Pearls of Knowledge: Ventricular Hypertrophy
Monday, April 07, 2025
12-Lead ECG Interpretation: Ventricular Hypertrophy
Pearls of Knowledge © BrainyNurses.com
The QRS complex represents ventricular depolarization and is measured from the beginning of the QRS complex to the end of the QRS which is the J point.
The QRS is composed of three waveforms with many variations in shape. Normal duration is less than 0.12 seconds. A prolonged QRS complex is known as an intraventricular conduction delay (IVCD). The QRS may be ≥ 0.12 seconds in multiple conditions including ventricular hypertrophy, bundle branch block, Wolff-Parkinson-White, hyperkalemia, tricyclic overdose, and phenothiazine overdose.
The QRS is prolonged in ventricular hypertrophy since the electrical impulse needs more time to get through the thickened myocardium. The hypertrophy will be interpreted on the 12-Lead ECG and will be part of the overread. When using a standard telemetry monitor, ST and T wave changes will be seen due to altered repolarization due to the amount of muscle mass. ST segment depression with down sloping and inverted T waves will be present.
Left Ventricular Hypertrophy
Very tall QRS complexes in Lead V5 and V6 and deep S waves in V1 and V2.
Down sloping and inverted T waves are not present in lead II, III, aVF in this tracing (but often are). However, they are present in V5, and V6.
The left axis deviation is due to the left ventricular hypertrophy.
• Lead I points up and aVF points down. They are pointing “apart” or away from each other.
• Axis Memory Hint: “Right together, Left apart” using Leads I and aVF.
Right Ventricular Hypertrophy
Tall QRS complexes in Lead V1, V2, and V3.
Down sloping and inverted T waves in Lead II, III, aVF, V1, and V2 (and extending through V6 on this tracing).
The right axis deviation is due to the right ventricular hypertrophy.
• Lead I points down and aVF points up. They are pointing “together” or at each other.
• Axis Memory Hint: “Right together, Left apart” using Leads I and aVF.
Summary
A systematic approach to 12-Lead ECG interpretation is essential in detecting changes and applying them to the clinical setting. Changes occur with numerous conditions including acute coronary syndrome, and many other abnormalities including chamber hypertrophy.
To enhance care provided for cardiac patients, check out Clinical Application and Interpretation of the 12-Lead ECG. It is on-line, on-demand, with voice-over-power-point, and a comprehensive review to use at the bedside.
The extensive handout is easy to follow and includes a composite reference sheet to use in the session and post on the clinical unit afterwards. In addition, “In My Pocket” cards are included as a ready reference tool.
