Programmed ventricular stimulation in structural heart disease: Implications of patterns of ventricular arrhythmias induced to long-term outcomes

Currently available data gives some credence to utility of VT induction studies in patients with stable ischemic cardiomyopathy, there are some unresolved questions as to define sensitive threshold for low-risk and the prognostic relevance of ill sustained or non-specific tachycardia on induction study.We evaluated potential ability of VT inducibility to predict likelihood of SHD(Structural heart disease) patients for subsequent arrhythmic or adverse cardiac events.All consecutive patients with syncope/documented arrhythmia who had VT induction done were included and patients with VT storm, ACS,uncontrolled HF were excluded. We studied in 4 groups-monomorphic VT,sustained polymorphicVT,ill sustainedVT/VF and no VT/VF induced.The primary-endpoints were - Sudden death, all-cause mortality and secondary-endpoints were - MACE(AICD shock,death,HF, recurrence of VT).We screened 411 patients and included 169 within inducible(n=79) and non-inducible group(n=90).There were a higher number of patients with coronary artery disease, LV dysfunction, patients on amiodarone in inducible group and no difference in usage of beta-blockers. Recurrence of VT,composite of MACE was significantly higher in inducible group(p0.05).Mortality was not different in 3 groups compared with no VT/VF group.We found that monomorphic VT group had significantly higher MACE as compared to others and also predicted recurrence of VT and AICD shock and showed a trend towards significance for prediction of mortality. Inducible patients on AICD had mortality similar to non-inducible group.Induction of monomorphicVT/polymorphicVT with3extrastimuli is associated with a higher number of MACE events on follow up.Induction of monomorphicVT predicts recurrence of VT/ICD shock.