A 46-year-old man underwent emergency surgery for heart rupture after acute infarction of the posterior wall. Echocardiography revealed limited myocardial thinning, so rather than sutureless repair, a covering patch was used in view of the risk of recurrent rupture. Postoperative echocardiography showed the myocardial thinning had progressed to a wide defect, and computed tomography demonstrated that the covering patch had prevented a repeat rupture.