Early repolarization syndrome (ERPS), as evidenced by the concave upwards ST segment elevation in leads V2 to V6. A closely similar pattern can occur in hyperacute phase of myocardial infarction. Moreover, persons with ERPS can also develop myocardial infarction. So if the clinical history is suggestive of ischemic cardiac pain, it is better to have follow up with serial ECGs and cardiac enzyme estimations. The ECG pattern of ERPS can be abolished by exercise or atropine which increases the heart rate. Potassium administration may also abolish the change. But these methods are not to be adopted in a person with suspected acute coronary syndrome.
Conventionally, ERPS is considered a benign condition, mostly confusing the diagnosis of ST elevation myocardial infarction. But a recent study published in NEJM by Haïssaguerre M et al has described an association between sudden cardiac arrest and ERPS 
Haïssaguerre M, Derval N, Sacher F, Jesel L, Deisenhofer I, de Roy L, Pasquié JL, Nogami A, Babuty D, Yli-Mayry S, De Chillou C, Scanu P, Mabo P, Matsuo S, Probst V, Le Scouarnec S, Defaye P, Schlaepfer J, Rostock T, Lacroix D, Lamaison D, Lavergne T, Aizawa Y, Englund A, Anselme F, O’Neill M, Hocini M, Lim KT, Knecht S, Veenhuyzen GD, Bordachar P, Chauvin M, Jais P, Coureau G, Chene G, Klein GJ, Clémenty J. Sudden cardiac arrest associated with early repolarization. N Engl J Med. 2008 May 8;358(19):2016-23.