Impact of Fontan operation on left ventricular size and contractility in tricuspid atresia

Five decades of Fontan palliation: What have we learned? What should we expect?

The Fontan procedure is the final palliative surgery in a series of staged surgeries to reroute the systemic venous blood flow directly to the lungs, with the ventricle(s) pumping oxygenated blood to the body. Advances in medical and surgical techniques have improved patients' overall survival after the Fontan procedure. However, Fontan-associated chronic comorbidities are common. In addition to chronic cardiac dysfunction and arrhythmias, complications involving other organs such as the liver, lungs, intestine, lymphatic system, brain, and blood frequently occur. This narrative review focuses on the immediate and late consequences in children, pregnant women, and other adults with Fontan circulation. In addition, we describe the technical advancements that might change the way single-ventricle patients are managed in future.

Management of circulatory failure after Fontan surgery

With improvement in survival after Fontan surgery resulting in an increasing number of older survivors, there are more patients with a Fontan circulation experiencing circulatory failure each year. Fontan circulatory failure may have a number of underlying etiologies. Once Fontan failure manifests, prognosis is poor, with patient freedom from death or transplant at 10 years of only about 40%. Medical treatments used include traditional heart failure medications such as renin-angiotensin-aldosterone system blockers and beta-blockers, diuretics for symptomatic management, antiarrhythmics for rhythm control, and phosphodiesterase-5 inhibitors to decrease PVR and improve preload. These oral medical therapies are typically not very effective and have little data demonstrating benefit; if there are no surgical or catheter-based interventions to improve the Fontan circulation, patients with severe symptoms often require inotropic medications or mechanical circulatory support. Mechanical circulatory support benefits patients with ventricular dysfunction but may not be as useful in patients with other forms of Fontan failure. Transplant remains the definitive treatment for circulatory failure after Fontan, but patients with a Fontan circulation face many challenges both before and after transplant. There remains significant room and urgent need for improvement in the management and outcomes of patients with circulatory failure after Fontan surgery.

Hepatocyte growth factor predicts failure of Fontan circulation

Aims

This study aimed to assess the value of the hepatocyte growth factor (HGF) as an independent predictor of a Fontan circulation failure.

Methods and results

This retrospective case–control study included 34 consecutive patients (19 men and 15 women) who underwent a post‐operative cardiac catheterization after a Fontan operation at the Saitama Medical University International Medical Center between April 2017 and December 2019. We divided the patients into two groups according to the HGF level: HGF < 0.4 ng/mL (n = 20, normal HGF group) and HGF ≥ 0.4 ng/mL (n = 14, elevated HGF group). The age at the time of the cardiac catheterization was 59.3 ± 7.9 months. The range of the duration between the Fontan operation and the cardiac catheterization was 37.5 ± 7.9 months. The age (P = 0.417), gender (P = 0.08), morphology of the functional ventricle (P = 0.99), presence or closure of the Fontan fenestration (P = 0.704), and rate of medication use (angiotensin‐converting enzyme inhibitors or angiotensin II receptor blockers) (P = 0.99) were equivalent between the two groups. Laboratory parameters including the brain natriuretic peptide level (P = 0.085), serum creatinine level (P = 0.27), and aspartate aminotransferase level (P = 0.235) were similar between the two groups. The elevated HGF group had a higher C‐reactive protein level than the normal HGF group (0.42 ± 0.14 and 0.05 ± 0.01 mg/dL, P = 0.005). The elevated HGF group had a higher central venous pressure (CVP) level than the normal HGF group (13.4 ± 0.7 and 9.7 ± 0.4 mmHg, P < 0.0001), and the HGF was positively correlated with the CVP (P = 0.0004, r² = 0.33). The SvO₂ level was significantly lower in the elevated HGF group than in the normal HGF group (61.9 ± 2.3% and 75.0 ± 1.2%, P < 0.0001), and the HGF was negatively correlated with the SvO₂ (P < 0.0001, r² = 0.65). Of the 34 patients, six underwent catheter interventions. Patients who underwent catheter interventions had a higher HGF level than those who did not (0.44 ± 0.03 and 0.37 ± 0.01 ng/mL, P = 0.032). The receiver operating characteristic curve created for the discrimination of a catheter intervention revealed that an HGF value of >0.405 ng/mL could detect the need for a catheter intervention with 75.0% sensitivity and 83.3% specificity. A multivariable regression analysis showed that an elevated HGF was an independent predictor of an elevated CVP (β‐coefficient 21.2, SE 5.5, P = 0.0005) and decreased SvO₂ (β‐coefficient −92.9, SE 12.4, P < 0.0001).

Conclusions

The HGF is an independent predictor of a failure of a Fontan circulation. The HGF is an indicator for an additional catheter intervention after a Fontan operation.

Heart failure in single right ventricle congenital heart disease: physiological and molecular considerations

Because of remarkable surgical and medical advances over the past several decades, there are growing numbers of infants and children living with single ventricle congenital heart disease (SV), where there is only one functional cardiac pumping chamber. Nevertheless, cardiac dysfunction (and ultimately heart failure) is a common complication in the SV population, and pharmacological heart failure therapies have largely been ineffective in mitigating the need for heart transplantation. Given that there are several inherent risk factors for ventricular dysfunction in the setting of SV in addition to probable differences in molecular adaptations to heart failure between children and adults, it is perhaps not surprising that extrapolated adult heart failure medications have had limited benefit in children with SV heart failure. Further investigations into the molecular mechanisms involved in pediatric SV heart failure may assist with risk stratification as well as development of targeted, efficacious therapies specific to this patient population. In this review, we present a brief overview of SV anatomy and physiology, with a focus on patients with a single morphological right ventricle requiring staged surgical palliation. Additionally, we discuss outcomes in the current era, risk factors associated with the progression to heart failure, present state of knowledge regarding molecular alterations in end-stage SV heart failure, and current therapeutic interventions. Potential avenues for improving SV outcomes, including identification of biomarkers of heart failure progression, implications of personalized medicine and stem cell-derived therapies, and applications of novel models of SV disease, are proposed as future directions.

Imaging of complications following Fontan circulation in children - diagnosis and surveillance

The Fontan operation is performed for various cardiac lesions with single-ventricle physiology. The survival rate of Fontan patients is increasing for adolescents and young adults, with an expected 30-year survival of >80%. Medical health care providers including specialists in organ systems and pediatric radiologists need to improve their knowledge about the Fontan circulation and the various organ complications to monitor care. In this review the author explains the basic anatomical and functional features of Fontan palliation and gives an overview of the multiple long-term organ complications that might present in the pediatric population. These include decreased physical capacity, ventricular dysfunction, atrioventricular valve regurgitation and arrhythmia, as well as protein-losing enteropathy, plastic bronchitis, growth/bone composition disturbances, renal dysfunction, and the recently recognized and important liver fibrosis (Fontan-associated liver disease). Neuropsychological and behavioral deficits occur frequently. This review focuses on the key role of radiology in making the diagnosis of these complications, monitoring therapy and predicting outcomes in the pediatric age group. The author discusses how and when radiology is important in Fontan patients, as well as how new techniques enabling quantitative measures in imaging with US, MRI and CT are adapted for pediatric use, and how they contribute to urgently needed surveillance strategies.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Pulmonary artery wall thickness in children with Fontan physiology: an optical coherence tomography case control study

INTRODUCTION

Failure of the Fontan circulation is not a well-understood clinical phenomena.For some patients, a gradual increase in pulmonary vascular resistance (PVR) and structural changes in the pulmonary artery may be an important causative factor. To further investigate this issue, we employed optical coherence tomography (OCT) to evaluate structural changes within the pulmonary arteries of Fontan patients and compared to those with a normal pulmonary circulation.

MATERIALS AND METHODS

Pulmonary artery OCT was performed, without complications, in 12 Fontan and 11 control patients. Wall thickness and wall:vessel cross-sectional area (CSA) ratio were calculated after image acquisition, using digital planimetry.

RESULTS

There was no difference in wall thickness between both groups. Median wall thickness for Fontan patients was 0.12 mm (IQR, 0.10-0.14) and for controls was 0.11 mm (IQR, 0.10-0.12; p = 0.62). Wall:vessel CSA ratio for Fontan patients was 0.13 (IQR, 0.12-0.16) and for controls was 0.13 (IQR, 0.11-0.15) (p = 0.73). There was no association between wall thickness and ventricle morphology, age at catheterisation, age at Fontan, years since Fontan completion, pulmonary artery pressure, and PVR. The vessel media was more readily visualised in control patients.

DISCUSSION

OCT of the pulmonary arteries in Fontan patients is safe and feasible. Our OCT findings suggest that during childhood, pulmonary artery wall dimensions are normal in Fontan children with reassuring hemodynamics. Further evaluation of Fontan patients with abnormal hemodynamics and serial evaluation into adulthood are required to conclude on the utility of OCT for identifying early pulmonary artery structural changes.

Role of Doppler echocardiography for cardiac output assessment in Fontan patients

BACKGROUND

To determine (1) correlation between Doppler stroke volume index (SVI) and cardiac magnetic resonance imaging (CMRI) SVI and (2) association between Doppler SVI and Fontan-associated diseases (FAD) and Fontan failure.

METHODS

Review of Fontan patients who underwent same-day CMRI and transthoracic echocardiography (TTE), 2005 to 2015. We defined FAD as cardiac thrombus, protein-losing enteropathy, arrhythmia, and hospitalization for heart failure. Fontan failure was defined as Fontan conversion or revision, heart transplantation or listing, or death.

RESULTS

Fifty-three patients with systemic left ventricle (LV) underwent 86 sets of TTE/CMRI. Mean (SD) age 31 (6) years. SVI (45 [16] vs 42 [13] mL/m²), CI (3.0 [1.1] vs 2.8 [0.8] L min^-1 m^-2), and ejection fraction (53 [4]% vs 51 [5]%) were similar for both modalities (P>.05 for all). Doppler SVI correlated with CMRI (r=0.68; P<.001). Sixteen patients had cirrhosis, and these patients had a higher CI (3.9 [0.9] vs 2.8 [1.0] L min^-1 m^-2; P<.01). Among the 37 patients without cirrhosis, Doppler SVI <39 mL/m² was associated with FAD (odds ratio [OR], 2.11; 95% confidence limit, 1.26-3.14; P=.02); Fontan failure was more common in patients with CI was <2.5 L min^-1 m^-2 (3/9 [33%] vs 0/28 [0%], P=.01). Another 11 patients with systemic right ventricle (RV) underwent 17 sets of TTE/CMRI, mean (SD) age 17 (3) years, and CMRI SVI also correlated with Doppler SVI (r=0.75; P<.001).

CONCLUSION

Doppler SVI correlated with CMRI SVI in patients with systemic LV and systemic RV. The association between output measures (SVI and CI) and FAD were seen only in single LV patients (single RV patients not assessed for this outcome due to small numbers). An association between low Doppler CI and Fontan failure was suggested in a small number of single LV patients.

The Fontan circulation after 45 years: update in physiology

The Fontan operation was first performed in 1968. Since then, this operation has been performed on thousands of patients worldwide. Results vary from very good for many decades to very bad with a pleiad of complications and early death. A good understanding of the physiology is necessary to further improve results. The Fontan connection creates a critical bottleneck with obligatory upstream congestion and downstream decreased flow; these two features are the basic cause of the majority of the physiologic impairments of this circulation. The ventricle, while still the engine of the circuit, cannot compensate for the major flow restriction of the Fontan bottleneck: the suction required to compensate for the barrier effect cannot be generated, specifically not in a deprived heart. Except for some extreme situations, the heart therefore no longer controls cardiac output nor can it significantly alter the degree of systemic venous congestion. Adequate growth and development of the pulmonary arteries is extremely important as pulmonary vascular impedance will become the major determinant of Fontan outcome. Key features of the Fontan ventricle are early volume overload and overgrowth, but currently chronic preload deprivation with increasing filling pressures. A functional decline of the Fontan circuit is expected and observed as pulmonary vascular resistance and ventricular filling pressure increase with time. Treatment strategies will only be successful if they open up or bypass the critical bottleneck or act on immediate surroundings (impedance of the Fontan neoportal system, fenestration, enhanced ventricular suction).

Usefulness of the Red Blood Cell Distribution Width to Predict Heart Failure in Patients With a Fontan Circulation

The red blood cell distribution width (RDW) is a quantitative measure of the variability in the size of circulating erythrocytes. We aimed to study whether higher levels of the RDW were associated with heart failure in a Fontan circulation and to analyze its clinical value compared to brain natriuretic peptide. This retrospective study included 38 consecutive pediatric patients with a Fontan circulation who underwent routine cardiac catheterization at the International Medical Center, Saitama Medical University from October 2010 to July 2014. We assessed the relation between the RDW and catheterization data such as the central venous pressure (CVP), mixed venous oxygen saturation (SvO2), and cardiac index (CI). The RDW was positively correlated with the CVP (p = 0.0002). The elevated RDW group had a significantly greater CVP than the normal RDW group (p = 0.0003). Also, the RDW was negatively correlated with the SvO2 (p = 0.0004). The elevated RDW group had a significantly less SvO2 than the normal RDW group (p <0.0001). The CI in the elevated RDW group was lower than that in the normal RDW group (p = 0.0421). In the multivariate regression analysis, the RDW was a significant independent predictor of the CVP and SvO2. The BNP level did not have any significant relation with the CVP, SvO2, or CI. The RDW is a convenient and powerful marker for detecting heart failure in a Fontan circulation.

Impact of Blalock-Taussig shunt size on tricuspid regurgitation in hypoplastic left heart syndrome

BACKGROUND

The prognosis for hypoplastic left heart syndrome (HLHS) has greatly improved over the past years, but there is still a significant risk of interstage mortality. Tricuspid valve regurgitation (TR) is known to be a risk factor for interstage mortality. We hypothesized that a modified Blalock-Taussig (BT) shunt with a smaller diameter would lead to a reduction in ventricular volume loading with a consequent reduction in TR.

METHODS

A retrospective review of all patients with HLHS who had a Norwood procedure in our institution between 2006 and 2011 was performed. Patient demographic, echocardiographic, cardiac magnetic resonance imaging, and operative data were reviewed. The impact of BT shunt diameter on severity of TR at the time of bidirectional cavopulmonary connection (BCPC) was analyzed.

RESULTS

Sixty-four neonates with HLHS underwent a Norwood procedure with a BT shunt. Thirty-two had a 3.5-mm BT shunt (3.5-mm group), and 32 had a 3.0-mm BT shunt (3.0-mm group). Survival to BCPC was 53 of 64 patients (83%) overall, with 25 of 32 patients (78%) in the 3.5-mm group and 28 of 32 (88%) in the 3.0-mm group (p = 0.51). The prevalence of significant TR (moderate or higher) before BCPC was 9 of 25 patients (36%) in the 3.5-mm group and 2 of 28 patients (7%) in the 3.0-mm group (odds ratio = 7.3; 95% confidence interval: 1.4-38; p = 0.018). Tricuspid valve repair was performed in 4 of 25 patients (16%) in the 3.5-mm group and 2 of 28 patients (7%) in the 3.0-mm group (p = 0.21).

CONCLUSIONS

A smaller-diameter BT shunt reduces the prevalence of significant TR at the time of BCPC. Further investigation and long-term follow-up are required to determine potential complications of this surgical strategy.

Surgical approaches for single ventricle palliation

In this document, we include under the heading of univentricular heart, complex cardiac malformations which have in common the presence of a functionally single ventricle. The evolution of the surgical management of univentricular hearts is discussed along with the indications, selection criteria, and operative approaches for staged palliation. Herein, we describe our technique for bidirectional cavopulmonary anastomosis and total cavopulmonary connection using an extracardiac conduit.

The adult with a fontan: a panacea without a cure? Review of long-term complications

The univentricular heart includes a spectrum of complex cardiac defects that are managed by staged palliative surgical procedures, ultimately resulting in a Fontan procedure. Since 1971, when it was first developed, the procedure has undergone several variations. These patients require lifelong management, including a thorough knowledge of their anatomic substrate, hemodynamic status, management of rhythm and ventricular function, together with multi-organ evaluation. As these patients enter middle age, there is increasing awareness of long-term complications and mortality. This review highlights the concept behind the staged surgical palliations, the unique single ventricle physiology and the long-term complications in this complex cohort of patients.

Renin-angiotensin-aldosterone genotype influences ventricular remodeling in infants with single ventricle

BACKGROUND

We investigated the effect of polymorphisms in the renin-angiotensin-aldosterone system (RAAS) genes on ventricular remodeling, growth, renal function, and response to enalapril in infants with single ventricle.

METHODS AND RESULTS

Single ventricle infants enrolled in a randomized trial of enalapril were genotyped for polymorphisms in 5 genes: angiotensinogen, angiotensin-converting enzyme, angiotensin II type 1 receptor, aldosterone synthase, and chymase. Alleles associated with renin-angiotensin-aldosterone system upregulation were classified as risk alleles. Ventricular mass, volume, somatic growth, renal function using estimated glomerular filtration rate, and response to enalapril were compared between patients with ≥2 homozygous risk genotypes (high risk), and those with <2 homozygous risk genotypes (low risk) at 2 time points: before the superior cavopulmonary connection (pre-SCPC) and at age 14 months. Of 230 trial subjects, 154 were genotyped: Thirty-eight were high risk, and 116 were low risk. Ventricular mass and volume were elevated in both groups pre-SCPC. Ventricular mass and volume decreased and estimated glomerular filtration rate increased after SCPC in the low-risk (P<0.05), but not the high-risk group. These responses were independent of enalapril treatment. Weight and height z-scores were lower at baseline, and height remained lower in the high-risk group at 14 months, especially in those receiving enalapril (P<0.05).

CONCLUSIONS

Renin-angiotensin-aldosterone system-upregulation genotypes were associated with failure of reverse remodeling after SCPC surgery, less improvement in renal function, and impaired somatic growth, the latter especially in patients receiving enalapril. Renin-angiotensin-aldosterone system genotype may identify a high-risk subgroup of single ventricle patients who fail to fully benefit from volume-unloading surgery. Follow-up is warranted to assess long-term impact.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT00113087.

Transition of ventricular function and energy efficiency after a primary or staged Fontan procedure

PURPOSE

The transitional changes of the ventricular function at different time points after total cavopulmonary connection (TCPC) were examined.

METHODS

A total of 29 patients were divided into a primary TCPC group and a staged TCPC group. In both groups, phase I was defined as within 2 months after TCPC and phase II as beyond at least a year after TCPC. Changes in ventricular end-diastolic volume (EDV), ventricular end-systolic elastance (Ees), effective arterial elastance (Ea), and ventriculoarterial coupling (Ea/Ees) were evaluated.

RESULTS

The results for the primary TCPC group are as follows. Phase I: The EDV decreased (P < 0.05). The Ees and Ea both increased (P < 0.05). Ea/Ees showed a tendency to increase (P = 0.08). Phase II: The EDV decreased (P < 0.05). The Ees increased significantly, and Ea showed no significant change. Ees/Ea showed a tendency to decrease (P = 0.07). The results for the staged TCPC group were as follows. Phase I: The EDV decreased significantly after bidirectional cavopulmonary shunt (BCPS). The Ees showed no significant change after BCPS and TCPC. Although Ea increased after BCPS (P < 0.05), it showed no significant change after TCPC. Ea/Ees showed no significant change. Phase II: The Ees increased (P < 0.05) without significant changes of EDV and Ea. As a result, Ea/Ees showed a tendency to decrease.

CONCLUSION

This study suggested improved ventricular function in both groups. These results suggest hemodynamic adaptation to the Fontan circulation. The deleterious effects on ventricular function caused by the Fontan procedure disappeared within a couple of years. This acute effect can be ameliorated by the staged approach to the Fontan circulation.

Characteristics of Doppler myocardial echocardiography in patients with tricuspid atresia after total cavopulmonary connection with preserved systolic ventricular function

BACKGROUND

Doppler myocardial echocardiography (DME) may be an excellent additional means of assessing determinants of systolic and diastolic ventricular function in patients with tricuspid atresia (TA) after total cavopulmonary connection (TCPC).

METHODS AND RESULTS

Thirty-three patients with TA and normal systolic shortening/ejection fraction (M-mode) after TCPC were studied by DME at a median age of 7.6 years (range 1.5-17 years). These results were compared to 16 age matched normal controls. Median time under a cavopulmonary shunt was 5.2 years (range 0.6-13.3 years). Isovolumic acceleration and isovolumic velocity did not differ significantly. All other systolic (S-wave acceleration-velocity and S-wave duration) and diastolic DME indices (E-deceleration-velocity, A-velocity and E/A ratio) were significantly lower in TCPC patients in comparison to normals (p<0.0001). Furthermore, isovolumic relaxation time (IRT) was significantly prolonged in the patient group (p<0.0001). Even though there was a significant correlation between the time of volume unloading and left ventricular end-diastolic diameter, exclusion of all patients with short period of volume unloading and relatively large systemic ventricles did not alter the results.

CONCLUSIONS

Patients with TA after TCPC and normal shortening and ejection fraction have normal isovolumic acceleration. Load dependent DME indices of systolic and diastolic function, however, were significantly reduced. These findings suggest that the described DME indices mirror the "normal" hemodynamics after TCPC in patients with TA. It needs to be assessed, whether this is an index of adverse prognosis in long-term surveillance of these patients.

Non-invasive assessment of ventricular force-frequency relations in the univentricular circulation by tissue Doppler echocardiography: a novel method of assessing myocardial performance in congenital heart disease

OBJECTIVE

To describe the first clinical application of a novel tissue Doppler derived index of contractility, isovolumic acceleration (IVA), in the assessment of the ventricular myocardial force-frequency relation (FFR) in the univentricular heart (UVH).

DESIGN

Prospective study.

SETTING

Tertiary referral centre.

INTERVENTIONS

Non-invasive assessment of the myocardial FFR by tissue Doppler echocardiography during atrial pacing.

RESULTS

IVA was used to measure the FFR of the systemic ventricle in patients with structurally normal hearts and in patients with UVHs. Basal IVA of the normal hearts (mean (SD) 1.9 (0.3) m/s2) was significantly greater than that of UVHs in patients with a dominant right ventricle (RV) (1.0 (0.3) m/s2) or left ventricle (LV) (0.8 (0.7) m/s2; p < 0.05 for both). Neither the absolute nor percentage change from basal to peak values of IVA with pacing differed between the three groups. Peak force developed by the normal LV was significantly greater than that of the UVH, dominant LV group but not different from that of the UVH, dominant RV group.

CONCLUSION

Contractility at basal heart rate is depressed in patients with UVH compared with the normal LV. Analysis of ventricular FFRs exposes further differences in myocardial contractility. There is no evidence that contractile function of the dominant RV is inferior to that of the dominant LV over a physiological range of heart rates.

Quantitative assessment of systolic and diastolic ventricular function with tissue Doppler imaging after Fontan type of operation

BACKGROUND

There is evidence that "inappropriate hypertrophy" of the single left ventricle, which occurs as a result of acute preload reduction, leads to adverse consequences on ventricular function. However, a systematic study of the capability of tissue Doppler imaging (TDI) to assess systolic and diastolic ventricular functions after the Fontan procedure is still missing.

METHODS

Twenty-four postoperative patients aged 12-33 years were prospectively evaluated with two-dimensional echocardiography equipped with TDI capabilities. Nineteen age-matched normal subjects were selected as controls. Good-quality echoes for the measurement of ejection fractions were available in 21 patients. Ten patients (group 1) had systolic dysfunction (ejection fraction < 50%), and 11 patients (group 2) had normal systolic function. Peak systolic and diastolic wall velocities were acquired from the two-chamber view in the myocardia and mitral annulus.

RESULTS

Compared with controls, the Fontan patients had a significantly reduced peak systolic velocity at wall and annulus sites. A linear correlation existed between ejection fraction and systolic myocardial velocity from the annular sites. Group 1 patients had lower wall velocities and lower annulus velocities both in systole and diastole. Group 2 patients had preserved systolic velocities but decreased regional and annular early diastolic velocities, suggesting impaired filling. Multiple correlation analysis showed a relation between peak early diastolic mitral velocity and ventricular ejection fraction, mean mitral annular motion at systole, mass/volume ratio, and the number of years post Fontan revision.

CONCLUSIONS

Myocardial velocities recorded after the Fontan operation give insight into systolic and diastolic ventricular functions. The peak systolic mitral annular velocity correlated well with the ventricular ejection fraction. The peak early diastolic velocity and the ratio between the early and late diastolic mitral annular velocity are reduced and reflect diastolic dysfunction even in the presence of normal systolic ejection fraction.

Hearts late after fontan operation have normal mass, normal volume, and reduced systolic function

OBJECTIVES

The purpose of this study was to assess ventricular mass, volume, and systolic function in patients late after Fontan operation by cardiac magnetic resonance imaging.

BACKGROUND

An assessment of determinants for ventricular function in post-Fontan patients was intended.

METHODS

Twenty-three unselected patients (9 female, 14 male) at a median age of 19.4 years (range, 7.8 to 31.3 years), at a median time of 10.5 years (range, 4.1 to 18 years) after Fontan operation were studied. A standard 1.5-T scanner was used, and analysis was performed using dedicated software. Ten healthy volunteers (median age 26.4, range 18 to 39.3 years) served as the control group.

RESULTS

Median end-systolic mass index was 72.2 g/m(2) (range, 43 to 138 g/m(2)) and 86.6 g/m(2) (range, 52 to 123 g/m(2)) in the control group (p = NS). Median end-diastolic ventricular volume was 64 ml/m(2) (range, 32 to 117 ml/m(2)) compared with 67.7 ml/m(2) (range, 59 to 75 ml/m(2)) in the control group (p = NS). Median ejection fraction was 49.3% (range, 20% to 63%) compared with 64.8% (range, 57% to 79%) in normals (p = 0.00001).

CONCLUSIONS

We conclude that long-term survivors of a Fontan operation have normal ventricular mass, normal volume, but reduced systolic ventricular function.

[Single-stage Fontan procedure: early and late outcome in 124 patients]

INTRODUCTION AND OBJECTIVES

The Fontan procedure was designed to palliate complex congenital heart disease with univentricular physiology. A retrospective study was made to document the determinants of early (</= 30 days) and late (>/= 31 days) mortality with the modified Fontan procedure performed in one-stage over a 22-year period.

MATERIAL AND METHODS

Between 1978 and 2000, 102 atriopulmonary, 16 cavopulmonary, and 6 Kawashima type anastomoses were performed to palliate complex congenital heart defects in 124 patients with a mean age of 7.3 4.7 years. Forty-five patient and procedure-related variables were analyzed in relation to mortality. All events were verified.

RESULTS

There were 29 early (23%) and 20 late (16%) deaths. Estimated survival at 30 days, 2 years, 5 years, and 20 years was 78, 75, 66, and 50%, respectively. Subaortic stenosis, protein-losing enteropathy, and arrythmia were observed in 8, 5 and 33 patients, respectively, after surgery. Univariate and multivariable analysis indicated that left ventricular end-diastolic pressure (>/= 13 mmHg), mean pulmonary pressure (>/= 19 mmHg), mitral stenosis/atresia, atrioventricular valve regurgitation, visceral heterotaxia, absence of fenestration, risk factors criteria, duration of extracorporeal circulation, and operative technique were associated with early mortality. Reoperation, arrhythmia, and pacemaker implantation were predictors of late death. Forty percent remained free from surgical or catheter reintervention after Fontan operation at 20 years.

CONCLUSIONS

The outcome of Fontan procedure is profoundly affected by patient-related variables (ventricular function and pulmonary circulation). Postoperative arrhythmia and reoperation shortened the lifespan of the Fontan circulation model in patients with atriopulmonary connections. Total cavopulmonary anastomosis improves the physiology of univentricular circulation. In the light of our findings, the modified Fontan procedure (one or two stages) should be performed early in life to better preserve ventricular and pulmonary vascular function.

Systolic and diastolic performance late after the Fontan procedure for a single ventricle and comparison of those undergoing operation at <12 months of age and at >12 months of age

To evaluate whether surgical history can influence systolic and diastolic properties of a functional single left ventricle after Fontan operation, we echocardiographically investigated 31 patients (mean age 93.7 months; range 21 to 276); 21 patients were >12 months of age (group A) and 10 were <12 months of age (group B) at the time of the Fontan and/or cavopulmonary procedure. In group A we found persistent abnormalities of left ventricular mass index (95.9 vs 64.1 g/m(2), p <0.05) at long-term follow-up, whereas group B had normal left ventricular mass (61.9 vs 64.1 g/m2, p = NS). In contrast, a diastolic pattern characterized by augmented late diastolic filling was present in both patient groups regardless of age at operation and length of follow-up (E/A in group A 1.3 +/- 0.4, E/A in group B 1.6 +/- 1.5, E/A in controls 1.7 +/- 0.6; A vs B, p = NS; A vs controls, p <0.05). We concluded that patients with a single left ventricle who undergo an unloading procedure performed within the first year of life have complete normalization of left ventricular mass, although a diastolic filling pattern suggestive of augmented compliance persists, regardless of the age at operation.

Fenestration of the Fontan baffle: Benefits and complications

Using a baffle fenestration or adjustable atrial septal defect in a modified Fontan operation is now a common practice. Hemodynamic benefits include increased cardiac index and systemic oxygen transport, as well as lower systemic venous pressure. The incidence and duration of pleural effusions is also reduced by this approach. Potential complications include those associated with the closure mechanism (snare or umbrella) as well as the possibility of paradoxical embolism. This review addresses our current understanding of the risks and benefits of this procedure. Copyright 1998 by W.B. Saunders Company

Serial assessment of left ventricular diastolic function after Fontan procedure

OBJECTIVE

To assess longitudinal changes in systemic ventricular diastolic function late after the Fontan procedure.

DESIGN AND PATIENTS

Prospective study of 13 patients at 2.8 (2.0) years (early) and again at 11.4 (2.0) years (late) after the Fontan procedure by Doppler echocardiography with simultaneous ECG, phonocardiogram, and respirometer.

SETTING

Tertiary paediatric cardiac centre.

RESULTS

The isovolumic relaxation time (IVRT) was significantly longer, and E wave deceleration time, E and A wave velocities, and E:A velocity ratio were reduced compared to normal both early and late after the procedure. The mean (SD) z score of IVRT decreased significantly from +2.50 (1.00) to +1.24 (0.80) (p = 0.002), and the z score of the E wave deceleration time decreased from -1.69 (1.31) to -2.40 (1.47) (p = 0.03) during follow up. The A wave deceleration time also tended to decrease (early 80 (12) ms v late 73 (11) ms, p = 0.13) with increased follow up. There were no changes of the E and A wave velocities and E:A velocity ratio. The E wave velocity was inversely related to IVRT both early (r = -0.82, p = 0.001) and late (r = -0.59, p = 0.034) after the operation. The prevalence of diastolic flow during isovolumic relaxation decreased from 85% (11/13) to 38% (5/13) (p = 0.04), while that of mid diastolic flow increased from 23% (3/13) to 77% (10/13) (p = 0.02) between the two assessments.

CONCLUSIONS

Left ventricular diastolic function remains highly abnormal late after the Fontan procedure. The longitudinal changes demonstrated on follow up are compatible with reduction of left ventricular compliance in addition to persisting abnormalities of relaxation.

Effects of arteriovenous shunt on ventricular function in dog

BACKGROUND

The bidirectional cavopulmonary shunt has been increasingly accepted as an interim step to the Fontan operation. However, the effect(s) of chronic volume overload on ventricular function are not yet well understood.

METHODS

Twelve mongrel dogs, with (chronic volume overload group), or without (control group) a femoral arteriovenous shunt created 8 weeks before the assessment, were subjected to a right heart bypass from the right atrium to the proximal pulmonary trunk. Nonpulsatile perfusion via the bypass was achieved using a centrifugal pump and cross-clamping of the pulmonary trunk. Left ventricular function was evaluated using the end-systolic elastance and the Doppler flow pattern on echocardiograms (epicardiac and transesophageal, simultaneously) during acute volume loading.

RESULTS

The left ventricular weight and the left ventricular weight/end-diastolic volume ratio showed no change from control values. The sum of the isovolumetric contraction time and the isovolumetric relaxation time divided by the ejection time remained constant during acute volume loading in the chronic volume overload group, while an increase was demonstrated in the control group. The chronic volume overload group showed a lower Ees (30.8 +/- 16.4 mmHg/cm2 vs. 107.6 +/- 70.3 mmHg/cm2, p = 0.03) than the control group.

CONCLUSIONS

The global ventricular performance changed with chronic adaptation to the arteriovenous shunt, and became resistant to acute volume loading. Left ventricular contractility under nonpulsatile pulmonary perfusion was impaired by chronic volume overload, which is deleterious to the Fontan operation.

Clinical results of the staged Fontan procedure in high-risk patients

BACKGROUND

For high-risk Fontan candidates, the introduction of a bidirectional Glenn shunt before total cavopulmonary connection (a two-staged strategy) may extend the indications for the Fontan procedure. The clinical results of the two-staged and one-staged Fontan procedure were thus reviewed and compared.

METHODS

Between November 1991 and July 1996, the two-staged strategy was performed in 40 high-risk Fontan candidates with a mean interval of 17.2 months after introducing the bidirectional Glenn shunt (staged group). We considered a young age (<2 years), high mean pulmonary arterial pressure (> or =20 mm Hg), high pulmonary vascular resistance (> or =3 Wood units), small pulmonary artery (Nakata index <200 mm2/m2), atrioventricular valve incompetence (> or = moderate), distortion of pulmonary artery, anomalous pulmonary venous return, and poor ventricular function as risk factors for the successful completion of Fontan circulation. During the same period, 68 patients underwent the modified Fontan procedure in a one-step fashion (primary group).

RESULTS

In the staged group after the bidirectional Glenn shunt, the mean pulmonary arterial pressure and ventricular end-diastolic pressure were both found to have decreased significantly to the same level as those in the primary group, whereas the pulmonary artery demonstrated a significantly smaller size than that in the primary group. Operative morbidity was similar in both groups. Operative mortality was also similar and low in both groups (1.5% in the primary group and 0% in the staged group).

CONCLUSIONS

A bidirectional Glenn shunt was found to be a useful interim palliation in high-risk Fontan candidates. This two-staged strategy may extend the operative indications for the Fontan procedure.

Comparison of three-dimensional echocardiographic assessment of volume, mass, and function in children with functionally single left ventricles with two-dimensional echocardiography and magnetic resonance imaging

Diminished systolic function or inappropriate hypertrophy are considered risk factors for outcome following the Fontan procedure. These parameters are difficult to assess in univentricular hearts that do not conform to the uniform shapes prescribed by conventional 2-dimensional imaging volume algorithms. Three-dimensional echocardiography requires no geometric assumptions and has been validated in both normal and distorted left ventricles. To assess the feasibility and accuracy of this technique in patients with univentricular hearts, we compared 2- and 3-dimensional echocardiographic estimates of ventricular volume, ejection fraction, and mass in patients with functionally single left ventricles with results obtained by magnetic resonance imaging (MRI). Twelve patients with functionally single left ventricles (6 months to 22 years) underwent examination by all 3 modalities. Correlation and agreement with MRI were calculated for volumes, ejection fraction, and mass. Three-dimensional echocardiographic comparison with MRI yielded a bias of 3.4 +/- 5.5 ml and 14.2 +/- 8.3 ml for systolic and diastolic volumes, respectively. Agreement analysis for mass showed a bias of 5.8 +/- 8.4 grams. Two-dimensional echocardiography showed less agreement for both volumes and mass (bias of -2.9 +/- 8.1, 2.9 +/- 10.4 ml and -8.3 +/- 12.0 g for volume and mass, respectively, p >0.05). Ejection fraction by 3-dimensional echocardiography showed significantly closer agreement with MRI (bias of 4.4 +/- 5.3%) than 2-dimensional echocardiography (bias of 8.5 +/- 10.3%, p = 0.04). Thus, 3-dimensional echocardiography provides estimates of ventricular volumes, ejection fraction, and mass that are comparable to MRI in this select group of patients with single ventricles of left ventricular morphology.

Automated echocardiographic analysis of systemic ventricular performance in hypoplastic left heart syndrome

In patients with hypoplastic left heart syndrome, the right ventricle is positioned as the systemic ventricle. Monitoring its function is important but difficult because of its unusual position and geometry. The purposes of this study were to determine the feasibility of applying automatic echocardiographic measurements to the evaluation of right ventricular function in patients with hypoplastic left heart syndrome and to compare their function with that of normal subjects. Eleven patients with hypoplastic left heart syndrome (mean age 1.6 years) were evaluated with automatic border detection. Images were adequate if greater than 85% of the endocardium was being tracked. Systolic indexes were fractional area change and peak emptying rate; diastolic indexes were peak filling rate and the proportion of filling that occurred during rapid filling, diastasis, and atrial contraction. These data were compared with those in 18 normal control subjects. Three patients had completed stage 1 (aortic reconstruction, surgical shunt, and atrial septectomy), three patients had completed stage 2 (hemi-Fontan), and five patients had completed stage 3 (Fontan). Images were adequate in all cases. Fractional area change and peak emptying rate were significantly lower in the patients with hypoplastic left heart syndrome compared with control subjects (38% +/- 6% versus 61% +/- 10% and 3.5 +/- 0.9 versus 5.3 +/- 1.3 sec-1, respectively). Peak filling rate was significantly lower (4.1 +/- 1.3 versus 6.6 +/- 2.3 sec-1) and atrial contribution was significantly higher (18% +/- 7% versus 12% +/- 4%) in the patients. Automated echocardiographic analysis is feasible in assessing systemic ventricular function in children with hypoplastic left heart syndrome. These patients have abnormal systolic and diastolic function. Automatic border detection may be useful in detecting and monitoring systemic ventricular dysfunction as these patients progress through the surgical stages of repair.

Late ventricular geometry and performance changes of functional single ventricle throughout staged Fontan reconstruction assessed by magnetic resonance imaging

OBJECTIVES

We sought to test the hypothesis that late ventricular geometry and performance changes occur in functional single ventricles as they progress through staged Fontan reconstruction.

BACKGROUND

Indexes of ventricular geometry and performance are important in evaluating the functional state of the heart. Magnetic resonance imaging determines these indexes in complex ventricular shapes with minimal geometric assumptions. Previous studies have shown that 1 week after hemiFontan, the mass/volume ratio markedly increases.

METHODS

Multiphase, multislice, spin echo (n = 5) and cine (n = 30) magnetic resonance imaging was performed in 35 patients with a functional single ventricle (1 week to 12 years old) at various stages of Fontan reconstruction (15 in the pre hemiFontan stage, 11 after [6 to 9 months] the hemiFontan procedure and 9 after [1 to 2 years] the Fontan procedure). Volume and mass were calculated at end-systole and end-diastole. Ventricular output was then obtained. Ventricular centroid motion was also calculated.

RESULTS

No difference was noted (power > 72%) from the pre hemiFontan stage to 6 to 9 months after the hemiFontan procedure in (mean +/- SD) end-diastolic volume (104 +/- 24 vs. 123 +/- 40 cc/m2), mass (171 +/- 46 vs. 202 +/- 61 g/m2), ventricular output (7.9 +/- 2.2 vs. 6.6 +/- 2.4 liters/min per m2) or centroid motion (6.9 +/- 2.8 vs. 6.7 +/- 2. mm/m2). Patients in the Fontan group demonstrated a marked decrease in all indexes, indicating significant volume unloading and decrease in mass and ventricular performance. Mass/volume ratio was not significantly different among all three groups.

CONCLUSIONS

No geometric and performance changes from the volume-loaded stage are noted 6 to 9 months after the hemiFontan procedure; however, major changes occur 1 to 2 years after the Fontan procedure. The dramatic changes in the mass/volume ratio seen early after the hemiFontan procedure were not detected at 6 to 9 months. Furthermore diminution of mass, volume and ventricular performance are present at least 2 years after the Fontan procedure.

Surgical preconditioning and completion of total cavopulmonary connection by interventional cardiac catheterisation: a new concept

A new, staged procedure for univentricular repair of "high risk" patients using a combined surgical transcatheter technique is reported. As first step a surgical hemifontan procedure was performed and a multifenestrated patch inserted into the right atrium. For later transcatheter completion of univentricular repair, a subtotal banding just above the cavoatrial junction was performed. Two months later transcatheter completion was performed by balloon dilatation of the banded cavo-atrial junction and additionally either by inserting a covered stent as intracardiac conduit between the superior and inferior vena cava or by inserting a (non-covered) stent into the cavo-atrial junction and occluding the fenestrations in the right atrial patch using Rashkind-PDA occluders. This new technique was successfully applied without mortality in eight patients with a preoperative mean pulmonary pressure of 18 to 23 mm Hg. No complications typical for Fontan-like corrections occurred within the follow up period of 4 to 14 months.

The adult patient with congenital heart disease

In adults with congenital heart disease who are confronted with noncardiac surgery, perioperative risks can be reduced, often appreciably, when problems inherent to this patient population are anticipated. The first necessity is to clarify the diagnosis and to be certain that appropriate information is obtained from a cardiologist with adequate knowledge of congenital heart disease in adults. Physiology and anatomy can vary significantly among patients who superficially carry identical diagnoses. Elective noncardiac surgery should be preceded by clinical assessment including review of clinical and laboratory data and securing the results of necessary diagnostic studies. Preoperative assessment should be performed far enough in advance of the anticipated date of surgery to allow critical assessment of the data and potential discussions with colleagues. Appropriate cardiovascular laboratory studies to be obtained or reviewed include electrocardiograms, chest radiographs, echocardiograms, and cardiac catheterization data, which may include specialized intracardiac electrophysiologic testing. Congenital heart disease in adults is a new and evolving area of special interest and expertise in cardiovascular medicine. Multidisciplinary centers for the care of these patients are being developed. The 22nd Bethesda Conference recommended that these centers include among their consultants anesthesiologists with special expertise in managing patients with congenital heart disease. These anesthesiologists can have the option of serving either as the attending anesthesiologists when patients require noncardiac surgery or as consultants and resource individuals to other anesthesiologists.

Acute changes in left ventricular geometry after volume reduction operation

BACKGROUND

After surgical removal of a volume load, regression of myocardial mass proceeds slowly relative to diminution in ventricular cavity size, resulting in increased wall thickness and decreased cavity dimensions, which may affect the filling properties and performance of the heart. We investigated the acute changes in ventricular geometry that occur after the Fontan operation and hemi-Fontan operation for tricuspid atresia, and compared them with closure of a ventricular septal defect in a two-ventricle heart.

METHODS

We reviewed the results of echocardiography performed before and 8 +/- 7 days after (1) Fontan operation for tricuspid atresia (n = 9), (2) hemi-Fontan operation for tricuspid atresia (n = 10), and (3) closure of a ventricular septal defect (n = 13). Measurements were made from images of the left ventricle at end-diastole: (1) apical, septal, and posterior wall thickness; and (2) long- and short-axis cavity diameters, cross-sectional areas, and ventricular volume. Posterior wall thickness to cavity dimension ratio was calculated.

RESULTS

Wall thickness increased in all groups, with the greatest degree of increase after the Fontan operation. Cavity measures decreased most dramatically after the Fontan operation, with less dramatic and equivalent changes noted after the hemi-Fontan operation and ventricular septal defect closure. Posterior wall thickness to cavity diameter ratios were equivalent in all before operation, increased after operation, and were greatest after the Fontan operation.

CONCLUSIONS

Changes in ventricular geometry identified as an increase in wall thickness and a decrease in cavity dimension are most dramatic after the Fontan operation. Changes seen after the hemi-Fontan operation are of a milder degree, which may in part explain the excellent clinical course after this operation.

Noninvasive assessment of myocardial contractility, preload, and afterload in healthy newborn infants

Assessment of ventricular contractility in the newborn infant using standard echocardiographic indexes can result in error due to the unique physiologic state that exists in the neonatal period. It has been suggested from animal and human studies that maturational alterations in contractility occur with birth and continue throughout infancy. To further investigate these developmental changes, 41 newborn infants aged 3 to 10 days and 37 children aged 3 to 18 years were evaluated with 2-dimensional and M-mode echocardiography. The rate-corrected velocity of circumferential fiber shortening (VCFc)-end-systolic wall stress (ESWS) relation was used as a load-independent estimate of contractility. Preload, afterload, and ventricular mass were also measured. Despite similar shortening fractions, the infant group had significantly higher mean VCFc and lower ESWS than the older age group (1.28 vs 1.08 circ/s and 30.2 vs 37.3 gm/m2, respectively). An inverse linear relation between VCFc and ESWS was found in both age groups. The y-intercept was higher in the infant group (p < 0.01), and the slope of the mean regression line was steeper than in the older children (p < 0.01). Ventricular mass in relation to body surface area increased with age. We conclude that (1) newborn infants have a higher basal contractile state that cannot be accounted for by lower afterload, (2) myocardial performance is more sensitive to afterload in the immature heart, and (3) shortening fraction may underestimate ventricular function in the newborn.

Asynchronous volume changes of the two ventricles after Fontan operation in patients with a biventricular heart

Coordinated contraction of the ventricle is an important determinant of pump function, which seems to be particularly important in Fontan circulation with one pumping ventricle. We analyzed the synchronism of contraction of the two ventricles in 11 patients with a biventricular heart who had undergone Fontan operation. Curves representing ventricular volume changes in a cardiac cycle measured on angiograms were smoothed and divided into 20 segments. We calculated the number of segments of the same directional volume changes (synchronous changes) between the two ventricles (synchronous ratio). We also calculated the total volume of the two ventricles (the two as one whole ventricle) by adding their volumes in each segment and calculated the ratio (stroke volume ratio) of the aortic stroke volume from the whole ventricle to the sum of stroke volumes of the morphological right and left ventricles. If the two ventricles ejected the blood in a completely synchronous manner, these ratios should be 1.0. In seven patients with synchronous ratios of 0.75 or greater and a stroke volume ratio of greater than 0.95, the cardiac index was 3.2 +/- 0.3 l/min/m2, the maximum total volume (corresponding to end-diastolic volume) was 106 +/- 45% normal, and the ejection fraction was 0.44 +/- 0.10. In four patients with ratios of less than 0.70 and 0.95, respectively, the parameters were 2.4 +/- 0.5 (P < 0.05), 193 +/- 92%, and 0.33 +/- 0.08, respectively. The synchronous ratio was inversely correlated with cardiac output. In conclusion, synchronism of the cardiac cycle of the two ventricles affects Fontan circulation in patients with a biventricular heart.

Fontan operation: influence of modifications on morbidity and mortality

The mortality rate of the Fontan operation for heart malformations with a single or dominant ventricle has been reduced by dividing the procedure into two stages. The hemi-Fontan procedure allows early reduction of the volume work of the single ventricle and remodeling of ventricular geometry before a completion Fontan operation. Despite the improvement of survival with this strategy (8% mortality for completion Fontan versus 16% mortality for primary Fontan operation), morbidity related to serous effusions remains substantial. Further technical modifications have been undertaken in an effort to reduce morbidity and further reduce mortality. From January 1990 through June 1993, 200 patients underwent completion Fontan procedures after previous hemi-Fontan operations. Mean age was 23 months, and 157 patients were less than 24 months of age. Diagnoses were hypoplastic left heart syndrome (127 patients), tricuspid atresia (19 patients), single left ventricle (17 patients), complex double-outlet right ventricle (16 patients), pulmonary atresia with intact ventricular septum (8 patients), and other (13 patients). Overall, early mortality rate was 8% (16 patients). In the last 112 patients, the procedure was modified technically by creating one or more fenestrations in the baffle used to separate systemic venous blood from pulmonary venous blood (36 patients), or by excluding one or more hepatic veins from the systemic venous pathway (76 patients). Early mortality for these 112 patients was reduced to 4.5% (5 patients). Substantial morbidity from serous effusions occurred at a rate of 45% (35 of 78 patients) among survivors who had received neither technical modification.(ABSTRACT TRUNCATED AT 250 WORDS)

Systolic and diastolic function in tricuspid valve atresia before the Fontan operation

Systolic and diastolic function were assessed at preoperative cardiac catheterization in 6 patients with classic tricuspid atresia and were compared with those in control subjects. All patients had systemic-to-pulmonary shunts. Left ventricular end-systolic and end-diastolic volumes and masses were significantly larger in the patient group; stroke volume and the ratio of volume to mass were also higher, but not significantly. Mean end-diastolic, peak systolic and end-systolic pressures were similar. Mean stress at end-systole and peak systole were significantly higher in the patient group. Operant chamber stiffness tended to be lower than normal, but was not statistically significant, and myocardial stiffness was normal for the patient group also. Indexes of systolic function were compared. The rate-corrected mean velocity of fiber shortening in the patient group was lower and its relation with stress at end-systole was variable with 4 abnormal patients. The ratio of stress at end-systole/end-systolic volume was significantly lower in patients. The duration of hospital stay did not correlate with end-diastolic volume or any parameter. Thus, this study found abnormalities of load-dependent and independent indexes of systolic function with normal diastolic function in young preoperative patients with tricuspid atresia.