Long-term importance of right ventricular outflow tract patch function in patients with pulmonary regurgitation.

Chronic pulmonary regurgitation (PR) has deleterious effects on right ventricular (RV) function in repaired tetralogy of Fallot (ToF). However, there are little data regarding right ventricular outflow tract (RVOT) contractile dysfunction in response to chronic PR and on both RV and LV volumes and function. We retrospectively identified consecutive patients with PR who were referred for magnetic resonance imaging quantification of "free PR" detected on echocardiography between 2003 and 2008. Patients had ToF and a transannular patch procedure (n = 30, 25.1 ± 1.2 years) or PR resulting from valvar pulmonary stenosis treated with surgical or percutaneous valvotomy (n = 30, 26.6 ± 1.8 years). The ToF and the PS groups were well matched for age at scan, age at repair surgery in ToF or initial valvotomy in PS, duration of exposure to PR, body surface area, heart rate, PR fraction, net forward pulmonary artery flow, and main and branch pulmonary artery dimensions. Severe PR fractions were identified in both groups (ToF: 40% ± 1% vs PS: 37% ± 2%, P = .2). Indexed RV and LV end-diastolic volumes were similar for both ToF and PS groups (RV end-diastolic volume index: 137 ± 6 mL/m(2) vs 128 ± 5 mL/m(2), P = .2, and LV end-diastolic volume index: 72 ± 2 mL/m(2) vs 67 ± 2 mL/m(2), P = .1, respectively). RV mass was also similar between groups (95 ± 5 g vs 81 ± 6 g, respectively, P = .08). However, indexed RV and LV end-systolic volumes were consistently higher in ToF when compared with PS (RV end-systolic volume index: 70 ± 5 mL/m(2) vs 54 ± 3 mL/m(2), P < .01, and LV end-systolic volume index: 29 ± 1 mL/m(2) vs 22 ± 1 mL/m(2), P < .01, respectively). These changes were reflected in lower biventricular systolic function in patients with ToF when compared with PS (RV ejection fraction: 52% ± 1.5% vs 59% ± 1%, P < .001, and LV ejection fraction: 61% ± 1% vs 67 ± 1%, P < .001, respectively). Although RV transannular plane systolic excursion was not significantly different between the groups (P = .86), the RV outflow tract was considered contractile in only 50% of patients with ToF compared with 93% of patients with PS (P = .0004). RV volumes and function were similar when only patients with contractile RV outflow tracts were compared. RV outflow tract patch dysfunction in repaired ToF is responsible for higher end-systolic volumes and thus lower global measures of ventricular systolic function. These findings were not evident in cases of PS treated with valvotomy with comparable amount of PR. These observations highlight the importance of the initial repair surgery in ToF for late outcomes.

Puranik R ，Tsang V ，Lurz P ，Muthurangu V ，Offen S ，Frigiola A ，Norman W ，Walker F ，Bonhoeffer P ，Taylor AM ... -  《-》

Impact of pressure load caused by right ventricular outflow tract obstruction on right ventricular volume overload in patients with repaired tetralogy of Fallot.

In correction of tetralogy of Fallot (TOF), surgical strategies to minimize right ventricular outflow tract (RVOT) enlargement have recently been preferred. However, we may be confronted with residual pulmonary stenosis (PS) combined with pulmonary regurgitation (PR), and how the pressure load affects these patients is not evident. We compared 51 patients with PR and significant PS (PR with PS group) with 87 patients with PR without significant PS (PR group) using echocardiography and cardiac magnetic imaging. We evaluated the differences in parameters derived by magnetic resonance imaging between the 2 groups and the influence of the pressure load on right ventricular (RV) volume and function. Although the PR fraction was similar between the 2 groups, the PR with PS group showed significantly smaller RV end-diastolic volume (136.7 ± 26.5 mL/m(2) vs 151.2 ± 34.7 mL/m(2); P = .01), RV end-systolic volume (68.1 ± 23.7 mL/m(2) vs 80.2 ± 27.5 mL/m(2); P = .01), and slightly better RV ejection fraction (51.1% ± 9.8% vs 47.6% ± 8.9%; P = .03) than the PR group. For influence of the pressure load, PR fraction (r = -0.18, P = .03), RV end-diastolic volume (r = -0.25, P = .003), and RV end-systolic volume (r = -0.24, P = .005) were decreased as peak pressure gradient of PS was higher. Linear regression analysis revealed that both PR fraction and peak pressure gradient of PS were independent predictors for RV volume. Our study demonstrated that the RV pressure load prevented RV dilatation from chronic PR without systolic dysfunction. It is suggested that a proper relief of RVOT obstruction with acceptable residual stenosis is more advantageous than aggressive RVOT enlargement in the long-term outcome of repaired TOF.

Yoo BW ，Kim JO ，Kim YJ ，Choi JY ，Park HK ，Park YH ，Sul JH ... -  《-》

Right ventricular function in adults with repaired tetralogy of Fallot assessed with cardiovascular magnetic resonance imaging: detrimental role of right ventricular outflow aneurysms or akinesia and adverse right-to-left ventricular interaction.

Davlouros PA ，Kilner PJ ，Hornung TS ，Li W ，Francis JM ，Moon JC ，Smith GC ，Tat T ，Pennell DJ ，Gatzoulis MA ... -  《JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY》

Differential Impact of Pulmonary Regurgitation on Patients With Surgically Repaired Pulmonary Stenosis Versus Tetralogy of Fallot.

Patients with repaired pulmonary stenosis (PS) or tetralogy of Fallot (TOF) both develop pulmonary regurgitation (PR) leading to right ventricular (RV) dilatation and dysfunction. We aimed to characterize differential effects of chronic PR in these populations. Patients with surgically repaired PS were matched 1:2 by age and PR fraction with patients with TOF. Patients with previous pulmonary valve replacement were excluded. Cardiovascular magnetic resonance data were compared; peak longitudinal and circumferential systolic strain by feature tracking were compared to evaluate differential contribution of the RV sinus and outflow tract, respectively. PS (n = 24, 41 ± 13 years old) and TOF (n = 47, 39 ± 13 years old) patients did not differ in RV end-diastolic volume (153 ± 45 vs 154 ± 45 ml/m(2), p = 0.99) or diastolic function. However, patients with PS had preserved RV ejection fraction (54.3 ± 4.4% vs 48.0 ± 7.1%, p <0.0001). Differences were greater in RV circumferential (-15.8 ± 3.3 vs -11.8 ± 3.4, p <0.0001) than longitudinal strain (-18.0 ± 3.8 vs -15.9 ± 3.8, p = 0.04), with particular decrease in the infundibulum (-17.4 ± 7.5 vs -6.8 ± 6.3, p <0.0001). Late gadolinium enhancement in the RV outflow tract was more frequent in patients with TOF (70.2% vs 45.8%, p = 0.001). In conclusion, surgical repair of PS leads to similar RV dilatation and diastolic dysfunction compared to patients with TOF, but differential effects on ventricular systolic function, largely related to differences in the outflow tract. With different patterns of scarring and ventricular remodeling, further study is needed to clarify whether criteria for pulmonary valve replacement in patients with PS should differ from those with TOF.

Joynt MR ，Yu S ，Dorfman AL ，Ghadimi Mahani M ，Agarwal PP ，Lu JC ... -  《-》

Power loss and right ventricular efficiency in patients after tetralogy of Fallot repair with pulmonary insufficiency: clinical implications.

To quantify right ventricular output power and efficiency and correlate these to ventricular function in patients with repaired tetralogy of Fallot. This might aid in determining the optimal timing for pulmonary valve replacement. We reviewed the cardiac catheterization and magnetic resonance imaging data of 13 patients with tetralogy of Fallot (age, 22 ± 17 years). Using pressure and flow measurements in the main pulmonary artery, cardiac output and regurgitation fraction, right ventricular (RV) power output, loss, and efficiency were calculated. The RV function was evaluated using cardiac magnetic resonance imaging. The RV systolic power was 1.08 ± 0.62 W, with 20.3% ± 8.6% power loss owing to 41% ± 14% pulmonary regurgitation (efficiency, 79.7% ± 8.6%; 0.84 ± 0.73 W), resulting in a net cardiac output of 4.24 ± 1.82 L/min. Power loss correlated significantly with the indexed RV end-diastolic and end-systolic volume (R = 0.78, P = .002 and R = 0.69, P = .009, respectively). The normalized RV power output had a significant negative correlation with RV end-diastolic and end-systolic volumes (both R = -0.87, P = .002 and R = -0.68, P = .023, respectively). A rapid decrease occurred in the RV power capacity with an increasing RV volume, with the curve flattening out at an indexed RV end-diastolic and end-systolic volume threshold of 139 mL/m(2) and 75 mL/m(2), respectively. Significant power loss is present in patients with repaired tetralogy of Fallot and pulmonary regurgitation. A rapid decrease in efficiency occurs with increasing RV volume, suggesting that pulmonary valve replacement should be done before the critical value of 139 mL/m(2) and 75 mL/m(2) for the RV end-diastolic and end-systolic volume, respectively, to preserve RV function.

Fogel MA ，Sundareswaran KS ，de Zelicourt D ，Dasi LP ，Pawlowski T ，Rome J ，Yoganathan AP ... -  《-》