The Mechanism of Commotio Cordis

The video explains commotio cordis, a rare cardiac event caused by a blunt force to the chest, leading to cardiac arrest. It details the cardiac action potential phases and how a blow during the T wave can induce ventricular fibrillation. The video also discusses the risk factors, such as high-impact sports, and the rarity of the event due to specific timing and location requirements.

What is commotio cordis primarily caused by?

• Excessive exercise

• High blood pressure

• A blunt force to the chest

• A genetic heart defect

Which phase of the cardiac action potential is associated with ventricular contraction?

• U wave

• T wave

• QRS complex

• P wave

What happens if a second ventricular depolarization occurs before relaxation is complete?

• The heart rate increases

• Ventricular fibrillation occurs

• The heart stops completely

• The atria contract prematurely

During which part of the T wave is the heart most at risk for commotio cordis?

• Beginning

• Second half

• First half

• End

What is the role of mechanosensitive ion channels in commotio cordis?

• They cause muscle relaxation

• They regulate blood flow

• They prevent heart attacks

• They trigger extra depolarization

What is the minimum impact energy required to potentially cause commotio cordis?

• 10 joules

• 30 joules

• 50 joules

• 70 joules

Why is commotio cordis considered a rare event?

• It is caused by common daily activities

• It needs precise timing and location of impact

• It only occurs in older adults

• It requires a specific genetic mutation