When Having a Big Heart Can Be Dangerous: The Apnea Connection
Last updated: March 2023
It seems there should be no downside to having a big heart. Compassion and love are widely embraced qualities in all cultures.
However, when it comes to the physical properties of the heart, bigger isn’t better. In fact, an enlarged heart can be downright dangerous. The clinical term for an enlarged heart is cardiomegaly.1
Sometimes, people are born with cardiomegaly. Sometimes it may occur as the result of a heart attack or unchecked arrhythmias (abnormal heart rhythms).1
In cases of untreated obstructive sleep apnea (OSA), cardiomegaly may also result. In these cases, we really don’t want a big heart!2
Obstructive sleep apnea and heart disease
Scientists have long confirmed untreated OSA as a major risk factor for most forms of heart disease. Especially severe OSA can cause the heart to enlarge.2
The heart muscle requires oxygen to function. Long pauses in breathing (apneas) lead to drops in blood oxygen. They also cause increases in carbon dioxide in the bloodstream.3
The brain, as we sleep, tunes into these chemical changes in our blood. When oxygen drops and carbon dioxide increases, the brain interprets this as a threat. After all, every cell in our body needs oxygen to thrive. Cells die when deprived of oxygen even for a short period of time.3
When the brain discovers these imbalances in blood chemistry during sleep, it signals the heart to pump harder to provide more oxygen in response. It’s a smart system … unless you have OSA. Then, an obstruction in the airway – the one causing the apnea – continues to prevent more oxygen from entering the bloodstream. Meanwhile, the blood vessels experience added stress trying to coordinate the delivery of blood with a heart working overtime. This causes elevated blood pressure.3
Eventually, the person experiencing the apnea breathes again – the characteristic gasps and snores we associate with OSA. When enough oxygen reenters the bloodstream (and enough carbon dioxide leaves with each fresh exhale), the heart and blood vessels eventually calm down. Until the apneas return. Again. And again. And again.3
As you can see, this creates constant stress on your heart and blood vessels (cardiovascular system). This can result in long-term increases in blood pressure and the “pumped up” heart muscle characteristic of cardiomegaly.3
How will I know if my heart is enlarged?
It’s more common than you think. It is estimated that around 6 million people in the United States have an enlarged heart.4
Even if you haven’t been diagnosed with OSA or heart disease, you could still have an enlarged heart. Symptoms include:4
- Chest pain or discomfort
- Dizziness, fainting, or shortness of breath
- Tiring quickly during activity
- Swelling in the legs
- Irregular heartbeat or a feeling of fluttering in your chest
If you experience any of these symptoms, please have a doctor take a look. This is serious business. They’ll likely have you undergo cardiac testing and review your history, signs, and symptoms.4
They may also ask about your sleep:
- Do you snore?
- Are you sleepy during the day?
- Do you awaken with your heart pounding in your chest?
- Do you sweat in your sleep?
- Do you experience what feels like panic attacks during sleep?
OSA is a stealthy disease. It affects more than 25 million adults in the United States. But some estimate that 75 percent of people with severe OSA remain undiagnosed. That's a lot of people! The odds suggest that many who haven’t been diagnosed still live with OSA, untreated.3
A chief way to prevent heart disease: address its risk factors. That means identifying – and treating – hidden conditions like OSA.
Can CPAP help?
Absolutely! Literally any treatment for OSA that successfully reduces or eliminates OSA breathing patterns – including continuous positive airway pressure or CPAP – will prevent or reduce ongoing problems with the heart and blood vessels.5
This includes PAP therapies, neurostimulation implants, oral appliances, surgical procedures, and more. Not only could cardiomegaly respond to these treatments, but so could high blood pressure and atrial fibrillation, a common arrhythmia.5
Good sleep means a healthier heart
Always remember: Any time sleep is disrupted by irregularities linked to the heart, our brains and bodies lose precious opportunities to fight disease and repair injuries.6
Not only that, but unhealthy sleep conditions lay the groundwork for ongoing concerns like heart disease, which is dangerous and can be difficult to reverse.7
Having enough uninterrupted sleep every night is necessary for overall health and well-being. The Centers for Disease Control and Prevention advises that adults strive for between 7 and 9 hours per night.8
When you give your cardiovascular system several consecutive hours of restful sleep every night (and during naps, too!), it can support body-wide healing, thanks to the adequate, consistent flow of oxygen to each and every cell.
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