Venticular paced rhythm makes diagnosis of acute myocardial infarction difficult. We present a case of a 77-year-old woman with cardiac DDD pacemaker, suffering from diabetes, arterial hypertension and renal insufficiency. She was admitted to hospital due to heavy chest pain, radiated to neck and jaw and shortness of breath. The electrocardiogram recorded on admission showed ventricular paced rhythm and ST segment elevation > 0.5 mV, which fulfilled Sgarbossa's criteria for indetermined acute coronary syndrome in a patient with pacemaker. Troponin levels were not increased. Severe stenosis of left anterior descendent coronary artery was revealed in coronarography and percutaneus coronary angioplasty with stent implantation was performed immediately.