Why Sleep Is So Important After a Heart Attack

Scientists have discovered that the heart signals the brain to sleep more after a heart attack.
This response is essential for recovery, as restful sleep is “an important factor for heart healing,” according to a new study published in Nature on Wednesday.
Sleep helps the body heal by limiting further damage to the heart, lead investigator Cameron McAlpine, assistant professor of cardiology at the Icahn School of Medicine at Mount Sinai, told The Epoch Times.
In contrast, mice with disrupted sleep experienced more serious heart problems, including dangerous heart rhythms and higher mortality rates.
Human studies mirrored these findings. Among 78 patients, those who reported good sleep quality in the four weeks after their heart attacks experienced significant improvements in heart function over two years; their hearts could pump blood better, as shown with echocardiography within six months of their leaving the hospital.
They also had fewer serious heart-related problems, such as additional heart attacks or hospital visits.
Conversely, people who slept poorly faced a higher risk for additional heart problems and did not show the same improvements, according to the study.
A key element of this discovery is how the heart communicates with the brain through immune cells called monocytes. After a heart attack, these cells move to the brain and produce a molecule called tumor necrosis factor (TNF). This protein activates neurons in the thalamus, a brain region crucial for regulating sleep, consciousness, and memory.
This process promotes “restorative sleep to aid heart healing after injury” by reducing stress on the heart and limiting inflammation, which is vital for recovery, according to the researchers.
“What we identified was that the increase in sleep really lowers the amount of sympathetic stress that occurs in the heart, and this enables this healing process of reduced inflammation and eventually helps the heart recover its function” to how it was before the heart attack, McAlpine said.
Sympathetic stress increases heart rate and blood pressure, putting additional strain on the heart and increasing inflammation.
While sleeping, a person’s heart rate and blood pressure drop, and their breathing becomes stable and regular.
“It’s essential to recognize that increased sleep is a healthy response during recovery,” McAlpine said. “Health care providers should support their patients in getting sufficient rest after a heart attack.”
“Many cardiac management programs do not prioritize sleep as they should,” McAlpine said.
Coronary artery disease, the most common type of heart disease in the United States, can lead to heart attacks. This condition occurs when plaque builds up in the arteries that supply blood to the heart and body, narrowing them and potentially blocking blood flow. A heart attack happens when the heart muscle does not receive enough blood, leading to damage and impaired function.