Electrocardiogram (EKG/ECG) Quick Reference

These flashcards cover key concepts regarding electrocardiograms, their interpretations, and related cardiac conditions.

Electrocardiogram (EKG/ECG)

A test that records the electrical activity of the heart over a period of time.

Sinus bradycardia

A heart rate that is less than 60 beats per minute with normal P-waves.

Sinus tachycardia

A heart rate that exceeds 100 beats per minute with normal P-waves.

Atrial fibrillation

An irregular heart rhythm characterized by the absence of discernible P-waves.

PR interval

The time period between the onset of atrial depolarization and ventricular depolarization.

QRS complex

The electrical impulse that triggers ventricular depolarization.

ST segment

The flat section of the EKG between the end of the QRS complex and the beginning of the T-wave.

Ventricular tachycardia

A fast heart rate originating from the ventricles, typically greater than 100 beats per minute.

Myocardial Infarction (NSTEMI)

Non-ST elevation myocardial infarction characterized by T-wave inversions and ST segment depression.

ST elevation Myocardial Infarction (STEMI)

A type of heart attack caused by a prolonged blockage of blood supply; characterized by ST segment elevation.

Wellens’ Syndrome

Characteristic T-wave changes on an EKG indicative of critical stenosis of the left anterior descending artery.

Brugada Syndrome

A genetic condition that results in a specific EKG pattern and increases the risk of sudden cardiac death.

Hypertrophic cardiomyopathy

A condition where the heart muscle becomes abnormally thick, often affecting the heart's ability to pump blood.

Atrial flutter

An abnormal heart rhythm that results in a rapid heart rate, featuring a saw-toothed pattern of P-waves.

3rd degree heart block

A condition in which the electrical signals from the atria do not reach the ventricles, requiring a pacemaker.

Where are the leads for V1 and V2 placed?

V1 is placed to the right of the sternal border, and V2 is situated to the left of the sternal edge.

How do you determine where lead V4 is placed?

V4 is placed at the level of the fifth intercostal space in the mid-clavicular line. V4 should be placed before V3.

How do you determine where lead V3 should be placed?

V3 is placed between V2 and V4.

How do you determine where lead V6 is placed?

V6 is placed at the level of the fifth intercostal space in the mid-axillary line.

How do you determine where lead V5 is placed?

V5 is placed directly between V4 and V6.

How soon after arrival should a patient with acute chest pain have an EKG completed?

Within 10 minutes

When should you absolutely obtain an EKG?

Chest pain, palpitations, altered mental status, intoxication/poisoning, shortness of breath, dizziness, lightheadedness

Which leads represent the septal area

V1-V2

Which leads represent the anterior area?

V3-V4

Which leads represent with lateral area?

I, aVL, V5-V6

Which leads represent the inferior area?

II, III, aVF

What 2 leads should you look at to determine if the axis is normal?

I and aVF

What are “contiguous leads”?

Leads that are anatomically adjacent and provide overlapping views of the heart's electrical activity, such as V1-V2, V2-V3, and V4-V5, or similar anatomic area, such as II, III, and aVF for the inferior area of the heart. They help in diagnosing conditions affecting specific areas of the heart.

How can you differentiate SVT vs A fib or A flutter?

SVT typically presents with a narrow QRS complex and a regular rhythm, while atrial fibrillation (A fib) shows an irregularly irregular rhythm with no distinct P waves, and atrial flutter presents with a characteristic 'sawtooth' pattern of P waves. SVT can be >150 beats per minute, A fib and flutter are generally less than 150 beats per minute.

How is a STEMI diagnosed?

A STEMI (ST-Elevation Myocardial Infarction) is diagnosed through an ECG displaying new ST elevation in two or more contiguous leads, alongside clinical symptoms such as chest pain and elevated cardiac biomarkers. This elevation is typically defined as 2mm in males and 1.5mm in females in leads V2 and V3, all other leads as 1 mm.

What are the typical findings in pericarditis?

Typical findings in pericarditis include sharp, pleuritic chest pain that worsens with inspiration or lying flat, a pericardial friction rub upon auscultation, and ECG changes such as widespread ST elevation or PR segment depression.

Why does a right bundle branch block have a Rsr’ pattern?

A right bundle branch block (RBBB) produces an Rsr' pattern on the ECG due to delayed conduction through the right bundle branch, resulting in an initial R wave, followed by an S wave, and a subsequent R' wave as the right ventricle depolarizes later than the left ventricle.

What are typical EKG findings in hypertrophic cardiomyopathy?

Typical EKG findings in hypertrophic cardiomyopathy include left ventricular hypertrophy patterns, deep Q waves in the inferior leads, and possible repolarization abnormalities such as ST segment flattening or T wave inversions.