Background:The cardiovascular illnesses are in the middle of the foremost reasons of death around the world. Deaths in Europe, from sudden cardiac death (SCD), reach nearby 700,000 individuals every year. In the United States, statistics point to the existence of nearly 1 million yearly deaths from cardiovascular sickness, of which 330,000 are the consequence of abrupt. The significance of automatic implantable cardioverter-defibrillator (ICD) has been proven in subjects with preceding myocardial infarction and stark systolic left ventricular dysfunction (secondary prevention).Case Presentation:In this case, we describe a female patient, 94 years old, with a dual-chamber pacemaker since 2014, normal functioning, and controlled hypertension. The patient was in use of bisoprolol 10 mg daily, hydrochlorothiazide 25 mg daily, and candesartan cilexetil 16 mg daily. She presented 2 episodes of syncope associated with the high ventricular rate (HVR), which characterizes sustained ventricular tachycardia (SVT) due to its instability, besides 1 episode of cardiorespiratory arrest. During an attempt to position the active monocoil shock lead in the right ventricle, there was perforation of the upper posterolateral wall of the right atrium, transfixing the pericardium and constituting a pericardial-pleural fistula with hemothorax formation in the right hemithorax. We chose to remove the electrodes and suture the left pocket. There was no cardiac tamponade or pericardial effusion, verified by a pericardial puncture. Thoracic drainage was introduced into the right hemithorax, and 3 L of blood were drained acutely with volume replacement and hemotransfusion. We maintained thoracic drainage in water seal. The ICD was implanted on the right side.Conclusion:So, in this case, we reported a rare complication during pacemakers or ICD implantation that is the pericardial-pleural fistula with hemothorax formation in the contralateral hemithorax. Despite the patient's advanced age, we had the dexterity and luck to save her life.