A Novel Correction Method for QT Interval in the Presence of Left Bundle Branch Block Morphology

The study addressed the challenge of accurately measuring QT interval in patients with prolonged QRS complex, which occurs during ventricular pacing or conduction abnormalities. The research included 94 patients undergoing electrophysiology examination. Researchers found a significant positive relationship between QRS duration and QT interval at all pacing sites (correlation 0.52-0.74). Using statistical analysis, they determined that QRS is a strong independent predictor of QT interval with a consistent relationship regardless of pacing location. The analysis demonstrated that a correction coefficient of 0.65 provides the most accurate results. Researchers proposed a simple correction formula: QT corrected = QT - 0.65 × (QRS - 100 ms), which is practical and accurate for patients with conduction abnormalities or ventricular pacing.