The extraordinary advances and dramatic successes of pediatric cardiology and surgery over the past 50 years have witnessed an increase in children born with congenital heart disease (CHD) who survive into adulthood. This success in survival has created a new population of patients of adults with congenital heart disease (ACHD). The number of ACHD will very likely continue to increase in the near future.1 The 32nd Bethesda Conference had estimated that there were approximately 800,000 adults with CHD in the United States in the year 20002; in the United Kingdom alone there are currently approximately 250,000 ACHD patients.3
Since about 0.8 percent of live births are complicated by cardiovascular malformations (disregarding the two most common congenital cardiac anomalies: functionally normal congenital bicuspid aortic valve and mitral valve prolapse), approximately 2800 adults per million population will have some form of CHD, with half of them having moderate- or high-complexity defects.2 These patients are at significant risk of early mortality from complications of future treatment including reoperation, especially if undertaken in facilities or by physicians not resourced or trained in their care. At present, there is shortage of facilities dedicated to the care of adults with CHD.4 Care givers and ACHD should have been taught in adolescence about their condition, their future outlook, and the possibility of further surgery and complications, as appropriate. They should be advised about their responsibility in ensuring self-care and professional surveillance. Copies of operative reports should accompany patients being transferred for adult care, along with other key documents from pediatric medical records. Recommendations on transfer of care, organization of ACHD service network, infrastructural requirements, involvement of multidisciplinary teams and their training/certification have been dealt with in detail in the ESC5 and ACC/AHA6 taskforce guidelines. A well-working network of specialist centers with general adult care is of paramount importance since, although complex defects can be easily recognized and assigned to high-level care, even simple defects may still require specialist care under certain circumstances [i.e., atrial septal defects (ASD) in the setting of pulmonary hypertension (PAH)].
A detailed history from an ACHD patient aims at analyzing present and past symptoms including any significant intercurrent event. Changes in lifestyle should be recorded. Clinical examination during initial and follow-up visits should lay special emphasis on any changes in oxygen saturations, auscultatory findings, blood pressure measurements or signs of heart failure development. A 12-lead electrocardiography (ECG) and pulse oximetry should be part of the examination. Chest x-ray is performed if the clinical situation demands, and provides useful information on changes in heart size, configuration, and pulmonary vascularity.
Noninvasive investigative modalities like echocardiography, cardiac MRI (CMR) are being increasingly used for delineating the anatomy and pathophysiology in ACHD patients in preference to invasive angiographic techniques. Evaluation of arrhythmias with Holter monitoring, event recorders and detailed electrophysiological testing makes management more objective. Cardiopulmonary exercises testing (CPET) has also been gaining popularity in the assessment and follow-up of ACHD patients, especially in deciding about timing of interventions.
Echocardiography remains the first line investigation, and 2D transthoracic echo is an essential tool to objectively document the findings after a thorough clinical evaluation. Recent developments in the field of echocardiography like 3D echo, Doppler tissue imaging, strain rate imaging, contrast echocardiography, and perfusion imaging have significantly improved its ability of functional and anatomical lesion assessment. Transesophageal echo (TEE), with its superior image quality is a useful adjunct; however, supplants 2D echo only in minority of situations like echo guided ASD closure, percutaneous valve implantations etc. It remains a versatile tool for guiding a surgeon during repair of complex pathologies; confirmation of repair quality by intraoperative TEE is a standard of care.
Echocardiography provides information on basic anatomy including cardiac position and orientation, venous return, atrioventricular and ventriculoarterial concordance. It allows evaluation of cardiac chamber morphology, ventricular function, morphology, and function of valves and detection and evaluation of shunt lesions. Echocardiographic distinction between ventricular volume overload (increased end-diastolic volume and stroke volume) and pressure overload (hypertrophy, increase in ventricular pressure) is of crucial importance in deciding the timing of intervention. Doppler echocardiography provides useful hemodynamic information such as gradients across obstructive lesions, right ventricular (RV) pressure, pulmonary artery (PA) pressure, and flow velocities.
Despite its versatility, echocardiography still remains a highly user-dependent investigation that requires special expertise for ACHD patients. Evaluation of ventricular volumes and function may be complicated by geometry and regional incoordination especially in systemic and nonsystemic RV and single ventricle pathologies. Doppler gradients may be misleading when two or more stenotic lesions lie in series. Venous return and great arteries may be difficult to image. Echocardiography is, however, the first line investigative modality, while further noninvasive imaging and invasive hemodynamic assessment are considered to supplement information missing after echocardiographic assessment.
CMR is an essential tool in the assessment of ACHD patients. It allows 3D anatomical reconstruction, not restricted by body habitus and acoustic windows and has an excellent spatial and temporal resolution. It is of immense value in volumetric assessment, anatomical delineation of great vessels and detection of myocardial fibrosis.
CMR is an alternative to echo and can provide all the information obtained by echo. Echo, however, is superior to CMR in estimating gradients, PA pressure and detecting small mobile vegetations. CMR can add value to the diagnostic work-up when echo measurements are ambiguous, e.g., ventricular volume, ejection fraction measurement and quantification of valve regurgitant fraction and help in deciding about timing of valve-related surgery.
CMR is superior and should be performed in preference to echocardiography8 for: (1) quantification of RV volume/ejection fraction in tetralogy of Fallot (ToF); (2) evaluation of RV outflow tract obstruction (RVOTO) and RV–PA conduits; (3) quantification of pulmonary regurgitation; (4) evaluation of PA and aortic pathologies (Fig. 90-1); (5) evaluation of systemic and pulmonary venous anomalies/obstructions; (6) collaterals and arteriovenous malformations; (7) quantification of myocardial mass; (8) evaluation of myocardial fibrosis with gadolinium late enhancement and (9) tissue characterization (fibrosis/iron/adipose tissue). Patients with permanent pacemakers/defibrillators and those who are severely claustrophobic cannot be imaged with CMR; high-resolution spiral computed tomography (CT) provides in these cases a valid alternative, albeit in the setting of increased radiation exposure.
CT plays an ever increasing role in the evaluation of ACHD patients in view of its excellent spatial resolution, ECG-gated image acquisition and rapid scanning with use of newer rotational techniques. It is particularly suited and is superior to CMR for imaging epicardial coronary arteries, collaterals and for evaluating parenchymal lung disease. Its major drawback is its high dose of ionizing radiation, which makes it unattractive for serial evaluations.
Cardiac catheterization is now reserved for resolution of specific anatomical and physiological questions or for therapeutic intervention. Continuing indications include evaluation of pulmonary vascular resistance (PVR), left ventricular (LV) and RV diastolic function, pressure gradients, and shunt quantification, evaluation of aortopulmonary collaterals especially when noninvasive modalities are equivocal.
Accurate measurement of PVR in patients with shunt lesions is crucial for therapeutic decision making. Estimation of PVR requires accurate calculation of pulmonary flow, often difficult to ascertain with echo in patients with complex CHD. Measurement of oxygen uptake rather than estimation is required when the reversibility of PAH would determine the optimal treatment. Preoperative coronary angiography should be performed in men above the age of 40 years, postmenopausal women and patients with family history of or risk factors for coronary artery disease (CAD).
CPET including assessment of objective exercise capacity (VO2 max), ventilation efficiency (VE/VCO2 slope), chronotropic and blood pressure response, and exercise-induced arrhythmias give a broader evaluation of function and fitness and has end points which correlate well with mortality and morbidity in ACHD patients.9 Serial exercise testing should be an integral part of long-term follow-up protocols and intervention trials in these patients, and has an important role in determining the timing of reinterventions.
Medical management in ACHD patients with heart failure, arrhythmias, pulmonary and systemic hypertension is largely supportive. Prevention of thromboembolic events and endocarditis require appropriate prophylactic measures to be instituted at appropriate times and when significant residual structural abnormalities need reintervention.
Congestive heart failure (CHF) is a common problem in ACHD patients. Specialists caring ACHD patients should follow current guidelines.10 However, given the contrasting and different pathophysiological mechanisms at work in this group of patients, direct extrapolation of results from published studies to ACHD patients may be difficult; this is particularly true for patients with atrial switch repair for transposition of great arteries (TGA) or those with Fontan circulation. The relative lack of published data for these patients makes it difficult to specify the management of heart failure in this group of patients. Cardiac resynchronization therapy (CRT) has gained increasing interest recently in a specific subset of ACHD patients with CHF; however, objective indications for use and outcome measures are at present not clear.
Arrhythmias are one of the most important causes for hospitalization and morbidity and mortality in ACHD patients. Risk stratification, investigation, and management algorithms are often different from those with acquired heart disease with structurally normal hearts.11 Moreover, the onset of arrhythmia may herald hemodynamic decompensation, with amplified detrimental effects in the presence of an abnormal circulatory physiology. Results of catheter ablation are generally unpredictable in ACHD patients compared to those with ischemic heart disease. Technological improvements, however, allow consideration of catheter ablation for tachyarrhythmias for documented indications in a center with specific expertise. Antiarrhythmic drug therapy with its antecedent negative inotropic effect is poorly tolerated and there are limited data on its long-term safety and efficacy.
Sudden cardiac death (SCD) is of particular concern in ACHD patients. Five defects with greatest risk of late SCD are ToF, TGA, ccTGA, aortic stenosis (AS), and single ventricle lesions.12,13 Unexplained syncope is alarming. Current guidelines13 for prevention of SCD in ACHD patients recommend as follows:
AICD implantation is indicated in survivors of cardiac arrest after exclusion of reversible causes (level of evidence IB).
Patients with spontaneous sustained ventricular tachycardia (VT) should undergo invasive hemodynamic and electrophysiology (EP) evaluation. Recommended therapy includes catheter or surgical ablation as deemed appropriate and, if this is not successful, ICD implantation should be considered (level of evidence IC).
Invasive hemodynamic and EP evaluation is reasonable in patients with unexplained syncope and impaired ventricular function. In absence of defined, reversible cause, ICD implantation is reasonable (level of evidence IIaB).
EP testing may be considered for patients with recurring ventricular couplets or nonsustained VT to determine the risk of sustained VT (level of evidence IIbC).
Prophylactic antiarrhythmic therapy is not indicated for asymptomatic patients with isolated premature ventricular contractions (level of evidence IIIC).
Many ACHD patients will have undergone surgery in childhood, but reintervention during adulthood may be required for: (1) patients with prior repair with new and/or residual hemodynamic complications; (2) patients with conditions not diagnosed during childhood; (3) patients with palliative procedures; and (4) rarely, patients who have not been offered surgery due to the lack of expertise at the time the diagnosis was initially made.
ACHD patients requiring surgery have to be assessed and managed quite differently from those undergoing cardiac surgery for other acquired pathologies. Therefore, it is vital to concentrate all resources into a specialist unit for both treatment and training.5 Even noncardiac surgery may carry a high risk in this particular group of patients, and appropriate consultation from specialists should be sought; careful preoperative planning and intraoperative monitoring are vital to ensuring a successful outcome.
One of the most challenging surgical issues in ACHD patients is heart and heart–lung transplantation. Risk-stratification scores are available for terminal CHF but may not correctly apply to ACHD patients, making decisions regarding timing of transplantation difficult. In addition to the standard pretransplant work-up, specific issues in ACHD patients are: (1) sensitization from previous transfusions that increases the risk of rejection. Treatment to reduce HLA antibody levels may be needed prior to transplant. (2) The assessment of PVR is difficult in patients with low cardiac output, residual lesions, and shunts/collaterals and has direct outcome on early graft function. (3) Detailed planning of surgical approach is crucial in many complex lesions and all anatomic details, including systemic and pulmonary venous returns that need to be defined. (4) Nonadherence to posttransplant medications is a major problem in young adults, and preexisting psychosocial issues require thorough evaluation before listing. (5) Issues that are specific to patients with Fontan circulation such as protein-losing enteropathy (PLE) and pulmonary arteriovenous malformations need to be accounted for and treated if possible before listing. (6) An increasing number of patients with end-stage cardiopulmonary lesions have underlying chromosomal anomalies which further complicate decision making. (7) Surgical issues in previously operated patients include difficulties during reentry, dissection, cannulation, bleeding, longer bypass, all of which have the potential to raise pulmonary arterial pressure (PAP) and jeopardize right heart function following engraftment. Additional point to consider during procurement for ACHD patients is to harvest extra length of vessels/pericardium for reconstruction.
As per the 2008 UNOS report 1-, 5- and 10-year survival after heart transplantation in non-ACHD patients is 88, 74 and 55 percent. For heart–lung transplantation survival is similar at 71, 50, and 30 percent. Survival after transplantation in ACHD patients is significantly lower, primarily due to higher early attrition.14 Late attrition after transplantation has not improved significantly in the last 10 to 20 years despite introduction of newer immunosuppressants. The increasing donor shortage and inferior results in ACHD patients may influence organ allocation, strongly penalizing this particular population of recipients. Alternatives, such as long-term mechanical support and/or xenotransplantation will therefore remain important areas of research.
There has been a marked increase in the number and range of interventional catheterization procedures in ACHD patients, sometimes obviating the need for surgery and, in other cases, facilitating surgical intervention by the intraoperative deployment of stents (hybrid approach). Newer techniques include stenting of systemic or pulmonary vessels and percutaneous valve implantation. The decision to perform an intervention should involve a process of rigorous peer review and multidisciplinary discussion, as currently limited data exist to demonstrate noninferiority over surgery for many of these approaches.
Infective endocarditis (IE) risk in ACHD patients is substantially higher than in the general population, with marked variation between lesions. It has been emphasized that good oral hygiene and regular dental care and evaluation have an essential role in reducing the risk of IE. Aseptic measures are mandatory during manipulation of venous catheters and during invasive procedures. ACHD patients should be discouraged from getting piercings and tattoos.
Current recommendations for antibiotic prophylaxis for prevention of endocarditis in ACHD patients are as follows: (1) patients with a prosthetic valve/material used for cardiac valve repair; (2) patients with previous IE; and (3) CHD patients prior to repair, if they are cyanotic or post repair with residual shunts. These recommendations are limited to dental procedures only, and are not always advocated for respiratory, gastrointestinal, genitourinary, dermatological or musculoskeletal procedures especially in absence of preexisting infections.
ACHD patients are confronted with various challenges aside from their cardiac issues. These include interventions/surgery for noncardiac problems, ability to participate in exercise and sports, psychosocial issues, obtaining/maintaining employment as well as health and life insurance and finally contraception and pregnancy. Multidisciplinary teams caring for these patients need to be aware of these issues and to have established protocols for assisting them into a meaningful social life. Initiation of discussions on the issues mentioned above between treating physicians, family, and the patient needs to start as soon as the decision of transferring the ongoing care from pediatric to ACHD service is made; this process needs to be gradual and comprehensive. We will briefly touch upon these issues; a detailed discussion of these problems can be found in the ACC/AHA-20086 and ESC-20035 taskforce guidelines.
Counseling for participation in sports and exercise needs to be individualized for each patient based on their ability and the impact on underlying hemodynamics and risk of arrhythmias and acute decompensation. Formal testing is of great value in mitigating the fear of physicians and their patients. Participation in regular exercise has well-documented benefits for fitness, psychological well-being, social interaction, and reduction of future risk of developing atherosclerotic disease. In general, dynamic exercise (i.e., running) is safer than static exercise (i.e., weight lifting). Risk of SCD in patients with known cardiac condition during exercise is rare.15 However, some lesions are not compatible with competitive sports in view of their physiological complexity and tendency to be associated with serious arrhythmias (Eisenmenger syndrome, PAH, single ventricle palliations with Fontan circulation, unoperated coronary artery anomalies, Ebstein anomaly and ccTGA and TGA repaired by atrial switch or Rastelli procedure among others).16
The majority of ACHD patients tolerate pregnancy well but are best cared for in a clinical setting with inputs from ACHD cardiology, obstetrics, anesthesia, hematology, neonatology, and genetics. Timely counseling and early involvement of this multidisciplinary team is essential to ensure a successful outcome for the mother and the child. Severe PAH (Eisenmenger patients and others) remains a condition with high maternal (50 percent) and fetal (30–40 percent) mortality; women with this condition should be advised against pregnancy.17 Other conditions associated with high maternal mortality include severe left outflow/inflow obstructive lesions, poor systemic ventricular function [ejection fraction (EF) <40 percent], and aortic root dilation in Marfan and other related syndromes. Cyanosis poses a significant risk to the fetus, with a live birth unlikely (<12 percent) if oxygen saturation is <85 percent.18 The significant increase in cardiac output and decrease in peripheral vascular resistance in pregnancy, in conjunction with its hemodynamic consequences for different lesions, must be taken into account and recommendations be made on an individual basis for each lesion. Functional status before pregnancy and history of previous cardiac events are of particular prognostic value. A prospective study identified systemic ventricular EF <40 percent, NYHA class II or more, cyanosis, left heart obstruction (aortic valve area <1.5 cm2 and gradient >30 mm Hg, mitral valve area <2.0 cm2), and prior cardiac events (CHF, stroke, arrhythmia) as risk factors.19 Patients without these findings and no PAH/mechanical valve or aortic dilation can be considered to be at low risk for a poor outcome from pregnancy.
Fetal echo screening should be recommended at 16 to 18 weeks of gestation. Potential for drugs and their teratogenic effects should be considered, in particular, for patients on warfarin, amiodarone, angiotensin converting enzyme inhibitors, and angiotensin-receptor blockers.
For contraception, barrier methods are safe, protect against sexually transmitted disease, and are effective for compliant couples. Hormonal contraception are efficacious but have limited data regarding safety in ACHD patients and combined oral contraceptives are best avoided in patients with preexisting thrombotic risk (Fontan circulation, cyanotic patients, poor systemic ventricular function). Progesterone-only contraceptives, in contrast to combined pills, have lower thrombotic risk. Progesterone-coated intrauterine devices have high efficacy (>95 percent) and seem to be a reasonable alternative. Sterilization should be considered after careful discussion with family/partner, keeping the long-term prognosis and underlying chromosomal aberrations in mind.
The recurrence rate of CHD in offspring ranges from 2 to 50 percent and risk is higher if mother has CHD than when father is affected. Highest recurrence risks are associated with single gene defects such as Marfan, Noonan, 22q11 deletion syndromes, and Holt Oram syndrome. For others, risk of passing on the defect to the offspring lies between 2 and 4 percent on average and may reach 13 to 18 percent for AS and 6 to 10 percent for ventricular septal defect (VSD).20
Despite recommendation from cardiac societies, availability of insurance varies considerably not only between but also within countries, with surprising discordance between insurance policies and available outcome data. Health insurance, in particular, may exclude treatment for the cardiac condition in some countries and has important consequences in “insurance-based medical” systems. Patients currently need to shop around. Problem is more acute for patients with moderate-to-high complexity ACHD and if medical care for these patients is not to be compromised by financial considerations, consistent national strategies for health and life insurance need to be developed.
Detailed anatomical classification, pathophysiology and its impact on treatment decisions in the pediatric age group is detailed in specific chapters devoted to each lesion in this book. In this section, we will try to highlight issues specific to adults (young and old) with CHD. Some of the general considerations discussed previously apply to all the subsequent sections.
ASD may remain undiagnosed until adulthood as patients are asymptomatic well into their 30s. The majority of these patients will be symptomatic by the fourth decade and present with reduced functional capacity, exertional dyspnea, palpitations and occasionally chest infections/right heart failure. Life expectancy is reduced overall. PAP can be normal but tends to increase with age. Severe PAH, however, is rare (<5 percent) and its development requires additional factors like genetic predisposition (similar to idiopathic PAH). With increasing age and PAP, tachyarrhythmias become more common (atrial flutter/fibrillation-AF)21 and systemic embolism (paradoxically or from AF) results in premature death and morbidity.
Key clinical findings include fixed splitting of the second heart sound and a systolic flow murmur over the pulmonary area. Presence of cyanosis in ASD patients should make one suspect: (1) shunt reversal as in Eisenmenger complex; (2) large Eustachian valve directing the inferior vena cava (IVC) flow across the ASD, causing large right-to-left shunt; and (3) Sinus venosus defect of the IVC and superior vena cava (SVC) type, with streaming of desaturated blood to the left atrium. ECG shows incomplete right-heart block with right-axis deviation [superior left-axis deviation in partial atrioventricular septal defect (AVSD)]. Chest x-ray frequently will show increased pulmonary vascularity.
Echocardiography remains the key diagnostic modality to distinguish between the different anatomic ASD variants (secundum, primum, sinus venosus and/or coronary sinus type) as well as relative size, rim, presence of associated mitral valve cleft, drainage of pulmonary veins, and hemodynamic assessment (shunt and PAP). TEE is better at delineating anatomy and should be considered for cases in which device closure is being considered. CMR/CT can help in supplementing echo data, particularly for quantification of RV volume overload and pulmonary venous connections. Cardiac catheterization is required for cases of high PAP to determine PVR and assess operability.
Surgical repair has low (<1 percent) mortality and good long-term prognosis, with normal life expectancy when performed at <25 years of age and in absence of PAH.22 ASD closure after 40 years of age does not affect frequency of arrhythmia development during follow-up but should still be considered as correction improves exercise capacity and stabilizes right heart function,23 especially if amenable to device closure.
Device closure has become the treatment modality of choice for secundum ASDs with a stretched diameter <38 mm and sufficient rim of 5 mm except toward aorta. This is the case for around 80 percent of secundum ASDs. Atrial tachyarrhythmias after device closure tend to be transient, and complications such as erosion into atrial wall/aorta and thrombo–embolic events are reported in <1 percent cases. Patients require antiaggregant therapy with aspirin for at least 6 months. Studies comparing surgery and catheter-based device closure have reported similar success rates and mortality but with lower morbidity and shorter hospital stay in the nonsurgical cohort.24
Poor left ventricular function (systolic and diastolic) may cause pulmonary congestion after ASD closure and may require preinterventional testing with balloon occlusion and hemodynamic assessment. In patients with atrial fibrillation, simultaneous modified Maze procedure should be considered during surgical repair. Closure of ASD should not be considered in patients with Eisenmenger complex. In adults with advanced age and ASDs not amenable to device closure, associated comorbidities should allow individualized recommendations to be made.
Patients with prior ASD closure should have assessment of residual shunt, RV size and function, presence of TR and PAP. A history of arrhythmias and an ECG should be obtained and Holter monitoring should be requested accordingly. Patients repaired <25 years of age without any sequelae (no residual shunt, normal PAP/RV and no arrhythmias) do not require regular follow-up and should get in touch with their physicians only if they experience any late-onset arrhythmia. Patients with residual shunt, hemodynamic issues and those repaired >40 years age should be followed regularly in ACHD specialist center.
Late arrhythmias after surgical repair at <40 years of age are mostly intra-atrial reentrant tachycardias/atrial flutter, and are easily amenable to radiofrequency ablation. With or without repair >40 years of age, AF becomes increasingly common and patients should be treated with antiarrhythmics and anticoagulation. Limited data exist on the efficacy of ablation therapy in this subgroup of patients.
Asymptomatic ASD patients, pre- or postintervention with normal PAP and no significant history of arrhythmia have no restriction for engaging in sports and exercise. Those with PAH should restrict themselves to low-intensity recreational sports.
The risk from pregnancy in patients without PAH is low. Defect closure prior to conception may reduce the chances of paradoxical embolism and worsening ventricular function during gestation. Pregnancy is contraindicated in patients with Eisenmenger syndrome. Recurrence rate of CHD is 3 to 10 percent (excluding familial ASD and Holt–Oram syndrome with autosomal dominant inheritance).
Prophylaxis for bacterial endocarditis is recommended for 6 months after device or prosthetic patch closure of ASD.
Excluding bicuspid aortic valve, isolated VSD is the most common congenital malformation at birth (30–40 percent). VSD is also common component of complex anomalies like ToF, ccTGA etc. Spontaneous closure can occur, most often in muscular/trabecular defects, occasionally in perimembranous VSDs, almost never in outlet defects and those that close do it during childhood.
The direction and severity of shunt depends on PVR, size of defect, LV/RV systolic & diastolic function and presence of RVOTO. Clinical presentation in adults could be as: (1) VSD closed in childhood with no residual shunt; (2) closed in childhood but with residual shunt, whose severity and above factors will determine the degree of symptoms; and (3) small VSD with nonprogressive small shunt without LV-volume overload, not considered for repair during childhood. These three categories of patients do not require surgery, especially if they remain asymptomatic.25
Patients with large VSD/shunt, LV volume overload and PAH, those with Eisenmenger syndrome and few patients with small defects who will have progressive symptoms need to be assessed and put forward for surgical repair.
Several problems may occur in these patients and each of the issues merits consideration for surgical repair:
Endocarditis, with a reported incidence of two per 1000 patient years (six times higher than in the normal population)
Heart failure due to increasing L–R shunt
Double-chamber right ventricle (DCRV) can develop overtime as a result of the high-velocity VSD jet.
Discrete sub-AS can develop
In case of supracristal outlet and high perimembranous defects progressive aortic regurgitation (AR) may develop
Arrhythmias are less frequent than in other forms of CHD.
Complete heart block, rare these days, was a common surgical complication requiring permanent pacemakers in older patients. Patients who develop bifascicular or transient trifascicular block after repair are at high risk for developing complete heart block in later years.
Echocardiography remains the standard investigative modality and provides information on location, number, size of defects, severity of LV volume overload, estimated PAP, and AR due to prolapse of right/noncoronary cusp in case of supracristal and high perimembranous defect. Presence of DCRV must be excluded. CMR is an alternative if echo quality is suboptimal and cardiac catheterization is required only if shunt reversal and established PAH is suspected. It helps to quantify PAP and shunt fraction accurately and can also distinguish between fixed and reversible PAH.
Surgical closure with a pericardial patch has low (1-2 percent) operative mortality and with good long-term results, remains the treatment of choice. Transcatheter closure can be considered in patients with increased surgical risk and those that are poorly accessible surgically. Muscular VSDs located centrally in the septum are particularly amenable to treatment with this technique. Long-term data regarding safety and efficacy of catheter-based techniques in all other types of VSD are limited.
Patients with LV dysfunction, residual shunt, PAH, AR, RVOTO or left ventricular outflow tract obstruction (LVOTO) should be seen annually. Patients with small isolated VSDs with normal LV/PAP, who are asymptomatic, need to be seen once every 3 to 5 years. After device closure of VSDs, patients should be seen regularly for first 2 years and then the interval can be increased to once every 2 to 5 years.
Asymptomatic VSD patients, pre- or postintervention with normal PAP and no significant history of arrhythmia have no restriction for engaging in sports and exercise. Those with PAH should restrict themselves to low-intensity recreational sports.
The risk from pregnancy in patients without PAH is low. Pregnancy is contraindicated in patients with Eisenmenger syndrome. Recurrence rate of CHD is 6 to 10 percent.
Infectious endocarditis prophylaxis is recommended only for those with residual shunts. Patients with patch repair of VSD using prosthetic material should also have IE prophylaxis for the first postoperative 6 months.
AVSDs account for around 3 percent of all CHD. Thirty-five percent of patients with AVSD have Down syndrome. Most complete AVSDs occur in Down patients (>75 percent), and most partial AVSDs occur in non-Down patients (>90 percent). AVSD may occur in association with ToF and other complex heterotaxy syndromes.
Since surgical treatment in the past was frequently withheld for Down syndrome patients, they may frequently present as adults with complete AVSD and Eisenmenger syndrome, unless the VSD is small. Unrepaired partial AVSD is not uncommon in adults. The presenting clinical symptoms are those of L–R shunt and left-AV valve regurgitation in the area of the zone of apposition (also known as “left”). Progressive symptoms develop with increasing age and most patients are symptomatic by 40 years if not operated.
Clinical presentation mainly depends on the presence and size of ASD/VSD, competence of the AV valves, and direction/degree of shunting. With time, exertional dyspnea, arrhythmia, cyanosis, and sub-AS may progressively develop.
Fifty percent of these patients have prolonged AV conduction and virtually all have left axis deviation. Echocardiography remains the key diagnostic technique and provides assessment of each anatomic component of AV valves and their connections (straddling, overriding), the severity and substrate of AV valve regurgitation, degree and direction of shunting, LV and RV function, PAP, and presence of sub-AS. CMR may be required for accurate quantification of ventricular volume, while cardiac catheterization is indicated in those cases with high PAP where surgical repair is being considered.
Repair is surgical as no catheter-based options are available. All symptomatic and asymptomatic patients with echo evidence of moderate-to-severe AV valve regurgitation and impaired LV function should be considered for surgical repair. Surgery should be avoided in patients with Eisenmenger syndrome. Of note, patients with residual shunts requiring pacemakers and high PVR should be considered for epicardial leads in view of increased risk of paradoxical embolism associated with the implantation of intracardiac leads.
Lifelong follow-up is recommended for all operated and unoperated patients with AVSD. Particular attention should be paid to residual shunts, AV valve malfunction, LV/RV dysfunction, PAP, sub-AS, and arrhythmias. Patients with no significant defect should be seen every 2 to 3 years and those with residual abnormalities more frequently. One of the most common problems arising during long-term follow-up is increasing left AV valve regurgitation and, in order to preserve the functional integrity of the left ventricle, most patients will require further surgery. This may either be in the form of further repair or replacement of the valve.
Asymptomatic AVSD patients (postrepair) have no restriction for engaging in sports and exercise. For residual defects, recommendations should be individualized.
The risk from pregnancy in patients with complete repair and no residual defects is low. AVSD closure prior to conception may reduce the chance of paradoxical embolism and worsening ventricular function. Patients with isolated mild-to-moderate left AV valve regurgitation can tolerate pregnancy well.26 Pregnancy is contraindicated in patients with Eisenmenger syndrome. Recurrence rate of CHD is high (11 percent), and genetic counseling is necessary. Prophylaxis for IE is recommended for high-risk patients.
Presentations of adult patients with PDA include: (1) asymptomatic patients with small ducts and no signs of LV volume overload; (2) moderate-sized PDA with LV volume overload and occasionally signs of CHF; (3) moderate-sized PDA with predominant PAH and RV dysfunction and finally; and (4) large PDA with Eisenmenger physiology with differential cyanosis (lower extremity and left arm cyanotic as compared to right arm). Risk of endocarditis is small, and rarely aneurysmal duct dilation may compress the left main coronary.
A continuous machinery murmur, which disappears after development of Eisenmenger syndrome, is typical of this malformation. The role of echo is to look for the presenting features mentioned above and associated complications. CMR and cardiac catheterization are occasionally required.
Calcification of the duct is very common in adults and hence device closure (Fig. 90-2) rather than surgical closure is the preferred method, even when other concomitant lesions may necessitate an open repair. Results are good and complication rates of device closure are very low.27 Surgery is reserved for rare patient with large, aneurysmal duct with unsuitable anatomy. All symptomatic PDAs with signs of LV volume overload should be closed to the exception of patients with Eisenmenger syndrome.
Echo evaluations should include LV size and function, PAP, residual shunt, and associated lesions. Patients with no residual shunt, normal LV, and PAP do not require follow-up beyond 6 months. Those with residual shunt, LV dysfunction and PAH should be followed regularly every 1 to 3 years depending on rapidity of deterioration.
Asymptomatic patients, pre- or postintervention with normal PAP have no restriction for engaging in sports and exercise. Those with PAH should restrict themselves to low-intensity recreational sports.
The risk from pregnancy in patients without PAH is low. Pregnancy is contraindicated in patients with Eisenmenger syndrome.
Prophylaxis for IE is recommended for high-risk patients.
LVOTO can occur at valvular (most common >75 percent), supra- and subvalvular levels.
Most common cause of valvular AS is congenital bicuspid aortic valve, affecting 1 to 2 percent of the general population. Clinical presentation in adults, management considerations, treatment modalities and follow-up in this group of patients are discussed extensively in the adult cardiac surgery section of this textbook.
Supravalvular aortic stenosis (supra-AS) accounts for <7 percent of all forms of fixed LVOTO. It can occur as a localized fibrous diaphragm just distal to coronary ostia or, more commonly, as an external hourglass deformity with corresponding luminal narrowing/diffuse AS. It frequently occurs as a part of the Williams-Beuren syndrome when it is associated with hypoplasia of the entire aorta, involvement of coronary ostia, or stenosis of major aortic branches/PA stenosis. It is important to appreciate that, although site of stenosis may be localized in the ascending aorta, the pathologic process involves the entire aortic root.28 When present, these lesions are usually significant enough to warrant surgical intervention in infancy/childhood to ensure survival.
Freedom from reoperation at 10 years is 70 to 85 percent with a 10-year actuarial survival of 90 to 95 percent.29 Reoperation and late death are most commonly related to progressive valve dysfunction and not recurrence of supra-AS.29 Surgery for diffuse supra-AS as seen with Williams syndrome is less successful, and poor aortic growth persists in both localized and diffuse forms despite successful relief of obstruction initially.30 These patients are also prone to developing premature CAD.31
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