[Electro-vectorcardiogram in myocardial infarct with involvement of the right ventricle in humans]

The electrocardiograms of 7 patients with anatomical diagnosis of right ventricular infarction, were studied. Electrocardiographic and vectorcardiographic records of 11 patients surviving the acute stage of myocardial infarction, were also analized. In 10 cases, both ventricles were involved. All patients had echocardiograms, ventriculograms and cineangiograms of coronary arteries, which showed the damaged vessels and the severity of their alterations. A severe obstrucción of the right coronary artery was found in all the cases, except one, in each group. The signs of necrosis were recognized in DIII, aVF, right unipolar thoracic leads and abdominal leads MD, ME, less frequently MI. They consisted in QS, Qr or W complexes in the absence of intraventricular blocks, and in slurred QR complexes in the cases with right proximal or distal blocks. Q wave duration fluctuated between 35 and 60 msec. The orientation of the initial vectors resulting from the ventricular activation sequence (20 - 40 msec) as well as ARST were different if obtained from usual precordial loads or the right thoracic ones. The latter was concordant with the orientation observed in the standard leads. VCGF suggested the posterior-inferior necrosis by its clockwise rotation and delayed downward crossing (32.5 - 50 msec) or by the situation of the entire ventricular curve above and to the left of E point. The duration of QF loop as increased in 9 (17.5 - 35 msec) Analysis of VCGH made possible the diagnosis of anterior septal necrotic zone because of the changes in QH loop. VCGS generally started upward and showed a delayed crossing of the anterior-posterior axis downward.