Defibrillator Procedures

An implantable cardioverter defibrillator (ICD) is a small device that's placed in the chest or abdomen. Doctors use the device to help treat irregular heartbeats called arrhythmias (ah-RITH-me-ahs).

An ICD uses electrical pulses or shocks to help control life-threatening arrhythmias, especially those that can cause sudden cardiac arrest (SCA).

SCA is a condition in which the heart suddenly stops beating. If the heart stops beating, blood stops flowing to the brain and other vital organs. SCA usually causes death if it's not treated within minutes.

A problem with any part of the heart's electrical system can cause an arrhythmia. Most arrhythmias are harmless, but some can be serious.

ICDs use electrical pulses or shocks to treat life-threatening arrhythmias that occur in the ventricles (the heart's lower chambers).

When ventricular arrhythmias occur, the heart can't pump blood well. You can pass out within seconds and die within minutes if not treated.

To prevent death, the arrhythmia must be treated right away with an electric shock to the heart. This treatment is called defibrillation (de-fib-ri-LA-shun).

An ICD has wires with electrodes on the ends that connect to your heart chambers. The ICD will monitor your heart rhythm. If the device detects an irregular rhythm in your ventricles, it will use low-energy electrical pulses to restore a normal rhythm.

If the low-energy pulses don't restore your normal heart rhythm, the ICD will switch to high-energy pulses for defibrillation. The device also will switch to high-energy pulses if your ventricles start to quiver rather than contract strongly. The high-energy pulses last only a fraction of a second, but they can be painful.

If you have additional questions, please review our FAQ page.

Biventricular pacemaker is a special pacemaker, which is used to synchronize the contractions of the left ventricle with the right ventricle, to improve the ejection fraction in patients with severe and moderately severe symptoms of heart failure.

Ejection fraction is a measure of blood that is pumped out by the left ventricle of the heart and is expressed in percentage. A normal ejection fraction usually lies between 50% and 70%. A patient with heart failure has a low ejection fraction, hampering the blood supply to various parts of the body, and leads to symptoms of heart failure, that include shortness of breath, dry cough, swelling of the ankles and legs, weight gain, increased urination, fatigue and rapid or irregular heartbeat.

Biventricular implantation is considered in heart failure patients with:

  • Severe or moderately severe heart failure symptoms.
  • Delayed electrical activation of the heart.
  • Either a risk or history of cardiac arrest.
  • On long-term medications for heart failure
Similar to a standard pacemaker, a biventricular pacemaker can be implanted either by an endocardial (transvenous) approach or an epicardial approach. A biventricular pacemaker usually has three leads: one is guided to the right ventricle, one to the left ventricle and the third (which is not always present) is guided to the right atrium. The lead in the left ventricle is guided through the coronary sinus.

When the heart rate drops below the rate set with the pacemaker, it senses the drop and transmits electrical impulses to the left as well as the right ventricle to contract simultaneously, improving the ejection fraction and the cardiac function. The lead placed in the right atrium helps the heart to function in a more balanced way.Biventricular pacemaker implantation is also called cardiac synchronization therapy and is only a part of any comprehensive heart failure management program. Medications, life style changes and regular follow up with a cardiac specialist are all crucial for managing the symptoms and improving the quality of life in heart failure patients.

If you have additional questions, please review our FAQ page.

When a patient has an implantable cardioverter-defibrillator (ICD), they may have a change in their health or medications that can potentially interfere with how the device works. If your physician needs to evaluate to make sure that your ICD is functioning properly to stop a life-threatening arrhythmia, he or she will schedule you for a NIPS. Similar to a cardioversion, a NIPS is a brief procedure where your heart is stimulated into a rapid heart rate and your ICD delivers a shock or rapid pacing sequence to restore a normal rhythm. Your physician can then adjust the ICD's programming, if needed. You will be under anesthesia for the testing and able to go home a few hours later.