Our study aims to assess the relationship between the Seismofit® derived VO2 peak estimate and CPET-measured VO2 peak in patients who are having CPET as part of their preoperative workup. Our aim is to establish whether Seismofit® can be considered a cheaper, less resource intensive and better tolerated alternative to the CPET, or whether it might be useful as a screening tool to efficiently identify patients with exercise intolerance who may benefit from further characterisation by CPET.

Inclusion Criteria:

1. Age ≥18
2. Scheduled for elective surgery for resection of HPB, colorectal or gastro-oesophageal primary or secondary cancer
3. Undergoing CPET as part of routine pre-operative investigations

Exclusion Criteria:

1. Subjects unable to give voluntary written informed consent to participate in this study
2. Diagnosis of moderate or worse stenosis or regurgitation of any cardiac valve
3. Previous aortic or mitral valve surgery, valvuloplasty or transcatheter valve implantation
4. Permanent pacemaker or cardiac resynchronisation device in situ
5. Diagnosis of severe pulmonary hypertension
6. Permanent atrial fibrillation

All HPB, gastro-oesophageal or colorectal cancer patients undergoing preoperative assessment for major surgery