Predicting Ventricular Arrhythmias in Patients With Ischemic Heart Disease: Clinical Application of the ECG-Derived QRS-T Angle

• Published in: Circulation. Arrhythmia and electrophysiology Vol. 2; no. 5; pp. 548 - 554
• Main Authors: Borleffs, C Jan Willem, Scherptong, Roderick W.C., Man, Sum-Che, van Welsenes, Guido H., Bax, Jeroen J., van Erven, Lieselot, Swenne, Cees A., Schalij, Martin J.
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Heart Association, Inc 01.10.2009; Lippincott Williams & Wilkins
• Subjects: Arrhythmias, Cardiac - etiology; Arrhythmias, Cardiac - mortality; Arrhythmias, Cardiac - physiopathology; Arrhythmias, Cardiac - prevention & control; Biological and medical sciences; Cardiac dysrhythmias; Cardiology. Vascular system; Cardiovascular system; Coronary heart disease; Defibrillators, Implantable; Electrocardiography - methods; Female; Heart; Humans; Investigative techniques of hemodynamics; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Myocardial Ischemia - complications; Predictive Value of Tests; Primary Prevention; Proportional Hazards Models; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Survival Analysis; ventricular arrhythmia; Prognosis; Arrhythmia; QRS interval; ischemic heart disease; Cardiovascular disease; Cardioversion; Myocardial ischemia; Male; Epidemiology; Myocardial disease; Incidence; Result; Vascular disease; Prevention; Electrodiagnosis; Primary; Electrocardiography; primary prevention; Ventricular ejection; Stratification; Age; Hazard; implantable cardioverter-defibrillator; Human; Intensive cardiocirculatory care; Critically ill; Mortality; Prediction; Instrumentation therapy; Method; Coronary heart disease; Left ventricle; Angle; Low; Implanted; Risk factor; Hemodynamics; Technique; Predictive factor; Application; Defibrillator
• ISSN: 1941-3149; 1941-3084; 1941-3084
• DOI: 10.1161/CIRCEP.109.859108

BACKGROUND—In patients with primary prevention implantable cardioverter-defibrillators (ICDs), the incidence of life-threatening ventricular arrhythmias resulting in ICD therapy is relatively low, prompting for better risk stratification. The aim of this study was to assess the value of the QRS-T angle for prediction of ICD therapy and mortality in primary prevention patients with ischemic heart disease. METHODS AND RESULTS—ICD patients (n=412, 361 men; age, 63±11 years) with ischemic heart disease and a left ventricular ejection fraction ≤40% were included. After device implantation, the occurrence of appropriate ICD therapy and mortality was noted. A survival analysis was performed comparing patients with a planar QRS-T angle ≤90° (n=124, 30%) with patients with a planar QRS-T angle >90° before device implantation. Furthermore, patients with a spatial QRS-T angle ≤100° (n=56, 14%) were compared with patients with a spatial QRS-T angle >100°, before implantation. For patients with a planar QRS-T angle >90° as compared with ≤90°, the adjusted hazard ratio for the occurrence of appropriate device therapy was 2.4 (95% CI, 1.1 to 5.2); a spatial QRS-T angle >100° was associated with an adjusted hazard ratio of 7.3 (95% CI, 1.0 to 53.8). Furthermore, a spatial QRS-T angle ≤100° exhibited a positive predictive value of 98% (95% CI, 95 to 100) for the prediction of an appropriate therapy-free follow-up. CONCLUSIONS—A wide QRS-T angle is a strong predictor of appropriate device therapy in primary prevention ICD recipients with ischemic heart disease. Furthermore, a spatial QRS-T angle ≤100° might be of value in the identification of patients in whom, although currently indicated, ICD treatment should be reconsidered.