Key result
The presence of isolated potentials at central and proximal reentry circuit sites increased the incidence of ventricular tachycardia termination by radiofrequency ablation from 24% to 47.5% (p=0.05).
Why the study?
Does the presence of isolated potentials correlate with specific reentry circuit sites and predict successful VT termination by RF ablation in patients with prior MI?
Observational (n=36)
Does the presence of isolated potentials correlate with specific reentry circuit sites and predict successful VT termination by RF ablation in patients with prior MI?
Isolated potentials are useful for identifying central-proximal regions of VT reentry circuits and predicting successful ablation sites, complementing entrainment mapping.
May guide ablation to central-proximal sites; hypothesis-generating and requires prospective validation before changing practice.
OBJECTIVES: The purpose of this study was to determine the relation of isolated potentials (IPs) recorded during ventricular tachycardia (VT) to reentry circuit sites identified by entrainment. BACKGROUND: Reentry circuits causing VT late after myocardial infarction are complex. Both IPs and entrainment have been useful for identifying successful ablation sites, but the relation of IPs to the location in the reentry circuit as determined by entrainment has not been completely defined. METHODS: Data from catheter mapping of 70 monomorphic VTs in 36 patients with prior myocardial infarction were retrospectively analyzed. Entrainment followed by radiofrequency current (RF) ablation was performed at 384 sites. On the basis of entrainment, sites were classified as reentry circuit exit, central-proximal, inner or outer loop sites. Sites outside the circuit were divided into remote and adjacent bystanders. RESULTS: Isolated potentials were recorded at 50% (51 of 101) of reentry circuit exit, central and proximal sites as compared with only 8% (11 of 146, p < 0.001) of inner loop and outer loop sites and only 1.8% (2 of 106) of remote bystander sites (p < 0.001). Isolated potentials were also present at 45% of adjacent bystander sites. At central and proximal sites the presence of an IP increased the incidence of tachycardia termination by RF to 47.5% from 24% (p = 0.05). At exit sites tachycardia termination occurred frequently regardless of the presence or absence of IPs (45% vs. 48%, p = NS). Isolated potentials at exit, central and proximal sites had a shorter duration at sites where ablation terminated VT than at sites without termination (20.9 +/- 9.6 ms vs. 35.7 +/- 15.3 ms, p < 0.001). CONCLUSIONS: Isolated potentials are a useful guide to sites in the central-proximal region of the reentry circuit, but often fail to identify exit sites where ablation is successful. Entrainment and analysis of electrograms provide complementary information during mapping of VT.
No takes yet. Share an insight, caveat, or question.
Kocovic et al. (1999) conducted an observational in Ventricular tachycardia after myocardial infarction (n=36). Presence of isolated potentials at central and proximal sites vs. Absence of isolated potentials was evaluated on Tachycardia termination by radiofrequency ablation (p=0.05). The presence of isolated potentials at central and proximal reentry circuit sites increased the incidence of ventricular tachycardia termination by radiofrequency ablation from 24% to 47.5% (p=0.05).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: