Teachable moment in classrooms:
- heart chapter – order of contraction of chambers during cardiac cycle
- heart chapter – contraction of cardiac muscle cells are causing the contraction of heart chambers
- heart chapter – structures in the conduction system of the heart
- heart chapter – relationship of the ECG wave forms to contraction of heart chambers
The news item: Recently the following news appeared online:
Family sues Panera Bread after college student who drank Charged Lemonade dies
Panera Bread is facing a lawsuit from the family of 21-year-old University of Pennsylvania student Sarah Katz, who died after drinking a “charged lemonade.”
The article states that a college student age 21 died of cardiac arrest as a consequence of drinking a “Charged lemonade” drink.The drink had 390 mg of caffeine. The article also states that the student has been suffering from long QT syndrome which is caused by a malfunctioning of the heart’s electrical system. The syndrome causes fainting or heart palpitations upon excitement or exercise.
So, Why Do I Care?? Disorders of the heart may not show any symptoms during a sedentary life style. In the US alone there are over 100,000 people who has the long QT syndrome, and 2000-3000 people die a sudden death because of it. Because the symptoms appear mostly during stressful conditions, and therefore remain hidden in many people. If you know you have a heart disorder it is important to use your prescribed medications, and if you have symptoms of heart disorders then it is important to have them evaluated by medical professionals.
Plain English, Please!!!
First, let’s talk about heart rhythms. In order for the heart to move, to pump blood, the chamber must contract in a sequence during a single heartbeat. The atria contract first, and then, after a short delay, the ventricles contract. This proper order of contractions is orchestrated by electric impulses from the heart’s natural internal pacemaker, the conduction system. This conduction system activates the muscle of atria or ventricles just like a band-leader of a marching band directs the use of musical instruments during a parade.
Second, let’s talk about long QT syndrome. The name of the syndrome comes from name of wave forms on electrocardiograms. The Q wave represents the first step in the contraction of the ventricles, and the