Introduction: Underlying the presence of arrithmias in atrial infarction (AI). Because the ventricular depolarization partially overlaps on the atrial repolarization, AI is difficult to recognize on EKG and even anatomically if it is not a targeted research at least in the acute ventricular myocardial infarction (acVMI), where the frequency of AI is observed in approximately 10%. AI must be studied in all acVMI and not only in the cases with atrial fibrillation (AF), as it is usually done. Methods: We have analyzed the cardiac arrithmias in 8 cases, in 3 cases at the same time with the presence of acVMI on EKG and in 5 cases retrospectively, on a EKG collection. Results: 1 with anterior acVMI, AI and atrial extrasystoles. 2 with acVMI, transient LBBB, AVB of Ist deg. (when the atrial repolarization is not masked), RBBB, AI, atrial and ventricular extrasystoles. 3 with inferior acVMI, AI, ventricular fi brillation, death. 4 with inferior acVMI, sequences of BAV of IIIrd deg., AF and sinoatrial block which have wiped the P waves and the AI image, old septal MI, syncopes. 5 with unknown old septal MI and AI observed in the right intra-atrial registration, BAV of IIIrd deg., syncopes, atrial paroxistic tachycardia (APT) with atrial extrasystoles. 6 with old septal MI on EKG and AI, necropsic with extensive anterior acVMI without arrithmias. 7 with 3 old MI, isolated AI, RBBB, LAHB without arrithmias. 8 with isolated AI, AVB of IIIrd deg. Conclusions: In most of the cases, the presence of AI being associated with ventricular MI, it is diffi cult to separate the arrithmias induced only by AI, only by ventricular MI, or together by AI and ventricular MI. Th e heart blocks in 4 from 8 cases (50%) call attention. With atrial extrasystoles only case 1. With atrial extrasystoles associated with other cardiac arrithmias: With ventricular extrasystoles and AVB of Ist deg. in case 2; with AF, AVB of IIIrd deg., sinoatrial block in case 4; with APT with reciporocal beats and AVB of IIIrd deg. in case 5. With malign ventricular arrithmias in case 3. Without cardiac arrithmias in case 6 and 7. Th ere have been two cases with isolated AI, case 7 only with RBBB and LAHB and potential for AVB and in case 8 only with AVB of IIIrd deg.