Summary19 cases of parietal ectasy of the heart have been studied; among them, 12 cases were checked at post-mortem examinations. Pathogeny of parietal ectasy is mainly coronarial (18 cases out of 19). Ectasy takes place by progressive distention of the infarct under the influence of intraventricular pressure. All intermediate stages exist between true myomalacy and parietal aneurysm. Means of diagnosis are discussed. The clinical examination is not very interesting. The radiological aspect, often pathognomonic is sometimes confusing. The ECG often provides valuable elements of presumption.