JOURNAL ARTICLE

Heart rate-dependence of QTc intervals assessed by different correction methods in patients with normal or prolonged repolarization

John Chiladakis, Andreas Kalogeropoulos, Panagiotis Arvanitis, Nikolaos Koutsogiannis, Fani Zagli, Dimitrios Alexopoulos
Pacing and Clinical Electrophysiology: PACE 2010, 33 (5): 553-60
20025715

BACKGROUND: There is a continuing debate about the optimal method for QT interval adjustment to heart rate changes. We evaluated the heart rate dependence of QTc intervals derived from five different QT correction methods.

METHODS: Study patients (n = 123, age 68 +/- 11 years) were dual-chamber device recipients with baseline normal or prolonged QT interval who had preserved intrinsic ventricular activation with narrow QRS complexes. Patients were classified to either Normal-QT (n = 69) or Prolonged-QT (n = 54) groups. Serial QT intervals were recorded at baseline (52 +/- 3 beats per minute) and following atrial pacing stages at 60, 80, and 100 beats per minute. The QTc formulae of Bazett, Fridericia, Sagie-Framingham, Hodges, and Karjalainen-Nomogram were applied to assess the effect of heart rate on the derived QTc values by using linear mixed-effects models.

RESULTS: Heart rate had a significant effect on QTc regardless of the formula used (P < 0.05 for all formulae). The Bazett's formula demonstrated the highest QTc variability across heart rate stages (highest F values) in both patient groups (in the total cohort, F = 175.9). In the following rank order, the formulae Hodges, Karjalainen-Nomogram, Sagie-Framingham, and Fridericia showed similar QTc heart rate dependence at both slower and faster heart rates in both patient groups (F = 21.8, 25.6, 28.8, 36.9, in the total cohort, respectively).

CONCLUSIONS: Of the studied QTc formulae, the Bazett appeared the most heart rate dependent. Our results suggest the use of Hodges and the Karjalainen-Nomogram secondly to ensure least heart rate dependence of QTc intervals in patients with either normal or prolonged repolarization.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
20025715
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"