Cardiac arrhythmias during routine tests of pulmonary function in patients with chronic obstruction of airways

We studied the frequency of cardiac arrhythmias during routine tests of pulmonary function by using continuous electrocardiographic recording and a computerized method to quantitate arrhythmias. A total of 150 patients with chronic obstruction of airways were studied before, during, and after routine tests of pulmonary function performed before and after intermittent positive-pressure breathing (IPPB) with a bronchodilator aerosol. The only significant (P less than 0.01) change was an increased frequency of atrial premature beats during tests of pulmonary function. Spirometric studies, maximal voluntary ventilation, and IPPB with a bronchodilator aerosol were equally likely to induce atrial premature beats. Routine tests of pulmonary function represent an additional causal factor in producing arrhythmias in patients with obstruction of airways, although no clinical consequences were evident in the course of the study.