Early repolarization pattern in the coronary slow flow phenomenon

BACKGROUND: The coronary slow flow phenomenon (CSFP) is well-documented, and the early repolarization pattern (ERP) has recently been shown to be a risk factor for the development of malignant ventricular arrhythmias. METHODS: Those with true CSFP were included as cases and those with normal angiograms were included as controls. We assessed J-point elevation on surface electrocardiograms (ECGs) and defined ERP as notching or slurring of the terminal portion of the QRS takeoff. RESULTS: We enrolled 115 cases (33 females, 82 males; mean age, 51.9 ± 11.5 years) and 45 controls (13 females, 32 males; mean age, 50.8 ± 11.7 years). ERP was more common among cases than among controls (65% vs. 28%, p = .001). Compared with the controls, cases were more likely to have J-point elevation in the inferior leads (25% vs. 13%, p = .002), in the D1 to aVL leads (22% vs. 15%, p = .001), and in the lateral leads (17.3% vs. 0%), p = .001). Notching was also significantly more common in cases than in controls (26.0% vs. 2.2%, p = .0001). Finally, concave/ascendant ST segment (33.9% vs. 5.2%, p = .006), horizontal/non-ascendant ST segment (14.7% vs. 1.7%, p = .054), and horizontal/non-ascendant ST segment and notching (15.6% vs. 2.2%, p = .012) patterns were more common in cases than in controls. CONCLUSIONS: We report that CSFP is associated with J-wave and slurring ERPs. However, the clinical significance of these changes needs to be clarified.