Breathwork: Demystifying Cardiopulmonary Exercise Testing (CPET) with Ciarán Heatley

Join hosts Dr Margaret Higgins and Dr Marissa O’Callaghan as they sit down with respiratory physiology expert Ciarán Heatley to explore the science and clinical value of Cardiopulmonary Exercise Testing (CPET). Moving beyond static resting tests, this episode highlights how CPET provides dynamic, real-time insight into integrated cardiopulmonary, metabolic, and muscular responses to exercise. Ciarán, who leads the Respiratory Physiology Laboratory at Mater University Hospital Dublin, draws on over a decade of experience to explain what CPET truly measures and how it is applied in modern respiratory and cardiovascular care. The discussion covers CPET’s role in diagnosing unexplained dyspnoea, preoperative risk stratification, transplant assessment, pulmonary hypertension management, and personalised rehabilitation planning. Key Topics Covered 1. What CPET Really Measures CPET is more than a stress test—it evaluates ventilatory, cardiovascular, metabolic, and muscular responses during exercise. Core parameters discussed include VO₂ max, metabolic threshold (VT1), and respiratory compensation point (VT2), with emphasis on the distinction between aerobic capacity and functional capacity. 2. Clinical Applications CPET is valuable for: Investigating unexplained breathlessness Preoperative risk assessment for major surgery Heart and lung transplant evaluation Monitoring treatment response in pulmonary arterial hypertension Assessing pregnancy risk in congenital disease Individualised pulmonary rehabilitation planning 3. What the Test Involves A full CPET takes approximately 90 minutes, including setup, an 8–12 minute exercise phase, and interpretation. Bike ergometry is preferred clinically. Equipment includes ECG, spirometry, a metabolic mask, and continuous blood pressure monitoring. Safety protocols require two physiologists and one doctor present. 4. Interpreting CPET Data The episode breaks down: VT1 and VT2 identification Ventilatory efficiency (V̇E/V̇CO₂) Detection of V/Q mismatch and pulmonary hypertensionChronotropic incompetence and heart rate reserveVentilatory limitation vs maximum voluntary ventilationThe impact of obesity on interpretation 5. Referral Considerations Good referrals clearly state the clinical question, relevant comorbidities, and medications (especially beta-blockers). Contraindications include acute illness, recent MI, severe cognitive or mobility impairment, and significant claustrophobia. 6. CPET in Ireland CPET remains underutilised compared to the NHS, largely due to resource, training, and education gaps. However, there is growing recognition of respiratory physiology’s role within Irish healthcare. Educational Chapters 00:00 Introduction & disclaimer 03:28 What is CPET? 05:54 CPET procedure 09:32 Data interpretation 18:14 Clinical indications 22:51 Practical referrals 25:20 CPET in Ireland 29:32 Closing thoughts Further Learning ARTP CPET Course ERS Clinical Exercise Testing Course Cambridge CPET Course ATS/ACCP CPET Guidelines Wasserman’s Principles of Exercise Testing and Interpretation Guest: Ciarán Heatley, Chief II Respiratory Physiologist, Mater University Hospital Dublin Hosts: Dr Margaret Higgins & Dr Marissa O’Callaghan Disclaimer: Sponsored by AstraZeneca. Sponsor had no input into content. Always follow local clinical guidance.