Abnormal Heart Rhythm (Arrhythmia)
What Is Electrical Cardioversion?
If drugs are not able to control a persistent irregular heart rhythm (such as atrial fibrillation), cardioversion may be required. After administration of a short-acting anesthesia, an electrical shock is delivered to your chest wall that synchronizes the heart and allows the normal rhythm to restart.
What Is a Pacemaker?
A pacemaker is a device that sends small electrical impulses to the heart muscle to maintain a suitable heart rate. Pacemakers primarily prevent the heart from beating too slowly. The pacemaker has a pulse generator (which houses the battery and a tiny computer) and leads (wires) that send impulses from the pulse generator to the heart muscle. Newer pacemakers have many sophisticated features that are designed to help manage arrhythmias and optimize heart rate-related function as much as possible.
What Is an Implantable Cardioverter Defibrillator (ICD)?
An ICD is a sophisticated device used primarily to treat ventricular tachycardia and ventricular fibrillation, two life-threatening heart rhythms. The ICD constantly monitors the heart rhythm. When it detects a very fast, abnormal heart rhythm, it delivers energy to the heart muscle to cause the heart to beat in a normal rhythm again. There are several ways the ICD can be used to restore normal heart rhythm. They include:
- Anti-tachycardia pacing (ATP). When the heart beats too fast, a series of small electrical impulses may be delivered to the heart muscle to restore a normal heart rate and rhythm.
- Cardioversion. A low energy shock may be delivered at the same time as the heart beats to restore normal heart rhythm.
- Defibrillation. When the heart is beating dangerously fast or irregularly, a higher energy shock may be delivered to the heart muscle to restore a normal rhythm.
- Anti-bradycardia pacing. Many ICDs provide back-up pacing to maintain heart rhythm if it slows too much.
- Bradyarrhythmias. These are slow heart rhythms, which may arise from disease in the heart’s electrical conduction system. Examples include sinus node dysfunction and heart block.
- Sinus node dysfunction. A slow heart rhythm due to an abnormal SA (sinus) node. Significant sinus node dysfunction that causes symptoms is treated with a pacemaker.
- Heart block. A delay or complete block of the electrical impulse as it travels from the sinus node to the ventricles. The level of the block or delay may occur in the AV node or HIS-Purkinje system. The heart may beat irregularly and, often, more slowly. If serious, heart block is treated with a pacemaker.
What Is Catheter Ablation?
During an ablation, high-frequency electrical energy is delivered through a catheter to a small area of tissue inside the heart that causes the abnormal heart rhythm. This energy “disconnects” the pathway of the abnormal rhythm. Ablation is used to treat most PSVTs, atrial flutter, atrial fibrillation, and some atrial and ventricular tachycardias. Ablation may be combined with other procedures to achieve optimal treatment.
What Is Heart Surgery?
Heart surgery may be needed to correct heart disease that may be causing the arrhythmia. The Maze procedure is a type of surgery used to correct atrial fibrillation. During this procedure, a series (or “maze”) of incisions are made in the right and left atria to confine the electrical impulses to defined pathways. Some people may require a pacemaker after this procedure.
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