Boehringer I. Spain and the Order of Veterinarians of Madrid organized a masterclass of electrocardiography with the participation of Dr. Roberto Santilli and dr. Maria Dolores Vazquez Porteiro. During the seminar were analyzed several cases of clinical cardiology with emphasis on rhythm disorders, evaluating the electrocardiographic and echocardiographic findings, intracavitary mapping and different treatment options. The seminar was attended by 70 colleagues from different Spanish provinces.