title: Distribution of mean cycle length in cavo-tricuspid isthmus dependent atrial flutter.
abstract: Although cycle length (CL) constitutes a fundamental descriptor of any arrhythmia, there is not larger study describing mean CL in electrophysiologically confirmed cavo-tricuspid isthmus (CTI)-dependent atrial flutter (AFL). We analyzed retrospectively digital recordings of 121 patients (98 men; age 64+/-11 years) referred for radiofrequency ablation of persistent CTI-dependent AFL. Median of mean AFL CL was 240 ms (interquartile range (IQR) of 222-258 ms, overall range of 178-399 ms). The distribution of CL was not normal (Shapiro Wilk test, p<0.001). Both counterclockwise and clockwise (14.9 % of all cases) AFLs were comparable in their CL; 240 (IQR 222-258) ms vs. 234 (217-253) ms, respectively. AFL CL<200 ms and AFL CL<190 ms was noticed in 5 (4.1 %) and 3 cases (2.5 %), respectively. In multivariate regression analysis, age (increase by 6+/-3 ms per decade of age, p=0.036), treatment with specific antiarrhythmic drugs (increase by 11+/-6 ms, p=0.052) and the history of cardiac surgery (increase by 26+/-9 ms, p=0.004) were independently associated with AFL CL. In conclusions, the distribution of AFL CL is not normal. The prevalence of AFL with short CL is low. Short CL<200 ms does not rule out the CTI-dependent AFL, especially in young and otherwise healthy patients.
authors.affiliation: Second Department of Medicine - Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic. stepan.havranek@lf1.cuni.cz
authors.forename: S
authors.initials: S
authors.lastname: Havránek
authors.forename: J
authors.initials: J
authors.lastname: Simek
authors.forename: P
authors.initials: P
authors.lastname: Sťovíček
authors.forename: D
authors.initials: D
authors.lastname: Wichterle
mesh_terms: D000368:Aged; D001282:Atrial Flutter / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D014261:Tricuspid Valve / Q000503:physiopathology; D014682:Vena Cava, Inferior / Q000503:physiopathology