Catheter hemodynamic assessment of the univentricular circulation

Abstract

Children with very complex congenital heart disease not amenable to biventricular repair are increasingly being considered for a palliative univentricular care pathway. This involves a staged surgical approach culminating in the Fontan circulation with passive pulmonary blood flow and added resistances. The catheter based hemodynamic assessment at all three stages of this palliation is described in detail. Frequent pitfalls, inherent limitations and potential errors are discussed and clinical examples are illustrated.

Role of Cardiovascular Imaging in the Follow-Up of Patients with Fontan Circulation

“…However, the scientific literature shows that adverse outcomes correlate when pressures are severely abnormal. Moreover, cardiac catheterisation can detect obstructive lesions in the Fontan circuit and coronary circulation and the subsequent interventions by using ballooning or stenting procedures on the aforementioned (obstructive lesions); individualising venovenous (VV), pulmonary arteriovenous, and aortopulmonary collaterals; closing them with apposite coils; then assessing the patency of Fontan fenestrations; eventually closing these with proper devices; determining the function of the systemic ventricle; and, finally, identifying the regurgitation or stenosis of the aortic and systemic atrioventricular valves [ 59 ]. Although these are crucial advantages, cardiac catheterisation is an invasive investigation performed under general anaesthesia for paediatric patients or in non-compliant patients, and patients are also exposed to ionising radiation.…”

“…The transpulmonary gradient is the most critical pressure measurement in the whole circuit assessment, which equals the difference between the Fontan pressure and the pulmonary venous atrial mean pressure. The expected value is considered 3 mmHg; while it can reach 5 mmHg, which is already high, 20 mmHg is strongly associated with poor outcomes [ 59 , 60 ]. Saturations are also sampled, which can suggest the presence of arterial collaterals to the lung, when there is an important jump between the SVC and the distal pulmonary arteries or the potential presence of pulmonary arteriovenous fistulae in the case of low saturations in the pulmonary veins.…”

Cardiac Imaging in Patients After Fontan Palliation: Which Test and When?

“…Cardiac catheterization is the only method able to accurately measure end diastolic ventricular pressure, Fontan system pressure and transpulmonary gradient ( 46 ). In addition, in case of anatomical issues, such as residual aortic coartaction, or pulmonay branches or conduit stenosis, catheterization is the only technique for assessing real pressure gradients and thus the real hemodynamic significance of a lesion.…”

“…As catheter evaluation of estimated flows using the Fick principle and assumed oxygen consumption is limited and potentially incorrect ( 46 ), combined invasive catheter hemodynamics and simultaneous CMR evaluation is used in some centers to optimize vascular resistance evaluation ( 47 , 48 ). This is the best method for measuring real pulmonary vascular resistance in clinical practice, especially in patients who are listed for transplantation because of a failing Fontan palliation ( 46 ). Moreover, radiation exposure remains a major drawback of pediatric and congenital cardiac catheterization.…”

Pathophysiology, adaptation, and imaging of the right ventricle in Fontan circulation

“…Cardiac catheter-derived hemodynamic evaluation and cineangiography remain the gold standard practice in the lifelong management of patients with single ventricles (70). RV enddiastolic pressure provides important information about diastolic function.…”