The heartbeat is controlled by the electrical system of the heart. This system is made of several parts that tell the muscle of the heart when to contract. The SA node starts the heartbeat causing the atria, or upper chambers of the heart, to contract. The signal then travels through the AV node, the Bundle of His, Bundle Branches, and Purkinje fibers. This causes the ventricles, the lower chambers of the heart, to contract. The flow of electrical signals produces a normal heartbeat. Normal heartbeats can be seen on an electrocardiogram, or ECG.
In sinus tachycardia, the SA node fires rapidly, causing an rapid heartbeat. Fast heartbeats can be seen on an Electrocardiogram or ECG. Sinus tachycardia is the normal response to exercise or anxiety.
©2018 Medmovie.com. All rights reserved. Medmovie.com creates and licenses medical illustrations and animations for educational use. Our goal is to increase your understanding of medical terminology and help communication between patients, caregiver and healthcare professionals. The content in the Media Library is for your information and education purposes only. The Media Library is not a substitute for professional medical advice, diagnosis or treatment for specific medical conditions.