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Published on: May 23, 2021
Prediction of ventricular tachyarrhythmias by intracardiac repolarization variability analysis
Larisa G Tereshchenko1, Barry J Fetics, Peter P Domitrovich
1Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21287, USA. lteresh1@jhmi.edu
Background:
Arrhythmic sudden cardiac death (SCD) is generally mediated by ventricular fibrillation (VF) or fast ventricular tachycardia (FVT). We studied the predictive value of temporal QT variability detected from various sources of cardiac electric signal: surface ECG, far-field (FF), and near-field (NF) intracardiac electrograms (EGMs) in patients with implantable cardioverter-defibrillators (ICDs).
Methods And Results:
Surface ECG and FF and NF intracardiac EGMs were simultaneously recorded at rest (mean heart rate, 74+/-15 bpm) for 4.5+/-1.3 minutes in 298 patients (mean age, 59+/-14; 216 male [73%]) with structural heart disease and an implanted Medtronic ICD for primary (231 patients, 78%) or secondary (67 patients, 22%) prevention of SCD. During mean follow-up of 16+/-8 months, 52 (13.1% per person-year of follow-up) patients sustained VT/VF and received appropriate ICD therapies, but only 19 (4.8% per person-year of follow-up) patients sustained FVT/VF with cycle length
Conclusions:
Repolarization lability is present throughout the ventricular myocardium. Increased intracardiac QT variability predicts VT/VF events in patients with structural heart disease.
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