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I Heart Running: A Case Study on Tachycardia in Sam the Runner


James A. Carr
Department of Biological Sciences
Texas Tech University
Breanna N. Harris
Biological Sciences
Texas Tech University


"I Heart Running" is a case study in which students diagnose the cause of exercise-induced tachycardia in an otherwise healthy, 27-year-old female. The patient, Sam, is a long-distance runner and realizes that her exercising heart rate reaches over 200 beats per minute. As the story of Sam's encounters with her physician develops, students are given results from multiple laboratory tests and detailed patient background information.  Students are guided through the material with a series of questions with the ultimate goal of determining the cause of the exercise-induced tachycardia that Sam experiences. The case study is based on actual laboratory results and was designed for students in an upper-level undergraduate Human Physiology course. In this activity students will learn about heart rate, cardiovascular physiology, and oxygen carrying capacity, and factors which influence these concepts, as they try to diagnose Sam.


  • Explain how maximum heart rate is calculated, and understand how properties of cardiac muscles and the autonomic nervous system influence heart rate.
  • Understand the physiological control of heart rate and the associated changes that occur during exercise.
  • Understand the importance of oxygen carrying capacity in endurance activity
  • Compare and contrast patient symptoms to those which occur in specific diseases/disorders associated with tachycardia.
  • Understand, explain and interpret data from a complete blood count, fasting lipid panel, iron panel, metabolic panel, pregnancy test, thyroid function test, B12 and folate test, urinalysis, Bruce Protocol stress test, and echocardiogram.


Tachycardia; heart rate; ECG; Electrocardiogram; exercise; cardiovascular; running; cardiac myocyte; SA node; anemia; cardiac output; Bruce Protocol

Topical Areas


Educational Level

Undergraduate lower division



Type / Methods

Analysis (Issues), Directed, Interrupted



Subject Headings

Anatomy  |   Biology (General)  |   Nursing  |   Physiology  |   Sports Science  |  

Date Posted


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The following video(s) are recommended for use in association with this case study.

  • Echocardiogram hhmi/
    This video clip provides a live demonstration of an echocardiogram, with a description of the parts of the heart that are visualized. Running time: 4:45 min. Produced by HHMI BioInteractive.


Jon Darkow
Seneca East High School
I made this computer model to help my students understand Question 3 of Part I on the refractory period of cardiac myocytes: