Incidence, Determinants, and Prognostic Implications of True Pleomorphism of Ventricular Tachycardia in Patients With Implantable Cardioverter-Defribillators

Abstract

Background-The occurrence of monomorphic ventricular tachycardia (M-VT) with Ͼ1 QRS morphology during the same episode (pleomorphism [PL]) or in different episodes (multiple morphologies [MM]) has been described through ECG. Implantable cardioverter-defribillator (ICD) electrograms (EGs) provide the opportunity to analyze virtually all spontaneous M-VT episodes. We sought to study the incidence, determinants, and prognostic significance of PL and MM as assessed by ICD-EG in a prospective series of patients with ICDs. Methods and Results-Spontaneous episodes of M-VT were analyzed before ICD intervention. PL was defined as Ͼ1 ICD-EG morphology, each having Ն6 consecutive identical beats during the same VT episode, and MM as Ͼ1 ICD-EG morphology in different M-VT episodes in the same patient. We analyzed 1881 M-VT episodes from 315 patients followed for 17 months. PL and MM occurred in 6% and 19%, respectively, of the total population (16% and 62% of patients with M-VT). Recurrent M-VT as diagnosis for ICD indication predicted PL and MM. Patients with PL more frequently developed MM (85% versus 15%; PϽ0.001) compared to patients without PL. Total mortality (5%) was significantly higher in patients with PL (20%), in patients with MM (11.5%), and in women (12%). In multivariate analysis, only PL (odds ratio, 5.33; Pϭ0.009) and female sex (odds ratio, 3.1; Pϭ0.038) predicted mortality. Conclusions-In a prospective series of patients with ICDs, mostly indicated for secondary prevention, both PL and MM of VT, as judged by ICD-EG, were not uncommon and were strongly associated. Female sex and the development of PL VT were the only independent predictors of mortality. (Circ Arrhythm Electrophysiol. 2011;4:33-42.)

Sustained ventricular tachycardia in structural heart disease

“…In contrast, polymorphic VT has a continuously changing QRS configuration from beat to beat [7]. By analyzing 1,881 SMVT episodes in patients with ICD (> 80% with coronary heart disease) we found an incidence of 6% of spontaneous pleomorphism and 19% of multiple morphologies [39]. Both phenomena were associated to increased overall mortality, but only pleomorphism was an independent predictor of total mortality.…”

Resynchronization or Proarrhythmia? A Conundrum

“…The morphology of the tachycardia is initially stable for the first six beats with minimal variations in cycle length from 320 ms to 260 ms, and it changes into a second morphology very similar to the episode shown in Figure , with mean cycle length of 260 ms. This episode fulfills previously established criteria for pleomorphic VT, defined as a single VT episode having more than one stable ICD electrogram morphology, each lasting at least six consecutive beats.…”

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“…Female sex and the development of PL VT were the only independent predictors of mortality. 30 Summary: Injection of autologous bone marrow-derived mononuclear cells (BM-MNC) is a promising therapeutic option in patients with critical limb ischemia, but double-blind, randomized trials are lacking. The present study is the first randomized, placebo controlled trial showing that intraarterial BM-MNC administration accelerates wound healing and induces pain reduction until 3 months in patients with critical limb ischemia with stable ulcers but not in patients with extensive gangrene.…”