Right and left ventricular systolic function late after repair of tetralogy of Fallot

Clinical, Electroanatomic and Electrophysiologic Characterisation and Outcomes of Catheter Ablation for Ventricular Tachycardia Following Valvular Intervention

INTRODUCTION

Ventricular tachycardia (VT) can occur following valvular interventions. There are limited data describing substrate and ablation approaches in such patients. We sought to describe the clinical, electrophysiologic, electroanatomic features and catheter ablation outcomes of patients with VT following aortic and/or mitral valve intervention.

METHODS

Over 12-years, consecutive patients with aortic valve replacement (AVR) and/or mitral valve replacement (MVR) or repair, undergoing VT ablation, were identified from 2 centres. Clinical and procedural parameters, and outcomes are described.

RESULTS

Twenty-three patients (age 66±14years, 78% male, left ventricular ejection fraction 37±16%), with prior AVR (mechanical n=6, bioprosthetic n=2, transcatheter n=1), MVR (mechanical n=5, bioprosthetic n=1), mitral valve repair (n=6) and both mechanical AVR and MVR (n=2), underwent VT ablation. Sixteen had concurrent ischemic cardiomyopathy, 10 with prior bypass surgery. Left ventricular access was obtained in 21/23 (91%) patients (transseptal n=14, retrograde aortic n=5, transapical n=2), with perivalvular scar identified in 17/21 (81%). Re-entrant VT isthmi involved the perivalvular regions in 12/23 (52%) patients, and regions remote from the valve in the remainder; 9% had non-scar related VT. Intramural substrate was ablated from adjacent chambers in 5/23 (22%) patients and with half-normal saline irrigation in 8/23 (35%) patients. There were no instances of catheter entrapment. Following final ablation, VA-free survival was 78% at 13-months.

CONCLUSION

Only half of VT circuits following valvular interventions involve the valve regions themselves, whilst the remainder involve unrelated regions. Catheter ablation is safe and efficacious at treating VT following valvular intervention, but novel strategies may be required. This article is protected by copyright. All rights reserved.

Systolic and diastolic functional reserve of the subpulmonary and systemic right ventricles as assessed by pharmacologic and exercise stress: A systematic review

We performed a systematic review of the literature on the assessment of subpulmonary and systemic right ventricular (RV) functional reserve during pharmacological and exercise stress in congenital heart patients and patients with pulmonary arterial hypertension (PAH). Literature search was conducted using PubMed, EMBASE, and MEDLINE from their inception up to August 2020. Of 913 records identified, 56 studies with a total of 1730 patients were included. Of the 56 studies, 23 assessed subpulmonary RV functional reserve in repaired tetralogy of Fallot patients, 19 assessed systemic RV reserve in patients with transposition of the great arteries (TGA) after atrial switch and those with congenitally corrected TGA, and 14 assessed subpulmonary RV research in patients with PAH. Pharmacological and exercise stress was used, respectively, in 22 and 34 studies. The main findings were (1) impairment of RV systolic and diastolic functional reserve, (2) associations between impaired functional reserve and worse baseline functional parameters, and (3) prognostic implications of RV systolic functional reserve on clinical outcomes in patients with volume and/or pressure-loaded subpulmonary and systemic right ventricles. Further studies are required to establish the incremental value of incorporating stress studies of RV systolic and diastolic function in the clinical management algorithm of congenital heart patients and patients with PAH.

Right Ventricular Outflow Tract Surgical Resection in Young, Large Animal Model for the Study of Alternative Cardiovascular Patches

Tetralogy of Fallot (ToF) is a severe congenital heart defect (CHD) that requires surgical reconstruction soon after birth. Reconstructive surgery involves the implantation of synthetic cardiovascular patches to widen the right ventricular outflow tract (RVOT) and repair defects in the septal wall. However, synthetic patches can cause complications for these patients later in life as they do not integrate or adapt in the tissue of a growing patient; a limitation that could be solved with the development of a patch fabricated from a degradable biomaterial. Unfortunately, the lack of appropriate pre-clinical models has hindered the development of novel patch materials. Currently, most studies use rodent models to study the efficacy of new patch materials; however, large animal models are necessary to develop realistically sized patches in a clinically relevant growing heart where gradients in diffusion and length scales for cell migration are more similar to the human. Here, we describe a novel method by which a Satinsky vascular clamp is used to isolate RVOT muscle for resection followed by implantation of a cardiovascular patch in an appropriately young, rapidly growing porcine model.

Comparison of Long-term Outcomes of Valve-Sparing and Transannular Patch Procedures for Correction of Tetralogy of Fallot

IMPORTANCE

The choice of the right surgical technique for correction of tetralogy of Fallot (TOF) is contentious for patients with a moderate to severe right outflow tract obstruction. The use of a transannular patch (TAP) exposes patients to chronic pulmonary regurgitation, while valve-sparing (VS) procedures may incompletely relieve pulmonary obstruction.

OBJECTIVE

To compare 30-year outcomes of TOF repair after a VS procedure vs TAP.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective population-based cohort study was conducted among all patients with TOF born in the province of Quebec, Canada, from 1980 to 2015 who underwent complete surgical repair. Patients who received a TAP or VS procedure were matched using a propensity score based on preoperative factors in a 1:1 ratio. Data were analyzed from March 2020 through April 2021.

EXPOSURES

The study groups were individuals who received TAP and those who received VS. The VS group was further stratified by the presence of residual pulmonary stenosis.

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality, with 30-year survival evaluated using Cox proportional-hazards models. Secondary outcomes included the cumulative mean number of cardiovascular interventions, pulmonary valve replacements (PVRs), and cardiovascular hospitalizations were evaluated using marginal means/rates regressions.

RESULTS

Among 683 patients with TOF (401 patients who underwent TAP [58.7%] and 282 patients who underwent a VS procedure [41.3%]), adequate propensity score matching was achieved for 528 patients (264 patients who underwent a VS procedure and 264 patients who underwent TAP). Among this study cohort, 307 individuals (58.1%) were men. The median (interquartile range [IQR]) follow-up was 16.0 (8.1-25.4) years, for a total of 8881 patient-years, including 63 individuals (11.9%) followed up for more than 30 years. Individuals who received a VS procedure had an increased 30-year survival of 99.1% compared with 90.4% for individuals who received TAP (hazard ratio [HR], 0.09 [95% CI, 0.02-0.41]; P = .002). Patients who underwent TAP had an increased 30-year cumulative mean number of cardiovascular interventions compared with patients who underwent a VS procedure without residual pulmonary stenosis (2.0 interventions [95% CI, 1.5-2.7 interventions] vs 0.7 interventions [95% CI, 0.5-1.1 interventions]; mean ratio [MR], 0.36 [95% CI, 0.25-0.50]; P < .001) and patients who underwent a VS procedure with at least moderate residual stenosis (1.3 interventions [95% CI, 0.9-1.9 interventions]; MR, 0.65 [0.45-0.93]; P = .02). Results were similar for PVR, with a 30-year cumulative mean 0.3 PVRs [95% CI, 0.1-0.7 PVRs] for patients who underwent a VS procedure without residual pulmonary stenosis (MR, 0.22 [95% CI, 0.12-0.43]; P < .001) and 0.6 PVRs (95% CI, 0.2-1.5 PVRs) for patients with at least moderate residual stenosis (MR, 0.44 [95% CI, 0.21-0.93]; P = .03), compared with 1.4 PVRs (95% CI, 0.8-2.5 PVRs) for the TAP group. No statistically significant difference was found for cardiovascular hospitalizations.

CONCLUSIONS AND RELEVANCE

This study found that patients who underwent a VS procedure had increased 30-year survival, fewer cardiovascular reinterventions, and fewer PVRs compared with individuals who underwent TAP, even in the presence of significant residual pulmonary stenosis. These findings suggest that it is beneficial to perform a VS procedure when possible, even in the presence of moderate residual stenosis, compared with the insertion of a TAP.

The impact of native Fallot anatomy on future therapeutic requirements and outcomes at follow-up

Background

In patients with repaired Fallot, subsequent surgical or interventional procedures and adverse cardiac events are frequent. We aimed to evaluate the impact of a simple pre-operative anatomic classification based on the size of the pulmonary valve (PV) annulus and branches on future therapeutic requirements and outcomes.

Method

This is a single-center retrospective analysis of patients operated for Fallot before the age of 2 years, from January 1990. Pre-operative anatomy, surgical and interventional procedures and adverse events were extrapolated from clinical records.

Results

Among the 312 patients, a description of the PV and pulmonary arteries (PAs) native anatomy was known in 239 patients (male:147, 61.5%), which were divided in the following 3 groups: group 1 (65 patients) with normal size of both PV and PAs; group 2 (108 patients) with PV hypoplasia but normal size PAs; group 3 (66 patients) with concomitant hypoplasia of the PV and PAs. During the 12.7 years (IQR 6.7–17) follow-up time, 23% of patients required at least one surgical or interventional procedure. At Kaplan–Meier analysis, there was a significant difference in requirement of future surgical or interventional procedures among the 3 groups (p < 0,001). At multivariate Cox regression analysis, hypoplasia of PV and PAs was an independent predictor of subsequent procedures (HR:3.1,CI:1.06–9.1, p = 0.03).

Conclusion

Native anatomy in Tetralogy of Fallot patients affects surgical strategy and follow-up. It would be therefore advisable to tailor patient’s counseling and follow-up according to native anatomy, rather than following a standardized protocol.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-021-00249-y.

Detection of persistent systolic and diastolic abnormalities in asymptomatic pediatric repaired tetralogy of Fallot patients with preserved ejection fraction: a CMR feature tracking study

OBJECTIVES

A fast cardiovascular magnetic resonance (CMR) feature tracking was applied to assess ventricular systolic and diastolic function. This study sought to detect right ventricular (RV) systolic and diastolic abnormalities in asymptomatic pediatric repaired tetralogy of Fallot (rTOF) patients with preserved RV ejection fraction (EF).

METHODS

One hundred asymptomatic pediatric rTOF patients with preserved RVEF ≥ 45% and 52 control subjects underwent cine CMR examinations. Tricuspid annular plane systolic excursion (TAPSE); peak tricuspid annular systolic (S_m), early diastolic (E_m), and late diastolic (A_m) velocities; and biventricular global radial (GRS), circumferential (GCS), and longitudinal strains (GLS) were analyzed using CMR feature tracking.

RESULTS

TAPSE, S_m, E_m, A_m, and RV GLS were significantly lower in rTOF patients compared with controls (all p < 0.01). The lower limits (mean-2·standard deviations) of TAPSE, S_m, E_m, and A_m among controls were 10.9 mm, 6.3 cm/s, 8.9 cm/s, and 2.4 cm/s, respectively, and 78%, 75%, 75%, and 19% of rTOF patients had corresponding measurements below these thresholds. Among rTOF patients, RV GLS was significantly lower in females than in males (p < 0.05).

CONCLUSIONS

Despite preserved RVEF, there was a high prevalence of RV systolic and diastolic dysfunction among pediatric rTOF patients, which was detected using fast CMR feature tracking.

KEY POINTS

• There was high prevalence of systolic and diastolic dysfunction in asymptomatic pediatric repaired tetralogy of Fallot (rTOF) patients despite preserved right ventricular (RV) ejection fraction (EF). • Significant correlations were observed between right ventricular (RV) measurements (strains, tricuspid annular plane systolic excursion (TAPSE), peak tricuspid annular early diastolic velocity (E_m), peak tricuspid annular late diastolic velocity (A_m)), and left ventricular (LV) strain measurements, which indicates ventricular-ventricular interactions at systolic and diastolic function level. • Right ventricular (RV) global longitudinal strain (GLS) was lower in female repaired tetralogy of Fallot (rTOF) patients than in males, suggesting females with rTOF may be at a higher risk of developing RV systolic dysfunction than males.

Persistent left superior vena cava accompanying repaired tetralogy of Fallot: Does it pose a challenge for device implantation?

Persistent left superior vena cava is a thoracic venous return anomaly. Tetralogy of Fallot is one of the most common congenital anomalies seen with persistent left superior vena cava. We are presenting a successful cardiac resynchronisation therapy device implantation in a patient with repaired tetralogy of Fallot and persistent left superior vena cava combination which has not been previously reported in the literature.

How pulmonary valve regurgitation after tetralogy of fallot repair changes the flow dynamics in the right ventricle: An in vitro study

Tetralogy of Fallot is the most common cyanotic congenital disease, affecting 10% of children with congenital heart disease. The surgical management of patients with Tetralogy of Fallot leads, however, to significant detrimental effects on the right ventricle including pulmonary valve regurgitation. This experiment aimed to simulate different cases of pulmonary valve regurgitation with varying degrees of severity in order to observe the changes in flow structures present in the right ventricle. Planar time-resolved particle image velocimetry measurements have been performed on a custom-made double activation simulator reproducing flow conditions in a model of a right ventricle. Changes in flow characteristics in the right ventricle have been evaluated in terms of velocity fields and profiles, tricuspid inflow jet orientation and viscous energy dissipation. Our results show that pulmonary valve regurgitation significantly alters the flow in the right ventricle mostly by impairing the diastolic inflow through the tricuspid valve and by increasing viscous energy loss. This fundamental work should allow for a better understanding of such changes in the RV flow dynamics. It may also help in developing new strategies allowing for a better follow-up of patients with repaired TOF and for decision-making in terms of pulmonary valve replacement.

Ventricular Myocardial Deformation Imaging of Patients with Repaired Tetralogy of Fallot

In patients with repaired tetralogy of Fallot (TOF), dysfunction of the right and left ventricles remains an important issue. Adverse right ventricular (RV) remodeling has been related to RV dilation secondary to pulmonary regurgitation, electromechanical dyssynchrony, and myocardial fibrosis. Left ventricular (LV) dysfunction is attributed among other factors to altered ventricular-ventricular interaction. Advancements in echocardiography and cardiac magnetic resonance imaging have enabled direct interrogation of myocardial deformation of both ventricles in terms of myocardial strain and strain rate. Emerging evidence suggests that myocardial deformation imaging may provide incremental information for clinical use. In children and adults with repaired TOF, there is a growing body of literature on the use of myocardial deformation imaging in the assessment of ventricular mechanics and its clinical and prognostic values. The present review aims to provide an overview of impairment in RV and LV mechanics, associations between RV and LV deformation, changes in ventricular deformation after pulmonary valve replacement, and associations between measures of RV and LV deformation and outcomes and to highlight the clinical translational potential of myocardial deformation imaging in patients with repaired TOF.

Left Ventricular Stiffness in Adolescents and Young Adults with Repaired Tetralogy of Fallot

Left ventricular (LV) remodeling after tetralogy of Fallot (TOF) repair may influence LV stiffness. We hypothesized that LV stiffness is altered after TOF repair and related to myocardial calibrated integrated backscatter (cIB) and LV diastolic myocardial deformation. Seventy-seven TOF patients and 80 controls were studied. LV stiffness was assessed by diastolic wall strain (DWS) as defined by (LVPW_systole-LVPW_diastole)/LVPW_systole, where LVPW is LV posterior wall thickness, and stiffness index as defined by (E/e/LV end-diastolic dimension), where E and e are respectively early diastolic transmitral inflow and mitral annular velocities. Septal and LVPW cIB and LV diastolic strain rates were determined. Patients had significantly lower DWS (p < 0.001), higher stiffness index (p < 0.001), and greater cIB (p < 0.001). LV DWS correlated negatively with LV stiffness index (r = -0.31, p < 0.001), septal cIB (r = -0.21, p = 0.01), E/e ratio (r = -0.30, p < 0.001) and RV end-diastolic area (r = -0.31, p < 0.001), and positively with LV early (r = 0.33, p < 0.001) and late (r = 0.20, p = 0.01) diastolic strain rates and RV fractional area change (FAC) (r = 0.24, p = 0.003). Multivariate analysis revealed E/e (β = -0.26, p = 0.008), RV end-diastolic area (β = -0.20, p = 0.02), and RV FAC (β = 0.18, p = 0.01) as significant correlates of DWS. Left ventricular stiffening occurs after TOF repair and is related to impaired LV diastolic myocardial deformation, myocardial cIB, and RV volume overload.

Postsystolic Shortening Is Associated with Altered Right Ventricular Function in Children after Tetralogy of Fallot Surgical Repair

The aim of the study was to determine whether segmental interactions, as expressed by postsystolic shortening (PSS), affects RV mechanics and are connected with impaired systolic and diastolic function in rTOF children. Patients and Methods: 55 rTOF adolescent (study group), and 34 healthy volunteers (control group) were examined using classical Doppler flow (Doppler), Tissue Doppler Imaging (TDI) and Speckle Tracking Echocardiography (STE). PSS was found to occur when time to peak (TTP) was longer than pulmonary valve closure time (PVCT). TTP and strain were derived from RV lateral segments—basal (BL), medial (ML) and apical (AL) in STE. PVCT was measured from the beginning of QRS complex in the ECG to the termination of Doppler flow at the pulmonary valve. TDI was obtained at the lateral tricuspid annulus site and the systolic (S′), early (E′) and late diastolic (A’) peak velocities were measured along with isovolumic contraction (IVCT), and relaxation (IVRT) time. PW was used to measure early tricuspid inflow velocity (E) for calculating the E/E’ ratio. The TDI data in patients with PSS presence (TTP>PVCT) and those in whom it did not occur (TTP≤PVCT) were compared. Results: PSS in BL, ML and AL were observed respectively in: 27(51,9%), 9 (18%), and 8 (16,7%) patients. Mean values of TTP in BL, ML, and AL were respectively: 420.6±55.5ms, 389.8±50.0ms and 366.7±59.0ms. PVCT mean value was 396.6±33.5ms. In the study group, the mean E’ in TTP>PVCT was significantly lower (4.8±1.8 cm/s) compared to mean E’ in TTP≤PVCT (8.4±2.6 cm/s), p<0.01. The average E/E’ was significantly higher in TTP>PCVT than in TTP≤PVCT, respectively 21.6±7.3 vs 12.2±5.1, p<0.05. IVRT was significantly prolonged in TTP>PVCT compared to IVRT in TTP≤PVCT, respectively 95.9±38.7 vs 77.0±35.1, p<0.05. Furthermore, in TTP>PVCT, significantly higher strain in BL (-28.8±8.7%) was observed when compared to that parameter in TTP≤PVCT (-35.3±13.1%), p <0.05. Conclusions: Tissue Doppler Echocardiography and Speckle Tracking Echocardiography are useful techniques for detecting regional systolic and diastolic dysfunction in children after Tetralogy of Fallot surgical repair. Postsystolic shortening in the basal lateral segment is commonly seen in children after the Tetralogy of Fallot surgical repair, and is associated with altered right ventricular systolic and diastolic function.

Anesthetic Considerations for Adult Cardiac Surgery Patients with Congenital Heart Disease

The number of adults with congenital heart disease surviving into adulthood is increasing. The proportion of adults undergoing revision of a previous repair is increasing in comparison to those that present for a palliative or curative operation. At the Toronto Congenital Cardiac Centre for Adults, 528 patients underwent cardiac surgery between January 1, 1992 and December 31, 2001. The anesthetic management of the surgical correction of simple and complex congenital heart lesions includes general physiologic considerations such as dysrhythmias, hypoxemia, polycythemia, and pulmonary hypertension. Palliative shunts from early childhood have anatomical and physiologic implications for the adult. Preparation for the operating room and postoperative care are natural extensions of the anesthetic management of the surgical correction of the congenital heart lesions. Anesthetic management of septal lesions in the interventional suite and operating room is discussed. Complex lesions such as tetralogy of Fallot, transposition of the great arteries, Glenn anastomosis, and the Fontan operation are reviewed. The anesthetic management of these patients is rewarding but impossible without an integrated team approach involving cardiologists, surgeons, perfusionists, and nursing staff.

Sleep-Disordered Breathing in Patients with Pulmonary Valve Incompetence Complicating Congenital Heart Disease

OBJECTIVE

Long standing pulmonary regurgitation results in deleterious effects on right heart size and function with late consequences of right heart volume overload including ventricular dilatation, propensity to arrhythmia and right heart failure. As sleep disordered breathing may predispose to elevations in pulmonary vascular resistance and associated negative effects on right ventricular function, we sought to assess this in patients with underlying congenital heart disease.

DESIGN

We performed a pilot study to evaluate the incidence of sleep-disordered breathing in a patient population with a history of long standing pulmonary valve incompetence in patients with congenital heart disease using overnight oximetry.

PATIENTS

Patients with a background of tetralogy of Fallot repair or residual pulmonary incompetence following previous pulmonary valve intervention for congenital pulmonary stenosis were included.

RESULTS

Twenty-two patients underwent overnight oximetry. The mean age of the cohort was 34.3 ± 15.2 years with no patients observed to have severe underlying pulmonary hypertension. Abnormal overnight oximetry was seen in 13/22 patients (59.1%) with 2/22 (9.1%) patients considered to have severe abnormalities.

CONCLUSIONS

An important proportion of patients with a background of pulmonary incompetence complicating congenital heart disease are prone to the development of sleep-disordered breathing as assessed by overnight oximetry. Further study into the prevalence and mechanisms of sleep-disordered breathing in a larger cohort are warranted.

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.

Variability of Pulmonary Regurgitation in Proportion to Pulmonary Vascular Resistance in a Porcine Model of Total Resection of the Pulmonary Valve: Implications for Early- and Long-Term Postoperative Management of Right Ventricular Outflow Tract Reconstruction With Resulting Pulmonary Valve Incompetence

INTRODUCTION

Pulmonary regurgitation (PR) is a major concern after right ventricular (RV) outflow tract surgery. We assessed the impact of physiological changes in pulmonary vasculature on hemodynamic severity of PR and RV function and their potential clinical implications for postoperative management using a porcine model with severe PR.

MATERIALS AND METHODS

Eight porcine models of acute PR were established by means of resection of pulmonary valve on cardiopulmonary bypass. After separation from bypass and stabilization, blood flow in the main pulmonary artery was measured by a pulsed Doppler flowmeter, and RV systolic function was assessed on the basis of RV segment shortening (RVSS), which was analyzed by sonomicrometry. In the acute PR model, we verified the impact of pulmonary vascular resistance (Rp) on pulmonary regurgitant fraction (PRF) and RV function. Pulmonary vascular resistance was changed by manipulating the level of PaCo 2 and by inhalation of nitric oxide (NO).

RESULTS

After bypass, the mean PRF was 40% ± 5%, and there was a deterioration of RV function. Under each ventilation condition (high CO2, low CO2, and NO 20 ppm), Rp was 836 ± 207 dyne × s × cm(-5), 499 ± 125 dyne × s × cm(-5), and 340 ± 102 dyne × s × cm(-5), respectively, and PRF was 60% ± 10%, 37% ± 5%, and 24% ± 4%, respectively, under each condition. They also showed a positive correlation in all animals. Cardiac output and RVSS were decreased by hypercapnia, while they were significantly improved after NO inhalation.

CONCLUSIONS

This study indicates that low Rp after right ventricular outflow tract reconstruction (RVOTR) resulting in acute PR is advantageous in reducing the severity of PR and RV volume load. These findings may have clinical implications for early and long-term postoperative management of patients subjected to RVOTR with resulting pulmonary valve incompetence.

Echocardiographic assessment after surgical repair of tetralogy of fallot

Surgical correction of tetralogy of Fallot is still one of the most frequently performed intervention in pediatric cardiac surgery, and in many cases, it is far from being a complete and definitive correction. It is rather an excellent palliation that solves the problem of cyanosis, but predisposes the patients to medical and surgical complications during follow-up. The decision-making process regarding the treatment of late sequel is among the most discussed topics in adult congenital cardiology. In post-operative Fallot patients, echocardiography is used as the first method of diagnostic imaging and currently allows both a qualitative observation of the anatomical alterations and a detailed quantification of right ventricular volumes and function, of the right ventricular outflow tract, and of the pulmonary valve and pulmonary arteries. The literature introduced many quantitative echocardiographic criteria useful for the understanding of the pathophysiological mechanisms involving the right ventricle and those have made much more objective any decision-making processes.

Right heart and pulmonary vessels structure and function

The right ventricle (RV) can be described in terms of 3 components: the inlet, the apex, and the infundibulum. In the normal adult, the RV shows an arrangement suited for pumping blood against low resistance, with a mass about one sixth that of left ventricle (LV) mass, and a larger volume than the LV. The RV is able to manage a progressive increase in the afterload by increasing contractility and remodeling. The gold standard measurement of contractility is maximal elastance (Emax), or the ratio between end-systolic pressure (ESP) and end-systolic volume (ESV), and the best measurement of afterload is arterial elastance (Ea), or the ratio between ESP and stroke volume (SV). The ratio Emax/Ea defines RV-arterial coupling. The optimal energy transfer from the RV to the pulmonary circulation is measured at Emax/Ea ratios of 1.5-2. In the presence of pulmonary hypertension, the SV/ESV ratio may be an acceptable surrogate of Emax/Ea. The right atrium (RA) has 3 anatomical components: the appendage, the venous part, and the vestibule. It is a dynamic structure having different functions: reservoir, conduit, and booster pump function. In case of increased afterload, the RA is enlarged, denoting high RA pressure, as a consequence of elevated RV diastolic pressure. RA area is a strong predictor of adverse clinical outcome in pulmonary arterial hypertension. In patients with severe pulmonary hypertension, in several congenital heart diseases, and in Eisenmenger syndrome, symptoms and prognosis are greatly dependent on RV function and its ability to adapt to a chronic increase in afterload.

Prevalence of arrhythmias during exercise stress testing in patients with congenital heart disease and severe right ventricular conduit dysfunction

The utility of cardiopulmonary exercise testing (CPET) to define the risks of arrhythmia and sudden death in postoperative patients with congenital heart disease (CHD) remains uncertain. As part of the US Melody valve trial, prospective standardized CPET, along with echocardiography, cardiac magnetic resonance imaging, and cardiac catheterization, were performed in 170 CHD patients with right ventricular outflow tract conduit dysfunction before Melody valve implantation. Ventricular premature complexes (VPC) occurred in 75 patients (44%) and were common during all phases of CPET (13% baseline, 24% exercise, and 23% recovery). Although no subjects had sustained arrhythmias, 2 had nonsustained ventricular tachycardia and 3 had nonsustained supraventricular tachycardia during recovery. There were no statistically significant differences between patients with or without VPCs in echocardiographic, cardiac magnetic resonance imaging, or catheterization measures of cardiac function. However, clinical parameters of age, New York Heart Association functional class ≥II, and ≥3 cardiac surgical procedures were correlated with VPCs. Persistent ventricular ectopy during all exercise stages was present in 11 patients (6.5%), including 3 of the 4 patients who died during follow-up. In conclusion, VPCs were common during CPET, although they were not correlated with various measures of hemodynamic impairment; conversely, increased age, functional class, and number of surgeries were correlated with an increased prevalence of VPCs. CPET appears to be of minimal risk for sustained arrhythmia provocation in CHD patients with right ventricular outflow tract conduits and various degrees of advanced subpulmonary ventricular dysfunction.

Effects of pulmonary regurgitation on distensibility and flow of the branch pulmonary arteries in tetralogy of Fallot

Significant pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) may affect flow in the pulmonary artery (PA) side branches. We sought to assess flow changes and distensibility of the PA side branches in vivo and test correlation with the degree of PR and right-ventricular (RV) dilatation. Thirty patients after TOF repair and 16 controls underwent cardiovascular magnetic resonance for quantification of RV volumes and measurement of flow in the PA side branches. RV volumes and function, blood flow volumes, and cross-sectional area of the main, left (LPA), and right (RPA) PA were measured and regurgitant volumes and distensibility calculated. Results were compared between the LPA and the RPA and between patients and controls. Median regurgitation fraction of PR was 41 % (range 22-60 %). Regurgitant fraction was greater in the LPA (40 %) than in the RPA (29 %), resulting in lower net flow into the LPA (p < 0.001). LPA area was significantly greater than that of the RPA (303.9 vs. 232.7 mm(2)/m(2)) (p < 0.0001). The LPA showed lower distensibility than the RPA (39 vs. 44 %). PA side branch distensibility correlated with MPA regurgitant volume (p = 0.001), MPA regurgitant fraction (p = 0.001), and RV end-diastolic volume (p = 0.03). PA side branches have greater distensibility in patients with PR than in normal subjects. Significant PR leads to changes in flow profile and distensibility of the PA side branches. The LPA shows greater regurgitant volume and greater area but lower distensibility than the RPA.

Asymptomatic right ventricular dysfunction in surgically repaired adult tetralogy of fallot patients

Background:

Right ventricular (RV) dysfunction after surgical repair of Tetralogy of Fallot (TOF) is often asymptomatic and may be detected by tissue Doppler imaging (TDI). The severity of RV dysfunction is more after intracardiac repair with transannular patch (TAP).

Methods:

One hundred seventy-three adult patients who have undergone surgical repair for TOF were prospectively analyzed for RV function using 2D echocardiography and TDI. RV function was compared between patients who have undergone intracardiac repair with and without TAP.

Results:

In both the patient sub-groups, TDI derived myocardial performance index (MPI) and myocardial velocities were abnormal even when 2D echocardiography derived RV functional area change was normal. TDI derived MPI was significantly higher (0.5 ± 0.1 vs. 0.4 ± 0 P < 0.001) and Systolic tricuspid annular velocity (Sa) (9.2 ± 1.3 vs. 10.8 ± 1.6 P < 0.001) was significantly lower in the TAP group. Older age at surgery and severity of pulmonary regurgitation on follow-up were among the significant predictors of TDI derived MPI.

Conclusions:

Asymptomatic RV dysfunction in surgically repaired adult TOF atients can be detected by TDI. Extent of RV dysfunction was significantly greater with patients requiring TAP, in those operated at older age, and in patients with severe pulmonary regurgitation.

Relation of right ventricular mechanics to exercise tolerance in children after tetralogy of Fallot repair

BACKGROUND

Progressive right ventricular (RV) dysfunction and exercise intolerance are common problems after tetralogy of Fallot (TOF) repair. We investigated RV myocardial deformation and dyssynchrony in children after TOF repair and their association with exercise capacity.

METHODS

Asymptomatic children after TOF repair were investigated by 2-dimensional speckle tracking echocardiography, magnetic resonance, and metabolic exercise study. Patients with RV outflow obstruction were excluded. Peak RV longitudinal strain and strain rate (SR) and dyssynchrony (RV intraventricular delay) were compared with healthy controls. Associations between RV strain, dyssynchrony, and exercise capacity were analyzed.

RESULTS

Thirty-nine (81%) of 48 TOF patients and 40 healthy controls had adequate RV strain imaging. The TOF patients had moderately dilated RVs and normal RV ejection fraction. Right ventricular peak systolic strain (-23.2% ± 5.1% vs -28.5% ± 8.5%, P < .001) and SR (-1.46 ± 0.68 vs -2.1 ± 0.8, P < .001) were reduced in TOF patients compared with controls. Right ventricular intraventricular delay was higher in TOF patients (146.0 ± 159 vs 71.0 ± 92 milliseconds, P = .008). Decreased RV strain and SR were associated with increased RV dyssynchrony (strain parameter estimate [PE] 6.31 [2.30], P = .007; SR [PE] 11.32 [3.84], P = .004). Increased RV-left ventricular delay was associated with prolonged QRS duration (PE 0.13 [0.058], P = .03) and reduced RV ejection fraction (PE -2.95 [1.275], P = .02). Reduced RV peak SR was associated with decreased exercise peak oxygen uptake (PE 0.14 [0.07], P = .04).

CONCLUSIONS

After repair of TOF, asymptomatic children have reduced RV deformation in association with RV dyssynchrony and reduced exercise tolerance.

Valve-sparing tetralogy of Fallot repair with intraoperative dilation of the pulmonary valve

Deleterious long-term effects of pulmonary regurgitation after tetralogy of Fallot (TOF) repair have become evident during the last two decades. Subsequently, different groups have developed strategies aimed at preserving the pulmonary valve function. However, the results of these approaches are not well known. From July 2009 through March 2012, 38 patients underwent primary repair of TOF at the authors' institution. Of these, 12 children (7 boys) underwent attempted pulmonary valve-sparing surgery with intraoperative dilation of the pulmonary valve. The technical details as well as the echocardiographic preoperative and follow-up data for this repair were recorded, with a special focus on the feasibility of the technique and the effects on pulmonary valve function. No patient in the series died. At repair, the median age was 6 months (range 3.4-126 months), and the median weight was 7.6 kg (range 4.7-47 kg). Intraoperative dilation of the pulmonary valve was technically feasible for all the patients. Two patients had unsuccessful dilation and underwent a transannular patch procedure. During a median follow-up period of 22 months (range 6-30 months), the pulmonary valve diameter and z-score improved significantly. Moreover, the annular size normalized, whereas the mean right ventricular outflow tract (RVOT) gradient remained at the mild level (median, 24 mmHg; range 12-36 mmHg). At the most recent follow-up evaluation, three patients showed moderate pulmonary regurgitation. Intraoperative dilation of the pulmonary valve in patients undergoing TOF repair is feasible and provides good relief of obstruction. Moreover, the pulmonary valve annulus grows through the follow-up period. Longer follow-up studies are needed to evaluate the exact role of this strategy in this population.

Subaortic membrane late after surgical correction of tetralogy of Fallot

We herein report a rare case of subaortic stenosis in association with a previous tetralogy of Fallot (TOF) surgical repair, which was not taken into account as a differential diagnosis. Echocardiography plays a pivotal role in identification of this rare combination. Therefore, echocardiography should be performed periodically during follow-up of patients with surgically corrected TOF. Given the clinical complications that can result from subaortic stenosis (i.e., aortic regurgitation and infective endocarditis), early and aggressive management of this rare combination should be performed.

Right ventricular outflow tract strategies for repair of tetralogy of Fallot: effect of monocusp valve reconstruction

OBJECTIVES

The absence of a pulmonary valve (PV) after tetralogy of Fallot (TOF) repair has been shown to impact postoperative right ventricular (RV) function. The purposes of this study were to (i) compare early outcomes after PV-sparing vs transannular patching (TAP) with monocusp valve reconstruction or TAP alone and (b) assess the mid-term results after polytetrafluoroethylene (PTFE) membrane monocusp reconstruction.

METHODS

From 2003 to 2009, 163 patients underwent TOF repair. Sixty-nine patients (42.3%) underwent a PV-sparing procedure (Group A), 74 (45.4%) underwent PTFE membrane monocusp valve reconstruction (Group B) and 20 (12.3%) underwent TAP only (Group C). Early outcomes were evaluated by the right-to-left ventricular pressure ratio, RV outflow tract gradient, tricuspid and PV function, intensive care unit (ICU) parameters and need for reintervention. Group B patients were also evaluated at intermediate term for clinical and echocardiographic parameters, including tricuspid and monocusp valve function and mobility.

RESULTS

The median age, weight and PV Z-value of Group B patients were significantly lower; 20.5 months, 9.3 kg and -4, respectively. Postoperatively, the right-to-left ventricular pressure ratio was <0.5 in all groups. Mechanical ventilation time, fluid drainage duration and total ICU stay showed no significant difference between Groups A and B, while Group C was significantly longer (P < 0.01). There were five (3%) early deaths: three from Group A and two from Group B. The incidences of moderate or severe pulmonary insufficiency (PI) on discharge were 8.2% in Group A, 9% in Group B and 50% in Group C (P < 0.001). Among Group B patients, 85% of the evaluated patients had less than moderate PI in the intermediate-term follow-up, QRS duration <140 ms in 83.3% and right-to-left ventricular diameter ratio of 0.6 ± 0.2. Two (2.6%) patients underwent reoperation for monocusp replacement. There were two (2.7%) mid-term deaths.

CONCLUSIONS

The use of a PTFE membrane monocusp valve and a valve-sparing strategy prevents immediate PI and improves short-term clinical outcomes. PTFE membrane monocusp appears advantageous in preventing severe intermediate-term PI and facilitates the preservation of RV function.

Risk factors associated with morbidity and mortality after pulmonary valve replacement in adult patients with previously corrected tetralogy of Fallot

Patients with palliated tetralogy of Fallot (TOF) often require pulmonary valve replacement in adulthood, yet the data regarding their outcomes are scarce. This study aimed to identify risk factors associated with postoperative complications in these patients and to establish long-term survival data for this patient group. A retrospective cohort study investigated 153 consecutive patients with a history of TOF repair who underwent pulmonary valve replacement at a single large academic center between March 1996 and March 2010. In part 1 of the study, logistic models were constructed to assess demographic, medical, and surgical risk factors for operative mortality; occurrence of a major adverse event (stroke, renal failure, prolonged ventilation, deep sternal infection, reoperation, or operative mortality); and prolonged hospital stay (>7 days). Risk factors with a p value less than 0.10 by univariate analysis were included in the subsequent multivariate analysis. In part 2 of the study, long-term, all-cause mortality was determined by construction of a Kaplan-Meier curve for the cohort. Seven patients died (4.5%). Significant risk factors for mortality in the multivariable analysis included age older than 40 years (odds ratio (OR) 9.89) and concomitant surgery (OR 6.65). A major adverse event occurred for 22 patients (14.4%). The only significant risk factor in the multivariable analysis for an adverse event was concomitant surgery (OR 6.42). The hospital stay was longer than 7 days for 31 patients (20.3%). The significant risk factors for a prolonged hospital stay included the presence of preoperative arrhythmias (OR 4.17), New York Heart Association class 3 (OR 4.35), and again, concomitant surgery (OR 4.2). Among the 146 hospital survivors, only 5 patients died in the intervening period. The predicted survival rates were 98.5% at 1 year, 96.7% at 5 years, and 93.5% at 10 years. Pulmonary valve replacement in adults with palliated TOF is a safe procedure with excellent long-term survival, but there remain important risk factors for postoperative mortality, prolonged hospital stay, and major adverse events. Awareness and modification of important risk factors may help to improve outcomes.

Health-related quality of life and right ventricular function in the midterm follow-up assessment after tetralogy of fallot repair

BACKGROUND

Few data are available on quality of life after surgical repair of tetralogy of Fallot (ToF), and on its relationship to right ventricle function.

METHODS

Patients with at least 1 year of follow-up evaluation after surgery were studied. Right ventricle function was evaluated by the Doppler-derived myocardial performance index (MPI), and health-related quality of life (HRQL) was assessed by the Child Health Questionnaire, Parent Form-50. Findings were compared with those for an age- and sex-matched group of healthy children.

RESULTS

The study enrolled 35 successfully repaired ToF patients with 4.9 years (range, 3-7 years) of follow-up evaluation after surgery and 36 healthy children. The MPI demonstrated right ventricle dysfunction in patients compared with controls (0.34; range, 0.26-0.49 vs 0.2; range, 0.13-0.27; p < 0.01), although HRQL for the psychosocial domain was similar between patients and healthy children (summary score, 47.9; range, 45-52 vs 47.5; range, 44.5-50; p = 0.17). A trend for poorer physical area results was observed in patients (summary score, 44; range, 31-52 vs 48.5; range, 45.7-51.7; p = 0.06). Neither physical nor psychosocial summary scores for HRQL had any correlation with right ventricle MPI.

CONCLUSIONS

Right ventricle dysfunction is present in postoperative ToF patients. The psychosocial domain of HRQL is preserved after surgery. A trend for worse results was observed in the physical domain. The right ventricle function is not related to quality of life after surgical repair of ToF.