Diastolic Function and Left Atrial Strain in Young Patients with History of Aortic Coarctation Repair.

Aortic coarctation (AoCo) leads to long-term sequelae that may impair heart function. Data regarding new echocardiographic function parameters such as atrial strain, in affected patients, are scarce. This study aims to describe these parameters in AoCo patients and define their association with severity measures. 53 AoCo patients and 31 healthy controls, aged 12-40 years, were evaluated. Effectively corrected AoCo (cAoCo) was defined as aortic trans-isthmic corrected Doppler gradient (Dgrad) ≤ 20 mmHg (n = 36), and recoarctation (rAoCo) as Dgrad > 20 mmHg (n = 17). Dependent variables were: E/E'; atrial reservoir strain (Ares); and atrial conduit strain (Acd). T-tests/Mann-Whitney U tests were used to compare these among groups. Multivariable regression was used to test correlation with systolic blood pressure (SBP), indexed LV mass (ILVM), Dgrad, and the ratio between the narrowest diameter of aortic arch and aorta at diaphragm level (Aoratio). In cAoCo and rAoCo patients, E/E' was higher (p < 0.001), Ares, and Acd were lower (p < 0.001 for both) comparing with controls. Acd was higher in cAoCo than rAoCo (p = 0.045). Higher Ares was associated with higher Aoratio (p = 0.002), and lower Acd with higher Dgrad (0.014). EF and GLS were not different among groups. Young patients with effectively corrected aortic coarctation have persistent changes in diastolic function parameters (E/E' and atrial strain), and these are affected by anatomical sequelae. These patients' physiology is closer to patients with recoarctation, than to healthy individuals. This provides rationale for a stronger prevention, and treatment, of arterial dysfunction and high left ventricular afterload in these patients.

The Influence of Atrial Strain on Functional Capacity in Patients with the Fontan Circulation.

Speckle-tracking echocardiography has been used to assess atrial function. This analysis is feasible in univentricular hearts. The aim of this study was to characterize the relationship between atrial strain and functional capacity in the Fontan circulation. Apical four-chamber echocardiographic loops of 39 Fontan patients were reviewed. The dominant atrium was assessed for active (εact), conduit (εcon), and reservoir (εres) strain and εact/εres ratio. Cardiopulmonary exercise test was performed on the same day and oxygen uptake (VO2) at ventilatory threshold (VT) and peak VO2 were chosen as the dependent variables. Statistical analysis was performed using SPSS® version 23. Unpaired t test was used for binomial and continuous variable correlation; single and multivariable linear regression were used for continuous variable correlation. Statistical significance was defined as p value < 0.05. VO2 at VT as a percentage of predicted VO2 was 36.8% (SD 10.7). Peak VO2 was 64.7% (SD 18.9) of the predicted value. In univariate analysis, both were associated with age, atrioventricular regurgitation, ejection fraction, εres, εcon, and εact/εres. In multivariate regression, higher VO2 at VT and peak VO2 were associated with younger age (p = 0.003 and p = 0.001, respectively) and higher εcon (p = 0.026 and p = 0.020). Evaluation of heart function is difficult in the Fontan circulation, hindered by complex ventricular morphology and lack of normative data. VO2 provides a good surrogate. Atrial strain parameters are compromised in these patients and associated with VO2. Therefore, whenever possible, atrial strain should be measured as it may provide a new method of risk stratification.