ICD in post myocardial infarction LV dysfunction

Previous MI has been documented in as many as 75% of SCA. SCD rates in those with previous MI is 4-6 times that in general population. High risk indicators are late VT/VF, LV dysfunction, frequent VPC and NSVT and inducible VT at EPS. ICD is recommended in VT/VF survivors with no reversible etiology. If there is inducible VT/VF, those with LVEF less than or equal to 40% need an ICD. The cut off LVEF is less than or equal to 35% those in symptomatic patients. The cut off is lower at LVEF of 30% or less regardless of any arrhythmic events or symptoms. ICD does reduce mortality significantly in those with post MI LV dysfunction.

Early ICD implantation was not shown to reduce mortality in previous studies, though recent studies, especially with risk stratification haves shown some promise. The earlier negative trial was DINAMIT.