Hypercapnea is associated with cardiac arrhythmias in COPD

Background: Myocardial dysfunction may accompany acute exacerbations (AE) of COPD and contribute to poor outcome. One manifestation of myocardial dysfunction is cardiac arrhythmia. Aims and objectives: To study determinants of self-limiting tachy-arrhythmias in COPD, and to test the hypothesis that cardiac arrhythmias are more prevalent in AECOPD, independent of COPD-severity and co-morbidity. Methods: A 24h Holter-registration was collected in 74 patients with stable COPD and 45 patients with AECOPD (mean age 54y, 56% women). Any supraventricular tachycardia, frequent (>30/h) ventricular extrasystoles (VES) and any complex ventricular ectopy (bigeminy, trigeminy or non-sustained ventricular tachycardia) were registered and the associations with AECOPD and COPD-related factors (forced expiratory volume during one second, forced vital capacity, pO2, pCO2, leucocytes, high-sensitivity (hs) C-reactive protein) were analyzed. Age, gender, history of coronary heart disease, hypertension or diabetes, packyears, use of beta-blocker, systolic blood pressure, heart rate, body mass index, left ventricular hypertrophy and hs-troponin T were adjusted for in multivariate logistic regression analyses. Results: Supraventricular arrhythmias, frequent VES or any complex ventricular ectopy were present in 35%, 18% and 32%, respectively . Hypercapnea (pCO2>6.3kPa) was independently associated with complex ventricular ectopies (odds ratio 2.7, p=0.022). Frequent VES was more prevalent in AECOPD than COPD (27% vs 12%, p=0.049), but not significant in the adjusted analysis. Conclusion: Cardiac arrhythmias were not per se augmented during AECOPD. Hypercapnea may be associated with a proarrhytmic effect.