An 87-year-old man attended A&E complaining of sudden chest and upper back discomfort for two hours. He had known mild coronary artery disease (by CT coronary angiogram 1 year ago) with hypertension, which was not optimally controlled from the beginning. His blood pressure on admission was 160/95 mmHg. An ECG (Figure 1) and chest X-ray (Figure 2) were done. His first troponin-I level 2 hours post chest/back pain was not elevated.
Figure 1. ECG.
Figure 2. Chest X-ray.
Figure 3. CT thorax and aortogram.
The ECG of this gentleman showed Q waves over inferior leads but there was no gross ST elevation, although borderline ST elevation was noted. The negative instant troponin-I level, plus a recently documented non-significant coronary disease should lead to the suspicion of acute aortic dissection, particularly with the symptoms of upper back pain. The chest X-ray did not show the classical widened mediastinum as in many other cases of acute type A dissection, but the CT aortogram showed an extensive type B dissection in the descending aorta. It started just distal to the left subclavian artery and extended down beyond the origins of the renal arteries.
The choice of initial treatment depends on the presence of complications and extent of the dissection. If there is no involvement of the ascending aorta/arch, no leakage/rupture of the aorta and there was no immediate end-organ damage due to involvement of the origins of the major arteries (such as superior/inferior mesenteric arteries, celiac trunk and renal arteries), medical treatment may be a better approach, particularly in elderly patients.
Initial treatment should aim for an optimal blood pressure control, which should not be too high to extend the dissection and yet not too low to jeopardize organ perfusion. An initial target of 130–140 mmHg systolic blood pressure is reasonable and intravenous infusion of labetalol is often used. For long-term control, a systolic blood pressure of 120 mmHg would be a good target. Symptoms and signs of endorgan damage such as bowel ischaemia and renal ischaemia should be carefully monitored. A CT aortogram should be repeated in about 2 weeks and then 3 months to monitor for any acute extension of dissection and subsequent expansion of aortic aneurysm/dissection extension. When subsequent expansion of aortic aneurysm/dissection extension is noted, endovascular repair or open repair may be necessary.
Acute aortic dissection is a medical emergency which requires a high index of suspicion to make the correct diagnosis. Early diagnosis and appropriate treatment has an important prognostic implication. Hypertensive history with sudden back pain, as in this case, is a classical presentation.
