Adverse impact of chronic subpulmonary left ventricular pacing on systemic right ventricular function in patients with congenitally corrected transposition of the great arteries

Conduction System Pacing for Patients with Congenital Heart Disease

For patients with congenital heart disease (CHD), chronic ventricular pacing may lead to progressive cardiomyopathy owing to electromechanical dyssynchrony. Cardiac conduction system pacing (CSP) has been proposed as a physiologic pacing strategy-directly engaging the His-Purkinje system and preserving electromechanical synchrony. CSP may be indicated for a wide variety of children and adults with CHD and has emerged as an important tool in the armamentarium for cardiac implantable electronic device operators. This review provides the rationale, background, and supportive evidence for CSP in patients with CHD and discusses implant strategies and outcomes in the context of dominant ventricular morphologic categories.

End-stage heart failure in congenitally corrected transposition of the great arteries: a multicentre study

BACKGROUND AND AIMS

For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear.

METHODS

This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death.

RESULTS

From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome.

CONCLUSIONS

Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.

Cardiac resynchronization therapy using conduction system pacing after double-switch surgery for congenitally corrected transposition of the great arteries: a case report

Background

Patients with congenitally corrected transposition of the great arteries (ccTGA) are at risk of developing conduction disease and complete atrio-ventricular block and this risk increases after corrective cardiac surgery. However, the optimum pacing modality remains controversial.

Case summary

Twelve years after a double-switch surgery with ventricular septal defect correction, a 16-year-old ccTGA female was referred with an indication for cardiac resynchronization therapy. In the absence of coronary sinus (CS) or direct access to the conduction system, several therapeutic options were considered. Finally, using a three-dimensional navigation system and customized sheaths, a left bundle branch area pacing (LBBAP) lead was successfully implanted. The implantation resulted in stable pacing parameters and positive haemodynamic changes. At 9-month follow-up, pacing parameters were stable and the patient reported a significant improvement in quality of life.

Discussion

Cardiac resynchronization therapy in adults with repaired congenital heart disease remains challenging, especially in the absence of CS or direct access to the conduction system. In such a situation, LBBAP appears as an attractive alternative pacing modality. However, pre-operative management is critical to the success of the implantation.

Overview of Long-Term Outcome in Adults with Systemic Right Ventricle and Transposition of the Great Arteries: A Review

The population of patients with a systemic right ventricle (sRV) in biventricular circulation includes those who have undergone an atrial switch operation for destro-transposition of the great arteries (d-TGA) and those with congenitally corrected transposition of the great arteries (ccTGA). Despite the life expectancy of these patients is significantly increased, the long-term prognosis remains suboptimal due to late complications such as heart failure, arrhythmias, and premature death. These patients, therefore, need a close follow-up to early identify predictive factors of adverse outcomes and to implement all preventive therapeutic strategies. This review analyzes the late complications of adult patients with an sRV and TGA and clarifies which are risk factors for adverse prognosis and which are the therapeutic strategies that improve the long-term outcomes. For prognostic purposes, it is necessary to monitor sRV size and function, the tricuspid valve regurgitation, the functional class, the occurrence of syncope, the QRS duration, N-terminal pro B-type natriuretic peptide levels, and the development of arrhythmias. Furthermore, pregnancy should be discouraged in women with risk factors. Tricuspid valve replacement/repair, biventricular pacing, and implantable cardioverter defibrillator are the most important therapeutic strategies that have been shown, when used correctly, to improve long-term outcomes.

Heart failure in systemic right ventricle: Mechanisms and therapeutic options

d-loop transposition of the great arteries (d-TGA) and congenitally corrected transposition of the great arteries (cc-TGA) feature a right ventricle attempting to sustain the systemic circulation. A systemic right ventricle (sRV) cannot support cardiac output in the long run, eventually decompensating and causing heart failure. The burden of d-TGA patients with previous atrial switch repair and cc-TGA patients with heart failure will only increase in the coming years due to the aging adult congenital heart disease population and improvements in the management of advanced heart failure. Clinical data still lags behind in developing evidence-based guidelines for risk stratification and management of sRV patients, and clinical trials for heart failure in these patients are underrepresented. Recent studies have provided foundational data for the commencement of robust clinical trials in d-TGA and cc-TGA patients. Further insights into the multifactorial nature of sRV failure can only be provided by the results of such studies. This review discusses the mechanisms of heart failure in sRV patients with biventricular circulation and how these mediators may be targeted clinically to alleviate sRV failure.

Three-dimensional electroanatomical mapping guided right bundle branch pacing in congenitally corrected transposition of great arteries

Aims

The ideal pacing strategy has been the Achilles’ heel for patients with congenitally corrected transposition of great arteries (ccTGA) with bradycardia. Various pacing modalities were documented in the literature. This article describes a novel pacing strategy and its feasibility in ccTGA with an intact ventricular septum.

Methods and results

We prospectively recruited three patients with ccTGA who presented with symptomatic complete heart block to our institute and were evaluated. All patients were planned for conduction system pacing. Those who had more than moderate or severe systemic atrioventricular regurgitation and systemic ventricular dysfunction were planned for conduction system pacing with an additional lead in the coronary sinus (CS) tributary, i.e. bundle branch pacing optimized cardiac resynchronization therapy with the intention to achieve incremental benefit. Since right bundle pacing is not described previously and in view of anatomical complexity in location, three-dimensional (3D) anatomical mapping was done with the EnSite system and later right bundle capture is identified conventionally as that of a left bundle in a normal heart. All three patients have stable lead positions and adequate thresholds at short-term follow-up.

Conclusion

In this report, we demonstrated the feasibility of permanent physiological pacing of the systemic ventricle by capturing the right bundle with 3D anatomical mapping guidance, which results in physiological activation of the systemic ventricle.

Left bundle branch area pacing in congenital heart disease

AIMS

Left bundle branch area pacing (LBBAP) has been shown to be effective and safe. Limited data are available on LBBAP in the congenital heart disease (CHD) population. This study aims to describe the feasibility and safety of LBBAP in CHD patients compared with non-CHD patients.

METHODS AND RESULTS

This is a single-centre, non-randomized observational study recruiting consecutive patients with bradycardia indication. Demographic data, ECGs, imaging, and procedural data including lead parameters were recorded. A total of 39 patients were included: CHD group (n = 13) and non-CHD group (n = 26). Congenital heart disease patients were younger (55 ± 14.5 years vs. 73.2 ± 13.1, P < 0.001). Acute success was achieved in all CHD patients and 96% (25/26) of non-CHD patients. No complications were encountered in either group. The procedural time for CHD patients was comparable (96.4 ± 54 vs. 82.1 ± 37.9 min, P = 0.356). Sheath reshaping was required in 7 of 13 CHD patients but only in 1 of 26 non-CHD patients, reflecting the complex and distorted anatomy of the patients in this group. Lead parameters were similar in both groups; R wave (11 ± 7 mV vs. 11.5 ± 7.5, P = 0.881) and pacing threshold (0.6 ± 0.3 V vs. 0.7 ± 0.3, P = 0.392). Baseline QRS duration was longer in the CHD group (150 ± 28.2 vs. 118.6 ± 26.6 ms, P = 0.002). Despite a numerically greater reduction in QRS and a similar left ventricular activation time (65.9 ± 6.2 vs. 67 ± 16.8 ms, P = 0.840), the QRS remained longer in the CHD group (135.5 ± 22.4 vs. 106.9 ± 24.7 ms, P = 0.005).

CONCLUSION

Left bundle branch area pacing is feasible and safe in CHD patients as compared to that in non-CHD patients. Procedural and fluoroscopy times did not differ between both groups. Lead parameters were satisfactory and stable over a short-term follow-up.

Management Options for Congenitally Corrected Transposition: Which, When, and for Whom?

Management strategies for congenitally corrected transposition of the great arteries (ccTGA) historically consisted of a physiologic repair, resulting in the morphologic right ventricle (mRV) supporting systemic circulation. This strategy persisted despite the development of heart failure by middle age because of the reasonable short-term outcomes, and the natural history of some patients with favorable anatomy (felt to demonstrate the mRV's ability to function in the long-term), and due to the less-than-optimal outcomes associated with anatomical repair. As outcomes with anatomical repair improved, and the long-term risk of systemic mRV dysfunction became apparent, more have begun to realize its advantages. In addition to the decision on whether or not to pursue anatomical repair, and the optimal timing, studies demonstrating the nuance to morphologic left ventricle retraining have demonstrated its feasibility. Further considerations in ccTGA have begun to be better understood, including: the management of a poorly functioning mRV, systemic tricuspid valve regurgitation, the utility of morphologic left ventricle outflow tract obstruction (native or surgically created) and pacing strategies. While some considerations are apparent: biventricular pacing is superior to univentricular, tricuspid regurgitation must be managed early with either progression towards anatomical repair (pulmonary artery banding if needed for retraining) or tricuspid replacement (not repair) based on the patient's age; others remain to be completely elucidated. Overall, the heterogeneity of ccTGA, as well as the unique presentation with each patient regarding ventricular and valvular function and center-to-center variability in management strategies has made the interpretation of published data difficult. That said, more recent long-term outcomes favor anatomical repair in most situations.

Long-Term Risk of Heart Failure-Related Death and Heart Transplant After Congenital Heart Surgery in Childhood (from the Pediatric Cardiac Care Consortium)

We aimed to describe the longitudinal risk of advanced heart failure (HF) leading to death, heart transplantation, or ventricular assist device (VAD) placement after congenital heart surgery (CHS) and how it varies across the spectrum of congenital heart disease. We linked the records of patients who underwent first CHS in the Pediatric Cardiac Care Consortium between 1982 and 2003 with the United States National Death Index and Organ Procurement and Transplantation Network databases. Primary outcome was time from CHS discharge to HF-related death, heart transplant, or VAD placement, analyzed with proportional hazards models accounting for competing mortality. In 35,610 patients who survived a first CHS, there were 799 HF deaths, transplants, or VADs over a median of 23 years (interquartile range, 19 to 27). Cumulative incidence at 25 years was 2.3% (95% confidence interval [CI] 2.1% to 2.4%). Compared to mild 2-ventricle defects, the adjusted subhazard ratio for moderate and severe 2-ventricle defects was 3.21 (95% CI 2.28 to 4.52) and 9.46 (95% CI 6.71 to 13.3), respectively, and for single-ventricle defects 31.8 (95% CI 22.2 to 45.6). Systemic right ventricle carried the highest risk 2 years after CHS (subhazard ratio 2.76 [95% CI 2.08 to 3.68]). All groups had higher rates of HF-related death compared with the general population (cause-specific standardized mortality ratio 56.1 [95% CI 51.0 to 61.2]). In conclusion, the risk of advanced HF leading to death, transplantation, or VAD was high across the spectrum of congenital heart disease. While severe defects carry the highest risk, those with mild disease are still at greater risk than the general population.

Cardiac resynchronization therapy in patients with congenital heart disease and systemic right ventricle

BACKGROUND

Although patients with systemic right ventricle (SRV) represent a significant proportion of patients with congenital heart disease (CHD) implanted with cardiac resynchronization therapy (CRT), there are limited and conflicting data in this specific patient group.

OBJECTIVE

We aimed to analyze outcomes of patients with SRV implanted with a CRT device.

METHODS

Data were analyzed from an observational, retrospective, multicenter cohort study including all patients with CHD implanted with a CRT device from 6 French centers from 2004 to 2020. Response to CRT was defined as an increase in systemic ventricular ejection fraction of ≥10% and/or an improvement in New York Heart Association functional class by at least 1 grade.

RESULTS

A total of 85 patients with CHD were enrolled (mean age 39.8 ± 20.0 years; 55 [64.7%] males; 25 defibrillators [29.4%]), including 31 patients with SRV (36.5%) (mean age 43.9 ± 19.8 years; 16 [51.6%] males). The mean change in QRS duration after implantation was similar as compared with patients with systemic left ventricle (-46 ± 26 ms vs -35 ± 32 ms; P = .16). During a mean follow-up of 5.1 ± 3.5 years, late complications included 2 lead dysfunctions (6.5%), 3 CRT-related infections (9.7%), and 1 inappropriate implantable cardioverter-defibrillator shock (3.2%). The proportion of CRT responders at 6, 12, and 24 months were 82.6%, 80.0%, and 77.8% in patients with SRV vs 66.7%, 64.3%, and 69.6% in patients with systemic left ventricle (P = NS).

CONCLUSION

In this multicenter cohort, one-third of patients with CHD implanted with a CRT device had SRV. CRT in patients with SRV was associated with a high rate of responders, comparable to that of patients with systemic left ventricle.

Arrhythmias in adults with congenital heart disease and heart failure

Arrhythmias and heart failure are among the most common complications encountered by adults with congenital heart disease (CHD). In this contemporary review, we explore the interactions between arrhythmias and heart failure and discuss management strategies. Major knowledge gaps are highlighted throughout. Interactions between arrhythmias and heart failure are complex and bidirectional, with one begetting the other. Arrhythmias can provoke heart failure through various mechanisms: conduction disturbances may contribute to inefficient ventricular filling and contraction patterns; bradyarrhythmias and tachyarrhythmias can result in a reduction in cardiac output; hypoxemia may be exacerbated by right-to-left shunting; and tachycardia-induced cardiomyopathy has potentially devastating consequences if the diagnosis is delayed. In turn, heart failure promotes arrhythmogenesis through various structural (eg, fibrosis, chamber dilation, hypertrophy) and electrical remodeling effects that include changes to ion currents and channels and connexin expression, along with shortening of atrial and ventricular refractory periods with increased heterogeneity. Several shared comorbidities can contribute to, and modulate the impact of, arrhythmias and heart failure. Preemptive arrhythmia management can potentially mitigate effects on heart failure exacerbations. Similarly, optimal heart failure control could curtail its impact on arrhythmogenesis. Treatment strategies to prevent or treat heart failure in adults with CHD encompass pharmacological agents, catheter ablation, and device therapies including defibrillators, cardiac resynchronization therapy, and His bundle pacing. High-priority research avenues with major knowledge gaps include tachycardia-induced cardiomyopathy, catheter ablation of atrial fibrillation, defibrillator indications in high-risk subsets, and the role of cardiac resynchronization therapy and His bundle pacing in diverse forms of CHD.

Effect of medical treatment on heart failure incidence in patients with a systemic right ventricle

BACKGROUND

To date, clinical trials have been underpowered to demonstrate a benefit from ACE inhibitors (ACEis) or angiotensin II receptor blockers (ARBs) in preventing systemic right ventricle (sRV) failure and disease progression in patients with transposition of the great arteries (TGA). This observational study aimed to estimate the effect of ACEi and ARB on heart failure (HF) incidence and mortality in a large population of patients with an sRV.

METHODS

Data on all patients with an sRV under active follow-up at two tertiary centres between January 2007 and September 2018 were studied. The effect of ACEi and ARB on the incidence of HF and mortality was estimated using a propensity score weighting approach to control confounding.

RESULTS

Among the 359 patients with an sRV (32.2 (IQR 26.4-38.3) years, 59.3% male, 66% complete TGA with atrial switch repair and 34% congenitally corrected TGA), 79 (22%) had a moderate to severe sRV dysfunction and 138 (38%) were treated with ACEi or ARB. Fourteen (3.6%) patients died, 8 (2.1%) underwent heart transplantation and 46 (11.8%) had a new HF event over a median follow-up of 7.1 (IQR 4.0-9.4) years. On multivariate Cox analysis with adjustment using propensity score weighting approaches, ACEi or ARBs treatment was not significantly associated with a lower HF incidence or mortality in patients with an sRV.

CONCLUSIONS

Despite significant neurohormonal activation described in patients with an sRV, there is still no evidence of a beneficial effect of ACEi or ARB on morbidity and mortality in this population.

Pacing-associated cardiomyopathy in adult congenital heart disease

Objectives

Long-term single-site ventricular pacing may adversely affect ventricular function, due to dyssynchronous systemic ventricular contraction. We sought to determine the incidence, predictors and outcomes of pacing-associated cardiomyopathy (PACM) in an adult congenital heart disease (ACHD) cohort.

Methods

We retrospectively identified all patients in our database with a permanent pacemaker from 2000 to 2019. Patients were followed for the primary endpoint of unexplained decline in systemic ventricular function (PACM) and the secondary endpoint of heart failure admission.

Results

Of 2073 patients in our database, 106 had undergone pacemaker implantation. Over a median follow-up of 9.4 years, 25 patients (24%) developed PACM, but only in those with ventricular pacing percentage (VP%) ≥70%; PACM occurred in 0% of those with VP <70% and 47% of those with VP ≥70% (p<0.001). High-burden ventricular pacing (≥70%) remained predictive of PACM in transposition of the great arteries, tetralogy of Fallot and complex biventricular repair subgroups, but not in Fontan patients. Those with PACM were more likely to be admitted with heart failure (44% vs 15%, p=0.002). Cardiac resynchronisation therapy (CRT) upgrade was performed in 11 patients, with 9 responders (82%).

Conclusions

In a cohort of patients with ACHD followed long-term post-pacing, 24% developed cardiomyopathy that was significantly associated with a higher burden of ventricular pacing (VP ≥70%). Given promising response rates to CRT, patients with ACHD expected to pace in the ventricle should be closely monitored for systemic ventricular decline.

Cardiac resynchronization therapy for the failing systemic right ventricle: A systematic review

Patients with a systemic right ventricle (SRV) are at high risk for development of heart failure early in life. An SRV is encountered in patients with congenitally corrected transposition of the great arteries (CCTGA) or dextro-transposition of the great arteries (DTGA) with previous atrial switch repair (Mustard or Senning procedure). Progressive heart failure is one of the leading cause of mortality in these patients. Therefore, cardiac resynchronization therapy (CRT) has gained increasing momentum for use in this challenging congenital heart disease (CHD) population. However, current guidelines differ in recommendations for CRT in patients with an SRV as evidence supporting CRT has thus far only been described in case reports and retrospectively in relatively small study populations. In fact, the European Society of Cardiology Guideline for the management of grown-up congenital heart disease consider CRT to be 'experimental' in this population. This systematic review critically summarizes current literature on CRT in SRV patients and provides future perspectives for further research in this challenging and growing CHD population.

Diagnosis and treatment of right ventricular dysfunction in congenital heart disease

Right ventricular (RV) function is important for clinical status and outcomes in children and adults with congenital heart disease (CHD). In the normal RV, longitudinal systolic function is the major contributor to global RV systolic function. A variety of factors contribute to RV failure including increased pressure- or volume-loading, electromechanical dyssynchrony, increased myocardial fibrosis, abnormal coronary perfusion, restricted filling capacity and adverse interactions between left ventricle (LV) and RV. We discuss the different imaging techniques both at rest and during exercise to define and detect RV failure. We identify the most important biomarkers for risk stratification in RV dysfunction, including abnormal NYHA class, decreased exercise capacity, low blood pressure, and increased levels of NTproBNP, troponin T, galectin-3 and growth differentiation factor 15. In adults with CHD (ACHD), fragmented QRS is independently associated with heart failure (HF) symptoms and impaired ventricular function. Furthermore, we discuss the different HF therapies in CHD but given the broad clinical spectrum of CHD, it is important to treat RV failure in a disease-specific manner and based on the specific alterations in hemodynamics. Here, we discuss how to detect and treat RV dysfunction in CHD in order to prevent or postpone RV failure.

Implantable cardiac electronic device therapy for patients with a systemic right ventricle

The systemic right ventricle (SRV), defined as the morphological right ventricle supporting the systemic circulation, is relatively common in congenital heart disease (CHD). Our review aimed at examining the current evidence, knowledge gaps and technical considerations regarding implantable cardiac electronic device therapy in patients with SRV. The risk of sinus node dysfunction (SND) after atrial switch repair and/or complete heart block in congenitally corrected transposition of great arteries requiring permanent pacing increases with age. Similar to acquired heart disease, indication for pacing includes symptomatic bradycardia, SND and high degree atrioventricular nodal block. Right ventricular dysfunction and heart failure also represent important complications in SRV patients. Cardiac resynchronisation therapy (CRT) has been proposed to improve systolic function in SRV patients, although indications for CRT are not well defined and its potential benefit remains uncertain. Amongst adult CHD, patients with SRV are at the highest risk for sudden cardiac death (SCD). Nevertheless, risk stratification for SCD is scarce in this cohort and implantable cardioverter-defibrillator indication is currently limited to secondary prevention. Vascular access and the incidence of device-related complications, such as infections, inappropriate shocks and device system failure, represent additional challenges to implantable cardiac electronic device therapy in patients with SRV. A multidisciplinary approach with tertiary expertise and future collaborative research are all paramount to further the care for this challenging nonetheless ever increasing cohort of patients.

Permanent conduction system pacing for congenitally corrected transposition of the great arteries: A Pediatric and Congenital Electrophysiology Society (PACES)/International Society for Adult Congenital Heart Disease (ISACHD) Collaborative Study

BACKGROUND

Congenitally corrected transposition of the great arteries (CCTGA) is associated with spontaneous atrioventricular block and pacing-induced cardiomyopathy. Conduction system pacing is a potential alternative to conventional cardiac resynchronization therapy (CRT).

OBJECTIVE

The purpose of this study was to determine the outcomes of conduction system pacing for CCTGA.

METHODS

Retrospective data were collected from 10 international centers.

RESULTS

His bundle (HBP) or left bundle branch pacing (LBBP) was attempted in 15 CCTGA patients (median age 23 years; 87% male). Previous surgery had been performed in 8 and chronic ventricular pacing in 7. Conduction system pacing (11 HBP, 2 LBBP 2; nonselective in 10, selective in 3) was acutely successful in 13 (86%) without complication. In 9 cases, electroanatomic mapping was available and identified the distal His bundle and proximal left bundle branches within the morphologic left ventricle below the pulmonary valve separate from the mitral annulus. Median implant HV interval was 42 ms (interquartile range [IQR] 35-48), R wave 6 mV (IQR 5-18), and threshold 0.5 V (IQR 0.5-1.2) at median 0.5 ms. QRSd was unchanged compared to junctional escape rhythm (124 vs 110 ms; P = .17) and decreased significantly compared to baseline ventricular pacing (112 vs 164 ms; P <.01). At a median of 8 months, all patients were alive without significant change in pacing threshold or lead dysfunction. New York Heart Association functional class improved in 5 patients.

CONCLUSION

Permanent conduction system pacing is feasible in CCTGA by either HBP or proximal LBBP. Narrow paced QRS and stable lead thresholds were observed at intermediate follow-up. Unique anatomic characteristics may favor this approach over conventional CRT.

Early and Late Effects of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease

Background

There are limited data about cardiac resynchronization therapy (CRT) in adult congenital heart disease. We aimed to assess early and late outcomes of CRT among patients with adult congenital heart disease.

Methods and Results

We retrospectively studied 54 patients with adult congenital heart disease (median age, 46 years; range, 18–73 years; 74% men) who received CRT implantation (biventricular paced >90%) between 2004 and 2017. Clinical and echocardiographic data were analyzed at baseline and early (mean±SD: 1.8±0.8 years) and late (4.7±0.8 years) follow‐up after CRT. Compared with baseline, CRT was associated with significant improvement at early follow‐up in New York Heart Association functional class, QRS duration, and cardiothoracic ratio (P<0.05 for all); improvement in New York Heart Association class was sustained at late follow‐up. Among patients with a systemic left ventricle (LV; n=39), there was significant increase in LV ejection fraction and reduction in LV end‐systolic volume at early and late follow‐up (P<0.05 for both). For patients with a systemic right ventricle (n=15), there was a significant early but not late reduction in systemic right ventricular basal and longitudinal diameters. Eleven patients died, and 2 had heart transplantation unrelated to systemic ventricular morphological characteristics. Thirty‐five patients (65%) responded positively to CRT, but only baseline QRS duration was predictive of a positive response.

Conclusions

CRT results in sustained improvement in functional class, systemic LV size, and function. Patients with a systemic LV and prolonged QRS duration, independent of QRS morphological characteristics, were most likely to respond to CRT.

Clinical impact of cardiac computed tomography derived three-dimensional strain for adult congenital heart disease: a pilot study

To assess ventricular function and dyssynchrony using three-dimensional (3D) computed tomography (CT) strain in adult congenital heart disease (ACHD). We prospectively analyzed a multiphase cardiac CT data set for 22 adult patients with CHD, including 8 patients with congenital systemic right ventricle (RV) and 14 patients with repaired Tetralogy of Fallot (TOF). Eight patients had a cardiac pacemaker. Volume of Interest was drawn on a multiplanar reconstruction of the ventricle with strain overlay using a 3D-strain algorithm. Ventricular strain, inter- and intraventricular dyssynchrony, and right ventricle outflow tract (RVOT)-apex dyssynchrony were calculated. RVOT-apex dyssynchrony by ventriculography was also compared in 15 patients. Pulmonary ventricular strain, systemic ventricular strain, and septal wall strain were lower in ACHD patients than in the controls, and lower in the ACHD with pacing group than without pacing group as well. Maximum interventricular time difference and intraventricular time difference were longer than in ACHD than in the controls, and longer in the ACHD with pacing group than without pacing group as well. RVOT-apex delay was significantly longer in patients with a pacemaker than in those without a pacemaker (118.1 ± 31.9 ms vs. 76.1 ± 36.2 ms, p = 0.03). RVOT delay determined by 3D CT strain significantly correlated with that determined by ventriculography (Pearson r = 0.55, p = 0.03). 3D CT strain can detect reduced biventricular contraction and inter- and intraventricular and RVOT-apex mechanical dyssynchrony can be assessed in patients with ACHD.

Successful staged tricuspid valve replacement following cardiac resynchronization therapy in a congenitally corrected transposition of the great arteries

Simple tricuspid valve surgery for complex heart disease with systemic right ventricular dysfunction is a high-risk procedure; however, staged tricuspid valve surgery following cardiac resynchronization therapy seems to be a beneficial method to expect reverse systemic ventricular remodeling.

Trans-apical systemic tricuspid valve-in-ring replacement

Transcatheter valve replacement offers a safe and effective alternative to traditional surgical techniques in patients with congenital heart disease, especially those at high surgical risk. The most common causes of morbidity and mortality in patients with D-transposition of the great arteries status post Senning or Mustard repair is severe tricuspid valve (TV) regurgitation. Replacement of the systemic TV may be useful in those without severe systemic ventricular dysfunction. We present a case of a patient with D-loop transposition of the great arteries status post Mustard repair and TV ring placement with subsequent severe systemic TV regurgitation, at high surgical risk, who underwent a transcatheter valve replacement via a trans-apical approach using an Edwards Sapien XT valve.

Successful pregnancies after transvenous cardiac resynchronization therapy in a woman with congenitally corrected transposition of the great arteries

Congenitally corrected transposition of the great arteries is a rare heart defect that can be associated with systemic ventricular dysfunction and conduction disturbances. The use of cardiac resynchronization therapy in patients with congenital heart disease is not fully established, and achievement of successful pregnancies after implantation of transvenous, biventricular system has never been described, and which resulted in a significant clinical improvement.

We describe a 33-year-old female with congenitally corrected transposition of the great arteries, who achieved six pregnancies and successful vaginal deliveries. The two last pregnancies were achieved after cardiac resynchronization therapy for systemic ventricular dysfunction and complete heart block. A congenital cardiac disease has been identified in only one offspring.

Systemic Right Ventricle in Adults With Congenital Heart Disease

The systemic right ventricle (SRV) is commonly encountered in congenital heart disease representing a distinctly different model in terms of its anatomic spectrum, adaptation, clinical phenotype, and variable, but overall guarded prognosis. The most common clinical scenarios where an SRV is encountered are complete transposition of the great arteries with previous atrial switch repair, congenitally corrected transposition of the great arteries, double inlet right ventricle mostly with previous Fontan palliation, and hypoplastic left heart syndrome palliated with the Norwood-Fontan protocol. The reasons for the guarded prognosis of the SRV in comparison with the systemic left ventricle are multifactorial, including distinct fibromuscular architecture, shape and function, coronary artery supply mismatch, intrinsic abnormalities of the tricuspid valve, intrinsic or acquired conduction abnormalities, and varied SRV adaptation to pressure or volume overload. Management of the SRV remains an ongoing challenge because SRV dysfunction has implications on short- and long-term outcomes for all patients irrespective of underlying cardiac morphology. SRV dysfunction can be subclinical, underscoring the need for tertiary follow-up and timely management of target hemodynamic lesions. Catheter interventions and surgery have an established role in selected patients. Cardiac resynchronization therapy is increasingly used, whereas pharmacological therapy is largely empirical. Mechanical assist device and heart transplantation remain options in end-stage heart failure when other management strategies have been exhausted. The present report focuses on the SRV with its pathological subtypes, pathophysiology, clinical features, current management strategies, and long-term sequelae. Although our article touches on issues applicable to neonates and children, its main focus is on adults with SRV.

Right-sided cardiac resynchronization therapy with defibrillator implantation in a patient with corrected transposition of great arteries and persistent left superior vena cava

Patients with corrected transposition of great arteries (c-TGA) are generally known to develop atrioventricular block, systemic right ventricular dysfunction, and tricuspid regurgitation over time, which are associated with tachyarrhythmia and progressive heart failure. A 76-year-old man had been diagnosed with c-TGA. He developed a cardiopulmonary arrest while playing tennis, and an automated external defibrillator detected ventricular fibrillation (VF). Immediate cardiopulmonary resuscitation and intensive treatment were performed. He fully recovered without neurological sequelae. QRS duration was 172 ms. Echocardiography showed marked dysfunction and dyssynchrony of the systemic right ventricle (systemic right ventricular end-diastolic diameter/end-systolic diameter = 73/60 mm, systemic right ventricular ejection fraction = 34%). For secondary prevention and treatment of progressive heart failure, cardiac resynchronization therapy with defibrillator (CRT-D) implantation was recommended. Venography via the left cubital superficial vein revealed a persistent left superior vena cava (PLSVC) and giant coronary sinus that did not connect with the right superior vena cava (SVC). Because of the acute angle between the PLSVC and great cardiac vein, we selected a right-sided approach via the right SVC. We were finally able to deliver a coronary sinus lead to the lateral vein. CRT-D implantation can be achieved even in patients with c-TGA and PLSVC. <Learning objective: CRT-D implantation can be achieved even in a patient with c-TGA and PLSVC.>.

Echocardiography vs magnetic resonance imaging in assessing ventricular function and systemic atrioventricular valve status in adults with congenitally corrected transposition of the great arteries

BACKGROUND

The survival in adults with congenitally corrected transposition of the great arteries (ccTGA) might be reduced due to dysfunction of the systemic right ventricle (sRV). The quantitative echocardiographic assessment of sRV function and tricuspid (systemic atrioventricular valve) regurgitation (TR) is still a diagnostic challenge. Thus, the aim of this study was to compare echocardiographic indices of sRV function and the degree of TR with corresponding MRI (magnetic resonance imaging)-derived parameters in adults with ccTGA.

METHODS

A prospective cross-sectional study of adults with ccTGA referred to a tertiary congenital heart disease center was conducted. All patients underwent transthoracic echocardiography and MRI examinations. Thirty-three adults (19F/14M, mean age 34.1 years) were included.

RESULTS

We found significantly lower fractional area change (FAC) and global longitudinal strain (GLS) values in patients with MRI-derived RV ejection fraction (EF) <45%. A cutoff GLS<-16.3% identified sRV EF ≥45% with a sensitivity of 77.3% and specificity of 72.7%. A very strong correlation between MRI- and echocardiography-derived TR volume was observed (r=.84; P<.0001).

CONCLUSIONS

GLS is the variable with the best sensitivity but less specificity to distinguish between systemic RV EF ≥45% and below 45%, and it seems to be the preferred echocardiographic index of systemic RV function in adults with ccTGA. The quantitative assessment of TR by MRI and echocardiography showed a very strong agreement in patients with ccTGA.