P waves show that the top of the heart received electrical activity.
QRS waves reflect the electrical activity that causes the heart to contract. The information provided herein should not be used for diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Inc. Any duplication or distribution of the information contained herein is strictly prohibited. We subscribe to the HONcode principles of the Health On the Net Foundation By using this service, you accept our Terms of Use .