08_McClure_08.indd 225 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 226 Common presentations The cardiovascular examination in children is described on b p.32. The majority of children with cardiovascular disease will present with one or more of the foll owing three clinical problems: \200 \200 \200 cyanosis; heart failure ( heart murmur ( b p.226); b p.228). Cyanosis Distinguishing between respiratory and cardiac causes of cyanosis is important (se e b pp.55, 60 \200\22362). Heart failure Heart failure may be manifested by symptoms of poor tissue perfusion alone (e .g. fatigue, poor exercise tolerance, confusion) and/or by symp- toms of congestion of circ ulation (e.g. dyspnoea, pleural effusion, pul- monary oedema, hepatomegaly, peripheral oede ma), without evoking compensatory mechanisms. The underlying pathophysiology mechanisms that lead to compromise of cardiac stroke volume, cardiac decompensation, and heart failure include: \200 \200 \200 \200 increased afterload (pressure work); increased preload (volume work); myocardial abnormalit ies; tachyarrhythmias. Causes of heart failure In children the most common cause of heart failure is congenital st ructural defects of the heart. \200 \200 Large left to right shunt: Left-sided obstructive lesions: of heart (within \201 rst few days of life). Cardiomyopathy: Myocarditis: Endocarditis. Myocardial ischaemia: disease. Ta chyarrhythmias: Acute hypertension. High-output: e.g. large VSD (not in \201 rst few days of life). coarctation of aorta; hypoplastic left side \200 \200 \200 hypertrophic; dilated; restrictive. viral; rheumatic fever. anomalous left coronary artery; Kawasaki \200 \200 supraventricular tachycardia. severe anemia; thyrotoxicosis; AV malformations. 08_McClure_08.indd 226 11/14/2012 2:33:24 PM HEART FAILURE 227 Clinical features The clinical features of heart failure depend on the degree of cardiac re serve. The most common symptoms and signs are those in keeping with increased compensatory sympathetic drive: \200 \200 \200 \200 \200 \200 sweating; breathlessness, tachypnoea, coughing, lung crepitations; poor feeding (infant), p oor weight gain, and failure to thrive; hepatomegaly; cardiomegaly; tachycardia/ \200\231ga llop \200\231 heart rhythm. There are usually few signs of systemic congestion as observed in adults. Only children wit h chronic heart failure, or adolescents, may have \200\230adult \200\231 signs such as oed ema, orthopnoea, paroxysmal nocturnal dyspnoea, ankle oedema and elevated JVP. Investigations These are directed at \201 nding a cause and quantifying function. \200 Chest radiograph: \200 \200 Echocardiography: Arterial blood gas: ECG: Serum electrolyt es: cardiac enlargement; lungs \200\224oligaemic/oedema. \200 \200 \200 congenital heart defects. reduced PO2/metabolic acidosis. not diagnostic, but may assist in establishing etiology. hyponatraemia due to water retention. Management The underlying cause of heart failure must be treated. General measures \200 \200 \200 \200 \200 Bed rest and nurse in semi-upright position: infants in chair/seat. Supplemental oxygen (no t in left to right shunt). Diet: Diuretics. Angiotensin converting enzyme inhibitors. suf \201 cient calorie intake. 08_McClure_08.indd 227 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 228 Heart murmurs Heart murmurs should be characterized in terms of type, location, radia- tion , and quality of sound. Murmurs are classi \201 ed as follows: Systolic: Diastolic: \200 pansystolic; ejection systolic. early diastolic; mid-diastolic. The location where a murmur is best heard may give a clue to the underly- ing etiology. \200 \200 \200 VSD \200\224often loud; innocent heart murmur \200\224soft. : aortic stenosis; pulmonary st enosis. Lower sternal edge: Upper sternal edge Base of neck: aortic valve lesion. Pathological heart murmur Characteristic features of pathological heart murmurs: \200 \200 \200 \200 \200 \200 \200 All diastolic murmurs. All pansystolic murmurs. Late systolic murmurs. Loud murmurs >3/6. C ontinuous murmurs. If there are associated cardiac abnormalities. Abnormal symptoms or sign s: \200 shortness of breath (SOB); \200 tiredness/easy fatigue; \200 failure to thriv e (FTT); \200 cyanosis; \200 \201 nger clubbing; \200 hepatomegaly. Innocent heart murmurs This is the commonest cause of a heart murmur in children. It arises due to the rapid \202 ow and turbulence of blood through the great vessels and across no rmal heart valves. It does not signify the presence of any under- lying cardiac abnormality or any other pathology. Characteristics of innocent heart murmur \200 \200 \200 \200 \200 \200 \200 Systolic in timing \200\224always. Short duration/low intensity sound. Intensi \201 es wit h increased cardiac output (e.g. exercise/fever). May change in intensity with change in po sture and head position. No associated cardiac thrill or heave. No radiation. Asymptomatic patient. Never diastolic. Types of innocent heart murmur Venous hum (uncommon) \200 \200 \200\230Machinery \200\231 quality sound. Upper left sternal edge. Due to blood \202 ow in great veins. Flow murmur \200 Short systolic murmur. Mid-left sternal edge. 08_McClure_08.indd 228 11/14/2012 2:33:24 PM HEART MURMURS 229 Often heard during acute illness with fever, disappears when fever resolves. Musical murmur Systolic murmur. Lower left sternal edge. 08_McClure_08.indd 229 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 230 Murmurs: clinical features A likely diagnosis can be assessed using the clinical examinatio n and fea- tures from CXR and ECG. Tables 8.1 and 8.2 summarize likely diagnoses given the characteristics of the murmur and the \201 ndings from your initial investigations. Table 8.1 Likely diagnoses based on clinical features of murmur Location of murmur Diagnoses Features Continuous murmur PDA (b p.234) Left clavicular (machinery) in child; LSE in preterm infant Acyanotic; bounding pulse; Long systolic murmur VSD (b p.234) Lower LSE (pansystolic) parasternal thrill Acyanotic Apex Mitral regurgitation Acyanotic Rheumatic fever Mid-LSE Tetralogy of Fallot (b p.235) Cyanotic; single S2 Ejection systolic murmur Upper LSE ASD secundum (b p.233) AVSD partial (b p.233) Acyanotic; \201 xed split S2; Acyanotic; \201 xed split S2; + Apical pan- systolic murmur PS (b p.238) CoA (b p.238) Upper LSE +/- thrill Acyanotic Upper LSE Acyanotic; weak or absent femoral pulses (if neonate); hypertensive in right arm (if older) AS (b p.237) Upper RSE Acyanotic; carotid thrill; delayed soft S2; small volume & slow rising pulse Key: AS, aortic stenosis; ASD, atrial septal defect; AVSD, atrioventricular septal defect; CoA, coarctation of the aorta;; LSE left sternal edge; RSE right sternal edge, LV, left ven tricle; PDA, persistent ductus arteriosus; PS, pulmonary stenosis; PV, pulmonary valve; S1, \201 rst heart sound; S2, second heart sound; VSD, ventricular septal defect. 08_McClure_08.indd 230 11/14/2012 2:33:24 PM INVESTIGATION OF SUSPECTED HEART PROBLEM 231 Investigation of suspected heart problem using CXR and ECG Table 8.2 Likely diagnoses based on CXR and ECG \201 ndings CXR \201 ndings ECG \201 ndings Diagnosis Normal Normal Normal or small VSD (b p.234) VSD (b p.234) ASD secundum (b p.233) AVSD partial (b p.233) P DA (b p.234) Mild cardiomegaly + increased pulmonary markings RVH + LVH + RAD +RBBB + LAD + RBBB prolonged PR Normal or LVH HLHS (b p.239) HOCM (b p.240) AS (b p.237) ToF (b p.235) Cardiomegaly Normal LVH Enlarged LV LVH Small boot-shaped heart + oligaemic lung \201 elds RAD, RVH TGA (b p.238) Narrow mediastinum, heart \200\230egg on side \200\231, + increased pulmonary vascular mar kings Normal CoA (b p.238) PS (b p.238) Rib-notching RVH (neonate); LVH PA post-stenotic dilatation Normal or RVH Key: HLHS; hypoplastic left heart syndrome, LAD; left axis deviation, LV left ventricle; LV H, left ventricular hypertrophy; PA, pulmonary artery; RAD, right axis deviation; RBBB righ t bundle branch block; RVH, right ventricular hypertrophy; ToF, tetralogy of Fallot. For ke y to diagnoses see footnote to Table 8.1. 08_McClure_08.indd 231 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 232 Acyanotic: congenital heart disease De \201 nition Failure of normal cardiac development o r persistence of the fetal circulation after birth. Incidence \200 \200 \200 8/1000 live births. 10 \200\22315% complex lesions with >1 abnormality. 10 \200\22315% of C HD also have a non-cardiac abnormality. Causes This is unknown in the majority of cases, but commonly associated with following con ditions: \200 \200 \200 \200 Chromosomal defects: Gene defects: Congenital infections: Teratogenic drugs: e.g. Down, Turner syndromes. e.g. 22q deletion, Noonan syndrome e.g. rubella. e.g. phenytoin, warfarin, alcohol. Classi \201 cation CHD can be classi \201 ed into acyanotic or cyanotic types depending o n whether predominant presentation is with or without central cyanosis. The latter is cause d by deoxygenated blood gaining abnormal access to systemic side of the circulation via the left side of the heart or the aorta. Acyanotic CHD \200 \200 \200 \200 \200 \200 \200 \200 \200 VSD. ASD. PDA. Pulmonary valve stenosis. Coarctation of the aorta. Aortic stenosis. Hypopla stic left heart syndrome. Hypertrohpic obstructive cardiomyopathy. Dextrocardia. Cyanotic CHD \200 \200 \200 \200 Tetralogy of Fallot. Transposition of the great arteries. Tricuspid atresia. Total anomalou s pulmonary drainage. The diagnosis of a speci \201 c lesion is made after clinical examination; CXR, ECG, and e chocardiography (see b pp.226 \200\223231). 08_McClure_08.indd 232 11/14/2012 2:33:24 PM LEFT TO RIGHT SHUNT: ATRIAL SEPTAL DEFECT 233 Left to right shunt: atrial septal defect ASD may be subtyped as ostium secundum or partial atrioventricular sep- tal defect (ostium primum). Ostium secundum defect This defect is in the region of the foramen ovale. The atrioventricu lar (AV) valves are normal. The defect is usually isolated, found incidentally, and 3 times more common in girls. \200 Clinical features: result in heart failure. Prognosis: and complications usually only prese nt in 3rd decade or later. ASD closure is required and advised for all patients, even Treat ment: if asymptomatic. This is achieved usually by insertion of an occlusion device at card iac catheterization or by open heart surgery. Intervention should be performed in early chi ldhood, before school entry. most children are asymptomatic. ASDs may rarely ostium secundum defects are well tolerated and symptoms Partial atrioventricular septal defect This is the more serious ASD, affecting the endocard ial cushion tissue that gives rise to the mitral and tricuspid valves. It is located in the lower atrial septum and is associated with a three lea \202 et mitral valve. These abnor- malities result in a left to right shunt with valve incompetence. AVSD are often seen in D own syndrome. \200 Clinical features: Those with larger defects are predisposed to recurrent chest infections and to heart failure. Prognosis: depends on the degree of left to right shunt, pulmonary hy pertension, and severity of mitral regurgitation. Without surgical repair congestive cardia c failure may develop in infancy/early childhood. Management: indicated pre-school. most children with small defects are asymptomatic. de \201 nitive treatment with surgical closure of the defect is 08_McClure_08.indd 233 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 234 Ventricular septal defect VSDs account for 25% of all CHD (2/1000 live births). They may oc cur in isolation or as part of complex malformations. The clinical features depend on the s ize and location of the defect. Subtypes \200 \200 \200 \200 Large/small VSD. Perimembranous. Muscular. Multiple/small defects (maladie de Roger). Clinical features \200 \200 \200 \200 \200 Asymptomatic (typical/early). Heart failure (breathlessness \200\224after the \201 rst fe w days of life). Recurrent chest infections. Cyanosis (rare after 1st decade of life) \200 \224 Endocarditis (late). s to Eisenmenger syndrome. Examination Pansystolic murmur \200\224lower left sternal edge parasternal thrill. Prognosi s The majority of defects will close spontaneously. Management \200 Medical: \200 Surgery: is performed at 3mths of age, before the pulmona ry hypertension causes pulmonary vascular disease (Eisenmenger syndrome). treat heart failure if present. indicated if severe heart failure; pulmonary hypertension. This Persistent ductus arteriosus PDA is common and seen in 1 \200\2232/1000 live births. Someti mes it follows on from a preterm delivery. It is de \201 ned as a duct still being present 1mth after the date that the child should have been born. Clinical features PDA results in a low diastolic pressure, due to blood \202 owing back i nto the pulmonary artery. There may be heart failure (breathlessness). Examination \200 \200 A wide pulse pressure or bounding peripheral pulses. A continuous or machinery murmur in th e left infraclavicular area. Prognosis The majority of defects will close spontaneously. Management \200 \200 \200 Medical: Cardiac catheter: Surgical: diuretics. device closure usually at 1yr. ligation (rarely). 08_McClure_08.indd 234 11/14/2012 2:33:24 PM RIGHT TO LEFT SHUNT: TETRALOGY OF FALLOT 235 Right to left shunt: tetralogy of Fallot This, the most common cyanotic CHD, is characteriz ed by 4 cardinal ana- tomical cardiac anomalies: \200 \200 \200 Large VSD. Overriding aorta. Right ventricular out \202 ow obstruction (infundibular and v alvular pulmonary stenosis). Right ventricular hypertrophy. Systemic venous return to the right side of the heart is normal. In the pres- ence of pulmo nary stenosis, however, blood is shunted across the VSD into the aorta and arterial desatur ation and cyanosis result. The severity of cyanosis is dependent on the degree of right ven tricular out \202 ow obstruc- tion and, when this is moderate, a balanced shunt across the VSD occurs and cyanosis may be mild or absent. Clinical features Tetralogy of Fallot presents in early infancy with the following. \200 usually not present at birth and leading to clubbing. \200 Cyanosis: Paroxysmal hypercyanotic spells (infancy): onset; tachypnoea; restlessness; and i ncreasing cyanosis, then becoming white and \202 oppy. Potentially dangerous. Duration ra nges from a few minutes to hours; severe episodes result in syncope and occasionally convul sions/hemiparesis. spontaneous/unpredictable Treatment Severe tetralogy of Fallot with worsening cyanosis in early neonatal period requi res prostagladin E infusion; (see b p.58) and surgery (e.g. modi \201 ed Blalock \200\223T aussig shunt) in order to maintain pulmonary blood \202 ow and oxygenation. De \201 niti ve surgery to repair the underlying heart defects is carried out from 4mths of age onwards. Management of hypercyanotic spells See b p.63. Prognosis Untreated, the combination of right to left shunt, chronic cyanosis, and polycyth aemia predispose to: \200 \200 \200 \200 Cerebral thrombosis and ischaemia. Brain abscess. Bacterial endocarditis. Congestive cardia c failure. Patients are often asymptomatic after surgical corrections. Long-term follow-up (up to 30yr s) suggest that improved quality of life is maintained and most are able to lead unrestrict ed lives. Some will require pulmonary valve replacement in teenage years. Cardiac conductio n defects, including complete heart block, are seen post-operatively and require treatment. 08_McClure_08.indd 235 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 236 Transposition of the great arteries The normal \200\230 \201 gure of eight \200\231 syste mic/pulmonary blood \202 ow circuit is replaced by two separate parallel circuits, i.e. s ystemic venous blood pass- ing through the right side of heart returns directly to the syst emic circu- lation via a connecting aorta. Pulmonary venous blood returning to the left sid e of the heart is retuned directly to the pulmonary circulation via a connecting pulmonary artery. This condition is not compatible with life unless there is adequate mixing of the b lood from both circulations via an ASD or PDA. Clinical features Infants usually present in the \201 rst few hours or days with worsenin g duct- dependent cyanosis. Hypoxia is usually severe, but heart failure is not a feature. This is a medical emergency and early diagnosis and intervention are required to avoid seve re hypoxia. Treatment Once diagnosed care is needed to maintain body temperature as hypo- thermia will worsen the metabolic acidosis of hypoxaemia. Prompt cor- rection of acidosis and hypoglycae mia is essential. Before cardiac surgery, systemic arterial oxygenation can be improved wit h prostaglandin E infu- sion (see b p.58) and balloon atrial septostomy. De \201 nitive ar terial switch procedure is performed in the \201 rst 2wks of life. Common mixing: complete atrioventricular septal defect Complete AVSD is often found in conj unction with Down syndrome. There is a large defect often from the middle of the atrial sep tum down to the middle of the ventricular septum. In addition there is not a separate mitra l and tricuspid valve, but there is a common atrioventricular valve of 5 lea \202 ets guar ding the atrioventricular junction. Clinical features Most patients with Down syndrome are screened for congenital heart diseas e with an echocardiogram. An ECG will show a superior axis. Treatment \200 Medical \200 Surgery: causes pulmonary vascular disease (Eisenmenger syn drome). : treat heart failure if present. is performed at 3mths of age, before pulmonary hypertensi on 08_McClure_08.indd 236 11/14/2012 2:33:25 PM TRICUSPID ATRESIA 237 Tricuspid atresia In tricuspid atresia (TA) there is no connection between the right atrium and the right ventricle. Venous blood is diverted to left side via a patent foramen ovale. Pulmonary blood \202 ow is dependent on associated VSD or PDA. Clinical features Most patients with TA present in the \201 rst few days to early months of life with increasing cyanosis. The clinical features will vary depending on other associ ated cardiac abnormalities. The ECG shows a superior axis. Treatment In an emergency, duct patency is achieved with prostaglandin E infusion (see b p. 58). Surgical palliation and procedures include: \200 \200 \200 \200 Blalock \200\223Taussig shunt (neonatal period). Pulmonary artery banding (neonatal period) . Glenn shunt (6mths of age). Fontan procedure (pre-school). Aortic stenosis Congenital aortic stenosis accounts for about 5% of all causes of CHD and i s the commonest cause of left ventricular out \202 ow obstruction. It is due to thickening of the aortic valves, although subvalvular (subaortic) stenosis is also an important form of obstruction. Congenital aortic stenosis is more common in boys (3:1). A supravalvular fo rm of aortic stenosis is also rec- ognized, which may be sporadic or familial. Supravalvula r aortic stenosis is also associated with Williams syndrome (b pp.373, 941). Clinical features Are dependent on the severity of obstruction and age at presentation. Mil d stenosis is usually asymptomatic and found on routine examination. Severe defects in the neonate may present with heart failure and collapse. In the older child sudden unexpected s yncope and chest pain on exertion may occur. Management Surgical or balloon dilatation is i ndicated if symptomatic, or if a high rest- ing pressure gradient of >64mmHg is present; av oidance of competitive sports recommended if severe. Prognosis Good in the majority with mild or moderate stenosis. In severe stenosis sudden de ath may occur. Eventually, aortic valve replacement will be re- quired. 08_McClure_08.indd 237 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 238 Pulmonary stenosis This is a common form of CHD due to the following: \200 \200 \200 Pulmonary valve stenosis is seen in Noonan syndrome (b p.941). Isolated thickened deformed pulmonary valves (usually). Isolated infundibular stenosis; sup ravalvular pulmonary stenosis. Branch pulmonary artery stenosis. Clinical features \200 \200 \200 Asymptomatic (mild to moderate stenosis). Poor exercise tolerance (severe stenosis). Right ventricular failure/cyanosis (critical stenosis). Prognosis Mild to moderate stenosis is compatible with normal activities, but patients requ ire monitoring because worsening obstruction and signi \201 cant pressure gradients may de velop, which will predispose to heart failure when very severe. Treatment Severe pulmonary valve stenosis requires treating by trans- venous catheter balloon dilatation. Coarctation of the aorta Constrictions of the aorta (CoA) may occur at any point. In the ma jority (98%) of cases, it is usually distal to the origin of the left subclavian artery at the level of the ductus arteriosus. Most often, this occurs in the neonatal period and the infants present at 48hr old when the duct closes. In older children, the BP is elevated in blood vessels proximal to the obstru ction and an extensive collateral circulation develops. CoA is seen more often in boys than girls (2:1), although it is common in Turner syndrome (b p.948). In \231\200, 0% an abnor - mal bicuspid aortic valve is present. Clinical features In severe defects a PDA is required to maintain the systemic circulation; heart failure and collapse may occur in the neonatal period. CoA results in a disparity in pulse volume with weak or absent femoral pulses. Mild defects may present later with hyper tension (right arm). Prognosis Outside the neonatal period, mortality from untreated hypertension is high and us ually occurs when aged 20 \200\22340yrs. Complications include pre- mature coronary artery disease, congestive cardiac failure, hypertensive encephalopathy, and intracranial hemorrha ge. Treatment Neonates require resuscitation and early surgery. Older children or adolescen ts require stent insertion at cardiac catheter or sur- gical resection. 08_McClure_08.indd 238 11/14/2012 2:33:25 PM HYPOPLASTIC LEFT HEART SYNDROME 239 Hypoplastic left heart syndrome This term is used to describe a group of disorders associat ed with under- development of the left side heart structures. The left ventricle is small a nd non-functional and the right ventricle maintains both pulmonary and systemic circulation s. The latter is achieved by pulmonary venous blood passing through an ASD or patent forame n ovale, or via retrograde \202 ow through a PDA. Clinical features Hypoplastic left heart syndrome (HLHS) presents with early onset (days) o f cyanosis and heart failure leading to collapse and death within the \201 rst few days o f life. Most infants will appear sick (grayish-blue color) with poor peripheral perfusion a nd weak peripheral pulses. Central cyanosis and evidence of heart failure will be present. Treatment Medical management aimed at maintaining patency of the ductus is nec- essary to s upport systemic blood \202 ow. Surgery is either palliative (2 \200\2233 stages, Norwood operation or Hybrid procedure) or de \201 nitive (heart transplantation). Total anomalous pulmonary venous connection All blood returning to the heart (systemic and pulmonary) returns to the right atrium, and an obligatory patent foramen ovale or ASD is ne cessary for survival. The pulmonary veins form a single channel and join the sys- temic ven ous circulation through either a supracardiac superior vena cava (SVC), intra- or infracard iac IVC connection. Clinical features Infants usually present in the \201 rst few days of life with varying d egrees of obstruction, cyanosis, and congestive cardiac failure. Presentation will depend o n the degree of obstruction to the pulmonary venous return. Treatment This is often a surgical emergency and anastomosis of the common pulmo- nary chan nel to the left atrium, with closure of ASD, and interruption of connections to the systemi c venous circuit are required. 08_McClure_08.indd 239 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 240 Hypertrophic obstructive cardiomyopathy This condition is characterized by massive ventricu lar hypertrophy princi- pally involving the septum. All portions of the left ventricle are affected, although the right ventricle may also be involved. There is myocardial \201 bro sis resulting in a stiff muscle with decreased distensibility. Ventricular \201 lling is decreased, but systolic pumping is maintained until late in the course of disease. Hypertro phic obstructive cardiomyopathy (HOCM) has been recognized in all age groups and may occur in members of the same family. A dominant pattern of inheritance sometimes is observed. Clinical features Most children with HOCM are asymptomatic and are only detected fol- lowin g routine clinical examination and the discovery of an incidental heart murmur. Symptoms wh en present include fatigue and dyspnoea and chest pain and syncope on exertion. HOCM is an important cause of sudden unexpected death. Prognosis Unpredictable, especially in those wi thout symptoms. Treatment Avoidance of competitive sports and strenuous activity is encouraged. Therapy is aimed at reducing the out \202 ow obstruction: \200 \200 Medical Surgical therapy: beta blocking agents; calcium antagonists, pacemaker. therapy: ventricular septal myotomy, transplantation. Dextrocardia Abnormal position of the heart, with location of left atrium on right side and vise versa (i.e. situs inversus), is classi \201 ed according to the position of the left atrium, the main bronchi, and the abdominal organs. Inversion of viscera (abdominal situs inversus) is always associated with atrial inver- sion. Major malformations of heart struct ures are usually found in either of the following: \200 \200 Dextrocardia + normal position of abdominal organs. Normal position of heart (laevocardia) + abdominal situs inversus. Characteristic heart malformations include \200\224pulmonary stenosis; tricuspid atresia; t ransposition of the great arteries; anomalous pulmonary venous drainage; atrioventricular s eptal defects; single ventricle. No malformations of the heart structures are found when dextrocardia and abdominal situs in versus (i.e. mirror-image dextrocardia) are present in combination. 08_McClure_08.indd 240 11/14/2012 2:33:25 PM DEXTROCARDIA 241 08_McClure_08.indd 241 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 242 Infection: infective bacterial endocarditis There are both acute and subacute forms of infe ction of the endocardium. Children at risk are those with turbulent blood \202 ow through the heart or where prosthetic material has been inserted following surgery: e.g. \200 \200 \200 PDA or VSD; coarctation of aorta; previous rheumatic fever. The most common pathogens associated with infective bacterial endo- carditis are: \200 \200 \200 Streptococcus Staphylococcus Group D streptococcus viridans (50% cases): often after dental procedures. aureus: often related to central venou s catheters. (enterococcus): often after lower GI surgery. An organism is not found in up to 10% of cases. Clinical features \200 \200 In the early stage symptoms are mild. Prolonged fever persisting over several months may be the only feature. Alternatively, rapid onset of high intermittent fever can occur. Non-spe ci \201 c symptoms include: \200 \200 \200 myalgia and arthalgia; headache, weight loss, night sweats. Examination This may be variable, but classic signs include: \200 \200 \200 \200 \200 \200 \200 \200 \200 \200 pallor/anemia; nail bed \200\224splinter hemorrhages; tender nodules \200\224 \201 ngers/t oes (Osler \200\231s nodes); erythematous palms/soles of feet (Janeway lesions); \201 nge r clubbing (late); necrotic skin lesions; splenomegaly; haematuria (microscopic) retinal in farcts (Roth \200\231s spots); heart murmurs (change in character with time). Diagnosis A high index of suspicion is required. Blood tests include FBC (raised WCC), ESR (raised), CRP (raised) and repeated blood cultures. Echocardiography is needed to look for valve \200\230vegetations \200\231. Prophylaxis This is no longer routinely advised. 08_McClure_08.indd 242 11/14/2012 2:33:25 PM INFECTION: INFECTIVE BACTERIAL ENDOCARDITIS 243 Treatment \200 Antibiotic therapy: result in progressive endocardial damage and deterioration in cardiac f unction. High dose IV antibiotics (e.g. penicillin/vancomycin) are required for a minimum o f 6wks. Bed rest is recommended and heart failure should be treated. Surgery will be necess ary for removal of infected prosthetic material. should be started as soon as possible. Delays may \200 Prognosis Even with antibiotic treatment mortality may be as high as 20% and com- plication s (50 \200\22360%) include heart failure. Systemic emboli from left-sided vegetations may r esult in brain abscess and stroke. 08_McClure_08.indd 243 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 244 Rheumatic fever This is an important cause of heart disease worldwide, but rarely seen in d eveloped countries. Acute rheumatic fever (ARF) develops in response to infection with grou p A B-haemolytic streptococcus. It is seen in child- ren aged 5 \200\22315yrs and incidence is highest in those from socially and eco- nomically disadvantaged areas. Clinical features \200 There is a latent period of 2 \200\2236wks between onset of symptoms and previous streptoco ccal infection (e.g. pharyngitis). Symptoms are non-speci \201 c. The grouping together of clinical features makes the diagnosis more likely (Jones criteria). These are categorized into major or minor (see Box 8.1). \200 Box 8.1 Jones criteria Major features \200 \200 Pancarditis (50%): endocarditis/myocarditis/pericarditis Polyarthritis (80%): \200 \202 itting \200 migratory \200 joints \200\223knees/ankles/wrists Erythema marginatum (<5% ): \200 early/trunk and limbs \200 pink border/fading center Subcutaneous nodules (rare ): Sydenham \200\231s chorea (10%) (see \200 \200 Emotional lability \200\224<1wk \200\224to other joints over 1 \200\2232mths \200 pea size/hard/extensor surfaces b p.524): \200\2242 \200\2236mths post-infection late feature involuntary movements \200\224choreoathetoid Minor features \200 \200 \200 \200 \200 \200 Fever Arthralgia Abnormal ECG: Elevated ESR/CRP Evidence of streptococcal infection: Histor y of previous rheumatic fever prolonged P \200\223R interval e.g. raised ASO titres Diagnosis of ARF \200 \200 \200 Two major features; One major + two minor features; Evidence of previous group A streptococ cal infection. or and 08_McClure_08.indd 244 11/14/2012 2:33:25 PM RHEUMATIC FEVER 245 Management \200 In the acute phase treatment will include: \200 \200 \200 \200 \200 Long-term the rapy is aimed at rheumatic fever and the development of chronic rheumatic heart disease. An tibiotic prophylaxis (daily oral penicillin, or monthly IM penicillin G) is recommended. bed rest; anti-in \202 ammatory drugs (e.g. aspirin); corticosteroids (2 \200\2233wks); di uretics/ACE inhibitors if in heart failure; antibiotics (e.g. penicillin V for 10 days). s prevention of further attacks of acute Chronic rheumatic heart disease Recurrent bouts of ARF with associated carditis result in s carring and \201 brosis of the heart valves (most commonly mitral valve) and may result i n incompetent valves requiring replacement. 08_McClure_08.indd 245 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 246 Pericarditis In \202 ammation of the pericardium may be p or a manifestation of more gener alized illness. The principal causes of pericardial in \202 ammation are: \200 Infections: \200 \200 \200 \200 \200 Connective tissue: \200 \200 \200 \200 Metabolic: \200 \200 Malignancy Radiotherapy viral, e.g. coxsackie B, Epstein \200\223Barr virus (EBV); bacterial, e.g. streptocococcus, mycoplasma; tuberculosis; fungal, e.g. histoplasmosis; parasitic, e.g. toxoplasmosis. rheumatoid arthritis; rheumatic fever; systemic lupus erythematosus (SLE); sarcoidoisis. hyperuricaemia; hypothyroidism. \200 Clinical features The features depend on the extent of involvement of the pericardium. The predominant symptom is precordial pain that is typically sharp, exac- erbated and exaggerat ed by lying down, and relieved by sitting or leaning forward. The pain is often referred to the left shoulder. Other symptoms include cough, dyspnoea, and fever. The accumulation of suf \201 cient \202 uid to cause cardiac tamponade and heart failure is rare. Examination Speci \201 c diagnostic \201 ndings will relate to the amount of \202 uid within the pericardial sac, including pulsus paradoxus, pericardial rub, quiet/distant hear t sounds. Investigations Investigations directed at con \201 rming the diagnosis include: \200 \200 echocardiogram; ECG (typical low voltage QRS complexes). Other investigations should be directed at identifying the underlying cause of the pericard itis and will include: pericardiocentesis, bacterial/viral cul- ture and biochemical analys is; blood serology for viral studies, ASOT, and connective tissue disease. 08_McClure_08.indd 246 11/14/2012 2:33:25 PM PERICARDITIS 247 Management Treatment is directed both at the underlying cause, e.g. antibiotics, and sympto ms, e.g. the following: \200 Analgesia for pain relief. \200 Anti-in \202 ammatory dru gs to reduce pericardial in \202 ammation. \200 Pericardiocentesis for pericardial effus ion causing cardiac tamponade and heart failure. Constrictive pericarditis Previous pericardial in \202 ammation may predispose to this con dition. However, most cases of constrictive pericarditis occur in the absence of any preced ing illness or generalized systemic disease. The \201 brosed restric- tive pericardium im pairs cardiac contractility. Clinical features Include evidence of heart failure, hepatomegaly, and neck vein distention . On auscultation, heart sounds are distant and a characteristic pericardial \200\230knock \200\231 is often heard. CXR may reveal calci \201 cation of the pericardium. Treatment Requires pericardiectomy. 08_McClure_08.indd 247 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 248 Myocarditis Myocarditis may be due to: \200 \200 \200 \200 Infections: Kawasaki disease (see Drugs: adriamycin. Connective tissue disease: b p.774); r heumatic fever (see b p.244); sarcoidosis. viral, e.g. coxsackie B, EBV. b p.716). SLE (see b p.780); rheumatoid arthritis (see Clinical features Variable and will depend on the age of the patient and on the time course of underlying disease. Speci \201 c cardiovascular symptoms include progres- sive worseni ng of dyspnoea and congestive cardiac failure. Sudden onset of ventricular arrhythmia may o ccur. Examination Typical cardiovascular examination includes: \200 \200 \200 \200 weak pulses; tachycardia; gallop heart rhythm; distant heart sounds. Diagnosis Echocardiography shows poor ventricular function. De \201 nitive histological di agnosis is made after percutaneous endomyocardial biopsy. CXR shows cardiomegaly; ECG shows reduced QRS complex size. Treatment This is directed at the underlying cause and at controlling symptoms of congestiv e heart failure. Arrhythmias should be treated. Cardiac transplan- tation is needed in pati ents with refractory heart failure. 08_McClure_08.indd 248 11/14/2012 2:33:25 PM CARDIOMYOPATHY 249 Cardiomyopathy Cardiomyopathy may be primary, or secondary to systemic or metabolic disease (see b p.962). Primary cardiomyopathy may be classi \201 ed as: \200 \200 \200 b p.240); hypertrophic (obstructive; see dilated (congestive); restrictive (see b p.249). Dilated (congestive) cardiomyopathy This condition is rare and characterized by massive dil atation of the ven- tricles and cardiomegaly. The cause is unknown in most cases, although it is seen in association with other conditions: \200 \200 post-viral infection phenomenon; metabolic (e.g. mitochondrial disease, b p.971). Clinical features \200 \200 Insidious onset of progressive congestive cardiac failure is common. The course is usually progressive and the prognosis poor. Management Mainly directed at treating heart failure and, where possible, any underly- ing cause. Heart transplantation if severe heart failure. Restrictive cardiomyopathy This condition is rare and characterized by poor ventricular com pliance and inadequate ventricular \201 lling. The clinical features are similar to con- strictive pericarditis (b p.247). It is sometimes seen in the L f \202 er hypere- osinoph ilic syndrome (multisystem disorder of skin, lungs, nervous system, and liver) and results in endocardial \201 brosis of the AV valves and the ventricles. Prognosis is poor and car diac transplantation often required. 08_McClure_08.indd 249 11/14/2012 2:33:25 PM CHAPTER 8 Cardiovascular 250 Cardiac arrhythmias See b pp.42 \200\22343, 55 \200\22357. Sinus arrhythmia is normal in ch ildren and ado- lescents. Other arrhythmias are rare in childhood and may be transient or p ermanent. Congenital arrhythmias may occur in structurally normal or abnormal hearts. They may be secondary to myocardial disease (e.g. rheu- matic fever, myocarditis) or follow expo sure to toxins, drugs or surgery to the heart. Children with suspected arrhythmia require a detailed history and examination. The arrhythmia should be identi \201 ed and characteriz ed by ECG. Intermittent arrhythmias may be detected by 24hr ECG. Underlying congenital hear t disease should be excluded by echocardiography. Supraventricular tachycardia The most common abnormal arrhythmia in childhood. Re-entry wit hin the A \200\223V node is the most common mechanism of SVT. Clinical features Sudden onset (and cessation) lasting from seconds to hours; heart rate 25 0 \200\223300beats/min. SVT is well-tolerated in older children, but heart failure may occu r in the young infant. Often precipitated by febrile illness. Wolff \200\223Parkinson \200\223White syndrome Pre-excitation syndrome predisposing to SVT. This is due to an abnormal re-entry circuit of the AV node and an accessory conduction pat hway con- necting atrium to ventricle on the right or left lateral cardiac border, or withi n the ventricular septum. It may be associated with Ebstein anomaly, post-surgical repair, and cardiomyopathy. ECG shows short PR interval and delta wave (slow upstroke of QRS comple x). Treatment \200 Medical: amiodarone. Interventional: when a teenager. adenosine (emergency) -blocking medication, \202 ecainide, electrophysiological studies and intracardiac ablation Ventricular tachycardia Long QT syndrome may be associated with sudden loss of conscious- n ess during exercise, stress or emotion, usually in late childhood. If un- recognized, sudde n death from VT may occur. Inheritance is autosomal dominant; there are several phenotypes. Prolongation of the QT interval on ECG is associated with many drugs, electrolyte disorder s, and head injury.