Israel Medical Association Journal

Objectives: To investigate the results of PVS after MI, according to date of completion.

Methods: PVS results were interpreted according to the mode of MI management in 801 asymptomatic patients: 301 (group I) during the period 1982–1989, 315 (group II) during 1990–1999, and 185 (group III) during 2000–2010. The periods were chosen based on changes in MI management. Angiotensin-converting enzyme (ACE) inhibitors had been given since 1990; primary angioplasty was performed routinely since 2000. The PVS protocol was the same throughout the whole study period.

Results: Group III was older (61 ± 11 years) than groups I (56 ± 11) and II (58 ± 11) (P < 0.002). Left ventricular ejection fraction (LVEF) was lower in group III (36.5 ± 11%) than in groups I (44 ± 15) and II (41 ± 12) (P < 0.000). Monomorphic VT < 270 beats/min was induced as frequently in group III (28%) as in group II (22.5%) but more frequently than in group I (20%) (P < 0.03). Ventricular fibrillation and flutter (VF) was induced less frequently in group III (14%) than in groups I (28%) (P < 0.0004) and II (30%) (P < 0.0000). Low left ventricular ejection fraction (LVEF) and date of inclusion (before/after 2000) were predictors of VT or VF induction on multivariate analysis.

Conclusions: Induction of non-specific arrhythmias (ventricular flutter and fibrillation) was less frequent than before 2000, despite the indication of PVS in patients with lower LVEF. This decrease could be due to the increased use of systematic primary angioplasty for MI since 2000. 

Background: The predictive value of electrophysiologic studies depends on the aggressiveness of the programmed ventricular stimulation protocol.

Objectives: To assess if non-inducibility with an "aggressive" protocol of PVS[1] identifies post-infarction patients with low ejection fraction (EF[2] ≤ 30%) who may safely be treated without implantable cardioverter defibrillator.

Methods: We studied 154 patients during a 9 year period. Our aggressive PVS protocol included: a) stimulus current five times the diastolic threshold (≤ 3 mA) and b) repetition of double and triple extrastimulation at the shortest coupling intervals that capture the ventricle.

Results: Sustained ventricular tachyarrhythmias were induced in 116 patients (75.4%) and 112 (97%) of them received an ICD[3] (EPS[4]+/ICD+ group). Of the 38 non-inducible patients, 34 (89.5%) did not receive an ICD (EPS-/ICD- group). In comparison to the EPS+/ICD+ group, EPS-/ICD- group patients were older (69 ± 10 vs. 65 ± 10 years, P < 0.05), had a lower EF (23 ± 5% vs. 25 ± 5%,  P < 0.05) and a higher prevalence of left bundle branch block (45.5% vs. 20.2%, P < 0.005). Follow-up was longer for EPS+/ICD+ patients (40 ± 26 months) than for EPS-/ICD- patients (27 ± 22 months) (P = 0.011). Twelve EPS+/ICD+ patients (10.7%) and 5 EPS-/ICD- patients (14.7%) died during follow-up (P = 0.525). Kaplan-Meier survival curves did not show a significant difference between the two groups (P = 0.18).
Conclusions: The mortality rate in patients without inducible VTAs[5] using an aggressive PVS protocol and who did not undergo subsequent ICD implantation is not different from that of patients with inducible arrhythmias who received an ICD. Using this protocol, as many as one-fourth of primary prevention ICD implants could be spared without compromising patient prognosis