The Prevalence of J Waves in the Additional Right Precordial Leads and Posterior Leads

Abstract

The J wave may be observed in apparently healthy subjects and also in association with sudden cardiac death. We studied its prevalence in the additional 6 right precordial or posterior leads.
Thee hundred and ninety-three patients who visited the Tokyo Medical University Hospital underwent the 18-lead ECG. The J wave was measured in each lead of the 12- and 18-lead ECGs and diagnosed if it was 0.1mV or larger. J wave was predicted theoretically for the additional 6 leads by a new ECG recorder and compared with those of the actual records. The patients with bundle branch block or ventricular pacing were excluded.
The J wave was present in 150 patients (38.2%) in the 12-lead ECGs. Of these, 102 patients (26.0%) showed J waves in the posterior leads and 9 (2.3%) in the right precordial leads. In 30 (12.3%), J waves were observed in the posterior leads but not in the standard 12-leads. Among the 18 leads, the J wave was located most often in the back.
J waves theoretically derived for the right anterior or posterior leads were highly correlated with those of the actual recordings of the 6 leads (r= 0.872-0.965, p<0.001).
J waves are relatively common and might be present in the additional 6 leads. The presence of J waves can easily be predicted by a new ECG recorder. The pathogenesis and significance of such J waves are to be further determined.