EKG Flashcards
What are the types of leads in a 12 Lead EKG?
10 leads: 4 Limb, 6 Chest
The 12 Lead EKG includes limb leads (I, II, III, aVF, aVL, aVR) and chest leads (V1 to V6).
What does the P-wave represent in an ECG?
Atrial contraction
What does the PR interval represent?
Time taken for excitation to spread from the SA node across the atrium and down to the ventricular muscle via the bundle of His.
What does the QRS complex indicate?
Ventricular contraction
What does the ST segment represent?
Ventricular relaxation
What does the T-wave signify?
Ventricular repolarization
What patient details are essential for reading an ECG?
Patient’s name, date of birth, hospital number, location
What situation details should be noted when interpreting an ECG?
Time of ECG, ECG series number, chest pain presence, other relevant clinical details
How is the heart rate calculated on an ECG?
Count the number of QRSs on one line and multiply by six or count large squares between R waves and divide 300 by this number.
Is the rhythm regular or irregular? How can this be assessed?
Use the ‘paper test’ to assess rhythm regularity.
What does the axis on an ECG represent?
The sum of all the electrical activity in the heart.
What indicates a normal axis on an ECG?
Net deflections in leads I and aVF are positive.
What conditions can cause left axis deviation?
- Left ventricular hypertrophy (LVH) * Left anterior hemiblock * Inferior myocardial infarction * Hyperkalemia * Ventricular tachycardia (VT) * Paced rhythm
What conditions can cause right axis deviation?
- Right ventricular hypertrophy (RVH) * Pulmonary embolism (PE) * Anterolateral myocardial infarction * Left posterior hemiblock * Septal defect
What signifies the presence of a P-wave in an ECG?
If present, it indicates normal atrial activity; absence may indicate atrial fibrillation or flutter.
What is a q-wave in the context of an ECG?
An initial downward deflection in the QRS complex.
What is the normal duration of a QRS complex?
< 0.12 secs (3 small squares)
What can cause a wide QRS complex?
- Bundle branch blocks (LBBB or RBBB) * Hyperkalemia * Paced rhythm * Ventricular pre-excitation * Ventricular rhythm * TCA poisoning
What is the significance of the ST segment in an ECG?
Indicates myocardial ischemia or infarction.
What is considered significant ST segment elevation?
Elevation of 1 or more millimeters in 2 consecutive limb leads or 2 or more millimeters in 2 consecutive chest leads.
What is high-takeoff in an ECG?
A mimic of ST elevation, characterized by widespread concave ST elevation.
What does the QT interval measure?
The time between the start of the q-wave and the end of the t-wave.
What are some causes of a prolonged QT interval?
- Drugs (e.g., TCAs, Erythromycin) * Metabolic issues (e.g., hypokalemia) * Familial conditions (e.g., Long QT syndrome) * Other (e.g., myocarditis)
What changes might be seen in the T-wave for hyperkalemia?
Peaked T waves.
