Survival and outcomes of patients with unoperated single ventricle

Opportunities and short-comings of the axolotl salamander heart as a model system of human single ventricle and excessive trabeculation

Few experimental model systems are available for the rare congenital heart diseases of double inlet left ventricle (DILV), a subgroup of univentricular hearts, and excessive trabeculation (ET), or noncompaction. Here, we explore the heart of the axolotl salamander (Ambystoma mexicanum, Shaw 1789) as model system of these diseases. Using micro-echocardiography, we assessed the form and function of the heart of the axolotl, an amphibian, and compared this to human DILV (n = 3). The main finding was that both in the axolotl and DILV, blood flows of disparate oxygen saturation can stay separated in a single ventricle. In the axolotl there is a solitary ventricular inlet and outlet, whereas in DILV there are two separate inlets and outlets. Axolotls had a lower resting heart rate compared to DILV (22 vs. 72 beats per minute), lower ejection fraction (47 vs. 58%), and their oxygen consumption at rest was higher than peak oxygen consumption in DILV (30 vs. 17 ml min-1 kg-1). Concerning the ventricular myocardial organization, histology showed trabeculations in ET (n = 5) are much closer to the normal human setting than to the axolotl setting. We conclude that the axolotl heart resembles some aspects of DILV and ET albeit substantial species differences exist.

The Secrets of the Frogs Heart

The heart of the African clawed frog has a double-inlet and single-outlet ventricle supporting systemic and pulmonary circulations via a truncus, and a lifespan of 25-30 years. We sought to understand the unique cardiac anatomic and physiologic characteristics, with balanced circulation and low metabolic rate, by comparing the basic anatomy structures with focused echocardiography and cardiac magnetic resonance imaging. Twenty-four adult female African clawed frogs were randomly subjected to anatomic dissection (n = 4), echocardiography (n = 10), and cardiac magnetic resonance (n = 10). All anatomical features were confirmed and compared with echocardiography and cardiac magnetic resonance imaging. The main characteristics of the cardiovascular circulation in frogs are the following: Intact interatrial septum, with two separate atrio-ventricular valves, preventing atrial mixing of oxygenated and desaturated blood. Single spongiform ventricular cavity, non-conducive for homogeneous mixing. Single outlet with a valve-like mobile spiral structure, actively streaming into systemic and pulmonary arteries. Intact interatrial septum, spongiform ventricle, and valve-like spiral in the conus arteriosus are likely responsible for balanced systemic and pulmonary circulation in frogs, in spite of double-inlet and single-outlet ventricle.

Anesthetic management for cesarean section in parturient with an uncorrected single ventricle: A case report and literature review

RATIONALE

Patients with a single ventricle, who have not undergone surgery, reportedly have a lower survival rate. Furthermore, multiple pregnancies are rare among these females. We reported a case of anesthesia management of cesarean section in an uncorrected single-ventricular multi-pregnancy woman and review the anesthesia management of the published similar cases.

PATIENT CONCERNS

An uncorrected single ventricular pregnant woman with a cardiac function of New York Heart Association class II, who had experienced one spontaneous abortion and three vaginal deliveries, was scheduled for cesarean section at 37+6 weeks of gestation.

DIAGNOSES

: Echocardiography revealed a complex congenital heart disease in the mother: a single ventricle (the left ventricle is dominant), atrioventricular valve ectopic, double-inlet left ventricle, abnormal location of the great arteries, probably pulmonary stenosis, atrial septal defect, and left-to-right shunt. The fetus was in breech presentation with umbilical cord around the neck.

INTERVENTIONS

Cesarean section was successfully performed under the combined spinal epidural anesthesia with careful monitoring.

OUTCOMES

: Both mother and newborn recovered good and were discharged from the hospital 5 days after surgery without any adverse reactions.

LESSONS

Single ventricular pregnant woman with a cardiac function of New York Heart Association class I-II could tolerate pregnancy and delivery well. Both general and regional anesthesia are applicable to cesarean section in these patients. The principle of anesthesia management is to maintain the appropriate balance between systemic vascular resistance and pulmonary vascular resistance, as well as to maintain preload and cardiac output.

LONG TERM OUTCOMES OF ADULTS WITH SINGLE VENTRICLE PHYSIOLOGY NOT UNDERGOING FONTAN REPAIR: A MULTICENTRE EXPERIENCE

BACKGROUND

To describe long-term survival and cardiovascular events in adult patients with single ventricle physiology (SVP) without Fontan palliation, focusing on predictors of mortality and comparing groups according to their cardiovascular physiology.

METHODS

Multicentre, observational and retrospective study including adult patients with SVP without Fontan palliation since their first adult clinic visit. The cohort was subdivided into three groups. (Eisenmenger - Restricted Pulmonary flow - Aortopulmonary shunt) Death was considered the main endpoint. Other clinical outcomes occurring during follow-up were considered as secondary endpoints.

RESULTS

146 patients, mean age 32.5±11.1 years were analysed. Over a mean follow-up of 7.3 ± 4.1 years, 33 patients (22.6%) died. Survival was 86% and 74% at 5 and 10 years, respectively. Right ventricular morphology was not associated with higher mortality. Four variables at baseline were related to a higher mortality (at least moderate AV valve regurgitation, platelet count <150 × 10 ³ /mm ³ , GFR <60 ml/min/1.73m ² and QRS >120ms). 34.2% of patients were admitted to the hospital due to heart failure, and 7.5% received a heart transplant. Other cardiovascular outcomes were also frequent (atrial arrhythmias: 19.2%, stroke: 15.1%, pacemaker/ICD: 6.2%/2.7%).

CONCLUSIONS

Adult patients with SVP who had not undergone Fontan exhibit a high mortality rate and frequent major cardiovascular events. At least moderate AV valve regurgitation, thrombocytopenia, renal dysfunction and QRS duration >120 ms at baseline visit allow identification of a cohort of patients at higher risk of mortality.

Long-term survival without surgical intervention in a patient with a natural history of a single right ventricle: A case report

Single ventricle (SV), a complex cardiac anomaly, if left untreated, is thought to lead to a poor prognosis. Herein, we report the case of a long-term survivor with an unrepaired SV with right ventricle (RV) morphology. A 55-year-old man presented with a SV with RV morphology, with a double outlet, large atrial septal defect, common atrioventricular valve, pulmonary valve stenosis (PS), and dextrocardia. Because the native PS provided adequate restriction of the pulmonary blood flow, he did not develop pulmonary hypertension; however, he had severe cyanosis. In patients with SV and moderate PS, even if the SV has RV morphology, long-term survival may be possible without surgical intervention. <Learning objective: Single ventricle (SV) is a rare and complex congenital heart disease. Outcomes of patients with SV are generally poor; however, some patients can survive long-term without surgical intervention. In particular, it may be possible for patients with SV and moderate pulmonary artery stenosis to enjoy long-term survival without surgical intervention, even if the SV has right ventricular morphology.>.

Patients with Single-Ventricle Physiology over the Age of 40 Years

Background: Single-ventricle physiology (SVP) is associated with significant morbidity and mortality at a young age. However, survival prospects have improved and risk factors for a negative outcome are well described in younger cohorts. Data regarding older adults is scarce. Methods: In this study, SVP patients under active follow-up at our center who were ≥40 years of age at any point between January 2005 and December 2018 were included. Demographic data, as well as medical/surgical history were retrieved from hospital records. The primary end-point was all-cause mortality. Results: Altogether, 49 patients (19 female (38.8%), mean age 49.2 ± 6.4 years) were included. Median follow-up time was 4.9 years (interquartile range (IQR): 1.8–8.5). Of these patients, 40 (81.6%) had undergone at least one cardiac surgery. The most common extracardiac comorbidities were thyroid dysfunction (n = 27, 55.1%) and renal disease (n = 15, 30.6%). During follow-up, 10 patients (20.4%) died. On univariate analysis, renal disease and liver cirrhosis were predictors of all-cause mortality. On multivariate analysis, only renal disease (hazard ratio (HR): 12.5, 95% confidence interval (CI): 1.5–106.3, p = 0.021) remained as an independent predictor. Conclusions: SVP patients ≥40 years of age are burdened with significant morbidity and mortality. Renal disease is an independent predictor of all-cause mortality.

Results of surgery on adults with functional single ventricle without prior cardiac surgery in childhood

OBJECTIVES

Patients with unoperated functional single ventricle (FSV) rarely survive into adulthood with good functional status and there are few reports about surgical results of adult patients with FSV. This study retrospectively reviews our experience with surgery in adult patients with FSV.

METHODS

From January 2008 to September 2017, 65 adult patients with FSV underwent surgery in our hospital. Twenty underwent Blalock-Taussig shunt or bidirectional Glenn procedures in other hospitals prior, and four were lost to follow-up. Finally, 41 patients were included in this study.

RESULTS

The early postoperative mortality was 7.3% (3/41). Postoperative systemic arterial oxygen saturation (SpO₂ , 83.7% ± 4.8%) was significantly higher than preoperative SpO₂ (77.9% ± 10.1%, P < .01). The mean follow-up time was 3.9 ± 3.1 years (range 1-11 years). There was only one case of late mortality and massive hemoptysis was the cause of death. Right ventricular morphology and severe atrioventricular valve regurgitation (AVVR) were the risk factors of postoperative death for patients with pulmonary stenosis(PS). There was no death case in patients who received Fontan procedure. In a follow-up, we found the grade of AVVR was reduced and the grade of heart function (New York Heart Association) was improved.

CONCLUSIONS

Adult patients with FSV can also undergo surgery. The mortality was acceptable and late results were satisfactory. After surgery, oxygen saturations increased, grades of AVVR decreased and the heart functions improved. Right ventricular morphology and severe AVVR were risk factors for patients with PS.

Frontiers in Fontan failure: Innovation and improving outcomes: A conference summary

The initial "Frontiers in Fontan Failure" conference in 2015 in Atlanta, GA, provided an opportunity for experts in the field of pediatric cardiology and adult congenital heart disease to focus on the etiology, physiology, and potential interventions for patients with "Failing Fontan" physiology. Four types of "Fontan Failure" were described and then published by Dr Book et al. The acknowledgment that even Dr Fontan himself realized that the Fontan procedure "imposed a gradually declining functional capacity and premature late death after an initial period of often excellent palliation." The purpose of the second "Frontiers in Fontan Failure" was to further the discussion regarding new data and technologies as well as novel interventions. The 2017 "Frontiers in Fontan Failure: Innovation and Improving Outcomes" was sponsored by Children's Healthcare of Atlanta, Sibley Heart Center Cardiology, and Emory University School of Medicine. Future directions in the management of Fontan failure include further investigations into the risk of sudden cardiac death and how to properly prevent it, achievable interventions in modifying the Fontan physiology to treat or prevent late complications, and improved and refined algorithms in Fontan surveillance. Finally, further research into the interventional treatment of lymphatic-related complications hold the promise of marked improvement in the quality of life of advanced Fontan failure patients and as such should be encouraged and contributed to.

201Tl Myocardial Perfusion Imaging in a Case of Double-Inlet Left Ventricle: Correlate Anatomic Information of SPECT With MRI

Double-inlet left ventricle (DILV) is a congenital heart disease that only a single left ventricle and a rudimentary right ventricle are developed. Because of lack of anatomic landmark, interpretation of Tl myocardial perfusion imaging in DILV is essentially challenging for unusual anomaly. We report the case of a 44-year-old woman with DILV who presented exertional dyspnea and tachycardia and underwent Tl SPECT. The anatomic characteristics of cardiac Tl SPECT are correlated with MRI. To obtain accurate interpretation in DILV, it is absolutely necessary to realize the anatomy relationship between perfusion imaging and anatomic imaging such as CT or MRI.

Living with functionally univentricular heart: beating the odds?

An unoperated 45-year-old man with double-inlet single left ventricle, transposed great arteries, ventricular septal defect, and pulmonary stenosis presented with mitral and pulmonary valvular vegetations unresponsive to antibiotic therapy. The initial diagnosis was made with echocardiography, and the morphology was delineated with computed tomography and magnetic resonance imaging. The patient underwent mitral valve replacement with a mechanical valve and pulmonary valve vegetectomy. He recovered well and he is currently well two years after the operation.

Intracardiac anatomical relationships and potential for streaming in double inlet left ventricles

The aim of this study was to gain better understanding of the variable anatomical features of double inlet left ventricle hearts without cavopulmonary connection that would potentially facilitate favorable streaming. Thirty-nine post-mortem specimens of double inlet left ventricle without cavopulmonary connection were investigated. The focus was on anatomical characteristics that could influence the flow and separation of deoxygenated and oxygenated blood in the ventricles. Elements of interest were the ventriculoarterial connection, the spatial relationship of the ventricles, the position and size of the great arteries, the ventricular septal defect, the presence of relative outflow tract stenosis and the relationship of the inflow and outflow tracts. The most common anatomy was a discordant ventriculoarterial connection with an anatomically left-sided morphologically right ventricle (n = 12, 31%). When looking at the pulmonary trunk/aorta ratio, 21 (72%) hearts showed no pulmonary stenosis relative to the aorta. The ventricular septal defect created a relative subpulmonary or subaortic stenosis in 13 (41%) cases. Sixteen (41%) hearts had a parallel relationship of the inflow and outflow tracts, facilitating separation of deoxygenated and oxygenated blood streams. On the other end of the spectrum were 10 (25%) hearts with a perpendicular relationship, which might lead to maximum mixing of the blood streams. The relationship of the inflow and outflow tracts as well as the presence of (sub-) pulmonary stenosis might play a crucial role in the distribution of blood in double inlet left ventricle hearts. Additional in vivo studies will be necessary to confirm this postulation.