PURPOSE: Acute exacerbations of chronic obstructive pulmonary disease sometimes appear to occur without a precipitating cause. Heterogenous de- and re-polarization, and arrhythmias occur in COPD patients. Recognizing the close inter-relation between heart and lung, and the relation between vascular congestion and bronchial hyperreactivity, we hypothesized that unrecognized arrhythmias might be precipitants of acute exacerbations.
METHODS: Electrocardiograms (ECG) of thirty patients during acute exacerbations were compared with ECG during stable phase. To assess atrial depolarization heterogeneity, the width of P wave was measured in all 12 leads of the surface ECG. P wave dispersion was calculated by subtracting the maximum width of the P wave from the minimum P wave duration. The corrected QT interval (QTc) in all 12 leads was measured to assess ventricular depolarization and repolarization. The QTc dispersion was calculated by subtracting the maximum duration of the QTc interval from the minimum QTc duration. Further, V1 and V2 were defined as right sided leads and V5 and V6 were defined as left sided leads. Paired t-test was used to compare the groups. p< 0.05 was considered significant.
RESULTS: The mean age of patients was 70.3 (+/-11.8 SD) years. The P wave dispersion was greater during acute exacerbation (567+/-192 vs 477+/-159msec, p= 0.009). There was a trend toward longer QTc interval (425.2+/-20.2 vs 418.4+/-18.1 msec, p= 0.13) and greater QTc dispersion (108.3+/-61.7 vs 90.3+/-47.0 msec, p= 0.13) in acute exacerbation compared to stable phase. There was no difference between the QTc dispersions in the right versus left sided leads.
CONCLUSIONS: Greater dispersion of P waves during acute exacerbations indicates inhomogenous atrial depolarization, and a higher risk for supraventricular arrhythmias. This finding supports a role for arrhythmias during exacerbations.
CLINICAL IMPLICATIONS: Arrythmias might be a novel therapeutic targer for acute exacerbations of COPD
DISCLOSURE: The following authors have nothing to disclose: Surya Bhatt, Sudip Nanda, John Kintzer
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