Cardiac electronic devices are an integral part of contemporary cardiac care and have evolved remarkably. Such devices comprise of a pulse generator implanted in the chest under the collar bone which is connected to leads that are positioned in the appropriate cardiac chambers via a vein. The procedure is usually performed under local anaesthesia.
Pacemakers demystified
A Pacemaker, is implanted in patients with symptoms due to abnormally slow heart rates. Our heart rate/rhythm is normally controlled by an intrinsic natural conduction system. It’s a very sophisticated electrical circuit and failure of any of its components results in bradycardia or slowing of heart rate. Symptoms of bradycardia range from exertional fatigue or shortness of breath to even cardiac arrest. There are different types of pacemakers, the choice of which depends on the site of slowing in the heart and the underlying cardiac function. The recent inception of conduction system pacing is a paradigm leap in the field. It delivers the requisite cardiac pacing without the adverse effects of the conventional pacemakers like pacing induced heart failure or cardiomyopathy. This is achieved by precisely stimulating the intrinsic cardiac conduction system unlike the older devices. Conduction system pacing is being performed by trained Electrophysiologists in select centers.
Who needs an ICD?
An ICD is implanted in a patient who has survived a Sudden Cardiac Arrest (SCA) or is at risk of one. SCA is the result of a malignant rhythm abnormality called ventricular tachycardia. Patients with prior heart attacks or cardiac muscle dysfunction are vulnerable to SCA. ICD functions like a watchdog, constantly monitoring the cardiac rhythm and intervening when necessary. It terminates threatening or fatal arrhythmias by timely interventions when needed.
Is CRT the right device for you?
Some patients with severe heart failure are eligible for Cardiac Resynchronization Therapy (CRT). Well-selected patients show a notable improvement in exercise capacity and cardiac function in few weeks to months after implantation. CRT-D is a combination of CRT and ICD and combines the benefits of both the devices. Conduction system pacing as mentioned earlier has significantly improved and added value to cardiac resynchronisation therapy in recent times by delivering better results and is poised to evolve further.
All patients with cardiac devices are advised biannual checks. The pulse generator or battery is usually replaced every 8 to 14 years with a minor procedure. When the right device is used in the right patient, they have immeasurable impact on patients’ quality of life.