Exercise-induced desaturation and electrocardiogram changes in people with severe lung disease: An exploratory investigation of 25 serial cases

Background

Arterial desaturation is a commonly accepted clinical basis for discontinuing physical activity in people with chronic obstructive pulmonary disease.

Objective

The purpose of this exploratory study was to examine the electrocardiograms of people with severe chronic obstructive pulmonary disease recovering from exercise-induced arterial desaturation.

Subjects

Subjects (n = 25) walked for 6 minutes while oxygen saturation was monitored.

Methods

When the Spo₂ decreased below 90%, subjects were asked to sit and rest while the electrocardiograms were recorded. For all patients, Spo₂ decreased 11.6% on average below baseline during walking. Four patients developed dysrhythmias during desaturation, with a mean lowest Spo₂ of 85%. The Spo₂ in six other patients continued to decrease below 80% despite rest, yet these patients did not develop new dysrhythmias.

Conclusions

Our findings suggest that a decrease in Spo₂ during exercise does not necessarily correlate with cardiac rhythm.