[Out-of-hospital cardiac arrest].

An 84-year-old man called the emergency service from his home because of recent chest pain associated with dyspnea. He had a long-standing history of coronary artery disease and chronic obstructive pulmonary disease. One minute after the basic life support team arrived, the patient went into cardiac arrest. The rescuers deployed their automated external defibrillator, and 1 electric shock was delivered. Thereafter, the patient received cardiopulmonary resuscitation. The prehospital emergency physician arrived at the scene 10 minutes later. At this time, the patient had pulseless electric activity (PEA). The ECG monitoring (lead 2) during cardiopulmonary resuscitation is shown in Figure 1. He received 1 mg adrenaline, continuous chest compressions, and orotracheal intubation. A few minutes later, the patient had recovered spontaneous circulation. Cardiac and pulmonary auscultations were normal. The patient was connected to a ventilator, which displayed normal pressure levels. He was then transported to the emergency department without any new clinical complications. What abnormalities are present in the ECG, and might they relate to a particular cause of the cardiac arrest?