Correlation of QT Interval Correction Methods During Atrial Fibrillation and Sinus Rhythm

• Published in: The American journal of cardiology 2013-11, Vol.112 (9), p.1379-1383
• Main Authors: Musat, Dan L., MD, Adhaduk, Mehul, MD, Preminger, Mark W., MD, Arshad, Aysha, MD, Sichrovsky, Tina, MD, Steinberg, Jonathan S., MD, Mittal, Suneet, MD
• Format: Article
• Language: English
• Subjects: Anti-Arrhythmia Agents - administration & dosage; Atrial Fibrillation - drug therapy; Atrial Fibrillation - physiopathology; Cardiac arrhythmia; Cardiovascular; Dose-Response Relationship, Drug; Drug dosages; Electrocardiography; Female; Follow-Up Studies; Heart rate; Heart Rate - drug effects; Heart Rate - physiology; Humans; Male; Methods; Middle Aged; Patients; Phenethylamines - administration & dosage; Prognosis; Retrospective Studies; Sinuses; Studies; Sulfonamides - administration & dosage
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/j.amjcard.2013.06.027

The calculation of the corrected QT interval (QTc) is particularly problematic in patients during atrial fibrillation (AF). The aims of this study were to compare the QTc calculated using Bazett's formula in AF and sinus rhythm (SR) and determine whether alternative methods for QT correction were superior to Bazett's, in an effort to define the optimal method for QT correction in patients with AF. We evaluated consecutive patients with persistent AF admitted for initiation of dofetilide. The QT interval was corrected according to the following formulas: Bazett's, Fridericia, and Framingham. We compared the QTc interval on the last electrocardiogram in AF to the first electrocardiogram in SR. The cohort included 54 patients (age 60 ± 10 years, 80% men) with persistent AF for a median of 36 months. Bazett's overestimated QTc during AF compared with SR (464 ± 34 vs 445 ± 38 ms, p = 0.008); in contrast, Framingham underestimated it (385 ± 48 vs 431 ± 40 ms, p