Are implantable cardioverter defibrillators safe? effective?

Yes and Yes.: The risk of complication during implant is low. The most common issues are lead displacement, which is not dangerous but would require a second procedure (2%). The risk of a major complication is around 0.2-0.4%. In general, icds are considered very effective at terminating VT and vf, usually around 99%. They have been repeatedly shown to prolong the life of recipients.

Yes and yes: While there have been specific manufacturer recalls of various leads and devices, overall implantable cardiac defibrillators are among some of the safest medical devices implanted. They are extraordinarily effective at terminating the potentially fatal heart rhythms they are implanted to treat.