Understanding CPR: The Heart, Cardiac Arrest, and the Importance of Compressions

Knowing how the heart functions and the impact of cardiac arrest is crucial for delivering effective CPR. You can keep blood circulating with proper compressions until a defibrillator becomes available.

How the Heart Functions

The heart's natural pacemaker, the Sinoatrial Node, sends regular electrical impulses from the top chamber (Atrium) to the bottom chamber (Ventricle). This process keeps the heart pumping blood. In cardiac arrest, this normal functioning is disrupted, often due to electrolyte imbalances, potassium interference, or heart-related issues.

Cardiac Arrest and Ventricular Fibrillation

During cardiac arrest, the heart's electrical pathways are disrupted, causing the heart to experience ventricular fibrillation or ventricular tachycardia. In this state, defibrillation is necessary to restore normal heart function.

Effective CPR and Chest Compressions

While waiting for an Automated External Defibrillator (AED), perform effective CPR:

• Push down 5-6cm at 100-120 beats per minute.
• Place hands in the centre of the chest.
• Maintain a straight posture and use body weight.
• Switch rescuers every two minutes for optimal CPR.
• Allow the chest to recoil fully between compressions.

The Role of AEDs

AEDs work by passing electricity through the heart, momentarily stunning it and allowing the heart's pacemaker to restore normal function. In cases of cardiac arrest due to a lack of oxygen, the AED may indicate that no shock is necessary. Continue CPR and monitor the patient until emergency services arrive.

Remember: Anyone can perform CPR. The key is to maintain the correct rate and depth of compressions.