Cardiopulmonary exercise testing is widely used in the evaluation of
patients with
left ventricular dysfunction, and some of these
patients have an
implantable cardioverter-defibrillator (ICD). However, this test presents specific challenges because of the susceptibility to ventricular arrhythmias during maximal levels of
exercise.
Objective:
To evaluate the
safety of
cardiopulmonary exercise testing in
patients with ICD.
Methods:
The study included
patients with ICD
who underwent
cardiopulmonary exercise testing between 2007 and 2015. The tests were completed once the
electronic devices were programmed. The maximum allowed
heart rate reached during
exercise was 10 beats below the first
therapy zone programmed.
Results:
The study included 69
patients with mean age 53.7 ± 10.8 years, including 68%
men.
Exercise time was 8.7±2.3 minutes, with peak
oxygen consumption of 13.3 ± 4.3 ml.kg-1.min-1. Peak
heart rate was 62.9 ± 13.4% of the maximum rate predicted, with all
patients taking specific medication. Ventricular
arrhythmia was observed in 29% of the
patients, and paired
ventricular extrasystoles, ventricular bigeminism or non-sustained
ventricular tachycardia were observed in only 14.5% of the
patients. There was no sustained ventricular
arrhythmia resulting in ICD
therapy or other
complications, such as inappropriate
therapies. The frequency of severe events was 0%, 95% CI (0 - 5.2%).
Conclusion:
In the sample of
patients evaluated, the
cardiopulmonary exercise testing was shown to be safe during its performance in a
hospital setting, following the
safety standards