Correlation between Component Cardiac Weights and Electrocardiographic Patterns in 185 Cases

Abstract

The relationship between the electrocardiogram and the weights of the partitioned cardiac chambers of 185 adult hearts was analyzed. Several electrocardiographic variables were correlated with the combined weight of the left ventricle plus interventricular septum (LV + IVS), the weight of the right ventricle [see table in the PDF file] (RV), their ratio (LV+IVS/RV), and the weight of the atria. The voltage of the R wave in aV L was the best criterion for the diagnosis of left ventricular hypertrophy (LVH): among the cases in which the combined weight of LV+IVS and the ratio of LV+IVS/RV were elevated, 50 per cent had an R exceeding 7.5 mm., compared to a frequency of 4 per cent among the cases in which these two anatomic measurements were normal. The voltages of SV 1 , SV 2 , RV 5 , RV 6 , the sum of SV 1 plus RV 5 or V 6 , the sum of R plus S deflections in the precordial lead displaying the largest QRS complex, the S in V e and the Lewis index were larger in LVH than in normotrophic cases, but their diagnostic score was slightly inferior to the voltage of the R wave in aV L . Among all the cases with heavy LV+IVS, the diagnosis of left ventricular hypertrophy was most frequent with severe left ventricular [see table in the PDF file] hypertrophy, less frequent with moderate left ventricular hypertrophy and least frequent with combined hypertrophy. Left axis deviation was rare in cases with pure right ventricular hypertrophy. The frequency of left axis deviation in normotrophic hearts and in cases with heavy LV + IVS was about the same (52 per cent and 46 per cent, respectively); it was less common (33 per cent) among the cases in which the only anatomic evidence of left ventricular hypertrophy was a high LV + IVS/RV ratio. An axis greater than +60° was common in cases with pure RVH and not rare in normotrophic hearts (67 per cent and 15 per cent, respectively). An axis greater than +60° was not found in cases with heavy LV + IVS unless infarction was present as well. A QRS axis greater than +90° was almost pathognomonic of right ventricular enlargement. It was, however, of limited diagnostic value, being present in only a small minority of the cases with right ventricular hypertrophy. The timing of the intrinsicoid deflection was of limited value for the diagnosis of LVH and was not helpful for the diagnosis of RVH. The position of the transitional zone did not correlate with either RVH or LVH. The QRS duration tended to be longer in cases with LVH. This prolongation, however, seemed to be related not so much to the hypertrophy per se, but rather to the infarcts so frequently present in these large hearts. A very poor correlation was found between the right-precordial-lead patterns and RVH: as a whole the performance of the electrocardiogram in the diagnosis of RVH was highly unsatisfactory. Increase in weight of the left atrium tended to increase the P-wave duration and to shift the P axis to the left without affecting the voltage. No obvious relationship could be demonstrated between the weight of the right atrium and the voltage, duration, or axis of the P waves.