Cardiac Electrophysiology Flashcards

What is the primary function of the sinoatrial (SA) node in the heart?

Answer: To initiate and regulate the heart's electrical impulses

The sinoatrial (SA) node is often referred to as the heart's natural pacemaker. It is a specialized cluster of cells located in the right atrium that spontaneously generates electrical impulses. These impulses then spread throughout the atria, causing them to contract, and subsequently travel to the ventricles, initiating the entire cardiac cycle and regulating heart rate.

Which part of the heart’s conduction system is responsible for delaying the electrical impulse to allow the ventricles to fill with blood before they contract?

Answer: AV node

The atrioventricular (AV) node plays a critical role in the heart's conduction system by delaying the electrical impulse as it travels from the atria to the ventricles. This brief delay is essential because it allows the atria to fully contract and pump blood into the ventricles before the ventricles begin their own contraction. This ensures optimal ventricular filling and efficient cardiac output.

Which of the following arrhythmias is most commonly associated with an accessory pathway, such as in Wolff-Parkinson-White (WPW) syndrome?

Answer: Supraventricular tachycardia (SVT)

Wolff-Parkinson-White (WPW) syndrome is characterized by an accessory pathway, an abnormal electrical connection between the atria and ventricles that bypasses the AV node. This pathway can create a re-entry circuit, leading to rapid heart rhythms originating above the ventricles, most commonly supraventricular tachycardia (SVT). The presence of this extra pathway facilitates the rapid conduction of impulses, causing the heart to beat much faster than normal.

Which electrophysiological test is used to identify and map the origin of arrhythmias in the heart?

Answer: Electrophysiology study (EPS)

An electrophysiology study (EPS) is an invasive diagnostic procedure specifically designed to evaluate the heart's electrical activity and identify the source of arrhythmias. During an EPS, catheters with electrodes are threaded into the heart to record electrical signals and induce arrhythmias. This allows electrophysiologists to precisely map the abnormal pathways or areas of tissue causing the arrhythmia, guiding treatment decisions like ablation.

In cardiac electrophysiology, what is an "ablation" procedure primarily used for?

Answer: To destroy or isolate areas of heart tissue that are causing abnormal electrical signals

Cardiac ablation is a therapeutic procedure used to treat various arrhythmias by targeting and neutralizing the specific heart tissue responsible for generating or sustaining abnormal electrical signals. Using heat (radiofrequency ablation) or cold (cryoablation), the procedure creates small scars that block the faulty electrical pathways. This effectively restores a normal heart rhythm and prevents future episodes of arrhythmia.