Wave Reflection and Ventriculo-Arterial Coupling in Bicuspid Aortic Valve Patients With Repaired Aortic Coarctation

Impact of Obesity on Ventriculo-Arterial Interaction in Patients After Coarctation of Aorta repair

Survival of patients after repair of coarctation of Aorta (CoA) has improved significantly over the decades, but patients have decreased life expectancy as compared to the general population. This has been attributed to increased hypertension, cerebrovascular disease, and coronary artery disease. There has also been an increasing concern of overweight and obesity in patients with adult congenital heart disease. While there have been studies looking at the impact of long-term hypertension on myocardial performance and outcomes in this population, this study aims to assess the impact of obesity in these patients on their myocardial performance. Ventriculo-arterial coupling is used as a measure of myocardial performance which reflects the interaction between cardiac contractility and arterial elastance. Patients after CoA repair are known to have hypertension affecting the arterial elastance. Obesity affects cardiac contractility as well. This study demonstrated that in a group of young patients after CoA repair, body mass index (BMI) has a relationship with left ventricular (LV) contractility and myocardial performance. This relationship was independent of blood pressure. BMI itself was not seen to affect the determinants of diastolic function in this study, suggesting that LV contractility may be affected before one can notice a change in the diastolic function secondary to BMI.

Feasibility of Wave Intensity Analysis from 4D Cardiovascular Magnetic Resonance Imaging Data

Congenital heart defects (CHD) introduce haemodynamic changes; e.g., bicuspid aortic valve (BAV) presents a turbulent helical flow, which activates aortic pathological processes. Flow quantification is crucial for diagnostics and to plan corrective strategies. Multiple imaging modalities exist, with phase contrast magnetic resonance imaging (PC-MRI) being the current gold standard; however, multiple predetermined site measurements may be required, while 4D MRI allows for measurements of area (A) and velocity (U) in all spatial dimensions, acquiring a single volume and enabling a retrospective analysis at multiple locations. We assessed the feasibility of gathering hemodynamic insight into aortic hemodynamics by means of wave intensity analysis (WIA) derived from 4D MRI. Data were collected in n = 12 BAV patients and n = 7 healthy controls. Following data acquisition, WIA was successfully derived at three planes (ascending, thoracic and descending aorta) in all cases. The values of wave speed were physiological and, while the small sample limited any clinical interpretation of the results, the study shows the possibility of studying wave travel and wave reflection based on 4D MRI. Below, we demonstrate for the first time the feasibility of deriving wave intensity analysis from 4D flow data and open the door to research applications in different cardiovascular scenarios.