Table 4 Supine ergometer exercise CMR studies in Congenital Heart Disease
From: Exercise cardiovascular magnetic resonance: development, current utility and future applications
Study | n. | Population | Variable assessed | Exercise intensity* | Imaging Technique | Findings |
|---|---|---|---|---|---|---|
Pedersen (2002) [98] | 11 | Children with prior TCPC operation | SVC, IVC tunnel, LPA & RPA flow | Low-Moderate | TFEPI Retrospective gating Breath hold Exercise cessation | IVC flow doubled with exercise with equal distribution to both lungs, suggesting pulmonary resistance rather than geometry decides exercise flow distribution in the TCPC circulation |
Roest (2002) [117] | 31 | Repaired ToF (15) & healthy volunteers (16) | Biventricular volume and pulmonary flow | Moderate | Repaired ToF patients demonstrated a decrease in PR with exercise but abnormal RV response to exercise compared to healthy controls. | |
Roest (2004) [71] | 41 | Atrial corrected-TGA (27), Healthy control (14) | Biventricular volumes | Moderate | Patients with atrial correction of TGA demonstrate abnormal biventricular response to exercise despite normal resting function. | |
Oosterhof (2005) [67] | 64 | Atrial corrected TGA (39) & Healthy volunteers (25) | Aortic flow and systemic ventricle function (exercise vs dobutamine stress) | Vigorous | A trial corrected TGA patients demonstrate an abnormal response to exercise with a decrease in systemic ventricle EF, but a normal response with dobutamine stress. Therefore these two methods cannot be used interchangeably in this group. | |
Lurz (2012) [118] | 17 | PPVI for PR/PS as a result of congenital heart disease | Biventricular volumes | Until exhaustion pre-PPVI** | Realtime radial K-T sense volumes | Post PPVI, PS patients had restoration of RVEF exercise reserves, PR patients only had a mild augmentation of exercise SV. |
Van De Bruaene (2014) [78] | 10 | Fontan circulation (10) | Systemic ventricle volumes, invasive radial and PA pressures | Submaximal | Un-gated real time, free-breathing. | Sildenafil improves cardiac index during exercise in Fontan patients suggesting pulmonary vasculature resistance is a physiological limitation in this patient group. |
Van De Bruaene (2015) [79] | 10 | Fontan circulation (10) | Systemic ventricle volumes, invasive radial and PA pressures | Submaximal | Demonstrated that systemic ventricular filling increases with inspiration, ‘respiratory pump’, which persisted throughout exercise. | |
Khiabani (2015) [119] | 30 | Fontan circulation | Ascending and descending aortic flow and SVC flow | Moderate/ to VAT | Retrospective gating, breath hold after exercise cessation | Computational fluid dynamics simulations performed on the measured flows demonstrated that power loss in the TCPC circulation increased exponentially as patients exercised towards ventillatory anaerobic threshold (VAT) |
Barber (2016) [85] | 30 | Pediatric: Repaired ToF (10) i-PAH (10) Control (10) | MR-CPEX Biventricular volumes & aortic cardiac output | Submaximal | Realtime radial K-T sense volumes Realtime UNFOLDed-SENSE flow | MR-augmented CPEX is feasible and safe in children with cardiac disease. Peak VO2 was reduced in children with PAH or repaired ToF compared with healthy controls. |
Wei (2016) [97] | 11 | Fontan circulation/TCPC | IVC, SVC and aortic flows | Moderate/ to VAT | Realtime shared velocity encoded EPI | Utilised a novel chest wall tracking technique to demonstrate respiration caused minimal net changes in mean flow, thus validating the routine use of breath held imaging in these patients and that IVC and descending aortic flows were interchangeable. |
Asschenfeldt (2017) [61] | 40 | Surgically repaired VSD (20) and control (20) | Aortic and pulmonary flow | Submaximal | Real time EPI with half-scan FB during exercise | Patients demonstrated impaired cardiac index vs controls related to increased retrograde flow in pulmonary artery with progressive exercise. |
Tang (2017) [120] | 47 | Fontan circulation/TCPC | SVC, ascending and descending aortic flows | Moderate/ to VAT | Free breathing Exercise cessation | Fontan patients with a smaller TCPC diameter index (which accounts for narrowing’s in the TCPC circulation) demonstrate increased indexed power loss and worse exercise performance. |
Habert (2018) [121] | 22 | Repaired ToF (11) Control (11) | Biventricular volumes & aortic distensibility | Low-moderate | Breath hold exercise cease | Repaired ToF demonstrated reduced bi-ventricular contractile reserve and reduced ascending aortic distensibility vs controls. |
Helsen (2018) [80] | 45 | Atrial corrected-TGA (23) CC-TGA (10) Control (12) | Systemic ventricle volumes | Maximal | Un-gated real time, free-breathing. | A trial corrected-TGA patients demonstrate deteriorating systemic ventricle volumes and stroke volume during exercise compared with CC-TGA patients; caution should be used in analysing pooled systemic right ventricle populations. |
Jaijee (2018) [100] | 48 | PAH (14) Control (34) | Biventricular volumes. Aortic and pulmonary flow | Submaximal | PAH patients demonstrated a decrease in RV contractile reserve with exercise and healthy controls had a reduced contractile reserve exercising during hypoxia (breathing 12% oxygen) | |
Claessen (2019) [77] | 30 | Fontan (10), Control (20) | Systemic ventricle volumes, invasive radial and PA pressures | Maximal | Fontan patients have a diminished heart rate reserve as a result of abnormal cardiac filling rather than sinus atrial node dysfunction causing chronotropic incompetence. |