Does the heart have two natural pacemakers?
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Discovery Health answered:The heart actually has two natural pacemakers. The sinoatrial node (SA node) is the primary pacemaker and the atrioventricular node (AV node) is the secondary. The AV node is in a bundle of tissues on the border that separates the right atrium and the right ventricle.
When the SA node sends out an electrical impulse, it goes straight to the AV node. The SA node sets the rhythm of your pulse. The AV node sets the rhythm of your heart contractions.
The AV node delays the electrical signal on its way to the ventricle, which gives the atrium time to contract first. The delay lasts for about a tenth of a second. If the ventricle and atrium were to contract at the same time, the ventricle would push out their blood before they were full, which would result in low blood pressure and other problems.
The heart actually has two natural pacemakers. The sinoatrial node (SA node) is the primary pacemaker and the atrioventricular node (AV node) is the secondary. The AV node is in a bundle of tissues on the border that separates the right atrium and... More -
Dr. Rex A. Outtrim of Intermountain Healthcare answered:The entire heart muscle has the ability to conduct electricity. The sinoatrial (SA) node acts as the primary "pacemaker" of the heart. It sends signals from the top chambers to the bottom chambers throughout a persons lifetime. The usual heartrate is 60-100 bpm with normal activities. The atrioventricular node (AV) acts as a governor for the signals coming from the top chambers and it conveys these signals down to the appropiate bottom chambers (ventricles). Sometimes the primary pacemaker (SA node), becomes too slow and the AV node may have to take over the rhythm. This is known as sick sinus syndrome, and depending on the circumstances, may require an artificial pacemaker. So in summary, yes, there are two natural pacemakers the SA node and the AV node. Normally they work together throughout a persons lifetime for optimal heart funtion.The entire heart muscle has the ability to conduct electricity. The sinoatrial (SA) node acts as the primary "pacemaker" of the heart. It sends signals from the top chambers to the bottom chambers throughout a persons lifetime. The usual... More
