NREMT EMT 6: Anatomy, Physiology, and Pathophysiology - Pathophysiology of Cardiac Arrest, Ischemia, Infarction, Arrhythmias

What This Is: Cardiac Arrest

Cardiac arrest is when the heart suddenly stops beating, cutting off blood flow to the brain and other vital organs. This can happen due to a heart attack, electrical problems, or other issues. Think of it like a car engine stalling – the heart is the engine, and without it, the body's systems shut down.

Key Steps / Core Facts:

• Ischemia: Reduced blood flow to the heart muscle, often due to a blockage (e.g., a clogged pipe). Ischemia can lead to cardiac arrest if not treated promptly.
• Infarction: When a part of the heart muscle dies due to lack of blood flow (like a tree dying from lack of water).
• Arrhythmias: Abnormal heart rhythms, which can be life-threatening (like a car's engine racing out of control).
• CPR compression depth: At least 2 inches – like pushing down a soda can. (AVPU, SAMPLE, OPQRSTI)
• CPR rate: 100-120 compressions per minute – like tapping your foot to a fast beat.
• CPR ratio: 30:2 (30 compressions, 2 breaths) – like taking 30 steps and then taking 2 deep breaths.
• Time to start CPR: Within 2 minutes of collapse – like calling 911 and starting CPR within 2 minutes.
• Cardiac arrest causes: Heart attack, electrical problems, drowning, or other issues (like a car's engine stalling due to a faulty spark plug).
• Cardiac arrest symptoms: Sudden collapse, no breathing, no pulse (like a car's engine dying with no warning).
• Normal heart rate: 60-100 beats per minute – like a steady drumbeat.
• Normal blood pressure: 90-140/60-90 mmHg – like a steady water pressure in a hose.

What Laypeople Can Do:

• If someone collapses, first check for danger (oncoming traffic, fire). Then shout and tap their shoulder.
• Call 911 or your local emergency number immediately.
• Start CPR if you're trained (or use an automated external defibrillator, AED, if available).
• Keep the person calm and comfortable until help arrives.

Common Mistakes:

• Mistake: Not calling 911 immediately.
• Fix: Call 911 right away – every minute counts in cardiac arrest.
• Mistake: Not starting CPR within 2 minutes of collapse.
• Fix: Start CPR as soon as possible – it can double or triple the chances of survival.
• Mistake: Not using an AED if available.
• Fix: Use an AED if you're trained or if the person is in cardiac arrest – it can help restore a normal heartbeat.

Quick Practice Scenarios:

1. A friend suddenly collapses while playing basketball. What should you do first?

Answer: Call 911 immediately. Reason: Every minute counts in cardiac arrest.

1. You're at the beach and someone drowns. What should you do first?

Answer: Start CPR if you're trained, or use an AED if available. Reason: Cardiac arrest can occur after drowning, and CPR can help restore a normal heartbeat.

1. Your child suddenly collapses while playing at home. What should you do first?

Answer: Call 911 immediately. Reason: Cardiac arrest can occur in children, and every minute counts in treatment.

Last-Minute Exam Cram:

• Cardiac arrest is a medical emergency – call 911 immediately.
• Normal heart rate: 60-100 beats per minute.
• Normal blood pressure: 90-140/60-90 mmHg.
• CPR compression depth: at least 2 inches.
• CPR rate: 100-120 compressions per minute.
• CPR ratio: 30:2 (30 compressions, 2 breaths).
• Time to start CPR: within 2 minutes of collapse.
• Cardiac arrest causes: heart attack, electrical problems, drowning, or other issues.
• Cardiac arrest symptoms: sudden collapse, no breathing, no pulse.
• Ischemia: reduced blood flow to the heart muscle.
• Infarction: when a part of the heart muscle dies due to lack of blood flow.
• Arrhythmias: abnormal heart rhythms.
• AED: automated external defibrillator, used to restore a normal heartbeat.
• Agonal breathing is NOT normal breathing – start CPR.