A simplified approach for assessment of intracardiac baffles and extracardiac conduits in congenital heart surgery with two- and three-dimensional magnetic resonance imaging

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Advanced imaging improves detection of baffle leaks and stenoses after atrial switch compared with transthoracic echocardiography

Current guidelines for adults with atrial switch repair recommend baseline cardiovascular magnetic resonance (CMR) for assessment of ventricular size and function, systemic and venous baffle obstruction and leaks, and valvular function. It also recommends transthoracic echocardiography (TTE) for outpatient follow up. Many such patients with implanted cardiac devices may need cardiac computed tomography (CCT) when CMR is not feasible. This study reviews and compares CMR, transesophageal echocardiography (TEE), CCT, cardiac catheterization with angiography and TTE in detection of baffle problems in patients after atrial switch operation. The medical records of patients who had at least one imaging study performed after atrial switch operation at our center from 2010 to 2020 were retrospectively reviewed. Results are reported as descriptive statistics for demographics and imaging findings. The principal outcome measure was detection of baffle leak and/or baffle stenosis. Fifty-seven patients had at least one cardiac imaging study after atrial switch operation (36 Senning and 21 Mustard operations) during the study period. Nearly 33% (19/57) had baffle complications of stenosis and/or baffle leaks identified. All 57 patients had TTE performed but baffle problems were noted by TTE in only 8 (14%) patients (7 baffle stenosis and 1 baffle leak). Of the 49 patients without known baffle problems by TTE, 24 had advanced imaging (TEE/CCT/CMR/angiography). Advanced imaging identified baffle problems in nearly half (11/24, 46%) of them (7 baffle leaks and 4 baffle stenosis). Baffle problems were present in (8/23) patients with transvenous cardiac devices. Baffle complications are common after atrial switch operations and in our study occur in 1/3rd of the patients. However, TTE is not sensitive enough to recognize these complications. Advanced imaging for detection of baffle complications should be considered in all patients after atrial switch operation.

SCMR Position Paper (2020) on clinical indications for cardiovascular magnetic resonance

The Society for Cardiovascular Magnetic Resonance (SCMR) last published its comprehensive expert panel report of clinical indications for CMR in 2004. This new Consensus Panel report brings those indications up to date for 2020 and includes the very substantial increase in scanning techniques, clinical applicability and adoption of CMR worldwide. We have used a nearly identical grading system for indications as in 2004 to ensure comparability with the previous report but have added the presence of randomized controlled trials as evidence for level 1 indications. In addition to the text, tables of the consensus indication levels are included for rapid assimilation and illustrative figures of some key techniques are provided.

Managing adult Fontan patients: where do we stand?

The Fontan operation is performed as a palliative procedure to improve survival in infants born with a functionally univentricular circulation. The success of the operation is demonstrated by a growing adult Fontan population that exists with this unique physiology. Late follow-up has demonstrated expected and unexpected sequelae, and has shown multisystem effects of this circulation. This review discusses the challenges of managing the late complications in terms of understanding this unique physiology and the innovative therapeutic interventions that are being investigated. The challenge remains to maintain quality of life for adult survivors, as well as extending life expectancy.

Innovative solutions are required to meet the challenges of the Fontan circulation faced in adult lifehttp://ow.ly/XTSm305oH8b

Factors impacting echocardiographic imaging after the Fontan procedure: a report from the pediatric heart network fontan cross-sectional study

Echocardiographic image quality in Fontan survivors may be limited by a variety of factors. We sought to describe echocardiographic quality and factors associated with study quality in subjects participating in the Pediatric Heart Network Fontan Cross-Sectional Study. Echocardiograms were obtained at 7 clinical sites using a standard protocol. Quality grading and analysis were performed by a core laboratory. Univariate and multivariable modeling were performed to assess factors associated with quality and ability to obtain images sufficient for prespecified quantitative analysis. A total of 543 echocardiograms were obtained. The quality of echocardiograms improved over the duration of the study. The great arteries, systemic veins, and pulmonary veins were less likely to be adequately imaged than other cardiac structures. Quantitative analysis of ventricular volume was possible in 76% overall, but only 41% of those with mixed ventricular morphology. Factors independently associated with better quality included younger age, levocardia, acquisition of the echocardiogram at a longer time since the beginning of enrollment, absence of a pulmonary artery stent, and clinical site. Patient and center-specific factors are associated with echocardiographic quality after the Fontan procedure. Increased familiarity and experience with a standard imaging protocol is likely to result in improved quality.

Complex Interventions in the Adult with Congenital Heart Disease: Percutaneous Solutions for Venous Baffles, Coronary Artery Fistulas, and Ruptured Sinus of Valsalva Aneurysms

We describe 3 distinct ACHD lesions amenable to percutaneous repair: (1) venous baffle obstruction in transposition of the great arteries, (2) coronary artery fistulas, and (3) ruptured sinus of Valsalva aneurysms. For each entity, we chronicle the typical clinical scenario and indications for intervention to supplement the technical approach and potential pitfalls with treatment.

Right aortic arch and coarctation: a rare association

OBJECTIVES

Understand anatomical and clinical correlatives to coarctation in right aortic arch.

BACKGROUND

Coarctation of the aorta is rare in patients with a functional right aortic arch. We reviewed a single institutional experience, examining associated diagnoses, diagnostic methodology, and surgical approaches.

METHODS

A retrospective study was performed of our echocardiographic, magnetic resonance imaging, catheterization, and surgical databases from 1988 to 2001.

RESULTS

Of 240 patients with right aortic arch, 10 (4.1%) had coarctation, constituting 1.9% of all native coarctations (n = 524). Nine (90%) had long-segment hypoplasia. Six (60%) had an aberrant left subclavian artery or retroesophageal diverticulum, 3 (30%) had mirror image branching, and 1 (10%) had a double arch with an atretic left arch. Other congenital heart defects were seen in 6 (60%) comprising 3 with ventricular septal defects, and one each with double-outlet right ventricle, cor triatriatum, and pulmonary valve abnormality. No patients with long-segment hypoplasia had bicuspid aortic valve. Six (60%) had vascular rings, and 5 (50%) had other associated syndromes. Magnetic resonance imaging and/or echocardiography successfully diagnosed all of these patients. Although long-segment right aortic arch coarctation courses behind the trachea posteriorly, only 2 needed an extra-anatomic (jump) graft; the remainders were repaired with patch angioplasty.

CONCLUSION

Coarctation with right aortic arch is rare, constituting 4.1% of all patients with right aortic arch, compared with 5-8% of patients with left aortic arch and congenital heart disease. Nearly all had long-segment hypoplasia without bicuspid aortic valve, and half were part of other syndrome complexes. This association can be diagnosed noninvasively and can often be repaired by patch angioplasty.

ACR appropriateness criteria on suspected congenital heart disease in adults

The number of adults with congenital heart disease is increasing in North America. This is attributable to a variety of factors, including improvements in surgical techniques and increases in immigration. Cardiac imaging is critical for the initial assessment of adults with newly suspected congenital heart disease as well as for the serial assessment of adults with known congenital heart disease. Chest radiography and echocardiography continue to be the initial tools used to evaluate adult congenital heart disease. However, cardiac computed tomography and magnetic resonance imaging have significantly improved over the years and have become integral to the evaluation of adult congenital heart disease, often precluding the necessity for invasive cardiac catheterization. Noninvasive imaging is particularly useful for the surveillance of patients with surgically corrected congenital heart disease, who often require 2 or more additional operations.

Non-invasive imaging in adult congenital heart disease using cardiovascular magnetic resonance

The population of adults with congenital heart disease is growing. Cardiovascular magnetic resonance can provide functional as well as structural data even in the setting of complex anatomy. Due to the lack of ionizing radiation cardiovascular magnetic resonance lends itself to serial follow-up of patients with adult congenital heart disease and can be used for the investigation of altered symptoms or signs, planning of transcatheter or surgical intervention, and for baseline post-operative assessment. Both in clinical practice and in research, cardiovascular magnetic resonance has distinct advantages for assessment of the right as well as left ventricle, as no geometrical assumptions are made, and it can quantify ventricular volumes, function and mass. The utility of cardiovascular magnetic resonance and its potential lifelong contribution to the management of different adult congenital heart disease patients is discussed below.

Transposition of the great arteries: long-term outcome and current management

There is a large group of young adults who survived atrial baffle repair of transposition of the great arteries. Most survivors are asymptomatic, although nearly all have decreased exercise capacity. Loss of sinus rhythm and atrial arrhythmias are common and increase with age. There is concern about the ability of the right ventricle to function long term as a systemic pump, and recent publications have highlighted right ventricular dysfunction in this patient population. Sudden death and congestive heart failure are the main causes of death, and outcomes beyond 30 years are unknown. Pulmonary artery banding, late arterial switch, and cardiac transplantation are employed when intractable arrhythmias or right ventricular failure threaten survival or quality of life.

In vivo MRI measurement of blood oxygen saturation in children with congenital heart disease

OBJECTIVE

The purpose of this prospective study was to measure in vivo blood oxygen saturation (%O2) by MRI in children with congenital heart disease (CHD) using population-based values for T2O (T2 signal decay of fully oxygenated blood) and K (a parameter representing the deoxyhemoglobin effect) and compare the %O2 with direct cardiac catheterization measurements.

BACKGROUND

MRI can determine %O2 using in vivo measurement of signal decay (T2) and an in vitro calibration curve relating T2 and %O2, based on the equation: 1/T2 = 1/T2O + K(1-%O2/100)2. Recent studies have correlated the T2/%O2 in children with CHD with the adult calibration statistics.

METHODS

A total of ten children (five male, five female) with single ventricle CHD (median age 4.8 months, range 2 months to 4.4 years) undergoing cardiac catheterization were included in the study. The blood T2 measurements for each patient were performed in a 1.5 T GE CV scanner. The %O2 was then calculated based on the equation using values of T2O determined from individual hematocrits, and a population average value of K derived for children. The %O2 values were compared with direct %O2 measurements from cardiac catheterization.

RESULTS

The %O2 values by MRI were strongly correlated with direct cardiac catheterization measurements (R = 0.825; P < 0.001).

CONCLUSION

The study indicates that the noninvasive measurement of %O2 by MRI can accurately measure oxygen saturation in children with complex CHD.

Physics-Driven CFD Modeling of Complex Anatomical Cardiovascular Flows?A TCPC Case Study

Recent developments in medical image acquisition combined with the latest advancements in numerical methods for solving the Navier-Stokes equations have created unprecedented opportunities for developing simple and reliable computational fluid dynamics (CFD) tools for meeting patient-specific surgical planning objectives. However, for CFD to reach its full potential and gain the trust and confidence of medical practitioners, physics-driven numerical modeling is required. This study reports on the experience gained from an ongoing integrated CFD modeling effort aimed at developing an advanced numerical simulation tool capable of accurately predicting flow characteristics in an anatomically correct total cavopulmonary connection (TCPC). An anatomical intra-atrial TCPC model is reconstructed from a stack of magnetic resonance (MR) images acquired in vivo. An exact replica of the computational geometry was built using transparent rapid prototyping. Following the same approach as in earlier studies on idealized models, flow structures, pressure drops, and energy losses were assessed both numerically and experimentally, then compared. Numerical studies were performed with both a first-order accurate commercial software and a recently developed, second-order accurate, in-house flow solver. The commercial CFD model could, with reasonable accuracy, capture global flow quantities of interest such as control volume power losses and pressure drops and time-averaged flow patterns. However, for steady inflow conditions, both flow visualization experiments and particle image velocimetry (PIV) measurements revealed unsteady, complex, and highly 3D flow structures, which could not be captured by this numerical model with the available computational resources and additional modeling efforts that are described. Preliminary time-accurate computations with the in-house flow solver were shown to capture for the first time these complex flow features and yielded solutions in good agreement with the experimental observations. Flow fields obtained were similar for the studied total cardiac output range (1-3 1/min); however hydrodynamic power loss increased dramatically with increasing cardiac output, suggesting significant energy demand at exercise conditions. The simulation of cardiovascular flows poses a formidable challenge to even the most advanced CFD tools currently available. A successful prediction requires a two-pronged, physics-based approach, which integrates high-resolution CFD tools and high-resolution laboratory measurements.

Role of MRI in clinical cardiology

Rapid progress has been made in cardiac MRI (CMRI) over the past decade, which has firmly established it as a reliable and clinically important technique for assessment of cardiac structure, function, perfusion, and myocardial viability. Its versatility and accuracy is unmatched by any other individual imaging modality. CMRI is non-invasive and has high spatial resolution and avoids use of potentially nephrotoxic contrast agent or radiation. It has been extensively studied against other established non-invasive imaging modalities and has been shown to be superior in many scenarios, particularly with respect to assessment of cardiac and great vessel morphology and left ventricular function. Furthermore, its clinical use continues to expand with increasing experience and proliferation of CMRI centres. As worldwide prevalence of cardiovascular disease continues to rise, CMRI provides opportunity for improved and cost-effective non-invasive assessment. Continued progress in CMRI technology promises to further widen its clinical application in coronary imaging, myocardial perfusion, comprehensive assessment of valves, and plaque characterisation.

Use of Intracardiac Echocardiography in Guiding Radiofrequency Catheter Ablation of Atrial Tachycardia in a Patient After the Senning Operation

A patient with D-transposition of the great arteries developed drug refractory atrial tachycardia 12 years after a Senning operation. Electrophysiological study confirmed the presence of atrial baffle-tricuspid valve isthmus dependent reentrant intraatrial tachycardia. Intracardiac echocardiography facilitated initial identification of structures, catheter positioning, and identification of the atrial baffle-tricuspid valve isthmus.

When to order cardiovascular magnetic resonance in adults with congenital heart disease

Cardiovascular magnetic resonance (CMR), where available, contributes to the informed management of patients with congenital heart disease. In contrast to echocardiography, CMR becomes easier as patients grow. It is versatile and gives unrestricted access to the heart and intrathoracic vessels, providing functional and structural information. Its relative strengths are discussed, and examples are given of congenital conditions in which it provides clinically important information. CMR can prevent the need for diagnostic catheterization or expedite intervention if indicated, enabling planned, directed procedures. In our practice, CMR is used for serial follow-up, investigation of altered symptoms or signs, planning of transcatheter or surgical interventions, and for baseline assessment after surgery. As CMR becomes more widely available, it will contribute increasingly to the lifelong management of patients with congenital heart disease.

Cardiac MR imaging

There has been tremendous progress for MR imaging depiction of cardiac morphology and function. Further advances toward achieving faster acquisition with real-time imaging, higher resolution for plaque imaging, and quantitative analysis are taking place at a rapid pace.