Intermittent heart rate-dependent early repolarization pattern (J-point ST elevation) demonstrated on Holter recordings.

The J-point elevation of the ST segment, the early repolarization (ER) pattern is diagnosed usually on a resting 12-lead ECG. We investigated the ER pattern on 24-h Holter recordings under physiological conditions in 9,200 consecutive cases. The patients' age varied between 14 days to 95 years. In 410 individuals (4.9% of the total) during at least one period of the 24-h recording J-point ST elevation of ≥ 1 mm was found in ≥ 2 of the 3 Holter leads, lasting for ≥ 3 min. In 382 patients (93.1% of the 410 with ER), the typical ER pattern was intermittent, i.e., seen only below heart rate (HR) of about 70/min, and as the HR climbed, beyond 65-75/min, the ER pattern disappeared and then reappeared when the HR slowed down again. This was observed during the 24 h period several times, usually 10-20 times during the 24-h period. In only 28 examinees (6.9% of the 410 cases with ER, 0.33% of the total 8,300 examinees included in the study) this pattern prevailed at HR faster than 75/min. Thus, if an ER pattern is seen on a "spot"-ECG recorded at slow HR, this does not ensure that this pattern will not disappear when HR rises. On the other hand, if no ER pattern is seen in a 12-lead ECG recorded on a relatively higher HR, we demonstrated that this pattern may temporarily appear when HR slows down.