Congenital heart disease

Congenital heart disease




Introduction


Congenital heart disease (CHD) is one of the commonest congenital defects, occurring in approximately 0.6–0.8% of newborns. i.e. there are about 5000 newborns with CHD each year in the UK. Advances in therapy have led to a dramatic improvement in outcome, such that over 85% of infants, even with complex CHD, are expected to reach adolescence and early adulthood. As a result of the success of paediatric cardiology and surgery, there are now more adults than children with CHD. In addition, there are patients with structural or valvular CHD who may present late during adulthood. It is estimated that there are approximately 1600 new patients per annum with moderate to complex CHD, of whom 800 might benefit from specialist follow-up in the UK. Most of these patients have had palliative or reparative rather than corrective surgery, and further cardiac operations will be necessary for many.


Role of specialist CHD centres





Initial assessment of adults with known or suspected CHD

Surgical and non-surgical interventions, e.g. transcatheter closure of atrial septal defect (ASD)/percutaneous valve implantation

Continuing care of patients with moderate and complex CHD

Advice and ongoing support for non-cardiac surgery and pregnancy

Training new specialists and providing evidence-based clinical decision making

Providing feedback of late results to refine early treatment

Transition from paediatric to adult care


A smooth transition from the paediatric to the adult CHD specialist is essential. This should be tailored to the individual patient, with inbuilt flexibility. Ideally, a speicialist transition clinic should be set up, with input from both the adult and paediatric services. Transfer to the adult unit should occur at around 18 years of age. Patient education about the diagnosis and specific health behaviour, including contraception/pregnancy planning, should be included. Patient passports that include detailed diagrams of the individual cardiac defect and relevant information on topics such as exercise and need for antibiotic prophylaxis should be prepared for each patient.




No patient with CHD should reach adulthood without a clear management plan.





Treat adult CHD with respect. Many problems or errors arise from arrogance or ignorance. The patients may often know more about their condition and its management than the ‘emergency’ medical team they consult; therefore be patient and listen. Patients are often accompanied by a parent/s even well into late teens/second or third decade. They can prove a great source of information and help; keep them on your side. Increasingly in the UK, adult congenital heart physicians are available for advice, either via email or by telephone. None will refuse a call for help. Get to know your local specialist centre!






Congenital heart disease in adults































Acyanotic lesions Cyanotic lesions
• Atrial septal defect p. 610 • Transposition of the great arteries p. 612
• Ventricular septal defect p. 278 • Tetralogy of Fallot p. 612
• Atrioventricular septal defect p. 610 • Fontan patients p. 613
• Pulmonary stenosis p. 610 • Congenitally corrected transposition of the great arteries p. 613
• Left ventricular outfl ow tract (LVOT) obstruction p. 611 • Severe Ebstein’s anomaly of the tricuspid valve p. 613
• Coarctation of the aorta p. 611
• Anomalous pulmonary venous drainage p. 611
• Ebstein’s anomaly of the tricuspid valve p. 613




Assessment of patients with CHD (1)


History





Family history of CHD

Exposure to teratogens/toxins during pregnancy

CHD suspected during pregnancy or at birth (ask the mother!!)

History of prolonged childhood illnesses

Prior interventions:

any previous hospitalizations for catheter- or surgical-based interventions

names of previous paediatric cardiologists and surgeons as well as the unit in which surgery, if any, was performed

Dental hygiene

Smoking/drug and alcohol intake

Current symptoms





Shortness of breath on exertion?

Ability to climb stairs, hills, walk on the flat, and distance covered?

Breathless on lying down?

Chest pain?

Precipitating/relieving factors?

Any associated symptoms?

Syncopal episodes?

Palpitations?

Onset, duration

Associated pre-syncope/chest pain?

Ask patient to tap out rate and rhythm of palpitations

Assess ability index

General inspection





Chart the patient’s height, weight, and blood pressure (always in the arm opposite thoracotomy scar!) and oxygen saturations

Does the patient have an obvious syndrome?

Down’s syndrome (1/3 associated with CHD, especially atrioventricular septal defect)?

William’s syndrome (supravalvar aortic and pulmonary stenosis)?

Noonan’s syndrome (dysplastic pulmonary valvular stenosis, hypertrophic cardiomyopathy)?

Turner’s syndrome (coarctation of the aorta/aortic valve stenosis)?

Is the patient anaemic or jaundiced?

Are there any features to suggest infective endocarditis?

Is there evidence of poor oral hygiene with dental caries or infected gums?

Any tattoos or body piercing?




Systematic approach to auscultation of a CHD patient


1. Listen to the heart sounds


First heart sound





The first heart sound is usually heard as a single sound but since mitral closure is loudest, it is best heard at the apex

A loud first heart sound may be heard in mitral stenosis or sometimes with an ASD

Soft first heart sounds are a feature of poor myocardial contractility or a long PR interval

Second heart sound





Fixed splitting in the presence of a significant ASD, and is best appreciated in the high or mid left sternal border

Accentuated in the presence of pulmonary hypertension

Widely split following repair of tetralogy of Fallot, the second heart sound is reflecting the right bundle branch block (RBBB), characteristic of the post-operative electrocardiogram (ECG)

2. Check for systolic/diastolic murmurs.


(Draw an imaginary line between the nipples)


Murmurs that are loudest above the nipple line





Ejection systolic in type

Arise from the right or left ventricular outflow tract (LVOT)

If associated with a carotid or suprasternal thrill, usually from the left ventricular outflow tract.

If an ejection click is heard, the murmur is valvar in origin.

Ejection click of aortic valve stenosis is best heard at the apex.

Ejection systolic murmur, best heard in the interscapular region and associated with a left thoracotomy, may indicate turbulence across a prior coarctation repair

Murmurs that are loudest below the nipple line





Pansystolic and arise from mitral/tricuspid regurgitation or from a ventricular septal defect (VSD)

A ‘to and fro’ murmur best heard at the upper left sternal edge following cardiac surgery usually results from combined right ventricular outflow tract (RVOT) obstruction and pulmonary regurgitation

The mid-systolic click and systolic murmur of mitral valve prolapse is best heard with the patient standing up

A continuous murmur arises from an arterial duct, systemic to pulmonary shunt, or arteriovenous fistulas

Measure height, weight, blood pressure, and oxygen saturation in all patients. 12-lead ECG is essential at every visit.




Assessment of patients with CHD (2)


Electrocardiogram





Rate and rhythm: consider atrial flutter with variable block if there is a constant rate of 100 or 150/minute—easily confused with ‘sinus rhythm’. Atrial tachycardias are especially common after all forms of atrial surgery e.g. intra-atrial repair for transposition of the great arteries.

Look for signs of chamber enlargement—atrial or ventricular hypertrophy.

Assess the presence/absence of bundle branch block.

Measure the duration of QRS in all post-operative tetralogy of Fallot patients: QRS duration >180 ms is associated with higher risk of arrhythmias, right heart dilatation, and late sudden death.

If tachycardia is suspected, record 12-lead ECG during administration of IV adenosine.

Role of exercise testing





Assess heart rate and blood pressure (BP) response to exercise (blunted response in important aortic valve stenosis).

Compare upper and lower limb BP following coarctation repair.

Monitor oxygen saturation by pulse oximetry to improve risk stratification in cyanosed patients.

Also, improves counselling and planning for pregnancy (most frequently used to assess potential impact of pregnancy).

Formal cardiopulmonary exercise testing is reserved for decision making and retiming of surgical or catheter-based intervention.

Can help to distinguish limitation due to lack of aerobic fitness, and assess maximal effort.

Chest X-ray





Chest X-ray (CXR) is a cheap and invaluable investigation in CHD.

Identify right–left orientation to assess cardiac and visceral positions.

Assessment of the bronchial branching permits diagnosis of isomeric cardiac defects, e.g. symmetric morphologic right bronchi characteristic of right atrial isomerism (usually associated with complex CHD—common right atria, a common atrioventricular (AV) orifice, a great artery arising from one ventricular chamber and total anomalous pulmonary venous connection).

Identify situs inversus (mirror image anatomy with liver on the left and stomach bubble on the right with cardiac apex in right chest). Consider Kartagener syndrome. Discordance between the position of the apex and visceral situs is usually associated with CHD.

Record the cardiothoracic ratio in the notes. Look for rib notching related to collateral blood supply in severe coarctation of the aorta. Assess pulmonary vasculature (see box on next page).


Mar 4, 2017 | Posted by in CARDIOLOGY | Comments Off on Congenital heart disease

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