During normal sleep, both airflow and heart rate remain steady, reflecting balanced autonomic control and a consistent oxygen supply. But during obstructive sleep apnea (OSA), airway collapse leads to: 👉 Interrupted nasal airflow: periods of apnea followed by gasping as breathing resumes 👉 Increased respiratory effort: chest and diaphragm working harder against obstruction 👉 Heart rhythm fluctuations: initial bradycardia during apnea, followed by a rebound tachycardia when airflow returns The