How to assess and treat right ventricular electromechanical dyssynchrony in post-repair tetralogy of Fallot: insights from imaging, invasive studies, and computational modelling.

BACKGROUND AND AIMS: Right bundle branch block (RBBB) and resulting right ventricular (RV) electromechanical discoordination are thought to play a role in the disease process of subpulmonary RV dysfunction that frequently occur post-repair tetralogy of Fallot (ToF). We sought to describe this disease entity, the role of pulmonary re-valvulation, and the potential added value of RV cardiac resynchronization therapy (RV-CRT). METHODS: Two patients with repaired ToF, complete RBBB, pulmonary regurgitation, and significantly decreased RV function underwent echocardiography, cardiac magnetic resonance, and an invasive study to evaluate the potential for RV-CRT as part of the management strategy. The data were used to personalize the CircAdapt model of the human heart and circulation. Resulting Digital Twins were analysed to quantify the relative effects of RV pressure and volume overload and to predict the effect of RV-CRT. RESULTS: Echocardiography showed components of a classic RV dyssynchrony pattern which could be reversed by RV-CRT during invasive study and resulted in acute improvement in RV systolic function. The Digital Twins confirmed a contribution of electromechanical RV dyssynchrony to RV dysfunction and suggested improvement of RV contraction efficiency after RV-CRT. The one patient who underwent successful permanent RV-CRT as part of the pulmonary re-valvulation procedure carried improvements that were in line with the predictions based on his Digital Twin. CONCLUSION: An integrative diagnostic approach to RV dysfunction, including the construction of Digital Twins may help to identify candidates for RV-CRT as part of the lifetime management of ToF and similar congenital heart lesions.

Influence of fenestration on long-term Fontan survival.

INTRODUCTION: Fenestration in the total cavopulmonary connection system may improve the outcome of patients with significant risk factors for Fontan haemodynamics. Our study aims to analyse the difference in long-term survival between non-fenestrated and fenestrated patients. METHODS: All consecutive patients (n = 351) who underwent total cavopulmonary connection between 1992 and 2016 were identified. Six early deaths were excluded resulting in a group of 345 patients. Median (interquartile range,) length of follow-up was 14.4 (7.1-19.7) years. Freedom from the composite endpoint of death, total cavopulmonary connection take-down or indication for a heart transplant was analysed. RESULTS: Fenestration was absent in 237 patients (68.7%, Group 1), was created and closed later in 79 patients (22.9%, Group 2), and remained open in 29 patients (8.4%, Group 3). Mean survival probability until composite endpoint was 97.1 and 92.9% at 10 and 20 years, respectively. Patients with patent fenestration had worse survival (p < 0.001) as compared to both the non-fenestrated and fenestration closure groups. Despite a similar outcome, exercise capacity was lower in Group 2 than 1 (p = 0.013). In 58 patients with interventional fenestration closure, Nakata index was lower at the time of closure than pre-operatively, and both the pressure in the circuit and oxygen saturation in the aorta increased significantly (p < 0.001). CONCLUSIONS: Patients with persisting risk factors preventing fenestration closure are at higher risk of reaching the composite endpoint. Patients after fenestration closure have the worse functional outcome; their survival is, however, not different from the non-fenestrated group.

Left ventricular apical pacing in children: feasibility and long-term effect on ventricular function.

AIMS: Left ventricular apical pacing (LVAP) has been reported to preserve left ventricular (LV) function in chronically paced children with complete atrioventricular block (CAVB). We sought to evaluate long-term feasibility of LVAP and the effect on LV mechanics and exercise capacity as compared to normal controls. METHODS AND RESULTS: Thirty-six consecutive paediatric patients with CAVB and LVAP in the absence (N = 22) or presence of repaired structural heart disease (N = 14, systemic LV in all) and 25 age-matched normal controls were cross-sectionally studied after a median of 3.9 (interquartile range 2.1-6.8) years of pacing using echocardiography and exercise stress testing. Pacemaker implantation was uneventful and there was no death. Probability of the absence of pacemaker-related surgical revision (elective generator replacement excluded) was 89.0% at 5 years after implantation. Left ventricular apical pacing patients had lower maximum oxygen uptake (P = 0.009), no septal to lateral but significant apical to basal LV mechanical delay (P < 0.001) which correlated with decreased LV contraction efficiency (P = 0.001). Left ventricular ejection fraction and global longitudinal LV strain were, however, not different from controls. Results were similar in both the presence and absence of structural heart disease. CONCLUSION: Left ventricular apical pacing is technically feasible with a low reintervention rate. Mechanical synchrony between LV septum and free wall is maintained at the price of an apical to basal mechanical delay associated with LV contraction inefficiency as compared to healthy controls. Global LV systolic function is, however, not negatively affected by LVAP.

Raw material consumption or total material consumption? Which indicator is better for evaluating material resource consumption and environmental pressure?

The article presents a time series of raw material consumption (RMC) and total material consumption (TMC) indicators for the Czech Republic for 1990-2017 calculated with the use of hybrid input-output life cycle assessment approach (hybrid IO-LCA). While the RMC indicator has already been calculated with the use of various alternatives of input-output or hybrid approaches for some other countries, we are not aware of any published TMC time series calculated with the use of these methods. We briefly discuss the time development of the indicators' material components. The core of the article lies in the assessment of the suitability of RMC and TMC indicators for (1) Quantification of material resource consumption of nations or groups of nations and (2) Evaluation of environmental pressure related to material resource consumption. We concluded that RMC is more appropriate for quantification of material resource consumption, as unused flows included in TMC are not consumed, but only displaced. Regarding the second purpose of the indicators, we found that trends of environmental pressure expressed by RMC and TMC are similar for the Czech Republic. We showed that RMC significantly underestimates total environmental pressure related to material resource consumption, which is particularly relevant for international comparison. Finally, we revealed that the material structure of the indicators differ and referring to an example of coal and construction and industrial minerals we argued that TMC is more appropriate for the evaluation of environmental pressure attributable to particular resources.

Acute right ventricular resynchronization improves haemodynamics in children after surgical repair of tetralogy of Fallot.

Aims: Right bundle branch block is associated with right ventricular (RV) electromechanical dyssynchrony, which may contribute to acute haemodynamic impairment after repair of tetralogy of Fallot (ToF). We sought to evaluate the effects of RV resynchronization on haemodynamics and tissue oxygenation during the first 24 h after surgery. Methods and results: Arterial pressures, cardiac output, and tissue oxygenation were measured in 28 consecutive patients (median age 10.1 months) during baseline sinus rhythm with right bundle branch block and after RV resynchronization by atrial-triggered RV free wall pacing in complete fusion with spontaneous activation. Studied variables were compared in a crossover design in four 5-min intervals (baseline rhythm and stimulation, 2x each). Resynchronization reduced the QRS complex duration from median 110 to 70 ms (P < 0.001), increased significantly median arterial systolic, mean and pulse pressure, cardiac index, left ventricular maximum +dP/dT and decreased central venous pressure (P < 0.001 for all). Both cerebral and renal oxygenation improved (P < 0.001). Eleven of the 28 patients showed a clinically highly significant resynchronization effect defined as an increase in arterial pulse pressure of ≥ 10%. The q-RV interval (expressed as % of QRS duration) at the RV pacing site during baseline rhythm was the only predictor of resynchronization effect. Conclusions: RV resynchronization carried short-term improvement of haemodynamics in children early after surgery for ToF and might be a useful non-pharmacologic adjunct to the management of haemodynamically compromised patients. Resynchronization effect was maximized when pacing from area of the latest RV activation.

Primary cardiac lipoblastoma of the right atrium.

Lipoblastoma is a rare neoplasm of the embryonal white fat. It occurs most commonly in children under the age of 3 years and usually inflicts the superficial soft tissues of trunk and extremities. We present the case of a 3-year-old male patient with a successfully resected primary cardiac right-atrial lipoblastoma with COL1A2::PLAG1 gene fusion.

Pregnancy Termination and Postnatal Major Congenital Heart Defect Prevalence After Introduction of Prenatal Cardiac Screening.

Importance: Prenatal cardiac screening of the first and second trimesters has had a major impact on postnatal prevalence of congenital heart defects (CHDs), rates of termination of pregnancy (TOP), and outcomes among children born alive with CHDs. Objective: To examine the prenatal and postnatal incidence of major CHDs (ie, necessitating intervention within the first year of life), detection rate trends, rates of TOP, and the association of cardiac screening with postnatal outcomes. Design, Settings, and Participants: In this cross-sectional study, 3827 fetuses with antenatally diagnosed major CHDs in the Czech Republic (population 10.7 million) between 1991 and 2021 were prospectively evaluated with known outcomes and associated comorbidities. Prenatal and postnatal prevalence of CHD in an unselected population was assessed by comparison with a retrospective analysis of all children born alive with major CHDs in the same period (5454 children), using national data registry. Data analysis was conducted from January 1991 to December 2021. Main Outcomes and Measures: Prenatal detection and postnatal prevalence of major CHDs and rate of TOPs in a setting with a centralized health care system over 31 years. Results: A total of 3 300 068 children were born alive during the study period. Major CHD was diagnosed in 3827 fetuses, of whom 1646 (43.0%) were born, 2069 (54.1%) resulted in TOP, and 112 (2.9%) died prenatally. The prenatal detection rate increased from 6.2% in 1991 to 82.8% in 2021 (P < .001). Termination of pregnancy decreased from 70% in 1991 to 43% (P < .001) in 2021. Of 627 fetuses diagnosed in the first trimester (introduced in 2007), 460 were terminated (73.3%). Since 2007, of 2066 fetuses diagnosed in the second trimester, 880 (42.6%) were terminated, resulting in an odds ratio of 3.6 (95% CI, 2.8-4.6; P < .001) for TOP in the first trimester compared with the second trimester. Postnatal prevalence of major CHDs declined from 0.21% to 0.14% (P < .001). The total incidence (combining prenatal detection of terminated fetuses with postnatal prevalence) of major CHD remained at 0.23% during the study period. Conclusions and Relevance: In this cross-sectional study, the total incidence of major CHD did not change significantly during the 31-year study period. The prenatal detection of major CHD approached 83% in the current era. Postnatal prevalence of major CHD decreased significantly due to early TOPs and intrauterine deaths. The introduction of first trimester screening resulted in a higher termination rate in the first trimester but did not revert the overall decreasing trend of termination for CHDs in general.

Raw material consumption of the European Union--concept, calculation method, and results.

This article presents the concept, calculation method, and first results of the "Raw Material Consumption" (RMC) economy-wide material flow indicator for the European Union (EU). The RMC measures the final domestic consumption of products in terms of raw material equivalents (RME), i.e. raw materials used in the complete production chain of consumed products. We employed the hybrid input-output life cycle assessment method to calculate RMC. We first developed a highly disaggregated environmentally extended mixed unit input output table and then applied life cycle inventory data for imported products without appropriate representation of production within the domestic economy. Lastly, we treated capital formation as intermediate consumption. Our results show that services, often considered as a solution for dematerialization, account for a significant part of EU raw material consumption, which emphasizes the need to focus on the full production chains and dematerialization of services. Comparison of the EU's RMC with its domestic extraction shows that the EU is nearly self-sufficient in biomass and nonmetallic minerals but extremely dependent on direct and indirect imports of fossil energy carriers and metal ores. This implies an export of environmental burden related to extraction and primary processing of these materials to the rest of the world. Our results demonstrate that internalizing capital formation has significant influence on the calculated RMC.

Exercise capacity after total cavopulmonary anastomosis: a longitudinal paediatric and adult study.

AIMS: Fontan palliation is a surgical strategy for patients with complex congenital heart disease, in whom biventricular circulation cannot be achieved. Long-term survival is negatively affected by the absence of sub-pulmonary ventricle and increased systemic venous pressure. Exercise capacity is a known predictor of overall survival and quality of life in congenital heart defects. We aim to track individual trends of peak oxygen uptake (V̇O2 peak) after total cavopulmonary connection (TCPC), identify predictors of deterioration, and derive a disease-specific reference V̇O2 peak dataset. METHODS AND RESULTS: A retrospective study of serial cardiopulmonary exercise testing (CPET) data, gathered from all patients who underwent TCPC in the Czech Republic between 1992 and 2016. Of 354 consecutive patients with TCPC, 288 (81.4%) patients underwent one or more CPETs yielding 786 unique V̇O2 peak values used as a reference dataset. Longitudinal data were available in 206 (58.2%) patients, who underwent a median (inter-quartile range) of 3.0 (2.0-5.0) CPETs over a mean (standard deviation) of 8.9 (5.5) years. The decline of exercise capacity with age was linear and not faster than in healthy peers (P = 0.47), but relative values of V̇O2 peak in TCPC patients were 12.6 mL/min/kg lower. Single ventricular morphology and pulmonary artery size had no significant influence on the exercise capacity dynamics. V̇O2 peak decline correlated negatively with the trend of body mass index z-score (P = 0.006) and was faster in women than men (P = 0.008). CONCLUSIONS: Total cavopulmonary connection patients have significantly reduced exercise capacity. The age-related decline paralleled the healthy population and correlated negatively with the body mass index trend. The presented V̇O2 peak reference dataset may help the clinicians to grade the severity of exercise capacity impairment in individual TCPC patients.

Long-Term Outcome of Patients With Congenital Heart Disease Undergoing Cardiac Resynchronization Therapy.

Background Cardiac resynchronization therapy (CRT) is rarely used in patients with congenital heart disease, and reported follow-up is short. We sought to evaluate long-term impact of CRT in a single-center cohort of patients with congenital heart disease. Methods and Results Thirty-two consecutive patients with structural congenital heart disease (N=30) or congenital atrioventricular block (N=2), aged median of 12.9 years at CRT with pacing capability device implantation, were followed up for a median of 8.7 years. CRT response was defined as an increase in systemic ventricular ejection fraction or fractional area of change by >10 units and improved or unchanged New York Heart Association class. Freedom from cardiovascular death, heart failure hospitalization, or new transplant listing was 92.6% and 83.2% at 5 and 10 years, respectively. Freedom from CRT complications, leading to surgical system revision (elective generator replacement excluded) or therapy termination, was 82.7% and 72.2% at 5 and 10 years, respectively. The overall probability of an uneventful therapy continuation was 76.3% and 58.8% at 5 and 10 years, respectively. There was a significant increase in ejection fraction/fractional area of change (P<0.001) mainly attributable to patients with systemic left ventricle (P=0.002) and decrease in systemic ventricular end-diastolic dimensions (P<0.05) after CRT. New York Heart Association functional class improved from a median 2.0 to 1.25 (P<0.001). Long-term CRT response was present in 54.8% of patients at last follow-up and was more frequent in systemic left ventricle (P<0.001). Conclusions CRT in patients with congenital heart disease was associated with acceptable survival and long-term response in ≈50% of patients. Probability of an uneventful CRT continuation was modest.

Pulmonary Right Ventricular Resynchronization in Congenital Heart Disease: Acute Improvement in Right Ventricular Mechanics and Contraction Efficiency.

BACKGROUND: Electromechanical discoordination may contribute to long-term pulmonary right ventricular (RV) dysfunction in patients after surgery for congenital heart disease. We sought to evaluate changes in RV function after temporary RV cardiac resynchronization therapy. METHODS AND RESULTS: Twenty-five patients aged median 12.0 years after repair of tetralogy of Fallot and similar lesions were studied echocardiographically (n=23) and by cardiac catheterization (n=5) after primary repair (n=4) or after surgical RV revalvulation for significant pulmonary regurgitation (n=21). Temporary RV cardiac resynchronization therapy was applied in the presence of complete right bundle branch block by atrial-synchronized RV free wall pacing in complete fusion with spontaneous ventricular depolarization using temporary electrodes. The q-RV interval at the RV free wall pacing site (mean 77.2% of baseline QRS duration) confirmed pacing from a late activated RV area. RV cardiac resynchronization therapy carried significant decrease in QRS duration (P<0.001) along with elimination of the right bundle branch block QRS morphology, increase in RV filling time (P=0.002), pulmonary artery velocity time integral (P=0.006), and RV maximum +dP/dt (P<0.001), and decrease in RV index of myocardial performance (P=0.006). RV mechanical synchrony improved: septal-to-lateral RV mechanical delay decreased (P<0.001) and signs of RV dyssynchrony pattern were significantly abolished. RV systolic stretch fraction reflecting the ratio of myocardial stretching and contraction during systole diminished (P=0.001). CONCLUSIONS: In patients with congenital heart disease and right bundle branch block, RV cardiac resynchronization therapy carried multiple positive effects on RV mechanics, synchrony, and contraction efficiency.