To correct abnormal heart rhythms (arrhythmias) and help your heart beat more efficiently, your doctor may recommend a device implant. The most common device implants are pacemakers and implantable cardioverter/defibrillators (ICDs). These devices are usually implanted in the cardiac cath lab, but may also be implanted during surgery.
Pacemakers: A pacemaker is a small implanted device that corrects heart rhythms that are too slow or are out of synch. This device mimics the action of your heart's natural pacemaker - the cluster of cells that creates an electrical impulse to make the heart beat. A pacemaker generally has two parts: a pulse generator (the battery and electrical circuitry that creates and regulates the electrical pulses) and one to three leads (small wires that send the electrical pulses to your heart). After the pacemaker is implanted, it monitors factors such as your blood temperature and breathing, and supplies the electrical pulses needed to adjust your heart rate to your body's needs.
Implantable Cardioverter/Defibrillators (ICDs): ICDs are usually used to prevent or treat dangerously fast or chaotic arrhythmias called ventricular tachycardia (v-tach) or ventricular fibrillation (v-fib). Here's how they work:
- If the heart begins to beat abnormally fast, the ICD sends a low-energy electrical impulse (shock) to the heart at the same time as the regular heartbeat.
- If the heart is beating dangerously fast or chaotically, the ICD sends a high-energy shock to the heart muscle to restore a normal rhythm.
A biventricular ICD helps coordinate the pumping action of the heart. Heart failure can sometimes distort the timing of the ventricles (the lower chambers of the heart) so they don't pump in unison. While a regular pacemaker sends an electrical signal to just the right ventricle, a biventricular ICD sends a signal to both ventricles to prompt them to pump at the same time. This helps the heart beat more efficiently and can improve heart failure symptoms.