AICD Implantation
An implantable cardioverter defibrillator (ICD or AICD) is a device that inserts a lead (wire) into the left ventricle and monitors the heart's rhythm.
It is implanted in the same manner as a single chamber pacemaker. The generator is located in the upper part of the chest, with venous access through the Subclavian vein. Therapies are delivered via anti-tachycardia pacemakers (ATP) and shocks that induce sinus rhythm after prolonged ventricular tachycardia or ventricular fibrillation, both of which are life-threatening conditions.
In order to prevent sudden heart death ICDs can be used:
ICDs can prevent sudden cardiac death in patients with a previous myocardial infarction and a left ventricular ejection percentage of less than 30%. The MI must have occurred at least 40 days prior to the event to allow for recovery of LV systolic function
Patients with systolic heart failure (New York Heart Association, functional classes II or III) and an ejection fraction less than 35%. The best medical treatment is required, and at least three months have passed if systolic function returns to an ejection percentage greater than 35% for patients with non-ischemic cardiomyopathy or those with ischemic cardiomyopathy who underwent bypass surgery.
ICDs may also be indicated in the case of hypertrophic obstructive cardiac myopathy (HOCM), if one or more of the following criteria are met:
Syncope
- The thickness of the interventricular septum is 30 mm or greater.
- A confirmed ventricular tachycardia or cardiac arrest.
- The family history is a risk factor for sudden cardiac death.
- Systolic function of the left ventricle, the development of wall thinned (also known as "burnt out" left ventricle).
