As Anatomy & Physiology professors, many things we like to be able to demonstrate to our students are the physiological parameters that make the human body function in a “normal” capacity. This is an easy thing to do when we hook our students up to the iWorx data recording systems and record their ECG, respiration, EMG or other parameters. What becomes difficult is the explanation of what data look like when there is something physiologically wrong with an individual.
It is definitely not a usual occurrence that we are able to record when someone is in cardiac arrest, nor would we want this to be happening in our labs. However, for many students, this is an important part of learning about normal vs. abnormal cardiac rhythms. iWorx introduces both known and unknown simulated and actual patient ECG files that include a variety of cardiac rhythms: normal sinus rhythms in adults and infants as well as many different arrhythmias. These include atrial fibrillation, toursade, bundle branch blocks and many others.
Normal sinus rhythm shows a definite pattern of the P wave, QRS complex, and T wave. Within that pattern, there are normal amplitudes generated for each wave form as well as the time interval for each section of the cardiac cycle. In cardiac arrhythmias, the wave forms generated show the inconsistencies between the normal rhythm and the particular arrhythmia being shown. As an example, in atrial fibrillation there is a “quivering” of the upper chambers of the heart, rather than a distinct P wave, the data show a very fast, chaotic rhythm in the atria. This occurs because the electrical impulses from the sinoatrial (SA) node are so chaotic, the atria cannot contract and/or squeeze blood effectively into the ventricle.
In this lab exercise, students will be able to record and analyze resting ECGs from themselves and other students. Students can then use the ECG files simulate the recording of a variety of different arrhythmias. Analysis of each cardiac rhythm will allow students to gain an understanding of the physiological parameters associated with normal sinus rhythm and cardiac anomalies. Students can also generate recordings from real patient data and do a “scavenger hunt” to gather and identify as many abnormalities as possible.
Physiology in Action
Overview of Abnormal Heart Rhythms – Merck Manual explanation of different cardiac rhythms
Electrocardiogram – Explanations of multiple cardiac rhythms
