Definition of Congenital Heart Disease:
A cardiac disease or condition that has been present since birth.
Causes
In the majority of cases the cause of a congenital heart condition is unknown. However, there are certain factors which are associated with an increased risk:
- 17% are associated with other syndromes (Downs Syndrome, DiGeorge and Williams)
- Certain medications, alcohol or drug abuse
- Maternal viral infections in the first trimester (such as Rubella)
- Type 1 and 2 diabetes
Different presentations
Most lesions are detected when the baby is under one years old (60%) and some conditions can be detected before the baby is born, on the mothers 18-20 week foetal scan. However, 10% are not detected until later on in adulthood.
For those adults who are unaware that they have congenital heart disease (CHD), they may present with arrhythmias: syncope or palpitations: chest pain: increasing shortness of breath: heart failure: and/ or hypertension. Some patients present for the first time during pregnancy or their condition is an incidental finding when the patient is having investigations for other reasons.
Prevalence
Historically, babies born with CHD had very poor chances of surviving into adulthood. However, with advances in medical management and paediatric surgery, and with improvements in imaging techniques, such as echocardiograms and MRI, there are now more adults than children with CHD and 96% of babies diagnosed are surviving into adulthood.
Approx 1% of the population, or 1 in every 145 births, will have CHD. Some conditions are more prevalent than others, for example, atrial and ventricular septal defects (ASDs and VSDs) being the most common.
It is estimated that there are approximately 150,000 adults in the UK living with CHD.
Investigations
There are a number of investigations that are used when diagnosing, assessing and managing the treatment of a patient with CHD.
| ECG | Should be routinely carried out at every hospital clinic appointment. 24 hr holter monitors should be used when patients report symptoms of palpitations or there is any suspicion that the patient may have an arrhythmia. |
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| Transthoracic echocardiogram | This is the first-line investigation for congenital patients. Ideally, a sonographer should be trained to scan CHD patients. |
| Transoesophageal echo (TOE) | Used during invasive procedures, prior to direct current cardioversion (DCCV) and also in cases where there is a suspicion of infective endocarditis (IE). |
| Cardiopulmonary exercise test (CPET) | Is a tool used to assess base line exercise tolerance and/or detect changes or a deterioration in a patient. It is used to aid decisions around the indication for, and timing of, intervention or surgery. It can also be used a way of measuring the impact an intervention has had on a patient. |
| Cardiac magnetic resonance imaging (cMRI) | Is an increasingly important tool for diagnosis and assessment of CHD patients. It is not suitable, however, for patients who have non MRI compatible pacemakers or ICD’s |
| Computed tomography (CT scans) | Can be used as an alternative for those patients who cannot undergo MRI scans. It is also used as the imaging modality of choice in situations such as assessing patient’s coronary arteries. The high doses of radiation that patients are exposed to will limit the number of scans they are be subjected to. |
| Right heart catheterisation (RHC) | These are carried out in a cath lab and are given to certain patients as part of their assessment. The main purpose of this procedure is to measure the pressures in the four different chambers of the heart, the pulmonary artery and also to assess any shunts that are present across an atrial-septal defect (ASD) or ventricular-septal defect (VSD). The data obtained can assist with planning future medical and/or surgical treatments. |
| Coronary angiogram | This may be undertaken prior to surgery for men over 40 years, post menopausal women and patients with risk factors of coronary artery disease (CAD). |
