Survival after cardiac arrest depends on prompt and effective cardiopulmonary resuscitation (CPR). Resuscitative teams are more frequently using mechanical chest compression devices, as documented in physiologic and experimental data, suggesting that these devices are more effective than manual CPR. A 41-year-old male patient presented with an ST-elevation myocardial infarction with cardiac arrest. The patient was immediately resuscitated by manual chest compressions; CPR was continued with a mechanical chest compression device (LUCAS 2). The patient had experienced a 15-minute period of "low-flow" without "no-flow" episode. After a discussion with the heart team, we decided that the patient was a candidate for extracorporeal membrane oxygenation (ECMO) therapy. During the ECMO implantation, we noticed that while performing transesophageal echocardiography, chest compressions were ineffective with the machine. After the ECMO implantation, we observed myocardial damage in the right-sided heart cavities. The present case report illustrates the likelihood that the mechanical chest compression device has limitations that might contribute to inadequate CPR. Therefore, rescuers should consider the efficacy of their chest compression through a continuous hemodynamic monitoring during CPR.