Definition: Sudden, unexpected loss of heart function, breathing, and consciousness. It’s often due to an electrical disturbance.

Symptoms: Sudden collapse, no pulse, no breathing, loss of consciousness.

Diagnosis: Clinical observation, ECG, defibrillator checks.

Treatment: Immediate CPR, defibrillation (AED), advanced cardiac life support (ACLS).

Definition: Blockage of blood flow to the heart muscle, usually due to a clot in a coronary artery.

Symptoms: Chest pain, shortness of breath, sweating, nausea, lightheadedness.

Diagnosis: ECG, troponin blood test, echocardiogram, coronary angiography.

Treatment: Aspirin, nitroglycerin, angioplasty, stenting, thrombolytics, bypass surgery.

Definition: The heart can't pump blood effectively, leading to fluid buildup and poor oxygen delivery.

Symptoms: Shortness of breath, fatigue, swollen legs, rapid heartbeat, fluid retention.

Diagnosis: Echocardiogram, BNP blood test, chest X-ray, ECG, stress test.

Treatment: Diuretics, ACE inhibitors, beta-blockers, lifestyle changes, pacemakers, heart transplant (in severe cases).