CARDIAC ELECTROPHYSIOLOGY
& PACING
(Cardiology Unit IV) - CMC VELLORE
Treating Abnormal Heart Rhythms
Our therapeutic services are broadly divided into device implants and radiofrequency ablations. The device implants include pacemakers for slow heart rhythms, cardiac resynchronization devices in those with heart failure, and ICDs [Implantable cardioverter defibrillators] in those with life-threatening heart rhythms. The rate of our device implant procedures is the lowest in the country since we give it to our patients at their cost price. Our radiofrequency ablation procedures are performed for patients with fast heart rhythms involving abnormal electric circuits.
PACEMAKER IMPLANTATION
If your heart beats slowly, you will have tiredness and fainting as symptoms. This slow heart rhythm can be due to a problem with electrical impulse formation or impulse conduction in the heart. The treatment involves giving current from a battery called pacemaker which is usually placed in the chest. The pacemaker appropriately senses the intrinsic heart rhythm and delivers electric impulses when there is no intrinsic impulse [own heartbeat].
CARDIAC RESYNCHRONIZATION DEVICE
This device is implanted in if your heart is weak and contracts poorly. You may suffer from breathlessness and fatigue. Poor heart contraction is sometimes due to electric current reaching different parts of the heart muscle at different times. This electrical dyssynchrony results in mechanical dyssynchrony. To help make all parts contract together, we place wires in different parts of the heart, and the current is given by the CRT device. By improving the heart contraction, your symptoms of heart failure will reduce.
IMPLANTABLE CARDIOVERTER DEFIBRILLATOR [ICD] IMPLANTATION
This device is implanted for those who have a high risk of sudden cardiac death. It senses the intrinsic rhythm and detects dangerous heart rhythms like ventricular tachycardia/fibrillation. It initially attempts to terminate the rhythm by pacing the heart faster than the abnormal rhythm (overdrive pacing). However, if that fails the device will deliver a DC shock to terminate the rhythm. If your heart contracts poorly and you have a history of surviving sudden cardiac death, or you have genetic abnormalities that cause abnormal rhythms you will require ICDs.
LEAD EXTRACTION AND DEVICE EXPLANTATION
Sometimes the device and leads that are implanted need to be removed. This happens if there is an infection involving the device or if the leads are old and not functioning properly. Lead extraction and device explantation is a niche area that helps avoid open-heart surgery. The expertise to perform such procedures is available in only a few centers. We have been doing lead extractions since 2003 and are one of the pioneering centers for the same in the country.
RADIOFREQUENCY ABLATION
If you have abnormally fast heart rate[tachyarrhythmias], we will identify the abnormal electrical pathways in the heart and get rid of them using radiofrequency energy. While the majority of arrhythmias are simple some of them are complex. Ablation of the complex arrhythmias is performed using 3D mapping with NavX or Carto systems and irrigated catheters. Individuals with poor ventricular function are ablated with ECMO back up which helps stabilize their BP and maintain cardiac and cerebral perfusion during the procedure. Some of these procedures are performed using Intracardiac ECHO [ICE]. We are one of the first centers in the country to use ICE for ablation procedures.
TRANSESOPHAGEAL PACING
The normal neonate`s heart rate ranges between 100-170 beats/minute. Since their cardiac output is rate dependent, a slow heart rate can lead to serious consequences. In certain slow heart rhythms, transesophageal pacing [TEP] is utilized because of its ease to perform and rapidity in stabilizing the baby. The proximity of the food pipe [esophagus] to the heart [left atrium] is the basis for using esophageal electrodes to deliver electrical stimuli to capture the heart. An electrode is placed in the esophagus through the nostril and the slow heart rate is overcome by pacing at a faster rate. This can help tide over the immediate crisis until a more permanent solution is found. This technique can also be used to study the presence of abnormal electrical circuits in the heart which results in the heart beating at a fast rate. This treatment modality has been available in CMC since 2014 and we are the second center in Asia and first in India to have this facility.
