The primary differentiating factor is whether the dissection involves the root, or is distal near the arch or further. Risk factors include hypertension, atherosclerosis, smoking, family history, connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome), cocaine use, and prior trauma.
A true root dissection can become rapidly fatal and is often described as severe chest pain radiating to the back, often between the shoulder blades. Diaphoresis is a highly sensitive reported symptom for coronary occlusion, and can also be just as crucial for diagnosing aortic dissection.
Chest pain is a common presenting complaint in acute care and emergency department settings. Often times, inexperienced medical providers can miss the subtle historical and exam findings that can make the difference between a routine chest pain workup and a true life-threatening catastrophe. Aortic dissection is a shearing between the tissue layers of the aorta - the intima (or inner layer), media, and adventitia.
Blood pressure discrepancies
Pulse and blood pressure discrepancies in the upper and lower extremities can also suggest this condition. These patients are also likely tachycardic and, in severe cases, hypotensive.
Traumatic thoracic aortic dissection presents with similar symptoms and has a high mortality. EKG findings may suggest inferior STEMI, which can happen with root dissections that dissect into the coronary vessels.
This retrograde dissection can obliterate coronary blood flow, and also destroy functional movement of the aortic valve. Chest radiographs may demonstrate a widened mediastinum, which suggests aortic dilation and rupture. Great care should be taken to exclude thoracic dissection prior to administering antiplatelet agents.
Contrast CT imaging
When aortic dissection is suspected, contrast CT imaging of the aorta is the gold standard, along with consultation of cardiothoracic surgery for definitive management. There are two classification systems that describe the location of the dissection, but from a clinical management perspective, root involvement is the most important discriminating factor for surgical management.
Patients with confirmed or suspected thoracic dissection should have aggressive management of blood pressure and heart rate to limit further dissection. Rate control should be accomplished first with beta-blockade, classically with Esmolol or Labetalol as a drip, which can be titrated to a goal rate of 60 beats per minute.
Additionally, blood pressure control can be accomplished with Nitroprusside or nitroglycerin on drip with a goal systolic blood pressure of 100 mm Hg. Six units of packed red cells should be ordered and held for surgical cases. The patient should be vigilantly monitored for hemodynamic compromise.
Blood pressure management
Patients with distal (non-surgical) dissections should have a similar treatment and admit to an ICU setting for continued blood pressure management and consultation. These patients will require lifelong blood pressure maintenance and lifestyle modification, along with regular screening.
Patients who have a non-dissecting thoracic aneurysm greater than 5.5 cm should be referred for elective surgery. Those between 4 cm and 5.5 cm should have regular interval screening to monitor for interval growth. Rapid expansion of 0.5 cm per year is also an indication for elective surgery. Isolated aortic arch aneurysms have similar criteria for repair, and may require vigilant monitoring as well.
Author:
Dr. Beatty received his Bachelor of Science in Biological Sciences from Clemson University and earned his Doctorate in Medicine from the University of South Carolina School of Medicine. He completed his residency training in Emergency Medicine at the Johns Hopkins Hospital in Baltimore, Maryland. Dr. Beatty has extensive experience as a clinician, medical leader, department chairman, medical director, regional medical director, and Chief Medical Officer. In addition to his clinical and administrative roles, Dr. Beatty has spoken at several national conferences and is an active expert medical witness.
He is an avid teacher, and regularly supervises Physician Assistants, Nurse Practitioners, and fellow physicians. He has served as a physician mentor to his medical staff, and as a member of hospital credentialing, medical executive and peer review committees. Having extensively recruited, interviewed, hired, and reviewed countless numbers of healthcare providers, his expertise in team building, recruitment, and the hiring process helps to deliver the message of our programs in a way that other courses can't match. In addition, having established an Advanced Practice Provider residency program in multiple hospitals, Dr. Beatty understands the key concepts needed to prepare Nurse Practitioners and Physicians Assistants for their transition to independent clinical practice.
