Hypoxia-induced Effects on ECG Depolarization by Time Warping Analysis during Recurrent Obstructive Apnea

Area of Science:

• Cardiology
• Physiology
• Biomedical Engineering

Background:

• Obstructive sleep apnea (OSA) is linked to cardiovascular dysfunction.
• Intermittent hypoxia (IH) during OSA episodes can alter cardiac electrical activity.
• Existing methods may not fully capture dynamic ECG changes during IH.

Purpose of the Study:

• To evaluate a non-linear approach for estimating morphological variations in ECG depolarization during intermittent hypoxia.
• To investigate QRS wave changes in a rat model of recurrent obstructive sleep apnea.

Main Methods:

• A rat model of recurrent obstructive sleep apnea (OSA) was established.
• Electrocardiogram (ECG) QRS waves were extracted and non-linearly aligned using dynamic time warping (DWT).
• Morphological changes in amplitude and time domains of QRS waves were analyzed during hypoxic and basal periods.

Main Results:

• A progressive increase in amplitude and time-domain QRS morphological markers was observed during the experiment.
• These non-linear markers strongly correlated with traditional QRS markers (r ≈ 0.9).
• Significant changes in time-domain analysis were found between pre-apnea and hypoxic measures (p<0.001).

Conclusions:

• Non-linear analysis of ECG QRS morphology effectively captures dynamic changes during intermittent hypoxia.
• Increased variability in ECG depolarization during recurrent hypoxic episodes may relate to cardiovascular dysfunction in OSA.
• This approach offers a novel way to assess cardiac impact in OSA.