Chp 13 ECG Lead System Flashcards

Questions and Answers

What are Standard Limb Leads comprised of?

Leads V1, V2, V3

Leads I, II, III

Leads I, II, III, aVR, aVL, aVF (correct)

Leads aVR, aVL, aVF

What is Lead I?

Right arm aVR to left arm aVL, with the right arm being negative and the left arm being positive.

What is Lead II?

Right arm aVR to left leg aVF, with the right arm being negative and the left leg being positive.

What is Lead III?

Left arm aVL to left leg aVF, with the left arm being negative and the left leg being positive. Signup and view all the answers

What does aVR indicate?

The right arm is positive; the right leg, left leg, and left arm are negative. Signup and view all the answers

What does aVL indicate?

The left arm is positive; the right arm, right leg, and left leg are negative. Signup and view all the answers

What does aVF indicate?

The left leg is positive; the right arm, right leg, and left arm are negative. Signup and view all the answers

What are Bipolar Leads?

Leads I, II, III Signup and view all the answers

What is Einthoven's Triangle?

An imaginary equilateral triangle with the heart at its center, formed by the axes of the three bipolar limb leads. Signup and view all the answers

What are Unipolar Leads?

Leads aVR, aVL, aVF that monitor electrical activity with a positive electrode and a reference point. Signup and view all the answers

What is an example of Frontal Plane?

The electrical activity that flows over the anterior surface of the heart; from the base to the apex of the heart, in the right to left direction. Signup and view all the answers

What do Left Lateral Leads monitor?

Leads I and aVL monitor the left lateral side of the heart. Signup and view all the answers

What is the role of Inferior Leads?

Leads II, III, and aVF view the lower surfaces of the heart. Signup and view all the answers

What do Precordial Leads monitor?

They monitor the heart from the horizontal plane and record electrical activity traversing the heart. Signup and view all the answers

What do V1 and V2 leads monitor?

Monitor the right ventricle. Signup and view all the answers

What do V3 and V4 leads monitor?

Monitor the ventricular septum. Signup and view all the answers

What do V5 and V6 leads view?

View the left ventricle. Signup and view all the answers

What do Anterior Leads comprise?

Leads V1, V2, V3, and V4. Signup and view all the answers

What do Lateral Leads comprise?

Leads V5 and V6. Signup and view all the answers

What is the duration of a Small Square on the ECG?

0.04 seconds. Signup and view all the answers

What is the duration of a Large Square on the ECG?

0.20 seconds. Signup and view all the answers

What does Amplitude represent in an ECG?

The vertical portion of each small square. Signup and view all the answers

What are Waveforms in an ECG?

Begins and ends at the baseline. Signup and view all the answers

What are Complexes in an ECG?

Two or more waveforms together. Signup and view all the answers

What are Segments in an ECG?

A flat, straight, or isoelectric line. Signup and view all the answers

What are Intervals in an ECG?

A waveform or complex connected to a segment. Signup and view all the answers

How are positive ECG tracings described?

All ECG tracings above the baseline are described as positive. Signup and view all the answers

How are negative ECG tracings described?

Waveforms below the baseline are described as negative. Signup and view all the answers

What does the P wave represent?

The normal cycle of electrical activity in the heart begins with atrial depolarization. Signup and view all the answers

What is the PR interval?

Starts at the beginning of the P wave and ends at the beginning of the QRS complex. Signup and view all the answers

What does the QRS complex represent?

Ventricular depolarization. Signup and view all the answers

What does the ST segment represent?

The time between ventricular depolarization and repolarization. Signup and view all the answers

Study Notes

ECG Lead System Overview

Standard limb leads consist of leads I, II, III, aVR, aVL, and aVF, derived from electrodes on arms and legs.

Lead Definitions

Lead I: Connects right arm (aVR, negative) to left arm (aVL, positive).
Lead II: Connects right arm (aVR, negative) to left leg (aVF, positive).
Lead III: Connects left arm (aVL, negative) to left leg (aVF, positive).

Unipolar and Bipolar Leads

Bipolar leads: Leads I, II, III use one positive and one negative electrode.
Unipolar leads: aVR, aVL, aVF monitor heart activity between one positive electrode and a reference point.

Einthoven's Triangle

An imaginary equilateral triangle encompassing the heart formed by the axes of the bipolar limb leads.

Heart Surface Monitoring

Frontal plane: Monitors electrical activity from the base to the apex in a right to left direction.
Left lateral leads: Leads I and aVL focus on the left lateral side.
Inferior leads: Leads II, III, aVF observe the lower surfaces.
Precordial leads: Unipolar; record electrical activity across a horizontal plane.

Precordial Lead Positions

V1 and V2: Monitor the right ventricle.
V3 and V4: Monitor the ventricular septum.
V5 and V6: View the left ventricle.

Lead Classification

Anterior leads: V1, V2, V3, V4.
Lateral leads: V5 and V6.

ECG Measurement

Small square: Has a duration of 0.04 seconds.
Large square: Comprises five small squares with a duration of 0.20 seconds.
Amplitude: Represented by the vertical portion of each small square.

ECG Waveforms and Segments

Waveforms: Begin and end at baseline.
Complexes: Composed of two or more waveforms.
Segments: Flat, isoelectric lines.
Intervals: Combination of waveforms or complexes with segments.

ECG Wave Characteristics

Positive deflections: Represented by ECG tracings above the baseline.
Negative deflections: Occur below the baseline.

Specific Wave Details

P wave: Indicates atrial depolarization; symmetric and upright shape; amplitude of 0.2 to 0.3 mV.
PR interval: From the start of the P wave to the beginning of the QRS complex; normal duration is 0.12 to 0.20 seconds.
QRS complex: Represents ventricular depolarization; duration is typically less than 0.12 seconds.
ST segment: Time between ventricular depolarization and repolarization; measures 0.12 seconds or less, starts at the J point.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of the ECG lead system with these flashcards. Each card covers different standard limb leads and their definitions, providing a comprehensive review of Chapter 13 concepts. Perfect for students preparing for exams on ECG interpretation.