Investigation of exertional dyspnoea by cardiopulmonary exercise testing with continuous laryngoscopy

Abstract

ObjectivesAbnormal breathlessness at maximal exercise may be caused by a range of conditions, including exercise-induced bronchospasm (EIB), breathing pattern disorder (BPD), or exercise-induced laryngeal obstruction (EILO). These three disorders may not be detected on standard cardiopulmonary exercise testing (CPET). The aim of this study was to describe diagnostic outcomes of an expanded protocol during CPET. DesignRetrospective cohort study. MethodsPatients presenting with abnormal breathlessness on maximal exercise underwent continuous laryngoscopy with CPET (CL-CPET) on stationary cycle ergometer. BPD was evaluated by video and ventilatory data. Pre and post-exercise spirometry was performed. Results24 adult patients were evaluated, 10 were professional athletes. Mean age was 40 years (range 18-73). Nine of 24 (38%) were diagnosed with EILO and referred for speech pathology. Six of these had supraglottic EILO; all were aged < 30 years; 5/6 were professional athletes. One patient had BPD and was referred for physiotherapy; one had EIB, requiring escalation of asthma medication; one had muscle tension dysphonia resulting in referral to an otolaryngologist who administered a laryngeal injection of botulinum toxin. A further four patients had unexplained lower maximal oxygen consumption with cardiac limitation and were referred for further cardiac investigation. ConclusionIn patients reporting abnormal breathlessness at maximal exercise, this expanded exercise protocol provided diagnostic information in 66.7% cases which contributed to further personalised management.