Early repolarization pattern on ECG recorded before the acute coronary event does not predict ventricular
Marina M Demidova1, Jonas Carlson2, David Erlinge2
1Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden; National Medical Research Center, St. Petersburg, Russia.
Background:
Generally considered benign, electrocardiographic (ECG) early repolarization (ER) pattern was claimed to be an indicator of increased susceptibility to ventricular arrhythmias during acute ischemia.
Objective:
The purpose of this study was to assess in a nonselected population whether ER pattern documented before ST-elevation myocardial infarction (STEMI) is associated with risk of hemodynamically unstable ventricular tachycardia (VT) or ventricular fibrillation (VF) during acute STEMI.
Methods:
For STEMI patients admitted for primary percutaneous coronary intervention from 2007-2010, the latest ECGs recorded before STEMI were exported in digital format. After excluding ECGs with paced rhythm and QRS duration ≥120 ms, the remaining ECGs were processed using the Glasgow algorithm allowing automatic ER detection. The association between ER pattern and VT/VF during the first 48 hours of STEMI was tested using logistic regression.
Results:
ECGs recorded before STEMI were available for 1584 patients. Of these patients, 124 did not meet inclusion criteria, leaving 1460 patients available for analysis (age 68 ± 12 years; 67% male). ER pattern was present in 272 patients (18.6%; ER+ group). ER+ and ER- groups did not differ with regard to clinical characteristics. VT/VF during the first 48 hours of STEMI occurred in 19 ER+ (7.0%) and 105 ER- patients (8.8%; P = .398). ER was not associated with any VT/VF (odds ratio [OR] 0.78; 95% confidence interval [CI] 0.47-1.29; P = .324); VT/VF before reperfusion (OR 0.48; 95% CI 0.23-1.001; P = .051); or reperfusion-related VT/VF (OR 1.28; 95% CI 0.55-3.01; P = .569).
Conclusion:
In a nonselected population of STEMI patients, the ER pattern on ECG recorded before the acute coronary event was not associated with VT/VF during the first 48 hours of STEMI.
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