How Hypoxia Causes Cardiac Arrest?

Prolonged or severe hypoxaemia causes tissue to become hypoxic, resulting in anaerobic metabolism and altering the patient's acid-base balance (Deranged Physiology 2020; Pruitt 2004). This can precipitate cardiac arrest.

How does hypoxia affect the heart?

Acute hypoxic exposure increases heart rate and cardiac output via β-adrenergic stimulation, and can result in higher blood pressure and rate pressure product. Chronic IH has been shown to result in long-term facilitation in sympathetic nerve activity associated with augmented blood pressure responses to hypoxia.

Can lack of oxygen cause cardiac arrest?

Significant hypoxia is required to cause cardiac standstill. It is likely that by the time of cardiac arrest caused by hypoxia, irreversible severe brain damage has already occurred. This should inform decisions on resuscitation.