The Role of Holter Monitoring in the Diagnosis of Early Repolarisation Pattern.

BACKGROUND: A slower heart rate can exaggerate J-point elevation in a 12-lead ECG. This study examined the role of Holter monitoring in the diagnosis of early repolarisation pattern (ERP). METHODS: We examined 24-hour Holter recordings of 4000 consecutive patients seen at an outpatient clinic, and found 500 patients (12.5%) with ERP (based on J-point elevation magnitude maximum value≥0.1mV on the Holter recording). The highest magnitude of J-point elevation, R wave amplitude, the ratio between J-point elevation magnitude and R-wave amplitude on the same ECG lead (J/R ratio), QRS interval, and QT/QTc interval were measured on the Holter recording and on a surface 12-lead ECG of the 500 patients with ERP. The magnitude of J-point elevation, J/R ratio, and QT/QTc interval were compared between three groups: nighttime Holter recording, daytime Holter recording, and daytime surface 12-lead ECG. RESULTS: The magnitude of J-point elevation of the nighttime Holter (0.20±0.10mV) was higher than that of the daytime in Holter (0.12±0.07mV, p<0.001) and the 12-lead ECG (0.12±0.06mV, p<0.001). There was no statistical difference in magnitude of J-point elevation between daytime Holter and surface 12-lead ECG. While all 500 patients were diagnosed with ERP based on J-point elevation maximum value J-point on Holter monitoring, only 425 (85%) patients could be diagnosed with ERP based on the surface 12-lead ECG. The J-point elevation maximum value on the nighttime Holter was negatively correlated with heart rate (r=-0.15, p=0.0007) and QTc (r=-0.13, p=0.0043), and positively correlated with R wave amplitude (r=0.46, p<0.0001), J/R ratio (r=0.69, p<0.0001), and QRS interval (r=0.29, p<0.0001). CONCLUSIONS: The J-point elevation on nighttime Holter recording was higher than that on daytime Holter and daytime surface 12-lead ECG, and there was misdiagnosis of ERP based on daytime surface 12-lead ECG. Holter monitoring has a complementary role in the diagnosis of ERP, especially in patients with a suspected diagnosis of ERP based on daytime surface 12-lead ECG.

The Role of the Ratio of J-Point Elevation Magnitude and R-Wave Amplitude on the Same ECG Lead in the Risk Stratification of Subjects With Early Repolarization Pattern.

BACKGROUND: Just as high-risk populations for cardiac arrest exist in patients with Brugada syndrome or long QT syndrome, high-risk and low-risk populations for cardiac arrest also exist in patients with early repolarization pattern (ERP). HYPOTHESIS: Electrocardiographic (ECG) characteristics can aid the risk stratification of patients with ERP. METHODS: Electrocardiographic parameters such as magnitude of J-point elevation and J/R ratio were measured. The magnitude of J-point elevation, leads with J points elevated, J/R ratio, morphology of the ST segment, and QT/QTc interval were used in comparative analysis in 2 groups: 57 patients with ERP and cardiac arrest (cardiac arrest group) and 100 patients with ERP but without cardiac arrest (control group). RESULTS: There was no statistical difference in clinical characteristics of the 2 groups. The J/R ratio in the cardiac arrest group was significantly higher than in the control group (26.8% ± 18.1% vs 16.3% ± 10.3%, respectively; P < 0.001) and the proportion of horizontal/descending ST segments (70.2%) was significantly higher than in the control group (29.0%), but the proportion of ascending/upsloping ST segments (29.8%) was significantly lower than in the control group (71.0%; P < 0.001). Multivariate logistic regression revealed that higher J/R ratio and horizontal/descending ST segment were independently associated with increased risk of cardiac arrest in patients with ERP. CONCLUSIONS: In patients with ERP and cardiac arrest, J/R ratios were relatively higher and mostly with horizontal/descending ST segments, suggesting that J/R ratio and ST-segment morphology may be used as indicators for risk stratification in patients with ERP.