Case Report

Found in Cath Lab: An Aortic Dissection

Tharen J. Leesch, CVT-AAS, Florida Hospital Zephyrhills, Zephyrhills, Florida
Tharen J. Leesch, CVT-AAS, Florida Hospital Zephyrhills, Zephyrhills, Florida
Case Report A 76-year-old female presented to the emergency department (ED) with severe angina. She stated that she had experienced pain in her right arm along with a feeling of pressure the day prior. At that time, she took her blood pressure (BP) and it was in the normal range, so she let it pass. The following day, she had an episode of angina severe enough to make her dizzy. A visiting neighbor gave her a nitroglycerin tablet, which provided some relief. The patient then came to the ED. She denied ever having diaphoresis, shortness of breath, or loss of consciousness. Her past medical history was significant for hypertension, hiatal hernia, coronary heart disease with one stent in the right coronary artery (RCA) eight years ago, tobacco use, arthritis, and severe kyphosis. The usual chest pain workup was performed by the chest pain-accredited ED. The electrocardiogram showed a rate of 63 beats per minute in normal sinus with left bundle branch block. Serial enzymes showed an elevated troponin level of 0.56 ng/ml and B-type natriuretic pepetide of 1072 pg/ml. An echocardiogram was performed and, due to the severe kyphosis, was technically difficult. It showed aortic insufficiency, pulmonary hypertension, dilated ascending aorta, and a possible aortic flap. At this time, the patient was brought to the cardiac catheterization laboratory (cath lab) and a left heart catheterization and coronary angiography (LHC/Cors) was performed. The patient, because of her severe kyphosis, was propped up with a wedge under the mattress along with three pillows to give her the ability to lay on the cath table. The LHC/Cors revealed mildly diffuse non-obstructive coronary artery disease with a patent stent in the distal RCA. Pressures were normal and the left ventriculogram showed an ejection fraction within the normal range. After the catheter was pulled back across the aortic valve, a aortic root angiogram was performed. It showed aortic insufficiency graded 4+ and an aortic dissection flap that started in the sinus of Valsalva and progressed through to the descending aorta; this was classified as a Stanford Class A Dissection (Figures 1-3). A cardiovascular surgical consultation was attained by our resident cardiovascular surgery group. After some discussion, the status of the dissection acuity was questioned. The possibility of it being chronic was discussed and options were presented to the patient. The surgeon had a detailed discussion with the patient and her family about the risks and benefits of the surgery, but in the end deemed the mortality of the surgery to repair the aortic valve and dissection to be extremely high. One of the main contributing factors to this decision was the severe kyphosis and the patient’s frail physical status. The patient decided that she wished to continue solely with medical therapy. Discussion Aortic dissection is the separation of the layers within the aortic wall where blood enters the intima-media space with further propagation of the dissection.1 This tear in the intima can fill with blood, creating a false lumen or “double-barrel,” which effectively means that it “balloons” within the aorta, and can partially or totally block the true aortic lumen. It is possible that the distal segment of the dissection can re-rupture back into the true lumen, creating an actual “double-barrel” aorta. According to the International Registry of Acute Aortic Dissection (IRAD), the incidence of aortic dissection has been estimated at 5-30 cases per one million people per year.1 The true incidence of dissection is difficult to estimate as most estimates are based on autopsy studies. Population-based studies estimate the incidence at roughly 6-10 new aneurysms per 100,000 person-years. Evidence of dissection is found in 1-3% of all autopsies.2 Statistics show that early mortality from type A AAD can be as high as 1% per hour, 50% at 72 hours, 75% at two weeks, and 90% at three months. With the diagnosis of an aortic dissection, the mortality rate, if treated with surgical intervention, is 23% for patients The author can be contacted at Tharen.Leesch@ahss.org This article received a double-blind peer review from members of the editorial board.
References
1. Hagan PG, Nienaber CA, Isselbacher EM, et al. The international registry of acute aortic dissection (IRAD): new insights into an old disease. JAMA 2000;283:897-903.

2. Clouse WD, Hallett JW Jr, Schaff HV, et al. Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture. Mayo Clin Proc Feb 2004;79(2):176-80.

3. Wiesenfarth JM. Dissection, Aortic. Emedicine from WebMD. Available at http://emedicine.medscape.com/article/756835-overview. Accessed December 1, 2009.

4. Tran TP, Khoynezhad A. Current management of type B aortic dissection. Vascular Health and Risk Management 2009;5:53-63.

5. Mehta RH, O’Gara PT, Bossone E. Acute type A aortic dissection in the elderly: clinical characteristics, management, and outcomes in the current era. J Am Coll Cardiol 2002; 40: 685-692.