Cardiac Dysrhythmias Overview

Study Notes

Sinus Bradycardia

Heart rate (HR) is less than 60 beats per minute.
Characterized by a normal rhythm and regular P waves.

1st Degree Heart Block

HR can be normal or slightly slow.
Regular rhythm is present; PR interval is prolonged (greater than 0.20 seconds).

2nd Degree Heart Block Type I (Wenckebach)

HR is typically slow.
Regular rhythm with a PR interval that progressively lengthens until a QRS complex is dropped.

2nd Degree Heart Block Type II

HR remains slow and has a regular rhythm.
PR interval may be normal or prolonged; often leads to multiple dropped QRS complexes.

3rd Degree Heart Block (Complete Heart Block)

HR is slow with a regular rhythm, but no correlation between P waves and QRS complexes.
P waves are normal; QRS complexes can be either normal or wide.

Junctional Dysrhythmias

HR can be normal or slow with a regular rhythm.
P waves are often hidden within the QRS complex due to retrograde conduction.

Atrial Fibrillation

HR ranges from 350 to 600 beats per minute.
Irregular rhythm with the presence of fibrillatory waves instead of distinct P waves.

Atrial Flutter

HR varies between 200 to 350 beats per minute.
Can be regular or irregular; characterized by "sawtooth" flutter waves.

Supraventricular Tachycardia (SVT)

HR exceeds 150 beats per minute.
Presents a regular rhythm with absent or hidden P waves among the rapid beats.

Ventricular Tachycardia (VT)

HR typically ranges from 150 to 250 beats per minute.
Regular rhythm with wide and distorted QRS complexes.

Ventricular Fibrillation (VF)

HR is not measurable due to chaotic electrical activity.
Irregular rhythm with no discernible waves or measurable parameters.

ST Depression

Indicative of myocardial ischemia.
Appears as a downward deflection from the baseline on the ECG.

ST Elevation

Often signifies acute myocardial infarction (heart attack).
Appears as an upward deflection from the baseline on the ECG.

Asystole

Represents a complete lack of electrical activity in the heart.
HR is absent, and there are no identifiable waves on the ECG.

Artifact

Refers to distortion or interference on an EKG that does not represent cardiac activity.
Generally caused by patient movement, poor electrode contact, or external electrical signals.

Description

This quiz covers various types of cardiac dysrhythmias, including sinus bradycardia, heart blocks, and junctional dysrhythmias. Each condition is defined by unique heart rates and rhythms, providing a clear understanding for students of cardiology. Test your knowledge of these critical concepts in heart function and rhythm irregularities.

Cardiac Dysrhythmias Overview

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Questions and Answers

What is the heart rate for Sinus Bradycardia?

What is the PR interval characteristic of 1st Degree Heart Block?

What happens to the PR interval in 2nd Degree Heart Block Type I?

What characterizes the QRS complex in 2nd Degree Heart Block Type II?

What is the state of the P Wave in 3rd Degree Heart Block?

In Junctional Dysrhythmias, how is the P Wave affected?

Atrial Fibrillation corresponds to what heart rate range?

What is the heart rate range for Atrial Flutter?

What characterizes Supraventricular Tachycardia?

What is the heart rate range for Ventricular Tachycardia?

In Ventricular Fibrillation, the heart rate is measurable.

What are the characteristics of ST Depression?

What is indicated by ST Elevation?

What is Asystole?

What is meant by the term Artifact in EKG readings?