- Cardiac origin: due to myocardial ischemia cardiac patients are at higher risk to develop:
- a. Ventricular fibrillation, during which the heart is not properly beating and maintaining the cardiac output instead the heart starts to have shaking type of movement that highly compromises the perfusion of vital organs such as the brain and subsequently patients collapse.
- b. Pulsels tachyarrhythmia's – due to the heart is beating very fast the stroke volume is diminished therefore the vital organs perfusion compromised and patients collapse due to hypoxia and hypo perfusion.
- c. Shock- different types of shock decreases the cardiac output and subsequently patient develop cardiac arrest due to adequate blood and oxygen is not reaching to the vital organs
- Respiratory origin:
- a. Airway obstruction- unconscious patients may develop airway obstruction and subsequently cardiac arrest secondary to aspiration of abdominal content, sudden choking, upper airway pathologies acute and chronic type
- b. drowning,
- c. smoke inhalation- carbon monoxide poisoning that suppresses the respiratory center and patients stop breathing
- d. drug overdose- due to respiratory center depression
- Metabolic disturbance:
- a. electrolyte imbalance due to different diseases such as renal failure
b. acid base imbalance- due to severe hypoxia, renal and endocrine diseases
- Cardio pulmonary arrest (CPA) out –of hospital .The primary rhythm for cardiac arrest is usually ventricular fibrillation, Pulsels tachyarrhythmia‘s due to ischemic heart disease,
- CPA in Hospital – Often have multi system abnormalities that are non cardiac in origin, commonly suffering a gradual deterioration in physiological state, with hypotension, hypoxemia or both prior CPA. The terminal event in these cases is usually pulseless electrical activity or asystole.