Role of the electrocardiogram in assessing irreversibly impaired left ventricular systolic function in chronic mitral regurgitation.

The study set out to determine whether the electrocardiogram (ECG) might be useful in assessing left ventricular (LV) volumes and systolic function in patients with pure, chronic mitral regurgitation. To do this preoperative haemodynamic and angiocardiographic data, QRS duration, total 12-lead QRS amplitude, R peak time in V6, R peak delay in V6 (RPDV6) (i.e. the R peak in V6 is later than the S peak in V2) and a T wave score assigned to the extent of LV strain were evaluated. Twenty-seven out of 62 patients were subjected to stepwise discriminant multivariate analysis. Radionuclide (RN) LV ejection fraction (EF) was obtained postoperatively; RPDV6, gender, LVEF and LV end-diastolic volume index (EDVI) were selected in decreasing order of discriminatory importance to identify 13 (81.3%) of 16 patients with RNEF greater than or equal to 50% and 10 (90.9%) of 11 with RNEF less than 50% at rest. Preoperatively, 18 subjects with RPDV6 had a significantly greater end-systolic volume index (ESVI) (75.6 +/- 37.8 ml.m-2 versus 50.7 +/- 31.5 ml.m-2, P = 0.003), greater EDVI (196.9 +/- 73.4 ml.m-2 versus 155.2 +/- 48.5 ml.m-2, P = 0.034) and lower LVEF (61.1 +/- 11.9% versus 68.8 +/- 12.7%, P = 0.014) compared to 44 cases without this finding. With respect to postoperative RNEF, eight subjects with RPDV6 had a significantly lower EF compared to 19 cases without this finding (40.1 +/- 8.2% versus 56.0 +/- 9.9%, P = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)