Partially Occluded Artery Worksheets

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Chris Anderson
MD · Clinical Education Director, Pediatrics
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Headshot of Kevin Hodges, Vice Chair, Emergency Medicine
Kevin Hodges
Vice Chair, Emergency Medicine
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Table of Contents

Intro paragraph? These worksheets are for self-study only. Answers will not be evaluated.

  1. Complete basic measurements.
  2. Do all previous work.
  3. Note if inverted T waves or ST segment depression is present in two or more leads that represent a pattern in Table 13.2. Here the ST segments are diffusely abnormal.
  4. Provide an interpretation.

 

 

Clinically-Based Critical Thinking: Interpretation

ST segment depression is consistent with ischemia or infarction. On a single EKG, the First Rule of the T Wave applies. The ST depression may represent infarction, which may be new or old. It may also represent ischemia. More information is needed. Is the patient symptomatic? Is there an old EKG available? If so, are these ST changes new?

Worksheet 13.1

Complete the basic measurements, evaluation, and interpretation for the EKG below.

Parameter Measurement Interpretation
HR    
Rhythm    
PR    
QRS    
QT    
QTc    
P direction    
QRS direction    
Abnormal parameter If present, note the leads or location
Inverted T waves  
ST depression  
ST elevation  
Q waves or equivalents  

HR 79, sinus rhythm. The PR is 0.16 to 0.18. The QRS is 0.08, normal. The QT is 0.40. QTc is 0.460 which is high. The T waves are abnormal and point away from the septum (V1 and V2), and anterior (V3) walls. Since this is the only EKG, the First Rule of the T Wave applies. There is ischemic heart disease, but it may be ischemia or infarction, and new or old. Said another way, clinically there may be an old NSTEMI, a new NSTEMI, or unstable angina. More information is needed.

Worksheet 13.2

Complete the basic measurements, evaluation, and interpretation for the EKG below.

Parameter Measurement Interpretation
HR    
Rhythm    
PR    
QRS    
QT    
QTc    
P direction    
QRS direction    
Abnormal parameter If present, note the leads or location
Inverted T waves  
ST depression  
ST elevation  
Q waves or equivalents  

HR 77. Rhythm sinus. PR is normal. QRS is 0.10 and ends rightward indicating RIVCD. The P direction is normal. The overall QRS direction is normal. The T direction is abnormal, and points away from the inferior wall since it is negative or inverted in leads II, III, and AVF. Since this is the only EKG available, the first rule of the T wave applies. This may represent an old MI, a new MI, or unstable angina.

Worksheet 13.3

Complete the basic measurements, evaluation and interpretation for the EKG below.

Parameter Measurement Interpretation
HR    
Rhythm    
PR    
QRS    
QT    
QTc    
P direction    
QRS direction    
Abnormal parameter If present, note the leads or location
Inverted T waves  
ST depression  
ST elevation  
Q waves or equivalents  

HR 65, sinus rhythm. PR is normal. The QRS interval is normal. The P and QRS directions are normal. The T direction is abnormal and points away from the septum (V1 and V2) and anterior (V3 and V4) consistent with ischemia or infarction. This may represent an old or new event. (First Rule of the T Waves) Less commonly, inverted T waves in leads V1–V3 can be pointing away from the free wall of the right ventricle as might occur in pulmonary hypertension and acute pulmonary embolism.