Basic EKG Flashcards
How many leads are included in a 12 lead EKG?
10 leads: 4 Limb and 6 Chest leads
What does the V1, V2 leads represent on an ECG?
Right ventricle (RV)
What does the V3, V4 leads represent on an ECG?
Septum
What does the V5, V6 leads represent on an ECG?
Left side of the heart
What does the PR interval represent?
Time taken for excitation to spread from the SA node to the ventricular muscle
What does the QRS complex indicate?
Ventricular contraction
What is indicated by the ST segment?
Ventricular relaxation
What does the T-wave represent?
Ventricular repolarization
What patient details are important when reading an ECG?
Patient’s name, date of birth, hospital number, and location
What situation details should be noted when interpreting an ECG?
Time of ECG, number of ECG in series, presence of chest pain
How can the rate on an ECG be calculated?
Count QRSs on one line and multiply by six or count large squares between R waves and divide 300 by this number
What are the characteristics to assess in an ECG rhythm?
Regularity, irregularity, and whether it is regularly or irregularly irregular
What defines the axis in an ECG?
The sum of all the electrical activity in the heart
What is the normal axis orientation in an ECG?
Normal axis lies to the left
What indicates right axis deviation in an ECG?
Lead I has a net negative deflection while aVF is positive
What can cause left axis deviation?
- Left ventricular hypertrophy (LVH) * Left anterior hemiblock * Inferior myocardial infarction * Hyperkalemia * Ventricular tachycardia (VT) * Paced rhythm
What can cause right axis deviation?
- Right ventricular hypertrophy (RVH) * Pulmonary embolism (PE) * Anterolateral myocardial infarction * Left posterior hemiblock * Septal defect
What is a characteristic of p-waves in atrial fibrillation?
P-waves may not be visible
What does a notched p-wave indicate?
Left atrial hypertrophy, often caused by mitral stenosis
What is the normal duration of the QRS complex?
< 0.12 seconds
What causes a wide QRS complex?
- Bundle branch blocks (LBBB or RBBB) * Hyperkalemia * Paced rhythm * Ventricular pre-excitation * Ventricular rhythm * TCA poisoning
What indicates ST segment elevation?
Infarction
What indicates ST segment depression?
Ischemia
What is high-takeoff in an ECG?
Benign early repolarization characterized by widespread concave ST elevation
What is the QT interval?
Time between the start of the q-wave and the end of the t-wave
What can cause a long QT interval?
- Drugs * Metabolic issues * Familial conditions * Other health issues
What are classic changes in hyperkalemia?
- Small p-wave * Tall, tented (peaked) t-wave * Wide QRS
What can cause flattened or inverted T-waves?
- Normal variant * Ischemia * Ventricular hypertrophy * LBBB * Digoxin * Hypokalemia
What is the significance of a tall QRS complex?
Suggestive of left ventricular hypertrophy (LVH)
What is the criteria for LVH on an ECG?
Height of R wave in V6 + depth of S wave in V1 > 35mm
What indicates a complete heart block?
P-waves not associated with QRS complexes
