You are called by the acute medicine registrar who wants advice on what to do with a normally fit and well patient admitted with aortic pain which appeared to be characteristic—sudden-onset sharp right paravertebral pain. The ECG demonstrated sinus rhythm with voltage criteria for LVH. The CXR was normal. A CT of the aorta was carried out and did not show an intimal tear or evidence of dissection. There was a comment about intramural haematoma proximal to the right subclavian artery.
What advice should you give him?
Intramural haematoma is a precursor of classic dissection and is due to ruptured vasa vasorum into the medial layers and communication with the lumen in response to aortic wall infarction. It progresses to aortic dissection in up to 47% of cases but can also resorb. It should be treated surgically if found in the ascending aorta as medical management is associated with a significantly worse outcome (55% versus 8%). If it involves the descending aorta, watchful waiting may be appropriate, although there is a trend towards endovascular repair. Aortic ulceration is also a precursor of dissection. However, these ulcers tend to be found in the descending aorta and if they measure more than 2 × 1 cm they should be treated with either surgery or endovascular repair.
Which one of the following is true regarding magnetic resonance imaging (MRI) of the aorta?
An MR examination takes two to four times longer than a CT examination. A comprehensive examination may include black blood imaging, basic spin-echo sequences, non-contrast white blood imaging, and contrast-enhanced MR. Black blood imaging is used to evaluate aortic anatomy and morphology. Whilst ECG gating increases acquisition times, it produces motion-free images of the aortic root and ascending aorta.
A 35-year-old woman is referred to the outpatient clinic for assessment. She has a confirmed diagnosis of Marfan syndrome from childhood but failed to attend follow-up clinics when she was a teenager. She takes no regular medication. Her blood pressure is 134/76 mmHg. The ascending aorta measures 43 mm on CT. She wants to start a family.
What would you advise?
Marfan syndrome is associated with a significantly increased risk of aortic aneurysm and dissection, and the normal threshold for aortic root replacement is 45 mm. If the aortic annulus and valves are affected, the patient may require aortic valve replacement as part of this, but otherwise the aortic valve is preserved where possible especially in a young woman in order to avoid long-term anticoagulation. Pregnancy is associated with significant changes in physiology with an increase in plasma volume and stroke volume. Hormonal changes result in subtle changes in the composition of the aortic wall. This makes pregnancy a high-risk situation for a woman with Marfan syndrome especially, but not exclusively, if the aortic root is already dilated. Dissection tends to occur in the last trimester or early in the post-natal period. Therefore it is recommended that the aortic root is replaced when the maximal diameter reaches 40 mm in this situation.
There is a 1% risk of dissection during pregnancy if the aorta measures <40 mm and a 10% risk of dissection if the aorta measures >40 mm. If vaginal delivery is planned the second stage should be short, and a caesarean section is recommended if the aorta measures >45 mm. Expert consensus document on management of cardiovascular disease during pregnancy. Eur Heart J, 2003; 24: 761–81.
A 63-year-old male is admitted to the ED of a district general hospital with a short history of sudden-onset sharp back pain and collapse. On examination he appears unwell, flushed, and diaphoretic. His blood pressure is 85/68 mmHg, his heart rate is 126 bpm, and his JVP is elevated. The emergency doctors suspect an acute dissection of the thoracic aorta which is duly confirmed on CT and extends from the sinuses of Valsalva to the aortic arch. A moderate pericardial effusion is noted and you are called to ‘drain this as the patient has cardiac tamponade’.
What should you do?
The priority is to transfer the patient to a cardiothoracic centre for urgent surgery. Drainage of the pericardial effusion will delay transfer and can accelerate bleeding and death. Patients with suspected aortic dissection with hypotension must be carefully evaluated before volume is replaced. Hypotension or shock may be due to haemopericardium/pericardial tamponade, mediastinal bleeding, acute aortic insufficiency due to dilatation of the aortic annulus, aortic rupture, lactic acidosis, or spinal shock. The mortality is high even with surgical repair—in-hospital mortality rates of 10% at day 1, 12% at day 2, and 20% at 2 weeks. Without surgical repair mortality is nearly 24% at day 1, 29% at day 2, and 50% at 2 weeks.
How should an individual with blood pressure recordings of 161/97 mmHg be classified?
Grade 2 (moderate) hypertension. The European Society of Hypertension and the World Health Organization–International Society of Hypertension guidelines classify blood pressure on clinic recordings. It is based on either systolic blood pressure (SBP) or diastolic blood pressure (DBP), and it is easier to remember the grades as follows:
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