Electrophysiology Flashcards Quiz 2.2

Questions and Answers

An electrical wave moving in the direction of a positive electrode will:

Manifest with narrow QRS complexes.

Cause a positive deflection on the ECG. (correct)

Cause a negative deflection on the ECG.

Produce a significant amount of artifact.

Depolarization, the process by which muscle fibers are stimulated to contract, occurs when:

Cell wall permeability changes and sodium rushes into the cell. (correct)

Potassium ions escape from the cell through specialized channels.

Calcium ions rapidly enter the cell, facilitating contraction.

Cardiac muscle relaxes in response to a cellular influx of calcium.

Atrial fibrillation can be interpreted by noting:

An irregularly irregular rhythm and absent P waves. (correct)

PR intervals that vary from complex to complex.

A regular rhythm with abnormal P waves.

The presence of wide QRS complexes and a rapid rate.

Which of the following statements regarding the SA node is correct?

The SA node is the dominant cardiac pacemaker in healthy patients. Signup and view all the answers

The P wave represents:

Atrial depolarization. Signup and view all the answers

A classic sign of atrial flutter is:

The presence of sawtooth P waves. Signup and view all the answers

The AV junction:

Is composed of the AV node and surrounding tissue. Signup and view all the answers

Changes in cardiac contractility may be induced by medications that have a positive or negative ___________ effect.

inotropic Signup and view all the answers

Automaticity is defined as the ability of the heart to:

Generate its own electrical impulses without stimulation from nerves. Signup and view all the answers

Sinus dysrhythmia is:

An irregular sinus rhythm. Signup and view all the answers

A 'run' of ventricular tachycardia occurs if at least ____ PVCs occur in a row.

Three Signup and view all the answers

Ventricular bigeminy occurs when:

Every second complex is a PVC. Signup and view all the answers

Patients with a heart rate greater than 150 beats/min usually become unstable because of:

Reduced ventricular filling. Signup and view all the answers

The layers of the wall of the heart, beginning with the outermost layer, are the:

Epicardium, myocardium, and endocardium. Signup and view all the answers

Study Notes

Cardiac Electrical Activity and Arrhythmias

An electrical wave toward a positive electrode causes a positive deflection on the ECG.
Depolarization in muscle fibers is triggered when sodium rushes into the cell due to changes in cell wall permeability.
Atrial fibrillation is characterized by an irregularly irregular rhythm and absent P waves.

Sinoatrial (SA) Node and Atrial Activity

The SA node serves as the dominant cardiac pacemaker in healthy individuals.
The P wave on an ECG signifies atrial depolarization.
Atrial flutter is identified by sawtooth P waves.

Atrioventricular (AV) Junction

The AV junction consists of the AV node and surrounding tissue.
Changes in cardiac contractility are influenced by inotropic medications.

Heart Function and Rhythms

Automaticity is the heart's ability to generate its own electrical impulses without neural stimulation.
Sinus dysrhythmia is recognized as an irregular sinus rhythm.
A run of ventricular tachycardia is defined as three or more consecutive PVCs.
Ventricular bigeminy occurs when every second complex is a PVC.

Complications from High Heart Rate

Heart rates exceeding 150 beats/min typically lead to instability due to reduced ventricular filling.

Heart Wall Structure

The outermost layer of the heart wall is the epicardium, followed by the myocardium, and the innermost layer is the endocardium.

Idioventricular Rhythm

Idioventricular rhythms can lead to hemodynamic instability and are often associated with nonconducted P waves.

Description

Test your knowledge on electrophysiology with these flashcards from Quiz 2.2. Each question focuses on key concepts related to electrical waves and muscle fiber depolarization in the context of ECG interpretation. Perfect for students and professionals alike!