Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android


In this section you will find twenty-five, 12-lead electrocardiograms for you to interpret. The clinical history is presented above each tracing. Apply the method of interpretation you learned in Chapter 24 and the criteria found in Chapter 25. Use the concept of structured reporting to measure, identify, and then synthesize the findings into a comprehensive interpretation. Include all of the items from the list below in your report.

Technical quality:


Atrial rate:

Ventricular rate:

PR interval:

QRS duration:

QT interval:




ECG #1

ECG #1 Interpretation

Technical quality: Satisfactory

Rhythm: Sinus

Atrial rate: 79 bpm

Ventricular rate: 79 bpm

PR interval: 0.14 seconds

QRS duration: 0.08 seconds

QT interval: 0.38 seconds

Axis: −75 degrees

Abnormalities: Axis leftward of −30 degrees. Abnormal P terminal force, lead V1. R wave voltage in leads V1-V3 <3 mm.

Synthesis: Sinus rhythm. Left axis deviation. Left atrial abnormality. Left anterior fascicular block. Poor R wave progression.

Comment: Marked left axis deviation is present indicative of left anterior fascicular block. Poor R wave progression is commonly seen in left anterior fascicular block as the loss of anterior forces in the horizontal plane reduces R wave voltage in leads V1-V3. Left atrial abnormality is present with abnormal P terminal force in lead V1. The notched P waves in leads II, III, and aVF support this diagnosis.

ECG #2

ECG #2 Interpretation

Technical quality: Satisfactory

Rhythm: Sinus

Atrial rate: 69 bpm

Ventricular rate: 69 bpm

PR interval: 0.20 seconds

QRS duration: 0.16 seconds

QT interval: 0.40 seconds

Axis: −15 degrees

Abnormalities: Prolonged QRS complex duration. Wide, notched QRS complex associated with ST segment depression and T wave inversion in leads I, aVL, V5-V6.

Synthesis: Sinus rhythm. Left bundle branch block with secondary ST segment and T wave abnormalities.

Comment: Left bundle branch block is frequently a marker for significant myocardial disease, left ventricular systolic dysfunction, and congestive heart failure.

ECG #3

ECG #3 Interpretation

Technical quality: Satisfactory


Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.