AICD/CRT
Automated Implantable Cardioverter Defibrillator (AICD) & Cardiac resynchronization therapy (CRT)
Automated Implantable Cardioverter Defibrillator (AICD)
An implantable cardioverter defibrillator (ICD or AICD) is small device similar to pacemaker implanted under the collar bone with a lead going to the heart to monitor the heart rhythm and treat it as required.
A common cause of sudden cardiac death is ventricular tachycardia and fibrillation where the heart starts beating too fast leading to sudden death. It can be a consequence of acute heart attack or can be seen in patients with some congenital diseases e.g., hypertrophic cardiomyopathy, long QT syndromes etc.
The device monitors the heart rhythm and when it finds that the heart is starting to beat fast it first gives high-rate pacing to correct the rhythm and if not, successful it ultimately gives a shock to the heart which corrects the heart rhythm and sudden death is prevented.

Cardiac resynchronization therapy (CRT)
This is a biventricular pacemaker where we put one lead in the right ventricle and another lead in the back of the left ventricle and pace both the ventricles. Actually, in patients with heart failure and dilated heart, sometimes the ECG indicates that there is gross dyssynchrony between the ventricular contraction. In these cases, CRT helps in getting back the synchrony and that leads to improvement in cardiac function.
