BACKGROUND: QT interval prolongation carries an increased risk of torsade de pointes and death. AIM: We sought to determine the prevalence of QT prolongation in medical inpatients and to identify determinants of this condition. METHODS: We enrolled consecutive patients who were admitted to the internal medicine ward and who had an electrocardiogram performed within 24 h of admission. We collected information on baseline patient characteristics and the use of QT-prolonging drugs. Two blinded readers manually measured the QT intervals. QT intervals were corrected for heart rate using the traditional Bazett formula and the linear regression-based Framingham formula. We used logistic regression to identify patient characteristics and drugs that were independently associated with QTc prolongation. RESULTS: Of 537 inpatients, 22.3% had a prolonged QTc based on the Bazett formula. The adjusted odds for QTc prolongation based on the Bazett correction were significantly higher in patients who had liver disease (OR 2.9, 95% CI: 1.5-5.6), hypokalaemia (OR 3.3, 95% CI: 1.9-5.6) and who were taking ≥1 QT-prolonging drug at admission (OR 1.7, 95% CI: 1.1-2.6). Overall, 50.8% of patients with QTc prolongation received additional QT-prolonging drugs during hospitalisation. CONCLUSIONS: The prevalence of QTc prolongation was high among medical inpatients but depended on the method used to correct for heart rate. The use of QT-prolonging drugs, hypokalaemia and liver disease increased the risk of QTc prolongation. Many patients with QTc prolongation received additional QT-prolonging drugs during hospitalisation, further increasing the risk of torsade de pointes and death.
BACKGROUND:QT interval prolongation carries an increased risk of torsade de pointes and death. AIM: We sought to determine the prevalence of QT prolongation in medical inpatients and to identify determinants of this condition. METHODS: We enrolled consecutive patients who were admitted to the internal medicine ward and who had an electrocardiogram performed within 24 h of admission. We collected information on baseline patient characteristics and the use of QT-prolonging drugs. Two blinded readers manually measured the QT intervals. QT intervals were corrected for heart rate using the traditional Bazett formula and the linear regression-based Framingham formula. We used logistic regression to identify patient characteristics and drugs that were independently associated with QTc prolongation. RESULTS: Of 537 inpatients, 22.3% had a prolonged QTc based on the Bazett formula. The adjusted odds for QTc prolongation based on the Bazett correction were significantly higher in patients who had liver disease (OR 2.9, 95% CI: 1.5-5.6), hypokalaemia (OR 3.3, 95% CI: 1.9-5.6) and who were taking ≥1 QT-prolonging drug at admission (OR 1.7, 95% CI: 1.1-2.6). Overall, 50.8% of patients with QTc prolongation received additional QT-prolonging drugs during hospitalisation. CONCLUSIONS: The prevalence of QTc prolongation was high among medical inpatients but depended on the method used to correct for heart rate. The use of QT-prolonging drugs, hypokalaemia and liver disease increased the risk of QTc prolongation. Many patients with QTc prolongation received additional QT-prolonging drugs during hospitalisation, further increasing the risk of torsade de pointes and death.
Authors: M Nosè; I Bighelli; M Castellazzi; G Martinotti; G Carrà; C Lucii; G Ostuzzi; F Sozzi; C Barbui Journal: Epidemiol Psychiatr Sci Date: 2015-10-15 Impact factor: 6.892
Authors: James E Tisdale; Heather A Wroblewski; Brian R Overholser; Joanna R Kingery; Tate N Trujillo; Richard J Kovacs Journal: Drug Saf Date: 2012-06-01 Impact factor: 5.606
Authors: C Franchi; I Ardoino; R Rossio; A Nobili; E M Biganzoli; A Marengoni; M Marcucci; L Pasina; M Tettamanti; S Corrao; P M Mannucci Journal: Drugs Aging Date: 2016-01 Impact factor: 3.923