heart

The Role of the Heart in Sleep

Dr. Sushil Sharma, M.D.

Cardiac MedicineWhen we sleep many parts of our body are resting, but not our heart. Cardiologists and Sleep Medicine specialists discovered unusually intensive heart activity heart in REM sleep and during dreams. While the body is lying quietly, the heart rate speeds up as if the person is running or fighting. Researchers have been surprised to find that the relationships between the heart and other organs in sleep were different from those during an awakened state. For example, if you start to breathe fast your heart rate will also speed up. In sleep however, (especially in REM sleep) if your breathing increases the heart rate might not follow, moreover, it might decrease. In addition, if the heart rate slows down for a few minutes oxygen saturation in the blood will decrease to a dangerous level.

Research in “Sleep Cardiology” demonstrated increases in many arrhythmias in sleep. Sleep can provoke irregular heart beats and exacerbate existing arrhythmias. What is more surprising for cardiologists is that heart arrhythmias (even heart attacks) might be caused not only by structural deficiencies of the heart muscles, but changes in the central nervous system. Strong emotions such as anger and stress (if not resolved) could magnify the REM-related turbulence of metabolism, increase adrenalin and cause heart attacks, strokes and other cardiovascular problems like hypertension.

Epidemiological studies showed that the time of death caused by heart problems is not evenly distributed throughout the 24-hour cycle. The most common period is in sleep especially between 2 and 6 am. This is very important for the treatment of the patient with different heart problems, breathing disorders or obesity.

Children who have large tonsils and adenoids preventing normal breathing in sleep frequently suffer from heart problems. In addition, many medications affect the normal work of the heart in sleep and can increase the risk of heart arrhythmias.

Heart problems in sleep can manifest as symptoms of loud snoring, screaming or thrashing in sleep, repetitive bad dreams, sudden awakening with gasping for air, sensations of choking, heart palpitation or irregular heart beats, profuse sweating or chills, headaches, dizziness or morning fatigue. If you or someone you love has these symptoms, please consult your doctor.

The good news is that the early detection of heart problems “hiding” in sleep is available and their treatment is very possible.

Ambulatory Cardiology and Sleep Medicine Institute at Rush North Shore Medical Center would be glad to answer your questions about diagnosis and treatment or direct you to the appropriate specialists in your area. Tel: (847) 933- 6061 or Sleep & Health Hotline (847) 673-7660