In this section we propose to outline the principles of a diagnostic approach that is applicable to newborns, infants and children with suspected CHD. We will address the following questions:
1) How does one recognise that a newborn, an infant or a child has congenital heart disease (CHD)?
2) What constitutes a cornplete diagnosis for a patient who has CHD? What are the various aspects that need to be defined as a part of making a diagnosis of CHD?
3) why is it necessary to make an accurate and a complete diagnosis in a patient with CHD?
4)Why is it often preferred to obtain a complete diagnosis early after presentation?
5) What investigative modalities are currently available for diagnosis of CHD and how can they be optimally used ?
Recognition of Congenital Heart Disease
The manifestations of CE-ID are different in a neonate, an infant or a child. It is often easy to recognise the presence of CHD in older children. In infants and pa-titularly in newborns, manifestations of heart disease can often be subtle.
The following clinical features should alert the pediatrician regarding the presence of CI-ID.
Cyanosis: Cyanosis may be peripheral or central. Peripheral cyanosis almost exclusively ilivolves lips and extremities. Normal neonates may have bluish extremities that respond to warming or moving the extremities. Saturations of 90 per cent or lower while breathing room air beyond the first 20 minutes are considered abnormal. Similarly, some infants may have peripheral cyanosis following exposure to cold. Central cyanosis involving the mucous membranes and trunk along with the lips and extremities, strongly suggests the likelihood of CHD. Unfortunately, however, cyanosis often remains unnoticed. This isparticularly true in the Indian context, where it is difficult to detect cyailosis is presence of a dark skin complexion. Further, cyanosis is often masked by anaemia. When central cyanosis is suspected, its presence should be confirmed and severity quantified by measuring oxygen saturation using a skin oxymeter
probe. Unfortunately, however, the availability of this instrument is limited to a few selected institutions.
Difficult Feeding and Poor Growth: The parent of an infant with CHD may complain that the child has difficulty with feeds. This is usually a feature of an infant with congestive heart failure resulting from CHD. The histoly may be of slow feeding, small volumes consumed during each feed, tiring easily following feeds and requirement of periods of rest duling feeds. Not infrequently, no histoly of feeding difficulty may be obtained, but exainination of the growth charts will reveal that the childs growth rate is not appropriate for age. A recent decline in . growth rate (falling oft' the growth curve) or weight that is inappropriate for age (<5th percentile) may result from a l a g e left to right shunt. Characteristically,growth retardation affects weight more that height.
Difficult Breathing: Tachypnea (respiratory rates consistently more than 451 min), is a characteristic manifestation of heart failure in ilewboills (pre-term newborns may normally have respiratoly rates of up to 60lmin). For inf'mts,subcostal or intercostal retractions together with flaring of nostrils alae nasii are frequently associated with tachypnoea.
Frequent Respiratory Infections: Respiratory infections that are frequent,severe and difficult to treat are cominon in infants with CHD associated with large left to right shunts resulting in increased lung blood flow. Not infrequently, heart disease may be detected for the first time duiing an episode of respiratoiy tract infection.
Clinical stigmata of specific syndromes: Evidence of preseilce of chromosoinal anomalies or other syndromes that are known to be associated with CHD should alert the clinician to the presence of specific cardiac defects that we known to be associated with these conditions. The list of such conditions is a long one.
Trisomy 21 is the commonest chromosomal anomaly that is associated with 11ea1-t disease. Other common examples include: trisomy 13, trisomy 18, Turner's Syndrome, Noonan's Syndrome, Velocardiofacial and the Di-Georges's Syndrome.
Cardio-vascular examination: A thorough and systelnatic cardio-vascular examination provides valuable clues to the presence of heart disease. With practice such an examination can be accomplished in a short time. For the paediatrician, a thorough familiarisation with what is normal is a useful initial step. It is useful to answer the following questions that can seive as a checklist for a preliminary cardiac examination. This checklist is, not at all,comprehensive and is designed piimarily for answeiing the question: Does the patient have heart disease? It can also help identify the broad physiologic category of heart defect.
1) Are the arterial pulsations normal?
Is the pulse volume normal or increased?
Is there a discrepancy of pulsation in any of the four extremities?
A careful evaluation of pulsations in all extremities should always be a part of physical examination. Coarctation is readily diagnosed when weak femoral pulsations are detected in comparison to brachials or radials. While a four extremity blood pressure measurement should ideally accolnpany clinical evaluation in all children with suspected heart disease, it is not always feasible.
Nonetheless, when a discrepancy in pulses is suspected, four extremity blood pressure measurements should be obtained. An automated non-invasive blood pressure instrument is preferred over manual recording for four extremety blood pressure ineasurernent.
2) Does the precordium feel normal?
Are these visible precordial pulsations?
Is the apex beat displaced, hyperdynamic or heaving?
Is there a thill palpable?
3) Are the heart sounds normal?
Can the two components of the second heart sound be separated?
Is there an additional heart souild in diastole ( such as S3)?
Are there any additional systolic sounds (ejection clicks)?
4)Is (or are) there a murmur (or murmurs)? If so:
Is it systolic or diastolic or both systolic and diastolic (diastolic murmurs always have a structural basis)?
Is it loud (grade 3 or louder murmurs are seldom innocent)?
The ECG and Chest X-ray: If there is a suspicion of heart disease on basis of the history or physical examination an ECG and a chest X-ray should be oblained.The X-ray also provides information about the location of abdominal organs (for determination of the situs) and the aortic arch. Beyond the neonatal period, a normal ECG and chest X-ray makes the diagnosis of a hemodynarnically significant heart defect unlikely. In newborns, however, ECG and chest X-ray changes, may take a few days to evolve. For the newborn, particularly in the first few days a "normal" ECG and a noimal X-ray does not rule out serious heart disease.
The Importance of a n Accurate and a Complete Diagnosis i n a Patient with CHI3 This, arguably, is one of the most important responsibilities of the paediatric cardiologist. The implications of an incomplete or incorrect diagnosis are often potentially serious, and sometimes, fatal. It is useful to remember that if there is one developmental defect in the heart, there may be others that need to be addressed. Very often, this is indeed the case.
Components of a Complete Diagnosis of Congenital Heart Disease
A complete diagnosis of congenital heart disease requires accurate and thorough description of the h e a t and great vessels in a systematic fashion in addition to a detailed description of the anatomy and physiology of the basic defect(s). Today this is often achievable through systematic 2D and Doppler echocardiogsaphy.again, a checklist of questions to be addressed is very useful are
1) What is the visceral and atrial situs (solitus, inversus or ambiguous)?
2) What are the systemic venous connections like? Is the IVC intact? Is there a separate LSVC? If so, how does it drain?
3) What is the relationship of the abdominal aorta to the IVC?
4) What is the appearance of the atria like? Is thq atrial septum intact? Is there an ASD or a patent foramen ovale? If so, what direction does blood flow?
5) How do the atria connect to the ventricles (concordant or discordant)?
6) Is it possible to identify two separate AV valves?
7) How are the AV valves in their appearance and function?
8) The ventricles: their size shape and function?
9) Are the various components of the inteiventricular septum intact?
10) Is there any outflow tract obstruction?
11) How do the ventricles connect to the great arteries?
12) What is the appearance and function of the semilunar valves?
13) What is the great artery relationship?
14) Are the branch pulmonary arteries in continuity? Is therc any branch pulmonary artery stenosis?
15) What side is the aortic arch? What is its branching pattern? Is there a PDA or a coarctation?
At any stage of the examination, if an abnormality is identified, the anatomy and physiology of the defect should be outlined as precisely as possible.Investigative Tools and their Optimal Use The investigative tools that are available for diagnosis of CHD include ECG, chest X-ray, 2D and Doppler echocardiography, transoesophageal echocardiography, cardiac catheterization and cineangiography and the cardiac MRI. All lests,excepting the ECG and chest X-ray are expensive. It is therefore inlportant to consider the cost-benefit ratio of these investigations. Echocardiography has revolutionised diagnosis of CHD and its high diagnostic yield makes this investigation very cost effective. Echocardiography has a few inherent limitations,however. It consistently fails to define certain structures such as the pulmonary artery branches beyond the hila of the lungs.
The role of diagnostic cardiac catheterization for patients with CHD has declined considerabl; with the availability of high quality echocardiography. Since cardiac catheterization is an invasive procedure its performance requires caref~il planning so that Cardiac MRI is a useful non-invasive imaging modality that can be of incremental benefit over an echocardiogram. It holds tremendous promise,Limitations include scarce availability of equipment, and what is more important, expertise for interpretation and requirement of general anaesthesia,
Congenital Cardiac Conditions Encountered in Adults
The entire population of adults with CHD is constituted by patients whose cardiac malformations have a natural history allows survival into adulthood and patients with CHD who have undergone corrective or palliative procedures in childhood In India, the former constistes the majority because specialized pediatric cardiac services are limited to very few centres.
Initial resuscitation and stabilization of a newborn with suspected heart
The ECG and Chest X-ray: Beyond the neonatal period, a normal ECG and chest X-ray makes the diagnosis of a hemodynamically significant heart defect unlikely.In young infants, assessing heart disease is often difficult because of a large thymus. The radiographic assessment of pulmonary blood flow is difficult even for the experienced observer but it is even more difficult in an infant where the arteries and veins are small.
The Echocardiogram
When doubts persist whether a patient has CHD or not despite a thorough clinical exam and chest X-ray, ECG, and hyperoxia test, an echocardiogram should be arranged .
Initial resuscitation and stabilization of a newborn with suspected heart disease.
Airway and Respiratory Support
Like in any other emergency situation a stable airway needs to be established first. Newborns with severe respiratory distress should immediately receive bag and mask ventilation and 100 per cent oxygen may be used for this purpose(although, later the oxygen concentration may need to be reduced).
Access
A secure peripheral or central intravenous access is very essential. Inotropic agents with vasoconstrictor properties like Dopamine and Adrenaline can only be administered via a reliable central access.
Oxygen
The potential dangers of excessive oxygen in a newborn with suspected help disease include acceleration of closure of the ductus arteriosus and unacceptable decline in the pulmonary vascular resistance.
Prostaglandin - Availability, Administration and Alternatives
Prostaglandin E l (available in India as Prostin VR, Pharmacia) is a very essential drug and should be available in every newborn nursery. It can restore ductal patency in most newborns with closing ducts and is therefore life saving in duct dependent situations. Its effect is usually confinned by improving saturations in newborns with duct dependent pulmonary circulation and resolution of the circulatory failure and acidosis in newborns with duct dependent systemic circulation. Its efficacy declines somewhat with increasing age particularly after 15 days and it is usually not effective in opening a closed duct after 30 days. The initial dose of prostaglandin is 0.05-0.1 microgram/kg/minute. Once the duct has opened up (this can be confirmed by the clinical response or by echocardiography),the dose may be reduced to as low as 0.01 mcg/kg/min. This allows maintenance of ductal patency with minimal adverse effects. Adverse effects of PGEl infusion include apnea, bradycardia, tachycardia, hflotension, fever, gastric distension and seizures. Leukocytosis frequently accoinpanies prostaglandin use. Administration over several days may result in increased lung and body water from capillary leak,thrombocytopenia, gastric outlet obstruction and cortical hyperosteosis.
Prostaglandin is available in most cities in India. Newborn nurseries should endeavor to obtain one or two ampoules of the drug and this should be stored in the refrigerator and replaced when consumed. The drug is expensive (- Rs, 10,000). It is, however, possible to extend the use of a single ampoule to about a week by using only small amounts of the divg to prepare the infusion on a daily basis. The be aspirated from the ampoule under strict sterile remainder of the drug c ~ m precautions (preferably under a laminar flow system) and stored in a sealed 1-cc syringe for as long as a week. Reducing the maintenance dose to a minimum can also help prolong the availability.
In the absence of prostaglandin, atropine 0.02 mgkg boluses may be used as an alternative. For patients with transposition and intact ventricular septum, anumbilical venous catheter may be passed into the left atiium under fluoroscopic guidance and this could "stent" the atrial septum open to maintain reasoilable oxygen saturations until transport to a center for balloon septostomy can be accomplished.
Circulatory Support and Inotropes
Colloid or Crystalloids: Hypotension after PGEl infusion is common. It is the result of relative intravasculu volume depletion because of a combination of peripheral vasodilation and increased vascular permeability. It is best treated by administration of 10-20 m l k g of a colloid solution (5 per cent albumin or plasma) as a bolus. If colloid solutions are unavailable, c~ystalloid solutions may be used in the same volume. Inotsopes are likely to be ineffective unless adequate volume replacement is done.
Dopamine: This should only be administered via a central line. Doses range from 5-15 mcg/kg. This is often the first choice in most centers. It has vasoconstrictor as well as inotropic effects and is often the only agent necessary
Dobutamine: Perhaps he only reason to use dobutamine du~ing initial resuscitation is that it done not require a central access. It has a potent inotropic effect and some vasodilatory effects. For this reason it is not as effective as Doparnine in hypotension, particularly if the myocardial contractility is normal.
Adrenaline: It has powerful vasoconstrictor and inotropic effects but is seldom required as an infusion prior to or during transportation unless the neonate sustains severe hypotension or a cardiac ail-est. Central access is a must and doses range fiom 0.01 -0.2 mcg/kg/inin.
Isoproterenol: Newborns with congenital complete heast block can be born with severe bradycardia and infusions of isoproterenol (0.01-0.05 mcg/kg/min) may be initiated prior to transport to center with facilities for pacemaker implantation.
Transportation of Sick Newborn Infants with Heart Disease Communication
The decision to transport a newboi-n to a tertiay refersal center with facilities for specialized care of neonates and infants with heart disease should be n joint one involving the referring pediatrician and the pediakic casdiology team.
Personnel for Neonatal transport
Whenever feasible, the newborn should be accompanied by the resident neonatologist/pediatrician taking care of the baby and a nurse. Both the team members should be familiar with the underlying condition and should be awase of the potential problems the newborn may Face during transport.
Monitoring During Transport
Ideally, it is necessay to continuously monitor ECG and oxygen saturations during transportation.
Care of the Newborn During Transport
A secure airway and an access are vital. Newborns on prostaglandin can have periods of apnea. For this reason a number of units in the west would routinely intubate and n~echanically ventilate a newborn on prostaglandin infusion during transpoit. For a number of reasons this is not practical in the Indian scenario.Transpoitation while on prostaglandin infusion does amount Lo taking a calculated risk.
1) How does one recognise that a newborn, an infant or a child has congenital heart disease (CHD)?
2) What constitutes a cornplete diagnosis for a patient who has CHD? What are the various aspects that need to be defined as a part of making a diagnosis of CHD?
3) why is it necessary to make an accurate and a complete diagnosis in a patient with CHD?
4)Why is it often preferred to obtain a complete diagnosis early after presentation?
5) What investigative modalities are currently available for diagnosis of CHD and how can they be optimally used ?
Recognition of Congenital Heart Disease
The manifestations of CE-ID are different in a neonate, an infant or a child. It is often easy to recognise the presence of CHD in older children. In infants and pa-titularly in newborns, manifestations of heart disease can often be subtle.
The following clinical features should alert the pediatrician regarding the presence of CI-ID.
Cyanosis: Cyanosis may be peripheral or central. Peripheral cyanosis almost exclusively ilivolves lips and extremities. Normal neonates may have bluish extremities that respond to warming or moving the extremities. Saturations of 90 per cent or lower while breathing room air beyond the first 20 minutes are considered abnormal. Similarly, some infants may have peripheral cyanosis following exposure to cold. Central cyanosis involving the mucous membranes and trunk along with the lips and extremities, strongly suggests the likelihood of CHD. Unfortunately, however, cyanosis often remains unnoticed. This isparticularly true in the Indian context, where it is difficult to detect cyailosis is presence of a dark skin complexion. Further, cyanosis is often masked by anaemia. When central cyanosis is suspected, its presence should be confirmed and severity quantified by measuring oxygen saturation using a skin oxymeter
probe. Unfortunately, however, the availability of this instrument is limited to a few selected institutions.
Difficult Feeding and Poor Growth: The parent of an infant with CHD may complain that the child has difficulty with feeds. This is usually a feature of an infant with congestive heart failure resulting from CHD. The histoly may be of slow feeding, small volumes consumed during each feed, tiring easily following feeds and requirement of periods of rest duling feeds. Not infrequently, no histoly of feeding difficulty may be obtained, but exainination of the growth charts will reveal that the childs growth rate is not appropriate for age. A recent decline in . growth rate (falling oft' the growth curve) or weight that is inappropriate for age (<5th percentile) may result from a l a g e left to right shunt. Characteristically,growth retardation affects weight more that height.
Difficult Breathing: Tachypnea (respiratory rates consistently more than 451 min), is a characteristic manifestation of heart failure in ilewboills (pre-term newborns may normally have respiratoly rates of up to 60lmin). For inf'mts,subcostal or intercostal retractions together with flaring of nostrils alae nasii are frequently associated with tachypnoea.
Frequent Respiratory Infections: Respiratory infections that are frequent,severe and difficult to treat are cominon in infants with CHD associated with large left to right shunts resulting in increased lung blood flow. Not infrequently, heart disease may be detected for the first time duiing an episode of respiratoiy tract infection.
Clinical stigmata of specific syndromes: Evidence of preseilce of chromosoinal anomalies or other syndromes that are known to be associated with CHD should alert the clinician to the presence of specific cardiac defects that we known to be associated with these conditions. The list of such conditions is a long one.
Trisomy 21 is the commonest chromosomal anomaly that is associated with 11ea1-t disease. Other common examples include: trisomy 13, trisomy 18, Turner's Syndrome, Noonan's Syndrome, Velocardiofacial and the Di-Georges's Syndrome.
Cardio-vascular examination: A thorough and systelnatic cardio-vascular examination provides valuable clues to the presence of heart disease. With practice such an examination can be accomplished in a short time. For the paediatrician, a thorough familiarisation with what is normal is a useful initial step. It is useful to answer the following questions that can seive as a checklist for a preliminary cardiac examination. This checklist is, not at all,comprehensive and is designed piimarily for answeiing the question: Does the patient have heart disease? It can also help identify the broad physiologic category of heart defect.
1) Are the arterial pulsations normal?
Is the pulse volume normal or increased?
Is there a discrepancy of pulsation in any of the four extremities?
A careful evaluation of pulsations in all extremities should always be a part of physical examination. Coarctation is readily diagnosed when weak femoral pulsations are detected in comparison to brachials or radials. While a four extremity blood pressure measurement should ideally accolnpany clinical evaluation in all children with suspected heart disease, it is not always feasible.
Nonetheless, when a discrepancy in pulses is suspected, four extremity blood pressure measurements should be obtained. An automated non-invasive blood pressure instrument is preferred over manual recording for four extremety blood pressure ineasurernent.
2) Does the precordium feel normal?
Are these visible precordial pulsations?
Is the apex beat displaced, hyperdynamic or heaving?
Is there a thill palpable?
3) Are the heart sounds normal?
Can the two components of the second heart sound be separated?
Is there an additional heart souild in diastole ( such as S3)?
Are there any additional systolic sounds (ejection clicks)?
4)Is (or are) there a murmur (or murmurs)? If so:
Is it systolic or diastolic or both systolic and diastolic (diastolic murmurs always have a structural basis)?
Is it loud (grade 3 or louder murmurs are seldom innocent)?
The ECG and Chest X-ray: If there is a suspicion of heart disease on basis of the history or physical examination an ECG and a chest X-ray should be oblained.The X-ray also provides information about the location of abdominal organs (for determination of the situs) and the aortic arch. Beyond the neonatal period, a normal ECG and chest X-ray makes the diagnosis of a hemodynarnically significant heart defect unlikely. In newborns, however, ECG and chest X-ray changes, may take a few days to evolve. For the newborn, particularly in the first few days a "normal" ECG and a noimal X-ray does not rule out serious heart disease.
The Importance of a n Accurate and a Complete Diagnosis i n a Patient with CHI3 This, arguably, is one of the most important responsibilities of the paediatric cardiologist. The implications of an incomplete or incorrect diagnosis are often potentially serious, and sometimes, fatal. It is useful to remember that if there is one developmental defect in the heart, there may be others that need to be addressed. Very often, this is indeed the case.
Components of a Complete Diagnosis of Congenital Heart Disease
A complete diagnosis of congenital heart disease requires accurate and thorough description of the h e a t and great vessels in a systematic fashion in addition to a detailed description of the anatomy and physiology of the basic defect(s). Today this is often achievable through systematic 2D and Doppler echocardiogsaphy.again, a checklist of questions to be addressed is very useful are
1) What is the visceral and atrial situs (solitus, inversus or ambiguous)?
2) What are the systemic venous connections like? Is the IVC intact? Is there a separate LSVC? If so, how does it drain?
3) What is the relationship of the abdominal aorta to the IVC?
4) What is the appearance of the atria like? Is thq atrial septum intact? Is there an ASD or a patent foramen ovale? If so, what direction does blood flow?
5) How do the atria connect to the ventricles (concordant or discordant)?
6) Is it possible to identify two separate AV valves?
7) How are the AV valves in their appearance and function?
8) The ventricles: their size shape and function?
9) Are the various components of the inteiventricular septum intact?
10) Is there any outflow tract obstruction?
11) How do the ventricles connect to the great arteries?
12) What is the appearance and function of the semilunar valves?
13) What is the great artery relationship?
14) Are the branch pulmonary arteries in continuity? Is therc any branch pulmonary artery stenosis?
15) What side is the aortic arch? What is its branching pattern? Is there a PDA or a coarctation?
At any stage of the examination, if an abnormality is identified, the anatomy and physiology of the defect should be outlined as precisely as possible.Investigative Tools and their Optimal Use The investigative tools that are available for diagnosis of CHD include ECG, chest X-ray, 2D and Doppler echocardiography, transoesophageal echocardiography, cardiac catheterization and cineangiography and the cardiac MRI. All lests,excepting the ECG and chest X-ray are expensive. It is therefore inlportant to consider the cost-benefit ratio of these investigations. Echocardiography has revolutionised diagnosis of CHD and its high diagnostic yield makes this investigation very cost effective. Echocardiography has a few inherent limitations,however. It consistently fails to define certain structures such as the pulmonary artery branches beyond the hila of the lungs.
The role of diagnostic cardiac catheterization for patients with CHD has declined considerabl; with the availability of high quality echocardiography. Since cardiac catheterization is an invasive procedure its performance requires caref~il planning so that Cardiac MRI is a useful non-invasive imaging modality that can be of incremental benefit over an echocardiogram. It holds tremendous promise,Limitations include scarce availability of equipment, and what is more important, expertise for interpretation and requirement of general anaesthesia,
Congenital Cardiac Conditions Encountered in Adults
The entire population of adults with CHD is constituted by patients whose cardiac malformations have a natural history allows survival into adulthood and patients with CHD who have undergone corrective or palliative procedures in childhood In India, the former constistes the majority because specialized pediatric cardiac services are limited to very few centres.
 |
| Corrective or palliative procedures |
Approxinlately 30 per cent of all newborns have critical CHD. These are congenital heart diseases that do not allow survival or correction beyond the first few years of life (the small fraction of these newborns that suilrive beyond the first few years usually have irreversible pulmonary vascular obstructive disease that precludes any operation). A large number of conditions including most complex congenital cardiac malformations come under this category (Table ). For some of these conditions there clearly is a spectrum of severity.
Bicuspid Aortic valves can result in aortic stenosis, aortic regurgitation or combination of both.
1 Small ventricular septal defects and patent ductus arteriosus allow survival to adulthood.Patients with large ventricular septal defects and patent ductus arteriosus often develop irreversible changes in the lung vasculature (Eisenmenger syndrome) when they survive to adulthood. #patients with tetralogy of Fallot's who survive to adulthood typically have mild or resting cyanosis during infancy. Cyai~osis increases $th age and may eventually become severe.Bicuspid aortic valve is the inost comnon form of CHD seen in adults.
Isolated bicuspid aortic valves may be stenotic or non-stenotic to start with. The non-stenotic BCAV may remain functionally noimal throughout a normal life span to start with. It may become stenotic through fibrocalcific thiclcening or may become regurgitant.Aortic regurgitation may occur either spontaneously or alter an episode of infective endocarditis.
Diagnostic Approach to Congenital Heart Disease
It is often easy to recognise the presence of CHD in older children and adults. As in any other form of heart disease a careful histoiy and systematic physical examination unravels many clues and allows identification of the physiologic category in most patients.The following clinical features indicates a strong possibilty of underlying CHD.These features also help in identifying ll1e physiologic category of the CHD.Cyanosis and Polycythemia: Central cyanosis involving the ~nucous membranes and trunk along with the lips and extremities in absence of obvious respiratoly difficulty strongly suggests the likelihood of CHD. The presence of cyanosis limits the diagnosis to a few physiologic categories.
Bicuspid Aortic valves can result in aortic stenosis, aortic regurgitation or combination of both.
1 Small ventricular septal defects and patent ductus arteriosus allow survival to adulthood.Patients with large ventricular septal defects and patent ductus arteriosus often develop irreversible changes in the lung vasculature (Eisenmenger syndrome) when they survive to adulthood. #patients with tetralogy of Fallot's who survive to adulthood typically have mild or resting cyanosis during infancy. Cyai~osis increases $th age and may eventually become severe.Bicuspid aortic valve is the inost comnon form of CHD seen in adults.
Isolated bicuspid aortic valves may be stenotic or non-stenotic to start with. The non-stenotic BCAV may remain functionally noimal throughout a normal life span to start with. It may become stenotic through fibrocalcific thiclcening or may become regurgitant.Aortic regurgitation may occur either spontaneously or alter an episode of infective endocarditis.
Diagnostic Approach to Congenital Heart Disease
It is often easy to recognise the presence of CHD in older children and adults. As in any other form of heart disease a careful histoiy and systematic physical examination unravels many clues and allows identification of the physiologic category in most patients.The following clinical features indicates a strong possibilty of underlying CHD.These features also help in identifying ll1e physiologic category of the CHD.Cyanosis and Polycythemia: Central cyanosis involving the ~nucous membranes and trunk along with the lips and extremities in absence of obvious respiratoly difficulty strongly suggests the likelihood of CHD. The presence of cyanosis limits the diagnosis to a few physiologic categories.
 |
| The broad pllysiologic categories of adult cyanotic co~lgcl~ital heart diseases |
Management Strategies for Adults with Congenital Heart Disease
The goals for management of congenital heart disease in adults are improving upon the natural history of the condition and providing symptoin rclieC Improving the natural history of adults with CND: As mentioned above the populations of adults with CHD are largely constituted by coilditiorls with a relatively favourable natural history that allow survival until adulthood. There is, however, considerable atlritioil during adult life and many of these conditions can benefit from intervention (surgery or trans-catheter intervention) c ren during adulthood. The decisioil regarding h e need for intervention and tiining of intervention needs to be individualized because of the enormous variety of conditions encountered in adulthood. The indications for surgery or transcatheter interventions for the individual conditioils have been summarized in below Table
The goals for management of congenital heart disease in adults are improving upon the natural history of the condition and providing symptoin rclieC Improving the natural history of adults with CND: As mentioned above the populations of adults with CHD are largely constituted by coilditiorls with a relatively favourable natural history that allow survival until adulthood. There is, however, considerable atlritioil during adult life and many of these conditions can benefit from intervention (surgery or trans-catheter intervention) c ren during adulthood. The decisioil regarding h e need for intervention and tiining of intervention needs to be individualized because of the enormous variety of conditions encountered in adulthood. The indications for surgery or transcatheter interventions for the individual conditioils have been summarized in below Table
Other Concerns in Adults with Congenital Heart Disease
Infective endocarditis prophylaxis: The standard guidelines for infective endocarditis prophylaxis should be followed for the various conditions.
Pregnancy: The specific recommendations for individual conditions are beyond the scope of this chapter.
Resuscitation, Stabilization and Transport of a Newborn with Suspected Heart Disease
Heart diseases that manifest during newborn period very often require urgent attention. Prompt treatment can often yield gratifying results and many instances excellent long-term event free survival can be expected. Today, some form of palliative or definitive treatment is feasible for most newborns with CHD.
Clinical Recognition of Neonatal Heart Disease
Presentation and physical examination
Infective endocarditis prophylaxis: The standard guidelines for infective endocarditis prophylaxis should be followed for the various conditions.
Pregnancy: The specific recommendations for individual conditions are beyond the scope of this chapter.
Resuscitation, Stabilization and Transport of a Newborn with Suspected Heart Disease
Heart diseases that manifest during newborn period very often require urgent attention. Prompt treatment can often yield gratifying results and many instances excellent long-term event free survival can be expected. Today, some form of palliative or definitive treatment is feasible for most newborns with CHD.
Clinical Recognition of Neonatal Heart Disease
Presentation and physical examination
- Prelinlinary investigations: ABG
- Hyperoxia test
- ECG and Chest X-ray
- Echocardiogram
Initial resuscitation and stabilization of a newborn with suspected heart
- disease
- Airway
- Respiratory Support
- Access
- Oxygen
- Prostaglandin: Availability, Administration and Alternatives
- Circulatory support and Inotropes
- Basic Laboratory work-up
Transport of a newborn with suspected heart disease
- Communication
- Personnel
- Temperature Control
- Monitoring
- Mechanical ventilation
Evaluation and Management at the Tertiary Care Center
- Detailed Diagnostic Evaluation
- Assessment of End-organ Insult
Definitive Weatment: Emergency Procedures
- Interventions
- Emergency Cardiac Surgery
Diagnosis of Heart Disease in the Newborn
Clinical diagnosis of heart disease in the newboin can be quite challenging.Manifestations of potentially life threatening CHD are often subtle and can be confused with non-cardiac conditions.
The hyperoxia test : The hyperoxia test is frequently used to rule out critical CHD(conditions that are fatal without specific interventions in the newboil1 pe~iod). This test is based on the principle that administration of 100 per cent oxygen can raise from the PO, of the arterial blood to a much higher level in absence of shunting cardiac causes. It requires estimation of PO,.
Clinical diagnosis of heart disease in the newboin can be quite challenging.Manifestations of potentially life threatening CHD are often subtle and can be confused with non-cardiac conditions.
The hyperoxia test : The hyperoxia test is frequently used to rule out critical CHD(conditions that are fatal without specific interventions in the newboil1 pe~iod). This test is based on the principle that administration of 100 per cent oxygen can raise from the PO, of the arterial blood to a much higher level in absence of shunting cardiac causes. It requires estimation of PO,.
The echocardiogram: When doubts persist wheather a patient has CHD or not despite a thorough clinical exam and chest X-ray and ECG, an echocwdiograin may be performed. This is especially true if the patients cliilical condition does not permit adequate cliilical evaluation. Such a situation is not infrequent in neonates.
The ECG and Chest X-ray: Beyond the neonatal period, a normal ECG and chest X-ray makes the diagnosis of a hemodynamically significant heart defect unlikely.In young infants, assessing heart disease is often difficult because of a large thymus. The radiographic assessment of pulmonary blood flow is difficult even for the experienced observer but it is even more difficult in an infant where the arteries and veins are small.
The Echocardiogram
When doubts persist whether a patient has CHD or not despite a thorough clinical exam and chest X-ray, ECG, and hyperoxia test, an echocardiogram should be arranged .
Initial resuscitation and stabilization of a newborn with suspected heart disease.
Airway and Respiratory Support
Like in any other emergency situation a stable airway needs to be established first. Newborns with severe respiratory distress should immediately receive bag and mask ventilation and 100 per cent oxygen may be used for this purpose(although, later the oxygen concentration may need to be reduced).
Access
A secure peripheral or central intravenous access is very essential. Inotropic agents with vasoconstrictor properties like Dopamine and Adrenaline can only be administered via a reliable central access.
Oxygen
The potential dangers of excessive oxygen in a newborn with suspected help disease include acceleration of closure of the ductus arteriosus and unacceptable decline in the pulmonary vascular resistance.
Prostaglandin - Availability, Administration and Alternatives
Prostaglandin E l (available in India as Prostin VR, Pharmacia) is a very essential drug and should be available in every newborn nursery. It can restore ductal patency in most newborns with closing ducts and is therefore life saving in duct dependent situations. Its effect is usually confinned by improving saturations in newborns with duct dependent pulmonary circulation and resolution of the circulatory failure and acidosis in newborns with duct dependent systemic circulation. Its efficacy declines somewhat with increasing age particularly after 15 days and it is usually not effective in opening a closed duct after 30 days. The initial dose of prostaglandin is 0.05-0.1 microgram/kg/minute. Once the duct has opened up (this can be confirmed by the clinical response or by echocardiography),the dose may be reduced to as low as 0.01 mcg/kg/min. This allows maintenance of ductal patency with minimal adverse effects. Adverse effects of PGEl infusion include apnea, bradycardia, tachycardia, hflotension, fever, gastric distension and seizures. Leukocytosis frequently accoinpanies prostaglandin use. Administration over several days may result in increased lung and body water from capillary leak,thrombocytopenia, gastric outlet obstruction and cortical hyperosteosis.
Prostaglandin is available in most cities in India. Newborn nurseries should endeavor to obtain one or two ampoules of the drug and this should be stored in the refrigerator and replaced when consumed. The drug is expensive (- Rs, 10,000). It is, however, possible to extend the use of a single ampoule to about a week by using only small amounts of the divg to prepare the infusion on a daily basis. The be aspirated from the ampoule under strict sterile remainder of the drug c ~ m precautions (preferably under a laminar flow system) and stored in a sealed 1-cc syringe for as long as a week. Reducing the maintenance dose to a minimum can also help prolong the availability.
In the absence of prostaglandin, atropine 0.02 mgkg boluses may be used as an alternative. For patients with transposition and intact ventricular septum, anumbilical venous catheter may be passed into the left atiium under fluoroscopic guidance and this could "stent" the atrial septum open to maintain reasoilable oxygen saturations until transport to a center for balloon septostomy can be accomplished.
Circulatory Support and Inotropes
Colloid or Crystalloids: Hypotension after PGEl infusion is common. It is the result of relative intravasculu volume depletion because of a combination of peripheral vasodilation and increased vascular permeability. It is best treated by administration of 10-20 m l k g of a colloid solution (5 per cent albumin or plasma) as a bolus. If colloid solutions are unavailable, c~ystalloid solutions may be used in the same volume. Inotsopes are likely to be ineffective unless adequate volume replacement is done.
Dopamine: This should only be administered via a central line. Doses range from 5-15 mcg/kg. This is often the first choice in most centers. It has vasoconstrictor as well as inotropic effects and is often the only agent necessary
Dobutamine: Perhaps he only reason to use dobutamine du~ing initial resuscitation is that it done not require a central access. It has a potent inotropic effect and some vasodilatory effects. For this reason it is not as effective as Doparnine in hypotension, particularly if the myocardial contractility is normal.
Adrenaline: It has powerful vasoconstrictor and inotropic effects but is seldom required as an infusion prior to or during transportation unless the neonate sustains severe hypotension or a cardiac ail-est. Central access is a must and doses range fiom 0.01 -0.2 mcg/kg/inin.
Isoproterenol: Newborns with congenital complete heast block can be born with severe bradycardia and infusions of isoproterenol (0.01-0.05 mcg/kg/min) may be initiated prior to transport to center with facilities for pacemaker implantation.
Transportation of Sick Newborn Infants with Heart Disease Communication
The decision to transport a newboi-n to a tertiay refersal center with facilities for specialized care of neonates and infants with heart disease should be n joint one involving the referring pediatrician and the pediakic casdiology team.
Personnel for Neonatal transport
Whenever feasible, the newborn should be accompanied by the resident neonatologist/pediatrician taking care of the baby and a nurse. Both the team members should be familiar with the underlying condition and should be awase of the potential problems the newborn may Face during transport.
Monitoring During Transport
Ideally, it is necessay to continuously monitor ECG and oxygen saturations during transportation.
Care of the Newborn During Transport
A secure airway and an access are vital. Newborns on prostaglandin can have periods of apnea. For this reason a number of units in the west would routinely intubate and n~echanically ventilate a newborn on prostaglandin infusion during transpoit. For a number of reasons this is not practical in the Indian scenario.Transpoitation while on prostaglandin infusion does amount Lo taking a calculated risk.
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.