Heart Problems and Sleep Disorders
Font Size : 

The time we sleep is that part of the 24-hour day when our body undergoes the maximum physiological changes. It is the period when complex activities take place within the body.

One of the organs majorly affected during sleep is the heart. The change in the activities and behavior of the heart is one of the most significant topics of discussion in recent years.

Sleep diseases affect the heart in a significant manner. Similarly, heart diseases disrupt and hamper normal sleep. Let us have a look at it in detail.

The impact of normal sleep on the heart:

We pass through many phases during sleep, of which the following two groups of stages are of key importance:

  1. The No Rapid Eye Movement group (NREM)
  2. The Rapid Eye Movement group or the dream stage (REM)
  • Sleep during (NREM):

Sleep could be divided into four stages of which the third and fourth stages are known as deep sleep. A normal person spends about 80% of his sleep in NREM.

The heart rate decreases during this stage resulting into a slight drop in blood pressure thus making the heart comfortable.

  • Sleep during REM:

In REM, the heart rate accelerates and the blood pressure rises, hence there is a higher need of oxygen for the heart. As 80% of the sleep period is spent in NREM or natural sleep, the overall effect of sleep over the heart is slight.

The heart rate acceleration and increase in blood pressure usually do not affect the heart, as there is an increase in the blood flow to the coronary arteries. However, for patients suffering from arteriosclerosis, the changes during REM may result in a decrease in cardiac ischemia, as observed on animals during scientific experiments.

Occlusion of the respiratory tract and heart during sleep:

This disorder results in repeated stopping of breath during sleep because of blockages of the upper respiratory tract and heart depression (failure). Sleep apnea is a common disease causing the person to frequently wake-up due to the deficiency of oxygen in the blood.

These changes are caused due to a frequent rise in blood pressure and heartbeats that in turn increase the need for oxygen and consequently a potential heart deficient ischemia. This is particularly observed in patients with narrow coronary arteries.

Some scientific studies suggest that, sleep apnea that occurs due to occlusion of the upper respiratory track could result in narrowness and sclerosis of the coronary arteries. A study conducted by the King Khalid Hospital, suggests that more than 50% of the patients were admitted to cardiac care for acute ischemia of the heart. These patients were found to be suffering with interruption or failure of breathing during sleep (sleep apnea.)

Sleep and Heart

Sleep disorder and high pulmonary arterial blood pressure:

Recent scientific studies have proved that frequent deficiency of oxygen because of the blockage of the upper respiratory track during sleep, results in an increase in the arterial blood pressure. Thus, there is a close connection between the two diseases.

The studies have also suggested that about 50% of patients with sleep apnea suffer from hypertension; and sleep apnea is amongst the serious factors that cause high blood pressure. This fact was reaffirmed through several recent scientific experiments with large groups of people suffering from sleep apnea. These studies demonstrated a strong relationship between sleep apnea and high blood pressure even after the exclusion of other factors that increase blood pressure such as increased weight, age, etc. 

Moreover, the oxygen deficiency in blood causes constriction in the arteries of the lungs, resulting into high blood pressure.

Over time, the hypertension in the lung's arteries becomes chronic. This may lead to failure and depression in the left pane of the heart resulting into leg tumefaction and sometimes ascites.

In addition to the aforementioned, the lack of oxygen in the blood during sleep could result in heart disorders that can lead to heart failure during sleep or acute ischemia of the heart.

Sleep apnea and heart failure:

Scientific studies and research suggests that about 40-50% of patients with heart failures, suffer from sleep apnea cause by occlusion of the upper respiratory track or central apnea (sleep apnea without occlusion of the upper respiratory track).

There are also evidences that indicate that apnea disorders may increase the severity of heart failure in the long-term. Several studies prove that the death rate for heart patients with sleep and central apnea is higher than heart patients without this disorder. Hence, there is a close relationship between breathing disorders during sleep and heart failure, as they both cause and aggravate the other.

Therefore, we infer that the treatment for sleep apnea improves the patient’s immunity against heart failure and depression, while treatment for heart failure can help reduce breathing disorders during sleep.

Finally, I would like to suggest to everyone suffering from heart diseases and sleep apnea, to consult a physician and get their medical condition diagnose accurately. Timely treatment should avoid any serious complications.


Ahmed BaHammam, FACP, FCCP
Professor of Medicine
Director, University Sleep Disorders Center
College ofMedicine, King Saud University