Surveillance of adults with congenital heart disease: Current guidelines and actual clinical practice

BACKGROUND AND AIM

Congenital heart disease (CHD) is the most common birth defect with prevalence of 0.8%. Thanks to tremendous progress in medical and surgical practice, nowadays, >90% of children survive into adulthood. Recently European Society of Cardiology (ESC), American College of Cardiology (ACC)/ American Heart Association (AHA) issued guidelines which offer diagnostic and therapeutic recommendations for the different defect categories. However, the type of technical exams and their frequency of follow-up may vary largely between clinicians and centres. We aimed to present an overview of available diagnostic modalities and describe current surveillance practices by cardiologists taking care of adults with CHD (ACHD).

METHODS AND RESULTS

A questionnaire was used to assess the frequency cardiologists treating ACHD for at least one year administrated the most common diagnostic tests for ACHD. The most frequently employed diagnostic modalities were ECG and echocardiography for both mild and moderate/severe CHD. Sixty-seven percent of respondents reported that they routinely address psychosocial well-being.

CONCLUSION

Differences exist between reported current clinical practice and published guidelines. This is particularly true for the care of patients with mild lesions. In addition, some differences exist between ESC and American guidelines, with more frequent surveillance suggested by the Americans.

Incidence and predictors of left atrial appendage thrombus on transoesophageal echocardiography before elective cardioversion

Introduction

Guidelines recommend transoesophageal echocardiography (TOE) before cardioversion in thrombogenic arrhythmias when the requirement of ≥3 weeks of anticoagulation is not met. Current data to support this approach, especially with direct oral anticoagulants (DOAC), are scarce.

Methods

We analysed consecutive elective pre-cardioversion TOE in a high-volume electrophysiology centre for the occurrence of LAA thrombi or reduced LAA flow velocity. Possible predictors were recorded and compared in a multivariate logistic regression analysis.

Results

Consecutive pre-cardioversion TOE in 512 patients (148 female, median age 69 years) were included. In all patients, indication for TOE was either intake of anticoagulation <3 weeks before cardioversion or uncertain adherence to the prescribed anticoagulation regimen. Of the 512 TOE, 19 (3.7%) depicted a LAA thrombus. An additional 41 patients (8.0%) showed either a reduced LAA flow velocity (≤20cm/s), LAA sludge, or both (see figure). In a multivariate logistic regression analysis, QRS width on admission 12-lead ECG emerged as a possible predictor of LAA thrombus and reduced LAA flow (p=0.008). Noteworthy, a high CHA2DS2-VaSc-Score was not associated with an increased risk of reduced LAA emptying velocity and LAA thrombi were even found in patients with a CHA2DS2-VaSc-Score of 0 (n=1) and 1 (n=1).

Conclusion

The presence of LAA thrombus before an elective cardioversion is a rare event in the age of direct oral anticoagulants. However, LAA thrombi occurred even in supposed low-risk individuals according to the CHA2DS2-VaSc score. QRS width may aid in identifying patients at a high risk of a reduced LAA flow velocity.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Representative images of a solid LAA thrombus (panel A), LAA sludge (panel B, not containing a solid thrombus on i.v. contrast imaging), and a LAA free of thrombus or sludge (panel C). Panel D shows the PW Doppler signal in a patient with LAA emptying velocity reduced ≤20cm/s while panel E shows a LAA with normal flow characteristics.

Predicting Survival in Repaired Tetralogy of Fallot: A Lesion-Specific and Personalized Approach

Objectives

This study sought to identify patients with repaired tetralogy of Fallot (rTOF) at high risk of death and malignant ventricular arrhythmia (VA).

Background

To date there is no robust risk stratification scheme to predict outcomes in adults with rTOF.

Methods

Consecutive patients were prospectively recruited for late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) to define right and left ventricular (RV, LV) fibrosis in addition to proven risk markers.

Results

The primary endpoint was all-cause mortality. Of the 550 patients (median age 32 years, 56% male), 27 died (mean follow-up 6.4 ± 5.8; total 3,512 years). Mortality was independently predicted by RVLGE extent, presence of LVLGE, RV ejection fraction ≤47%, LV ejection fraction ≤55%, B-type natriuretic peptide ≥127 ng/L, peak exercise oxygen uptake (V0₂) ≤17 mL/kg/min, prior sustained atrial arrhythmia, and age ≥50 years. The weighted scores for each of the preceding independent predictors differentiated a high-risk subgroup of patients with a 4.4%, annual risk of mortality (area under the curve [AUC]: 0.87; P < 0.001). The secondary endpoint (VA), a composite of life-threatening sustained ventricular tachycardia/resuscitated ventricular fibrillation/sudden cardiac death occurred in 29. Weighted scores that included several predictors of mortality and RV outflow tract akinetic length ≥55 mm and RV systolic pressure ≥47 mm Hg identified high-risk patients with a 3.7% annual risk of VA (AUC: 0.79; P < 0.001) RVLGE was heavily weighted in both risk scores caused by its strong relative prognostic value.

Conclusions

We present a score integrating multiple appropriately weighted risk factors to identify the subgroup of patients with rTOF who are at high annual risk of death who may benefit from targeted therapy.

Adult congenital heart care in the COVID-19 era, and beyond: A call for action

While virus epidemics are nothing new to man, the scale, speed of global spread and immediacy of the COVID-19 pandemic have been truly unprecedented [1]. The entire world has been turned on its head in less than a few months, with major implications beyond disease burden and loss of life, threatening the economic status quo and human psychosocial balance and wellbeing not only for patients, but for all of us. The primary aim of our Call for Action Viewpoint was to support and protect our adult congenital heart disease (ACHD) patients and their needs during these challenging and uncertain times. This goal had to be met while we, as individuals, teams, institutions and nations, came together in a global effort to combat this aggressive virus, that appears to spare no organs or systems, nor any borders, geographic or other. As with any crisis, there is always opportunity: we are submitting herewith a vision for a different and better model of ACHD care, and for a better life journey and health care experience for our patients, that should be in place in the aftermath of the Covid-19 pandemic. Many of the points and principles discussed in this article, need not be confined to ACHD patients, but have a broader reach. And we must not forget nor neglect the most vulnerable in society at this time, namely the elderly, disabled and other dependent or disadvantaged groups in this "We Are One" global operation. Last but not least, this maybe the time to take better care of ourselves (and others) and reflect on life.

P2574Sexual activity and dysfunction in adult patients with congenital heart disease

Background

Although the number of adults with congenital heart disease (CHD) is increasing, there is little research into the impact of CHD on sexual activity and -dysfunction. Whether and to what extent sexual function is discussed with patients in clinical practice is also unknown.

Purpose

To study the current knowledge level, problems, wishes and fears of adult CHD patients regarding sexual activity.

Methods

Patients recruited via the German National Register for Congenital Heart Defects were invited to an online survey about sexual function. Overall, 4,484 patients (2,264 female) were invited to the survey and 873 patients (502 female) participated (19.5%). Patients were divided into four groups based on the underlying CHD severity classification: simple CHD (136 patients), moderate CHD (354 patients), complex CHD (340 patients).

Results

301 (35.6%) patients reported that they had very rarely or no sex at all in the six months preceding the survey (simple CHD: 25.7%, moderate CHD: 33.6%, complex CHD: 38.2%, other CHD: 39.5%). Based on the last six months, 71.2% of the surveyed male patients estimated the probability of having and maintaining an erection as high or very high (simple CHD: 85%, moderate CHD: 71.4%, complex CHD: 69.7%). In addition, 60.6% of the interviewed male patients reported to be almost always or always able to get a full erection sufficient for sexual intercourse. In contrast, 14.6% of the male patients already had erectile dysfunction, but did not discuss this issue with their physician. Overall, only 3.5% of the male patients stated that they were offered a consultation regarding erectile dysfunction by their treating physician. In contrast, 29.6% of the male patients would like to receive such counseling during routine medical examinations. In the last six months, 56.4% of the interviewed female patients, reported no difficulties with lubrication. 44% of the female patients already received advice from their physician on sexuality, contraception and pregnancy and 64.5% of the female patients would like to receive additional medical advice and information on sexuality, contraception and pregnancy in the context of routine medical check-ups.

Conclusions

This study reveals important issues regarding sexual function in male and female adult patients with CHD. The study reveals important gaps in counselling patients regarding sexual issues beyond contraception and pregnancy.

P4697Complications and mortality related to non-cardiac surgery in adult congenital heart disease: Results of a nationwide study including 20,450 cases

Background

Adults with congenital heart disease (ACHD) represent a growing patient population with high morbidity and increasing health resource utilization. In addition to acute and chronic cardiac complications, these patients require numerous non-cardiac surgical procedures during their life-time. Limited data on the morbidity and mortality risk related to non-cardiac surgical procedures exist in contemporary CHD patients. The aim of this study was to analyse the frequency and outcome of non-cardiac surgical procedures in contemporary ACHD patients based on all hospital admissions in Germany between 2011 and 2016.

Methods

Based on the German diagnosis related groups data of patients treated between 2011 and 2016 we identified all ACHD patients treated surgically as inpatients for non-cardiac problems. The dataset contains information on patient demographics, primary and secondary diagnoses, interventional or surgical procedures, duration of stay and outcome including mortality. The primary endpoint of the study was surgery related mortality as well as major adverse events (defined as death or myocardial infarction, stroke, pulmonary embolism, sepsis or resuscitation).

Results

Overall, 48,872 ACHD cases were hospitalized during the study period. Of these, 20,450 (41.8%) were hospitalized for non-cardiac surgical procedures. The median age at surgery was 50.0 years and 62.9% of patients were male. The overall mortality rate following non-cardiac operations was 2.8% (95% CI 2.6–3.0%). The highest mortality rates were observed for procedure codes involving pharynx, larynx or trachea (27.2%; 95% CI: 22.3–32.1%) and lung surgery (15.4%; 95% CI: 13.3–17.8%). Abdominal surgery (9.2%; 95% CI: 7.7–10.9) and neurosurgical procedures (7.8%; 95% CI: 5.4–10.9) also had relative high mortality rates. The major adverse event rate overall was 12.7% (95% CI 11.7–12.7%). The highest major adverse event rates were observed for surgery of the airways (43.2%; 95% CI: 40.2%-46.4%).

Conclusions

Non-cardiac surgical procedures are common in ACHD patients and are associated with considerable mortality and morbidity in this cohort. Especially, surgical procedures involving the airways or neurosurgery emerged as risky procedures. However, even for routine abdominal or orthopaedic surgery considerable mortality and morbidity was observed. Overall, our data support careful pre-operative patient evaluation and concentration of surgical procedures at centres with extensive surgical and anaesthetic experience with ACHD patients.

2395LGE CMR predicts sudden death and VT in adults with repaired tetralogy of Fallot - a prospective study with 3500 patient follow up years

Background

Adults with repaired tetralogy of Fallot (rtoF) are at risk of ventricular arrhythmia and sudden cardiac death (SCD). Cross-sectional data suggest association of late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) with adverse clinical risk factors

Purpose

We sought to determine prognosis related to LGE CMR.

Methods

In this prospective cohort study the primary composite outcome comprised the first of cardiovascular death (SCD or heart failure-related), aborted SCD (successfully resuscitated cardiac arrest or appropriate AICD shock for ventricular fibrillation), and clinical sustained ventricular tachycardia (VT>30 seconds duration).

Results

In 531 rtoF patients (median age 32; 23–42, 296 (56%) male, NYHA≥II 17%) followed up after LGE CMR for median 5 (1.7–8.9) years, there were 39 primary composite outcomes: 10 SCD, 11 heart failure related deaths (2 perioperative RV failure), 2 aborted SCD and 16 clinical sustained VT events. At study end, there were 28 ventricular arrhythmic events in 28 rtoF patients (10 SCD, 16 clinical sustained VT, 2 aborted VF) that were significantly predicted by RV LGE extent (HR 1.45 CI: 1.3–1.6; P<0.001).

Univariable predictors of the primary outcome were RV LGE score; HR: 1.44 (1.31–1.57; p<0.001), (Figure) together with older age; HR: 1.05 (1.02–1.07; P<0.001), late repair; HR: 1.04 (1.02–1.07; p<0.001), lower RV ejection fraction; HR: 0.92 (0.89–0.95; p<0.001), larger RVOT akinetic length; HR: 1.04 (1.02–1.06; p<0.001) larger right atrial area; HR: 1.2 (1.12–1.29; p<0.001); higher BNP levels; HR: 1.01 (1–1.02; p<0.001), lower peak VO2; HR: 0.89 (0.83–0.96; p=0.001), prior atrial arrhythmia; HR: 5.3 (2.8–10.07; p<0.001), and non-sustained VT; HR: 4.1 (2.1–7.7; p<0.001). Inducible VT did not predict the primary outcome; HR: 2.1 (0.57–8; p=0.25)

In multivariable analysis both RV LGE score and indexed right atrial area (RAAi) only, remained predictive of the primary outcome (HR 1.29 CI: 1.12–1.49; p<0.001 and HR 1.1 CI: 1.02–1.12; p=0.01, respectively). Patients could accordingly be stratified such that supramedian RV LGE score (≥5) and RAAi ≥16cm2/m2 had 5-year event free survival 84% vs 94% for supramedian RV LGE score (≥5) and RAAi <16cm2/m2 or 98% for inframedian RV LGE score with RAAI<16cm2/m2. Figure.

Conclusions

For every unit increase in CMR defined RV fibrosis score there is a 44% increased risk of sudden cardiac death and VT. LGE CMR and maximal right atrial area should therefore be incorporated into risk stratification for sudden death in adults with rTOF.

Acknowledgement/Funding

British heart foundation

77Infective endocarditis in patients with congenital heart disease: Results of a nationwide study including 1494 endocarditis cases

Background

Infective endocarditis (IE) represents a major complication in patients with congenital heart disease (CHD) and is associated with high morbidity and mortality. The aim of this study was to analyse the frequency and outcome of IE in contemporary CHD patients based on all IE hospital admissions in Germany between 2011 and 2016.

Methods

Based on the German diagnosis related groups data of patients treated between 2011 and 2016, we identified all CHD patients with a diagnosis of IE. The data contains information on patient demographics, primary and secondary diagnoses, interventional or surgical procedures, duration of stay and outcome including mortality. The primary endpoint of the study was endocarditis-associated mortality as well as major adverse events (defined as death or myocardial infarction, stroke, pulmonary embolism, sepsis, resuscitation or intubation).

Results

Overall, 181,924 CHD patients were included in the analysis (55% male; 73% children, mean age 2.3 years; 27% adults, mean age 58.4 years; underlying heart defect of simple complexity 55%, moderate complexity 23% and complex heart defect 22%, respectively). During the study period 1494 cases were treated for IE corresponding to 0.82% of all inpatient treatment cases in CHD patients. Mortality rate was 6.6% (95% CI: 5.0–7.6%) with a major adverse events rate of 44.6% (95% CI: 41.3–48.2%). In total, 682 IE patients (45.7% CI: 42.3%-49–2%) required a surgical intervention. The relative risk of dying due to endocarditis in CHD patients was significantly lower compared to older IE patients without CHD (relative risk 0.39; 95% CI: 0.32–0.47).

Conclusions

Infective endocarditis accounts for a minority of CHD related hospitalizations but remains a deadly disease with a high proportion of patients requiring surgical intervention. In addition, major adverse events are common in this setting, with almost half of the IE population presenting with a major adverse event. Due to different demographic and comorbidity spectrum encountered in CHD patients, these younger patients tend to have significantly better survival prospects compared to non-CHD IE patients in the current era.

4971Blood viscosity and its relevance to the diagnosis and management of pulmonary hypertension: a new elephant in the cathlab

Background

Pulmonary vascular resistance (PVR) is an essential parameter assessed during cardiac catheterization. It is used to confirm pulmonary vascular disease, to assess response to targeted pulmonary hypertension (PH) therapy and to determine the possibility of surgery, such as closure of intra-cardiac shunt or transplantation. While PVR is believed to mainly reflect the properties of the pulmonary vasculature, it is also related to blood viscosity (BV).

Objectives

We aimed to assess the relationship between measured (mPVR) and viscosity-corrected PVR (cPVR) and its impact on clinical decision-making.

Methods

We assessed consecutive PH patients undergoing cardiac catheterization. BV was assessed using the Hutton method.

Results

We included 465 patients (56.6% female, median age 63y). The difference between mPVR and cPVR was highest in patients with abnormal Hb levels (anemic patients: 5.6 [3.4–8.0] vs 7.8Wood Units (WU) [5.1–11.9], P<0.001; patients with raised Hb: 10.8 [6.9–15.4] vs. 7.6WU [4.6–10.8], P<0.001, respectively). Overall, 33.3% patients had a clinically significant (>2.0WU) difference between mPVR and cPVR, and this was more pronounced in those with anemia (52.9%) or raised Hb (77.6%). In patients in the upper quartile for this difference, mPVR and cPVR differed by 4.0WU [3.4–5.2].

Adjustment of PVR required

Conclusions

We report, herewith, a clinically significant difference between mPVR and cPVR in a third of contemporary patients assessed for PH. This difference is most pronounced in patients with anemia, in whom mPVR significantly underestimates PVR, whereas in most patients with raised Hb, mPVR overestimates it. Our data suggest that routine adjustment for BV is necessary.

Does gender affect the prognosis and risk of complications in patients with congenital heart disease in the modern era?

Gender differences in the outcome of acquired cardiovascular disease are well known, but available literature on the influence of gender in congenital heart disease (CHD) is limited. Registries have provided valuable, albeit at times conflicting data. Higher mortality rates have been reported in older males with CHD, while sudden cardiac death is more prevalent in young males. However, mortality around surgery for CHD is higher in girls compared to boys, likely due to smaller body size. Women are at higher risk of developing pulmonary arterial hypertension, but at lower risk of adverse aortic outcomes, even though they are less likely to receive aortic surgery. Finally, women have a lower risk of presenting with infective endocarditis compared to men. The underlying reasons for gender differences in CHD can be attributed to genetic, hormonal, behavioural and other causes. The aim of the present paper is to provide an overview of available evidence on gender differences in CHD and their impact on outcome.

Pulmonary hypertension in adults with congenital heart disease: Updated recommendations from the Cologne Consensus Conference 2018

In the summer of 2016, delegates from the German Respiratory Society (DGP), the German Society of Cardiology (DGK) and the German Society of Pediatric Cardiology (DGPK) met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary hypertension (PH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines, aiming at their practical implementation, considering country-specific issues, and including new evidence, where available. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH in adults associated with congenital heart disease (CHD). As such patients are often complex and require special attention, and the general PAH treatment algorithm in the ESC/ERS guidelines appears too unspecific for CHD, the working group proposes an analogous algorithm for the management of PH-CHD which takes the special features of this patient group into consideration, and includes general measures, supportive therapy, targeted PAH drug therapy as well as interventional and surgical procedures. The detailed results and recommendations of the working group on PH in adults with CHD, which were last updated in the spring of 2018, are summarized in this article.

[Pulmonary hypertension in grown-ups with congenital heart disease: Recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. The guidelines contain detailed recommendations for different forms of PH, and specifically address PH associated with congenital heart disease (CHD). However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH in grown-ups with congenital heart disease (GUCH). This article summarizes the results and recommendations of this working group.

[Pulmonary hypertension associated with left heart disease: recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. While the guidelines contain detailed recommendations regarding pulmonary arterial hypertension (PAH), they contain only a relatively short paragraph on other, much more common forms of PH such as PH due to left heart disease. Despite the lack of data, targeted PAH treatments are increasingly being used for PH associated with left heart disease. This development is of concern because of limited ressources and the need to base treatments on scientific evidence. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease, representing an unmet need of targeted PH therapies. It that sense, the practical implementation of the European Guidelines in Germany requires the consideration of several specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, several working groups were initiated, one of which was specifically dedicated to PH associated with left heart disease. This article summarizes the results and recommendations of this working group.

Seeking optimal relation between oxygen saturation and hemoglobin concentration in adults with cyanosis from congenital heart disease

In patients with cyanosis from congenital heart disease, erythropoiesis is governed by many factors that can alter the expected relation between the oxygen saturation (O(2sat)) and hemoglobin concentration. We sought to define the relation between the O(2sat) and hemoglobin in such patients and to predict an ideal hemoglobin concentration for a given O(2sat). Adults with congenital heart defects and cyanosis were studied prospectively using blood tests and exercise testing. Nonoptimal hemoglobin was defined as any evidence of inadequate erythropoiesis (i.e., iron, folate, or vitamin B(12) deficiency, increased erythropoietin, reticulocytosis, or a right-shifted oxygen-hemoglobin curve). For patients without these factors, a linear regression equation of hemoglobin versus O(2sat) was used to predict the optimal hemoglobin for all patients. Of the 65 patients studied, 21 met all the prestudy criteria for an optimal hemoglobin. For all patients, no correlation was found between O(2sat) and hemoglobin (r = -0.22). However, a strong linear correlation was found for those meeting the criteria for optimal hemoglobin (r = -0.865, p <0.001). The optimal hemoglobin regression equation was as follows: predicted hemoglobin = 57.5 - (0.444 × O(2sat)). A negative correlation was found between the hemoglobin difference (predicted minus measured) and exercise duration on cardiopulmonary exercise testing (r = -0.396, p = 0.005) and the 6-minute walk distance (r = -0.468, p <0.001). In conclusion, a strong relation between O(2sat) and hemoglobin concentration can be shown in stable cyanotic patients and used to predict an optimal hemoglobin. This relation might be useful in defining functional anemia in this group.

Right Ventricular Mechanics and QRS Duration in Patients With Repaired Tetralogy of Fallot

Background— Patients after repair of tetralogy of Fallot (ToF) frequently have right ventricular (RV) dysfunction and prolonged QRS duration (QRSd) and thus could be candidates for cardiac resynchronization therapy. We aimed to assess the relationship between QRSd and the timing of RV wall motion, including the RV outflow tract (RVOT), in these patients.

Methods and Results— Sixty-seven repaired ToF patients (median age, 34 years; interquartile range, 24 to 43 years) and 35 age-matched control subjects were studied by echocardiography and cardiovascular magnetic resonance (n=55 of 67 ToF patients). Time intervals of the RV cardiac cycle were measured from Doppler recordings. Long-axis M-mode recordings were acquired from the right ventricular (RV) free wall and RV outflow tract (RVOT), and the delay in onset of long-axis shortening was measured. ToF patients showed minor abnormalities of the RV cardiac cycle unrelated to QRSd. RV ejection time was prolonged and correspondingly filling time was reduced compared with control subjects (22.3±2.6 versus 20.0±2.9 s/min, P <0.0001; 29.0±3.8 versus 32.7±3.5 s/min, P <0.0001). Total isovolumic time was normal in ToF patients (8.7±4.0 versus 7.4±2.9 s/min; P =NS). QRSd correlated with the delay in RV free wall motion ( r =0.55, P <0.0001) and more so with the delay in RVOT shortening ( r =0.82, P <0.0001). QRSd also correlated with measures of RVOT abnormality such as long-axis RVOT excursion and akinetic area length ( r =−0.46, P =0.004; r =0.33, P =0.01).

Conclusions— QRSd in postoperative ToF patients reflects mainly abnormalities of the RVOT rather than the RV body itself. Thus, prevention and treatment of mechanical asynchrony and malignant arrhythmia should focus on the RV infundibulum. Indications for cardiac resynchronization therapy after ToF repair warrant further investigation.