Cardiac Function and Arrhythmias

The video provides an overview of arrhythmias, explaining the heart's conduction system and how it affects heart rhythm. It covers the mechanisms of bradyarrhythmias and tachyarrhythmias, including reduced automaticity, conduction blocks, enhanced automaticity, triggered activity, and re-entry. The video also discusses how these conditions are represented on an ECG and their symptoms.

What is the primary role of the sinoatrial node in the heart?

• To filter blood entering the heart

• To store oxygen for the heart

• To pump blood throughout the body

• To initiate and regulate the heart's rhythm

What does the T wave on an ECG represent?

• Ventricular depolarization

• Atrial depolarization

• Ventricular repolarization

• Atrial repolarization

What is the typical heart rate range set by the sinoatrial node?

• 140 to 180 beats per minute

• 100 to 140 beats per minute

• 40 to 60 beats per minute

• 60 to 100 beats per minute

What does the PR interval on an ECG represent?

• The duration of a complete cardiac cycle

• The activation of the AV node and bundle of His

• The time between ventricular depolarization and repolarization

• The delay between atrial and ventricular contraction

Which nerve is responsible for reducing the heart rate by increasing vagal tone?

• Optic nerve

• Phrenic nerve

• Vagus nerve

• Sciatic nerve

What is the effect of a conduction block in the right bundle branch?

• Increased heart rate

• Decreased heart rate

• Prolonged QRS complex

• Prolonged PR interval

What is a common symptom of tachyarrhythmias?

• Increased appetite

• Palpitations

• Nausea

• Joint pain

What is the main cause of re-entry tachyarrhythmias?

• Increased vagal tone

• Re-excitation of cardiac fibers

• Triggered activity

• Enhanced automaticity

Which of the following is NOT a mechanism of tachyarrhythmias?

• Re-entry

• Reduced automaticity

• Triggered activity

• Enhanced automaticity

How are supraventricular arrhythmias characterized on an ECG?

• By prolonged PR intervals

• By narrow QRS complexes

• By wide QRS complexes

• By inverted T waves