Sleepy during daytime? Heart risk high! Cardiology Basics

Sleepy during daytime? Heart risk high! Cardiology Basics

Daytime sleepiness is not that uncommon. There are many who fall asleep while at work or while reading. Wait before taking it so lightly. It may mean something more sinister.

The Sleep Heart Health Study found that obstructive sleep apnea with excessive daytime sleepiness triples the chance of heart failure and doubles the risk of a cardiovascular event.

Obstructive sleep apnea known in short as OSA is transient apnea while sleeping due to obstruction of the upper air passages. The obstruction is manifest as noisy breathing or snoring. Poor quality of sleep at night leads to daytime sleepiness.

The Sleep Heart Health Study had 1200 patients with obstructive sleep apnea having 15 or more episodes per hour on sleep study or polysomnography. Polysomnography is a multichannel recording which monitors nasal airflow along with several other parameters like ECG, EEG, EMG and EOG (electrooculogram).

Chest and abdominal belts check respiratory movements. Microphone monitors snoring episodes. Pulse oximeter kept on the finger shows the oxygen saturation in blood. Sleep study can be done at the hospital or at sleep centres which do the testing. It can also be done at home with a limited set of sensors and a smaller portable equipment.

Important symptom subtypes noted in the Sleep Heart Health Study were:
Disturbed Sleep
Minimally Symptomatic
Excessively Sleepy
Moderately Sleepy

Excessively Sleepy subtype was associated with over 3 times increased risk of heart failure. The same subtype was associated with increased risk of new occurrence of heart disease.

Reference

  1. Mazzotti DR, Keenan BT, Lim DC, Gottlieb DJ, Kim J, Pack AI. Symptom Subtypes of Obstructive Sleep Apnea Predict Incidence of Cardiovascular Outcomes. Am J Respir Crit Care Med. 2019 Aug 15;200(4):493-506. doi: 10.1164/rccm.201808-1509OC. PMID: 30764637; PMCID: PMC6701040.