is critical that you reach out to a medical professional for diagnosis and effective treatment if you believe you have either of these conditions. Your life doesn’t have to be cut short because of these conditions, and you can return to a healthier lifestyle with active care from your physician.