title: Crescendo in depolarization and repolarization heterogeneity heralds development of ventricular tachycardia in hospitalized patients with decompensated heart failure.
abstract: BACKGROUND
  A critical need exists for reliable warning markers of in-hospital life-threatening arrhythmias. We used a new quantitative method to track interlead heterogeneity of depolarization and repolarization to detect premonitory changes before ventricular tachycardia (VT) in hospitalized patients with acute decompensated heart failure.
  
  
  RESULTS
  Ambulatory ECGs (leads V(1), V(5), and aVF) recorded before initiation of drug therapy from patients enrolled in the PRECEDENT (Prospective Randomized Evaluation of Cardiac Ectopy with Dobutamine or Nesiritide Therapy) trial were analyzed. R-wave heterogeneity (RWH) and T-wave heterogeneity (TWH) were assessed by second central moment analysis and T-wave alternans (TWA) by modified moving average analysis. Of 44 patients studied, 22 had experienced episodes of VT (≥4 beats at heart rates >100 beats/min) following ≥120 minutes of stable sinus rhythm, and 22 were age- and sex-matched patients without VT. TWA increased from 18.6±2.1 μV (baseline, mean±SEM) to 27.9±4.6 μV in lead V(5) at 15 to 30 minutes before VT (P<0.05) and remained elevated until the arrhythmia occurred. TWA results in leads V(1) and aVF were similar. RWH and TWH were elevated from 164.1±33.1 and 134.5±20.6 μV (baseline) to 299.8±54.5 and 239.2±37.0 μV at 30 to 45 minutes before VT (P<0.05), respectively, preceding the crescendo in TWA by 15 minutes. Matched patients without VT did not display elevated RWH (185.5±29.4 μV) or TWH (157.1±27.2 μV) during the 24-hour period.
  
  
  CONCLUSIONS
  This investigation is the first clinical demonstration of the potential utility of tracking depolarization and repolarization heterogeneity to detect crescendos in electrical instability that could forewarn of impending nonsustained VT. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00270400.
authors.affiliation: Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-3908, USA.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Nearing
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Wellenius
authors.forename: Murray A
authors.initials: MA
authors.lastname: Mittleman
authors.forename: Mark E
authors.initials: ME
authors.lastname: Josephson
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Burger
authors.forename: Richard L
authors.initials: RL
authors.lastname: Verrier
mesh_terms: D002316:Cardiotonic Agents / Q000627:therapeutic use; D018450:Disease Progression; D004280:Dobutamine / Q000627:therapeutic use; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D045283:Natriuretic Agents / Q000627:therapeutic use; D020097:Natriuretic Peptide, Brain / Q000627:therapeutic use; D011379:Prognosis; D011446:Prospective Studies; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000503:physiopathology
chemical_list: D002316:Cardiotonic Agents; D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain; D004280:Dobutamine