Left ventricular performance of pulmonary atresia with intact ventricular septum after right heart bypass surgery

Comparison of cardiac energetics after transcatheter and surgical aortic valve replacements

OBJECTIVES

The effect of transcatheter aortic valve replacement (TAVR) on cardiac energetics has not been described. We compared changes in cardiac energetics after TAVR with those after surgical aortic valve replacement (SAVR).

METHODS

We retrospectively estimated end-systolic elastance (Ees) and effective arterial elastance (Ea) using blood pressure and left ventricular (LV) volume obtained from echocardiography. LV efficiency [ventriculoarterial coupling (Ea/Ees) and the stroke work to pressure-volume area ratio (SW/PVA)] was calculated. Measurements were taken before, 1 week after and 1 year after bioprosthetic aortic valve replacement (TAVR, n = 56; SAVR, n = 61) in patients with severe aortic stenosis and preserved ejection fraction.

RESULTS

Patients with TAVR had a lower aortic valve pressure gradient and larger stroke volume 1 week after the procedure than those with SAVR. Ea was more markedly decreased, and LV efficiency was significantly improved 1 week after TAVR (SW/PVA 68.1% ± 8.4% to 72.0% ± 8.5%, P < 0.001), but LV efficiency was unchanged 1 week after SAVR (SW/PVA 70.1% ± 7.4% to 69.1%  ±  8.0%). LV efficiency was improved 1 year after both procedures (SW/PVA 75.5% ± 6.1% in TAVR; 74.7% ± 6.4% in SAVR).

CONCLUSIONS

TAVR decreases the transvalvular pressure gradient further without deteriorating stroke volume in the early postoperative period, which is accompanied by early improvement in afterload and LV efficiency compared with SAVR. Improvement in LV efficiency at mid-term follow-up is satisfactory after both procedures.

Left ventricular function after a Fontan operation in patients with pulmonary atresia with an intact ventricular septum

OBJECTIVES

In patients with pulmonary atresia with an intact ventricular septum (PA/IVS), there are no reports about the impact of sinusoidal communication (SC) on left ventricular (LV) performance after a Fontan operation; therefore, the purpose of this study was to fill this gap in the literature.

METHODS

We performed a single-centre, retrospective study of 46 patients with PA/IVS. Nineteen patients who underwent the Fontan procedure were enrolled and divided into 2 groups: those with SC (SC group) and those without SC (N group). The 2 groups were compared in terms of postoperative cardiac function.

RESULTS

Thirteen patients were in the SC group (4 patients with right ventricle-dependent coronary circulation) and 6, in the N group. Although 2 of the patients with right ventricular (RV)-dependent coronary circulation showed focal asynergy of the LV wall, others showed no findings of myocardial infarction. The patients' preoperative age and age during the observation period after the Fontan operation did not differ. There was no difference in LV ejection fraction, cardiac index and RV and pulmonary artery pressure before and after the Fontan operation. Preoperative RV volume in the N group was greater than that in the SC group. Brain natriuretic peptide levels were higher in the SC group after the Fontan operation. On ventricular efficacy analysis, contractility was lower (1.8 ± 0.32 vs 2.5 ± 0.40 mmHg/ml/m2, P = 0.001) and ventricular efficacy was worse (1.0 ± 0.15 vs 0.86 ± 0.11, P = 0.046) in the SC group during the postoperative period.

CONCLUSIONS

Compared to patients with PA/IVS without SC, patients with PA/IVS with SC had a low cardiac contractility and decreased cardiac output efficiency after the Fontan procedure.

Pulmonary Atresia With an Intact Ventricular Septum: Preoperative Physiology, Imaging, and Management

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare complex cyanotic congenital heart disease with heterogeneous morphological variation. Prenatal diagnosis allows for developing a safe plan for delivery and postnatal management. While transthoracic echocardiography allows for detailed delineation of the cardiac anatomy, additional imaging modalities such as computed tomography, magnetic resonance imaging, and catheterization may be necessary to further outline features of the cardiac anatomy, specifically coronary artery anatomy. The size of the tricuspid valve and right ventricular cavity as well as the presence of right ventricle–dependent coronary circulation help to dichotomize between biventricular repair versus univentricular palliation or heart transplantation, as well as predicting the expected survival. The delineation and understanding of these features help to dictate both medical and surgical management.

Quantification of ventricular unloading by 3D echocardiography in single ventricle of left ventricular morphology following superior cavo-pulmonary anastomosis and Fontan completion - a feasibility study

BACKGROUND

Three-dimensional echocardiography. (3DE) is comparable to cardiac magnetic resonance imaging for estimating ventricular volume in congenital heart diseases. However, there are limited data on estimation of ventricular volumes by 3DE in univentricular heart and change in ventricular volumes after surgical creation of cavopulmonary connection. We sought to quantify the unloading of the single ventricle of left ventricular. (LV) morphology by 3DE after superior cavopulmonary anastomosis. (SCPA) or Fontan operation over a period of 3 months and thereby derive a preliminary 3DE data set on this patient subset.

PATIENTS AND METHODS

Eighteen patients with functional single ventricle of LV morphology, who underwent SCPA or completion of Fontan circulation, were included in the study. Volume of the ventricle was estimated by 3DE before surgery and after surgery. (in the early postoperative phase and 3 months after surgery), and indexed end-diastolic volume. (EDV), end-systolic volume. (ESV), and ejection fraction. (EF) were derived.

RESULTS

Twelve patients underwent SCPA and six patients underwent staged completion of Fontan circulation. Before surgery, EDV was similar in both groups. There was a significant fall in EDV immediately after SCPA (from 48.3 ± 14.9 ml/m² to 39.5 ± 12.3 ml/m²). However, EDV increased at 3 months' follow-up to 41.3 ± 10.5 ml/m². There was no significant fall in EDV immediately after Fontan operation (47.2 ± 10.1 ml/m²-46.6 ± 14.2 ml/m²), but EDV continued to fall at 3 months of follow-up (44.7 ± 10. ml/m²). There was no significant change in ESV in either group, but EF fell significantly after SCPA.

CONCLUSIONS

We provide preliminary information on 3DE volume data of single ventricle of LV morphology and the pattern of unloading after SCPA and Fontan operation. Immediate significant volume unloading occurred after SCPA which tended to catch-up after 3 months, whereas continued fall in ventricular volume with time was noted after Fontan.

Sickle Cell Disease with Cyanotic Congenital Heart Disease: Long-Term Outcomes in 5 Children

Sickle cell disease is a risk factor for cerebrovascular accidents in the pediatric population. This risk is compounded by hypoxemia. Cyanotic congenital heart disease can expose patients to prolonged hypoxemia. To our knowledge, the long-term outcome of patients who have combined sickle cell and cyanotic congenital heart disease has not been reported. We retrospectively reviewed patient records at our institution and identified 5 patients (3 girls and 2 boys) who had both conditions. Their outcomes were uniformly poor: 4 died (age range, 12 mo-17 yr); 3 had documented cerebrovascular accidents; and 3 developed ventricular dysfunction. The surviving patient had developmental delays. On the basis of this series, we suggest mitigating hypoxemia, and thus the risk of stroke, in patients who have sickle cell disease and cyanotic congenital heart disease. Potential therapies include chronic blood transfusions, hydroxyurea, earlier surgical correction to reduce the duration of hypoxemia, and heart or bone marrow transplantation.

Cardiac energetics analysis after aortic valve replacement with 16-mm ATS mechanical valve

The 16-mm ATS mechanical valve is one of the smallest prosthetic valves used for aortic valve replacement (AVR) in patients with a very small aortic annulus, and its clinical outcomes are reportedly satisfactory. Here, we analyzed the left ventricular (LV) performance after AVR with the 16-mm ATS mechanical valve, based on the concept of cardiac energetics analysis. Eleven patients who underwent AVR with the 16-mm ATS mechanical valve were enrolled in this study. All underwent echocardiographic examination at three time points: before AVR, approximately 1 month after AVR, and approximately 1 year after AVR. LV contractility (end-systolic elastance [Ees]), afterload (effective arterial elastance [Ea]), and efficiency (ventriculoarterial coupling [Ea/Ees] and the stroke work to pressure-volume area ratio [SW/PVA]) were noninvasively measured by echocardiographic data and blood pressure measurement. Ees transiently decreased after AVR and then recovered to the pre-AVR level at the one-year follow-up. Ea significantly decreased in a stepwise manner. Consequently, Ea/Ees and SW/PVA were also significantly improved at the one-year follow-up compared with those before AVR. The midterm LV performance after AVR with the 16-mm ATS mechanical valve was satisfactory. AVR with the 16-mm ATS mechanical valve is validated as an effective treatment for patients with a very small aortic annulus. The cardiac energetics variables, coupling with the conventional hemodynamic variables, can contribute to a better understanding of the patients' clinical conditions, and those may serve as promising indices of the cardiac function.

Fetal cardiac interventions: rationale, risk and benefit

Fetal congenital heart disease may progress during pregnancy and may lead to irreversible myocardial or pulmonary damage. The rationale of fetal intracardiac interventions is to change fetal hemodynamics, prevent secondary damage and improve long-term outcome at an acceptable risk for mother and fetus. This review focuses on the current experience about patient selection, risks and benefits of this technique.

Left ventricular efficiency after ligation of patent ductus arteriosus for premature infants

OBJECTIVE

The purpose of this study was to evaluate the hemodynamic changes in left ventricular function before and after patent ductus arteriosus ligation in premature infants with regard to the energetic efficiency of left ventricular pumping.

METHODS

Thirty-five premature infants who underwent patent ductus arteriosus ligation were enrolled in this study. Left ventricular efficiency was evaluated at 4 points: within 24 hours before patent ductus arteriosus ligation, within 24 hours after patent ductus arteriosus ligation, between postoperative days 2 and 4, and on postoperative day 7. The indices of contractility (end-systolic elastance) and afterload (effective arterial elastance) were approximated on the basis of the systemic blood pressure and systolic or diastolic left ventricular volume. The ratio of stroke work and pressure-volume area, representing the ventricular efficiency, was estimated using the following theoretic formula: the ratio of stroke work and pressure-volume area = 1/(1 + 0.5 ventriculoarterial coupling).

RESULTS

Left ventricular efficiency was transiently deteriorated within 24 hours after patent ductus arteriosus ligation because of the marked increase of the afterload and the slight increase of contraction, and then recovered to preoperation levels by 2 to 4 days after patent ductus arteriosus ligation.

CONCLUSIONS

Analysis of indices representing the afterload, contractility, and energetic efficiency of the left ventricle may provide practical information for the management of premature infants during the postoperative period after patent ductus arteriosus ligation.

Long-term functional health status and exercise test variables for patients with pulmonary atresia with intact ventricular septum: a Congenital Heart Surgeons Society study

BACKGROUND

A bias favoring biventricular (BV) repair exists regarding choice of repair pathway for patients with pulmonary atresia with intact ventricular septum (PAIVS). We sought to determine the implications of moving borderline candidates down a BV route in terms of late functional health status (FHS) and exercise capacity (EC).

METHODS

Between 1987 and 1997, 448 neonates with PAIVS were enrolled in a multi-institutional study. Late EC and FHS were assessed following repair (mean 14 years) using standardized exercise testing and 3 validated FHS instruments. Relationships between FHS, EC, morphology, and 3 end states (ie, BV, univentricular [UV], or 1.5-ventricle repair [1.5V]) were evaluated.

RESULTS

One hundred two of 271 end state survivors participated (63 BV, 25 UV, and 14 1.5V). Participants had lower FHS scores in domains of physical functioning (P < .001) compared with age- and sex-matched normal controls, but scored significantly higher in nearly all psychosocial domains. EC was higher in 1.5V-repair patients (P = .02), whereas discrete FHS measures were higher in BV-repair patients. Peak oxygen consumption was low across all groups, and was positively correlated with larger initial tricuspid valve z-score (P < .001), with an enhanced effect within the BV-repair group.

CONCLUSIONS

Late patient-perceived physical FHS and measured EC are reduced, regardless of PAIVS repair pathway, with an important dichotomy whereby patients with PAIVS believe they are doing well despite important physical impediments. For those with smaller initial tricuspid valve z-score, achievement of survival with BV repair may be at a cost of late deficits in exercise capacity, emphasizing that better outcomes may be achieved for borderline patients with a 1.5V- or UV-repair strategy.

Early mitral valve surgery for chronic severe mitral regurgitation optimizes left ventricular performance and left ventricular mass regression

OBJECTIVE

The optimal timing of mitral valve surgery for severe mitral regurgitation is controversial. We aimed to evaluate the changes in left ventricular performance using ventricular energetics and left ventricular mass regression after the surgery to determine the appropriate surgical timing in asymptomatic patients with severe mitral regurgitation.

METHODS

Fifty consecutive asymptomatic or minimally symptomatic patients who electively underwent the surgery for severe mitral regurgitation were studied retrospectively. Contractility (end-systolic elastance), afterload (effective arterial elastance), and efficiency (ventriculoarterial coupling and ratio of stroke work to pressure-volume area), and left ventricular mass index were measured echocardiographically before and 1 month after surgery. Two-way repeated-measures analysis of variance was used to compare the parameters between patients with (n = 17) and without (n = 33) left ventricular dysfunction (ie, ejection fraction ≤60% and/or end-systolic dimension ≥40 mm).

RESULTS

Contractility did not change significantly (P = .94) but the afterload increased significantly (P < .0001) in both groups. Consequently, the efficiency deteriorated significantly (ventriculoarterial coupling, P = .0004; ratio of stroke work to pressure-volume area, P < .0001). Furthermore, the left ventricular mass index improved remarkably in both groups (P < .0001). Alternatively, the patients with normal left ventricular function had greater contractility (P < .0001), less worsened efficiency (P < .0001 and P < .0001, respectively), and a better left ventricular mass index (P = .0002) after surgery.

CONCLUSIONS

Early surgery for severe mitral regurgitation preserves left ventricular performance and improves left ventricular mass regression in asymptomatic patients with normal ventricular function.

Effect of ventricular volume before unloading in a systemic ventricle supporting the Fontan circulation

The influence of volume overload on ventricular performance has been previously investigated but primarily with respect to the duration of overload. The aim of the present study was to elucidate whether the magnitude of the preoperative volume overload, represented by the ventricular volume, has any effect on ventricular performance long after the Fontan operation in patients with tricuspid atresia. We evaluated consecutive changes in hemodynamic catheterization data obtained at 1, 5, and 10 years after primary Fontan repair. The variables were compared between patients with larger (n = 20) and smaller (n = 21) ventricles (preoperative end-diastolic volume [percentage of predicted] 262 ± 33%, maximum 320% vs 182 ± 22%, minimum 133%, respectively). In a subgroup of patients (n = 33) who underwent symptom-limited exercise at 10.7 ± 3.0 postoperative years, the peak oxygen uptake was measured, and the potential predictors were interrogated. The difference in ventricular contractility between the groups tended to increase with time, with those with a larger ventricle showing poorer contraction, irrespective of whether it was assessed in a load-dependent (ejection fraction) or load-independent (end-systolic elastance) manner. The differences in these variables reached statistical significance at 10 years (p = 0.028 and p = 0.032). Multivariate analysis indicated a larger ventricle was an independent risk factor of poorer aerobic capacity (p = 0.047). In conclusion, ventricular performance was less preserved in those with a larger ventricle, which might result in suboptimal aerobic capacity. Our findings suggest not only early unloading, but also avoidance of excessive volume overload is of importance to minimize the deleterious effect of volume overload on an inherently susceptible ventricle.

Critical care outcomes in pulmonary atresia and intact ventricular septum undergoing single-ventricle palliation

OBJECTIVE

To examine early outcomes for pulmonary atresia with intact ventricular septum undergoing single-ventricle palliation and to determine risk factors for mortality.

DESIGN

Retrospective observational study.

SETTING

Tertiary paediatric critical care unit.

INTERVENTION

Risk factors for mortality were sought for infants after the primary intervention whether surgical shunt or ductal stent.

MEASUREMENTS AND MAIN RESULTS

We reviewed outcomes of 19 infants with pulmonary atresia with intact ventricular septum undergoing single-ventricle palliation between July, 2000 and July, 2008. Echocardiograms, cardiac catheterisation findings, anaesthesia, and critical care management, as well as autopsy reports were reviewed. We modelled survival after surgery and looked for predictors of early mortality. A total of 19 infants underwent single-ventricle palliation and seven of these died. The risk of death was increased by a lower arterial pH at induction of anaesthesia (p = 0.01), a lower systolic blood pressure (p = 0.01), and technical problems during surgery (p = 0.03). On admission to the critical care unit, a lower mixed venous saturation (p = 0.02) and presence of tachyarrhythmia (p = 0.02) were associated with the need for mechanical support within the first 48 hours.

CONCLUSIONS

There is a high early mortality for those who undergo single-ventricle palliation. It is higher for those who are haemodynamically compromised before surgery; technical problems, and haemodynamic instability during surgery also increase mortality.

Ventricular energetics in aortic root replacement for annuloaortic ectasia with aortic regurgitation

Aortic root replacement (Bentall operation) is the standard operation for patients who have lesions of the ascending aorta associated with aortic valve disease. We analyzed the mid-term results for left ventricular energetics after the Bentall operation for annuloaortic ectasia with aortic regurgitation. We measured left ventricular contractility (end-systolic elastance; Ees), afterload (effective arterial elastance; Ea), and efficiency (ventriculoarterial coupling; Ea/Ees, and the ratio of stroke work and pressure-volume area; SW/PVA) based on transthoracic echocardiography data before, after, and approximately 1 year after the Bentall operation in 15 patients with annuloaortic ectasia with aortic regurgitation. Left ventricular volume was calculated by the Teichholz M-mode method. Ees and Ea were approximated as follows: Ees=mean blood pressure/minimal left ventricular volume, and Ea=systolic blood pressure/(maximal left ventricular volume--minimal left ventricular volume). Ea/Ees and SW/PVA were then calculated. Left ventricular volume was normalized with body surface area. Ees increased after the Bentall operation and around 1 year later (from 2.17+/-1.09 to 3.92+/-2.26 and 5.33+/-1.90 mmHg x m(2)/ml, P<0.001), thus resulting in an improvement in SW/PVA (from 68.8+/-8.2 to 70.9+/-9.5 and 74.7+/-5.2%, P=0.045). Ea also increased after the Bentall operation and 1 year later (from 1.77+/-0.61 to 2.88+/-1.28 and 3.54+/-1.43 mmHg x m(2)/ml, P<0.001). The mid-term results for ventricular contractility and efficiency after the Bentall operation for annuloaortic ectasia with aortic regurgitation are excellent and satisfactory.

Fetal intervention for cardiac disease: the cutting edge of perinatal care

Fetal cardiac valvuloplasty has been proposed for progressive cardiac disease with a poor prognosis, such as critical aortic stenosis and pulmonary atresia with intact ventricular septum and balloon atrial septostomy for hypoplastic left heart syndrome, or simple transposition of the great arteries with closed or restrictive inter-atrial communication. It is anticipated that early rescue of ventricles or the pulmonary veins from an unfavourable environment may promote healthier ventricular and vascular growth and improve postnatal outcomes. While close collaboration between the fetal medicine specialist and perinatal cardiologist may optimize the chances of technical success, obstacles to progress include the relative rarity of suitable cases and late referral for therapy. In common with other interventions in fetal medicine, there is a learning curve, and it would benefit progress if the procedures were initially concentrated in just a few centres to enable them to develop skills and experience. Following careful evaluation, it may then be desirable to train further centres and roll out best practice models.

Does a bidirectional Glenn shunt improve the oxygenation of right ventricle–dependent coronary circulation in pulmonary atresia with intact ventricular septum?

OBJECTIVE

There is a risk of myocardial ischemia in patients with pulmonary atresia and intact ventricular septum associated with the right ventricle-dependent coronary circulation. In this patient group, the oxygen delivery to the myocardium depends on the oxygen saturation of the right ventricular cavity. We hypothesized that bidirectional Glenn shunt would improve the oxygenation of right ventricle-dependent coronary circulation relative to a systemic-pulmonary artery shunt. The reduction of systemic venous return to the right atrium due to a bidirectional Glenn shunt could increase the oxygen saturation of the right ventricle in the clinical setting, when the mixture of systemic and pulmonary venous blood is unchanged at the atrial level.

METHODS

Patients with right ventricle-dependent coronary circulation were defined as those with right ventricle-coronary artery fistulas plus stenoses of the right or left coronary arteries. For 7 patients with right ventricle-dependent coronary circulation before and after bidirectional Glenn shunt, cardiac catheterization was performed and the oxygen saturation of the right ventricular cavity was measured.

RESULTS

For all 7 patients, the bidirectional Glenn shunt was performed at a mean age of 18 months. Ischemic changes in the electrocardiogram before the bidirectional Glenn shunt improved after the procedure in 2 patients. The oxygen saturation of the right ventricular cavity before the bidirectional Glenn shunt was 54.6 +/- 8.8%, and that after the BGS significantly increased to 75.6% +/- 5.8% (P < .01). All 7 patients have subsequently undergone the Fontan procedure with excellent results.

CONCLUSION

Early bidirectional Glenn shunt could prevent progression of myocardial ischemia in pulmonary atresia with intact ventricular septum with right ventricle-dependent coronary circulation.