Association between RS Time in Electrocardiogram and Right Ventricular Functions in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Objective: The occurrence of right ventricular (RV) dysfunction in chronic obstructive pulmonary disease (COPD) results in an increased risk of mortality. We aimed to study the diagnostic value of RS time in the recognition of COPD patients with RV dysfunction. Methods: 120 consecutive COPD patients were divided into two groups, patients with and without RV dysfunction, and compared them in terms of parameters including RS time. RS time was defined as the longest interval from the beginning of the QRS complex to the nadir of the S- or S′-wave in the inferolateral leads on an electrocardiogram. Results: RV dysfunction was observed in 36% of consecutive COPD patients with a mean age of 63.4 ± 9.8 years (83.3% male) and a mean forced expiratory volume in 1 s of 1.51 ± 0.62 lt. The heart rate, right QRS axis deviation frequency, S1S2S3 pattern frequency, and RS time (p < 0.01) were significantly higher in the patients with RV dysfunction than in those without. Body surface area, heart rate, and RS time (p < 0.001) were independent predictors of an RV dysfunction. An ROC analysis showed that the best RS time cutoff value for the prediction of RV dysfunction was 60 ms with a sensitivity of 81.4% and a specificity of 74.0%. Conclusion: In patients with COPD, RS time prolongation, which can be easily and quickly determined from the electrocardiogram, may be a marker for RV dysfunction.