be hypertensive when attending her GP for abdominal pains. Please examine her cardiovascular system.
Begin with a summary of
positive findings
Relevant peripheral signs to seek to identify include:
•
Simultaneous palpation of radial and femoral pulses reveals the characteristic radio-femoral delay. Indeed, delayed and diminished pulses distal to the coarctation with differential limb blood pressures are the characteristic features of this condition. Auscultatory features are supportive•
Upper body systolic hypertension and lower body systolic hypotension with a difference of greater than 20 mmHg in favour of the upper limb is significant. Also check blood pressure in both arms as the left subclavian artery can be either part of the coarctation itself, or used in repair of the defect.•
Visible, palpable large collateral arteries develop over the left scapula, left chest wall and anterior abdominal wall•
A thrill over the suprasternal notch may be palpated•
A heaving (pressure-loaded), undisplaced apex beat indicates left ventricular hypertrophy•
An underdeveloped left arm may represent a coarctation at the level of the left subclavian artery. There may also be underdevelopment of the lower limbs.•
Auscultatory features of aortic coarctation include:•
A systolic murmur, typically heard posteriorly in the left infrascapular region but can also be auscultated in the left infraclavicular region•
The continuous murmurs of collateral vessels can be heard bilaterally across the thorax•
An ejection click (with or without concomitant ejection systolic and early diastolic murmurs) of an associated bicuspid aortic valveFollow with a summary of
relevant negative findings
It would be prudent to mention the absence of clinical features consistent with Turner’s syndrome, as at least 35% of these patients also have aortic coarctation.Case 16: Coarctation of the aorta
•
Choose the most appropriatepharmacological strategy for either rate control, or rhythm control if the onset is within 48 hours
•
Treat underlying cause, most commonly infection in the acute settingFollowing the acute management of the patient, go on to investigate underlying causes and decide upon long-term anticoagulation and rate/rhythm control strategies.
Further reading
Fuster V, Rydén LE, Cannom DS, et al. 2011 ACCF/ AHA/HRS focused updates incorporated into
the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines developed in partnership with the European Society of Cardiology and in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. J Am Coll Cardiol 2011; 57:e101–198.
Camm AJ, Kirchhof P, Lip GY, et al. Guidelines for the management of atrial fibrillation: the task force for the management of atrial fibrillation of the European Society of Cardiology (ESC). Eur Heart J 2010; 31:2369–2429.
Case 16 Coarctation of the aorta
39
State the most likely diagnosis
on the basis of these findings
‘This patient has signs consistent with a coarctation of the aorta associated with a bicuspid aortic valve and evidence of aortic regurgitation. I would like to take a full history to establish her symptomatic status and my investigations of choice would be an echocardiogram and a CT or MRI of the aorta in the first instance to confirm the diagnosis and to look for associated pathology.’Offer relevant differential
diagnoses
In addition to offering the differential diagnosis of a systolic murmur (see Aortic stenosis, p. 2) it is important to consider associated valvar conditions:
•
Bicuspid aortic valve: up to 85% of patients with aortic coarctation also have a bicuspid aortic valve with or without associated stenosis or regurgitation•
Other cardiac defects include VSD, patent ductus arteriosus, aortic stenosis and mitral stenosis due to parachute mitral valve, and other left ventricular outflow tract obstructive lesions (which can be part of the Shone complex of left-sided obstructive lesions) Note from the relevant negatives that Turner syndrome is a genetic condition associated with aortic coarctation so this should be mentioned with regard possible aetiologies.Demonstrate the importance
of clinical context – suggest
relevant questions that would be
taken in a patient history
Many adult patients are asymptomatic, being diagnosed following the finding of hypertension. Those patients who are symptomatic patients may complain of:
•
Headache•
Nosebleeds•
Dyspnoea•
Leg claudication•
Abdominal angina•
Cold feetOther disease associations include: ascending aorta aneurysms (complicated by rupture or dissection), berry aneurysms of the circle of Willis (complicated by intracranial haemorrhage)
and premature coronary and cerebral artery disease.
Demonstrate an understanding of
the value of further investigation
Relevant investigations in the diagnostic work- up of cases of aortic coarctation include:•
A 12-lead electrocardiogram demonstrating left ventricular hypertrophy with or without an accompanying strain pattern•
A plain chest radiograph may demonstrate:–
Rib notching on the inferior borders of the posterior ribs, which represents the development of collaterals arising from intercostal arteries–
The coarctation can appear as an indentation in the proximal descending thoracic aorta, giving rise to the so-called ‘figure of 3’ sign•
Echocardiography is important in confirming the diagnosis of coarctation with measurement of the pressure gradient across the lesion which can be made by 2D echo, colour Doppler and continuous- wave Doppler. Aortic dimensions and left ventricular function and wall thickness are also assessed and associated cardiac lesions are ruled out•
Cardiac catheterisation can also be used to measure the pressure gradient across the coarctation.•
CT and MRI are appropriate imaging modalities. The narrowing of the aorta occurs most commonly just distal to the left subclavian artery. These imaging modalities allow visualisation and measurement of the aorta in its entirety, as well as demonstration of collateral vesselsAlways offer a management
plan
Patients with aortic coarctation should be considered for referral to a specialist adult congenital heart disease (ACHD) centre for life-long follow-up.
Hypertension persists despite coarctation repair and may be due to baroreceptor dysfunction. There is also loss of aortic compliance. This requires lifelong monitoring. Regular ambulatory BP monitoring and stress testing for exercise hypertension (SBP >220 mmHg), should be performed. Intervention for lone coarctation may be performed by stenting (method of choice) or surgically.