title: Reproducibility of heart rate turbulence indexes in heart failure patients.
abstract: Cardiovascular oscillations following spontaneous ventricular premature complexes (VPC) are characterized by a short-term heart rate fluctuation known as heart rate turbulence (HRT) described by the so-called turbulence onset (TO) and slope (TS). Despite a recent written consensus on the standard of HRT measurement, reproducibility data are lacking. Aim of the paper was a reproducibility study of HRT indexes in heart failure patients (HF). Eleven HF patients underwent two 24h ECG Holter recordings, spaced 7 ± 5 days. A paired t test was used to assess the clinical stability of patients during the study period and the number of PVC in Holter recordings' couples. Both TO and TS indexes were calculated for each isolated VPC, and due to their skewed distribution, reproducibility of median and mean TO and TS was studied by Bland-Altman technique. Results showed that median HRT indexes might be preferred to commonly suggested mean values and that, although TO showed lower bias value than TS, TS can be considered much more reproducible than TO, comparing limits of agreements with normal values. This preliminary results suggest the use of medians instead of mean HRT indexes values and a reliability of the turbulence slope greater than the turbulence onset index.
authors.affiliation: S. Maugeri Foundation, Bioengeneering Dpt. of Rehabilitation Institute of Telese, via Bagni Vecchi 82037 Telese Terme, (BN) Italy. gianni.daddio@fsm.it
authors.forename: Gianni
authors.initials: G
authors.lastname: D'Addio
authors.forename: Mario
authors.initials: M
authors.lastname: Cesarelli
authors.forename: Graziamaria
authors.initials: G
authors.lastname: Corbi
authors.forename: Maria
authors.initials: M
authors.lastname: Romano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Furgi
authors.forename: Nicola
authors.initials: N
authors.lastname: Ferrara
authors.forename: Franco
authors.initials: F
authors.lastname: Rengo
mesh_terms: D000368:Aged; D004562:Electrocardiography / Q000379:methods*; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015233:Models, Statistical; D018670:Monitoring, Ambulatory / Q000379:methods*; D009991:Oscillometry / Q000379:methods; D015203:Reproducibility of Results; D013997:Time Factors; D018879:Ventricular Premature Complexes / Q000503:physiopathology*