Abstract 12079: The Natural History of the ECG Pattern of Early Repolarization
BACKGROUND While it is known that the ECG pattern of early repolarization occurs most commonly in bradycardic young healthy males, its natural history is uncertain. To our knowledge, a serial study of this ECG entity has never been reported.
METHODS We considered the initial unique resting ECG from 29,281 ambulatory patients recorded during 1987 to 1999 at the Palo Alto VA. With PR interval as the isoelectric line and amplitude criteria as > 0.1mV, ST elevation was defined at the end of QRS, J-waves as upward deflection and slurs as conduction delay on the QRS down stroke. Using the computer measurement of QRS end in V5, 250 ECGs with greatest ER elevation were selected and associated patients were queried to determine who had a subsequent ECG more than 5 months later. They were paired for comparison, printed and coded by 3 interpreters.
RESULTS Of the 250 patients selected with the greatest amplitude of ER, after 6 were excluded for ECG abnormalities, 122 had another ECG at least 5 months later. Their average age was 42 ± 10 years and average time between the first and second ECG was ten years, there were only 5 cardiovascular deaths and no major changes in the diagnostic patterns. Of the 122 patients, 47 (38%) retained the amplitude criteria while majority (62%) no longer fulfilled it. Differences in heart rate, time interval between the ECGs or changes in the other diagnostic characteristics did not explain the loss of ER.
CONCLUSIONS The ECG pattern of early repolarization receded over time in over half of this young clinical cohort (average age 42 years) and was not due to higher heart rate, longer time between the ECGs or alterations in ECG diagnostic characteristics.
- © 2011 by American Heart Association, Inc.