Tan Tock Seng Hospital1
Goldberger described an electrocardiographic triad (SV1 or SV2 + RV5 or RV6≥3.5mV, total QRS amplitude in limb leads≤0.8mV, and R/S ratio<1 in lead V4) that was 70% sensitive and >90% specific for detecting severe left ventricular (LV) dysfunction. Our previous study showed 56% patients had SV1 or SV2 + RV5 or RV6≥3.5mV, 19% had total QRS amplitude in limb leads≤0.8mV, 85% had R/S ratio<1 in V4. 50% had SV1 or SV2 + RV5 or RV6≥3.5mV and R/S ratio<1 in V4. 6% fulfilled the triad. We tested the hypothesis that R/S ratio in V4 is a simple way to select patients with non-ischaemic cardiomyopathy (NICMP) with severe LV dysfunction.
386 patients, mean age 62.45 ± 13.96 years, male 72%, NYHA II-IV, with NICMP and mean LV ejection fraction (EF) 22.40 ± 8.49%. 76% hypertension, 39% diabetes mellitus, 32% atrial fibrillation. 18% had bundle branch block. Electrocardiographic triad was sought in ECG recorded at time of echocardiogram. Mean LV end-diastolic diameter 5.81 ± 1.53 cm.
For patients whose LVEF improved to >45%, R/S ratio shifted from <1 to >1 in 56/68 cases (82%). Those whose LVEF remained at <40%, 91/110 cases (83%) R/S ratio remained <1. In control subjects, mean age 68 ± 12.5 years, without coronary artery disease, with normal LVEF 58.40 ± 2.82%, LV end diastolic diameter 4.81 ± 0.46 cm, 2/50 cases (4%) had R/S ratio <1.
R/S ratio <1 in V4 is a simple way to select NICMP with severe LV systolic dysfunction.