The relationship between J waves and contact of lung cancer with the heart

J waves result mainly from an increased density of transient outward current (I_to ). Mechanical stretch to the heart activates multiple signal transduction pathways, in which I_to may be involved. The purpose of this study was to test the hypothesis that mechanical contact of lung cancer with the heart may manifest J waves.

We reviewed 12-lead electrocardiograms to examine whether J waves were associated with contact of lung cancer with the heart. J waves were defied as an elevation of ≥0.1 mV at the junction between QRS complex and ST segment with either notching or slurring morphology. The locational interaction between lung cancer and the heart was determined by computed tomography image.

A total of 264 patients (176 men; mean 68.5 ± 10.7 years) with lung cancer were evaluated. The prevalence of J waves was 25.4% in the total population. J waves were present in 40 of 44 (90.9%) patients with the contact. In contrast, J waves were present in 25 of 220 (11.4%) patients without the contact. The sensitivity and specificity of the contact for J waves were 90.9% and 88.6%, respectively. The odds ratio of the contact with the heart to the presence of J waves was 78 (95% confidence interval 25.7-236.4). The appearance of J waves that coincided with the development of lung cancer was observed in 12 patients.

The presence of J waves was associated with the contact of lung cancer with the heart.