Which QT Correction Formulae to Use for QT Monitoring?

• DOI: 10.1161/jaha.116.003264
• Publication Date: 2016-06-18T02:54:33Z
• Authors: Bert Vandenberk; Eline Vandael; Tomas Robyns; Joris Vandenberghe; Christophe Garweg; Veerle Foulon; Joris Ector; Rik Willems
• Keywords: Framingham Heart Study

Background Drug safety precautions recommend monitoring of the corrected QT interval. To determine which correction formula to use in an automated ‐monitoring algorithm our electronic medical record, we studied rate performance different formulae and their impact on risk assessment for mortality. Methods Results All electrocardiograms ( ECG s) patients >18 years with sinus rhythm, normal QRS duration <90 beats per minute (bpm) University Hospitals Leuven (Leuven, Belgium) during a 2‐month period were included. was performed Bazett, Fridericia, Framingham, Hodges, Rautaharju formulae. In total, 6609 included (age, 59.8±16.2 years; 53.6% male heart 68.8±10.6 bpm). Optimal observed using Fridericia Framingham; Bazett worst. A healthy subset showed 99% upper limits above current clinical standards: men 472 ms (95% CI , 464–478 ms) women 482 474–490 ms). Multivariate Cox regression, including age, rate, prolonged c, identified Framingham (hazard ratio [ HR ], 7.31; 95% 4.10–13.05) 5.95; 3.34–10.60) as significantly better predictors 30‐day all‐cause mortality than 4.49; 2.31–8.74). point‐prevalence study haloperidol, number classified be at possibly harmful prolongation could reduced by 50% optimal correction. Conclusions best improved prediction 1‐year With standards, overestimated potential dangerous c prolongation, lead unnecessary measurements withholding patient first‐choice medication.