OSA Sleep Apnea and Your Heart: What Sleep Apnea Heart Rate Changes Really Mean

What Your Sleep Apnea Heart Rate Reveals About Your Heart Health

Have you ever woken up in the middle of the night with a racing heart or gasping for air? These experiences can be alarming, however they are common symptoms of obstructive sleep apnea (OSA). OSA is a common sleep disorder where the airway becomes blocked during sleep, leading to pauses in breathing. These interruptions can cause increased sleeping heart rate and put stress on the cardiovascular system.

Many people with OSA experience high heart rates while sleeping, which reflects the impact of this condition on heart health and overall cardiovascular well-being. Recognizing the reasons behind this increase in heart rate is essential for managing OSA and lowering the risk of related cardiovascular complications. 

Impact of OSA on the Cardiovascular System

Obstructive sleep apnea is a sleep-related breathing disorder in which the upper airway becomes partially or completely blocked during sleep. This blockage causes breathing to either reduce (hypopneas) or stop entirely (apneas) for at least 10 seconds. 

These interruptions can occur multiple times per hour throughout the night. The obstruction happens because the muscles supporting the soft tissues in your throat, such as the tongue and soft palate, relax during sleep, causing narrowing or closing of the airway.

OSA causes fragmented sleep and significant drops in blood oxygen levels, putting strain on the body. The severity of OSA is measured by the apnea-hypopnea index (AHI), which counts the number of apnea and hypopnea episodes per hour of sleep, categorizing the condition as mild, moderate, or severe.

How OSA Affects Heart Health

OSA can have a significant impact on the cardiovascular system. When the airway becomes obstructed, airflow is reduced, leading to decreased blood oxygen levels. This triggers a defensive response from the brain and autonomic nervous system, briefly awakening you to restore normal breathing. 

These frequent awakenings disrupt sleep quality, causing surges in heart rate and blood pressure, and the heart is forced to work harder as it copes with repeated arousals from sleep.

This results in episodes of rapid heart rate during the night, elevated heart rate while sleeping, and increased variability in heart rate patterns.  If left untreated, this can cause hypertension, arrhythmias, and an increased risk of heart disease. In patients with OSA, increased heart rate and blood pressure at night is common, directly linking the sleep disorder to cardiovascular diseases. 

The Role of Heart Rate Variability (HRV)

Heart rate variability (HRV) indicates the balance and functioning of your autonomic nervous system, which controls factors such as heart rate. HRV measures how heart rate changes when exposed to stressors. A higher HRV generally indicates a healthy, responsive autonomic nervous system, while a lower HRV suggests reduced adaptability and heightened sympathetic nervous activity.

In patients with OSA, heart rate variability provides insights into the quality of your heart’s regulation and overall cardiovascular health during various sleep stages.

Impact of Sleep Apnea on Heart Rate

Obstructive sleep apnea significantly disrupts normal heart rate patterns. OSA causes reduced heart rate levels which means the body is in fight or flight response rather than rest response. This is because of reduced oxygen levels and repeated awakenings through the night, causing accelerated heart rate or sudden spikes in heart rate during sleep. 

Disrupted heart rate not only occur during sleep but can persist into daytime, placing additional strain on the cardiovascular system. Studies reveal that patients with more severe OSA and those experiencing excessive daytime sleepiness have even lower HRV values, highlighting a higher risk of cardiovascular complications. Monitoring HRV serves as a valuable, non-invasive tool to understand how OSA impacts autonomic function, emphasizing the need to manage the condition to protect heart health.

Symptoms of Cardiovascular Risk

Elevated Heart Rate

A common cardiovascular disturbance associated with OSA is elevated heart rate (tachycardia) during wakefulness. Patients have an elevated heart rate even while awake, caused by overactive nervous system.

The body's response to hypoxia and sleep disturbances leads to an overactive nervous system, which increases resting heart rate, blood pressure, and vascular resistance. Over time, these effects place continuous stress on the heart, raising the risk of hypertension and other cardiovascular diseases.

Elevated heart rates during the day often reflect the chronic strain that OSA exerts on the cardiovascular system and may serve as an early warning sign of developing heart complications.

Bradycardia and Arrhythmias During Sleep

While a rapid heart rate can be concerning, sleep apnea also triggers episodes of bradycardia—abnormally slow heart rates—during sleep. These occur during apneic events when the brain tries to conserve oxygen, significantly slowing the heart rate.

These bradycardic episodes alternate with periods of tachycardia, which occur when breathing resumes forcefully after an apnea. This can result in heart rhythm disturbances such as atrial fibrillation and other arrhythmias. It can cause damage which increases susceptibility to serious arrhythmias and heighten the risk of nocturnal sudden cardiac death. This is why it is essential to evaluate cardiovascular risk in patients with OSA and implement appropriate interventions.

Talk to Your Doctor

Obstructive sleep apnea (OSA) significantly affects heart health, leading to rapid changes in heart rate and an elevated risk of cardiovascular issues. Recognizing symptoms like high heart rates during sleep, arrhythmias, and situations where individuals wake up with a rapid heart beat is vital, as they may indicate underlying heart disease.

Taking action to address OSA can greatly lower these risks. Understanding the link between OSA and heart health empowers individuals to take proactive measures, such as seeking a diagnosis and undergoing treatments like CPAP therapy, to reduce cardiovascular complications. Speak to your doctor today to protect your heart and ensure overall well-being.