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

BACKGROUND: J waves result mainly from an increased density of transient outward current (Ito ). Mechanical stretch to the heart activates multiple signal transduction pathways, in which Ito 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. METHODS: 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. RESULTS: 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. CONCLUSION: The presence of J waves was associated with the contact of lung cancer with the heart.