Cardiac Arrhythmias: Implantable cardioverter-defibrillators (ICDs)

• this is like a pacemaker, and now every ICD has a pacemaker, too

• but in addition to pacemaking, ICDs also are able to shock the heart in tachycardia or fibrillation

• indications

  • primary

    • congenital predisposition to VT or VF (e.g. long QT syndrome)

    • patients with severe LV dysfunction, as in from heart attack—EF less than 30 or 35%

  • secondary: patients that survive a VT or VF event and do not have reversible predisposing condition

Implanting an ICD

• make incision right under clavicle and put in the pulse generator

• then, poke a lead into the vein and steer it into the heart wall

• with almost every pacemaker, there are leads in the atria and the ventricles so both atria and ventricles can be controlled

• ICD leads have coils that can deliver 35 J inside the heart to defibrillate the heart

Category: Cardiology Notes