Mitral valve stenosis, mitral valve regurgitation, and arrhythmia
A complication of mitral valve stenosis or mitral valve regurgitation (MR) is an irregular heartbeat (arrhythmia).
This irregular heartbeat is created by a disruption in a web of nerves covering the surface of the heart. These nerves send electrical signals that cause your heart to contract and pump blood out of the heart.
This web of nerves is controlled by a collection of cells on the right atrium called the sinoatrial node. As it fires, so do the rest of the nerves, causing all of the muscle cells in your heart to contract, producing one forceful pump.
As mitral valve stenosis or MR stretches out your heart, it too can disrupt this web of nerves. Communication pathways may weaken because the sinoatrial node is no longer working correctly. Without clear signals from this node, the nerves begin to fire randomly, creating a chaotic network of electrical signals. When this happens, the heart is no longer able to pump with one motion, and instead it starts beating irregularly (arrhythmia).
Atrial fibrillation is the most common arrhythmia that stems from mitral valve stenosis and MR. Since the atria are the top two chambers of the heart, atrial fibrillation refers to an irregular contraction and relaxation of these chambers. Atrial fibrillation can happen constantly and unpredictably. Although it can be a minor annoyance, it is often a serious condition and should be treated.
Because the heart does not pump uniformly and smoothly in atrial fibrillation, blood pools, allowing clots to form in the atrial chambers of the heart. If one of these clots detaches and travels to the brain, it may block the flow of blood, causing a stroke. Deprived of oxygen, these nerve cells cannot function and likely will die within minutes. The body parts and functions controlled by the affected nerves will be severely impaired as a result. Because it is not possible to replace dead brain cells, the effects of stroke are often permanent.
Most individuals with atrial fibrillation will need medicine on a regular basis either to control the continuing arrhythmia or to prevent recurrence. Three types of medicines can be used (and are often combined) to prevent and treat the arrhythmia:
- Medicines to slow the heart rate, such as digoxin, beta-blockers, or calcium channel blockers. These medicines suppress the flow of electrical impulses through the AV node and slow down the rate of ventricular contractions.
- Medicines to help return the heart to its normal rhythm, such as quinidine, propafenone, sotalol, and amiodarone. These medicines also can be used to maintain the heart's normal rhythm after it has been achieved and/or to reduce the heart rate while you are in atrial fibrillation.
- Medicines to thin the blood (anticoagulants), such as warfarin and aspirin. These medicines are designed to reduce any blood clot formation and chances of stroke.
For more information, see the topic Atrial Fibrillation.
| Author: | Robin Parks, MS | Last Updated: March 27, 2008 |
| Medical Review: | E. Gregory Thompson, MD - Internal Medicine Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology | |
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