[False diagnosis of myocardial infarction due to inversion of the electrocardiographic leads in the right limbs (author's transl)]. / Infarto de miocardio: falso diagnóstico por inversión de los electrodos del electrocardiógrafo en las extremidades derechas.

An abnormal ECG suggested the diagnosis of myocardial infarction in a 65-year-old man who had suffered a transient chest pain. When the patient was admitted to the Hospital a new ECG and biochemical enzymes were normal, but and identical pathologic ECG was registered following inversion of the electrocardiographic leads in the right superior and inferior extremities. A prospective study of 160 adult patients has demonstrated that inversion of the leads in the right limbs frequently causes the appearance of pathologic Q waves (37.14 percent) and ischemic T waves (51.22 percent), especially in lead I and aVL. Number of pathologic Q and T waves may vary when they are present in the basal register, but we never observed their disappearance in all the precordial lead series. A constant finding was the marked low voltage of P, QRS and T in lead II due to the "distance" of the electrocardiographic leads right leg-left leg. Technical recognition may be difficult because P waves and QRS complex are frequently negative or isoelectric in aVR.

[Jugular phlebogram after cardiac surgery]. / El flebograma yugular tras la cirugía cardíaca.

We studied several parameters of the jugular flebogram in 70 patients who had undergone cardiac surgery. Fifty six of them were on sinusal rithm and 14 in auricular fibrillation. We found among them 39 who had undergone commissurotomy and 16 who had got valvular prothesis. The results of these studies were analyzed and compared with those of 94 normal subjects, taking in consideration the type of surgical intervention and the time elapsed since the operation was performed--the latter in the more numerous group. It is interesting to observe that the sinus grows deeper after the intervention so making the relation xv/yv lower than the unit in 33% of the patients maintaining sinusal rithm. This alteration remained stationary during some years in some of the cases, the results suggesting a greater frequency during the first months of the post-operatory period. We didn't find any relation of this morphologic alteration with the presence of a pericardial construction, pulmonary hypertension, valvular injuries with repercussion on the right heart or modifications on the nenous pressure which we think due to functional changes following the pericardiotomy. It is interesting to observe these mechanographic signs in relation with the post-operatory period of cardiac surgery, but we must avoid hypervaluation of those cases suspicious of pericardial constriction.