The Wolf in Sheep's Clothing: An Illustrative Case Report Of Aortic Dissection And Review Of Diagnostic Clinical Features

摘要

A 54 year-old man with hypertension presented to the emergency department with chest pain, nausea and syncope. Initial arterial blood pressure was high and pulse examination was normal. Cardiac auscultation revealed a murmur of mild aortic sclerosis. 12-lead electrocardiogram showed normal sinus rhythm, 1 mm ST depression in the lateral leads and left ventricular hypertrophy and no dynamic ST or T wave changes were noted subsequently. Cardiac enzymes levels were negative. Chest pain subsided with initial treatment, but recurred after discontinuation of the medications. Chest X-ray (CXR) showed mild increase in cardiac silhouette size and slightly prominent ascending aorta. In view of recurrent chest pain, syncope and abnormal CXR, an emergent computerized tomogram (CT) of the chest was performed. A Stanford Type 'A' dissection of aorta with typical double barrel appearance (figure 1) was found. Emergent surgical repair of the dissecting aneurysm as well as pericardial effusion found intra-operatively was successfully performed and patient recovered. Introduction Chest pain is a common presenting symptom in the ED contributing to 5% of total ED visits. (1) Yet, only 15% of these patients have chest pain from acute myocardial infarction related to coronary artery disease (CAD). (2) Due to heightened awareness and malpractice litigation, (3) ED physicians tend to consider CAD as differential diagnosis in every individual presenting with chest pain. However, other diagnoses that are potentially lethal could be overlooked. We present a teaching case of “chest pain, rule out myocardial infarction” with interesting findings and discuss the pitfall of this routine approach to chest pain in the ED. Case Report A 54 yr-old male with uncontrolled hypertension, Parkinson's disease presented to the ED with acute chest pain, nausea, sweating and syncope. He described a severe pressure-like sensation in the left precordium with radiation to his left arm. Initial vitals were: BP 280/110 mmHg; Pulse Rate 80/min; Respiratory Rate 19/min. BP and pulse were equal in all four limbs. Cardiac exam revealed mild aortic sclerosis. There was no carotid bruit. Neurological examination was normal. 12-lead standard electrocardiogram (EKG) showed 1 mm ST segment depression in the lateral chest leads and left ventricular hypertrophy with no dynamic ST or T wave changes on subsequent recordings. CXR revealed mild increase in cardiac silhouette size and slightly prominent ascending aortic silhouette with normal mediastinal width. Initial cardiac enzyme set was negative. Lab data included hematocrit 39% and serum creatinine 1.3mg/dl. An initial diagnosis of “chest pain, rule out myocardial infarction” was entertained and a decision was made to admit the patient. He was initially administered aspirin, brief anticoagulation, parenteral morphine and nitroglycerin infusion. After initials vitals were stabilized, cardiac symptoms resolved momentarily. Soon after admission, severe chest pain recurred with discontinuation of nitroglycerin infusion. A repeat EKG was found to have similar ST segment changes compared to the initial EKG and had no other dynamic ischemic abnormalities. In view of recurrent chest pain disproportionate to the electro-cardiographic and roentgenographic abnormalities, anticoagulation and anti-platelet therapy was withheld and a computerized tomogram (CT) of the chest was performed. A Stanford Type ‘A' dissection of aorta extending from the aortic root to the bifurcation of aorta with typical double barrel appearance (Figure 1) was found.