Cardiac arrhythmias (CA) are a frequent and dangerous complication of respiratory and
cardiac failure in patients with
chronic obstructive pulmonary disease (
COPD). The aim of the study was to investigate the effects of
mexiletine on CA in patients with
cor pulmonale in a state of cardio-respiratory decompensation. We studied 32
COPD patients with severe airways obstruction; mean VC 2.35 +/- 0.53 litres; FEV1, 0.92 +/- 0.3 litres and
respiratory failure, PaO2 = 56 +/- 5 mm Hg, PaCO2 = 47 +/- 9 mm Hg allocated by random numbers to 20 treated and 12 controls. Continuous 24-hour Holter monitoring was performed for 3 consecutive days after admission to the department following routine treatment which consisted of low-flow
oxygen,
antibiotic,
bronchodilators and
diuretics. On the first day, the type and frequency of CA were analysed. Then the treated patients were given
mexiletine 250 mg i.v. + 200 mg orally followed by 200 mg every 8 h for the next 48 h. Controls continued the routine treatment only.
Mexiletine treatment resulted in a highly significant reduction in the mean number of
premature ventricular beats from 163 to 28 and 30/24 h, respectively (p less than 0.01). Episodes of
ventricular tachycardia were abolished. The mean number of
premature supraventricular beats also fell from 85 to 67 and 48/24 h (p less than 0.01). Number of episodes of
sinus tachycardia fell from 17 during the first day to 13 and 10 on the 2nd and 3rd days, respectively. In the controls, the frequency and type of CA remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)