64-Year-Old Woman With Chest Pain and Presyncope

Abstract

A 64-year-old woman went to her local emergency department because of sudden onset of severe burning anterior chest pain that extended into her abdomen and legs while she was shoveling snow. She also had light-headedness and diaphoresis. The pain was constant and nonpleuritic, and she denied experiencing any similar discomfort in the past. Her past medical history was remarkable for borderline hypertension, which had recently been discovered but was not being treated. The patient denied having fever, chills, upper respiratory symptoms, previous abdominal or chest pain, or gastrointestinal bleeding. Before shoveling snow, she had been feeling well. She denied a prior history of cardiovascular disease. 1Which one of the following diagnoses is least likely in this patient? a.Myocardial infarctionb.Aortic dissectionc.Penetrating aortic ulcerd.Aortic stenosise.Perforated peptic ulcer Myocardial infarction usually manifests with gradually increasing chest discomfort, dyspnea, and diaphoresis; however, pain extending to the lower extremities would be atypical. Despite this, because of the patient's history of hypertension and postmenopausal status, coronary artery disease producing angina pectoris and myocardial infarction cannot be excluded. Aortic dissection and penetrating aortic ulcer, clinically similar but pathologically distinct disorders, most commonly manifest with either anterior or posterior chest pain (or both), with variable radiation depending on the extent of dissection or site of the penetrating ulcer. Pre sync ope, diaphoresis, and abdominal or chest pain can accompany aortic dissection. The classic picture of symptomatic aortic stenosis can consist of chest pain, syncope, and dyspnea associated with exertion; however, chest pain that extends to the abdomen and legs is not typical. In addition, the patient denied having a history of heart murmur and had never experienced similar symptoms from exertion. Thus, symptomatic aortic stenosis is an unlikely diagnosis. A perforated peptic ulcer can cause sudden onset of epigastric pain, presyncope, and diaphoresis. Although the patient denied a previous history of abdominal pain, peptic ulcer disease must be included in the differential diagnosis. At the local emergency department, the patient was noted to be hypotensive with a systolic blood pressure of 80 mm Hg and an ann blood pressure difference of 20 mm Hg. A faint diastolic decrescendo murmur was heard along the right upper sternal border. Electrocardiographic (EeG) findings were normal. A chest roentgenogram revealed a widened mediastinum and a left pleural effusion. Shortly after she was admitted to the local hospital, her hemoglobin level declined from 12.0 to 8.5 g/dL. Aspartate aminotransferase (AST) was 12,000 U/L (normal, 12 to 31), and the serum creatinine was 2.5 mg/dl, (normal, 0.6 to 0.9). The creatine kinase MB (CK-MB) fraction was normal. 2Which one of the following studies would be most helpful initially in narrowing the differential diagnoses? a.Transthoracic echocardiographyb.Transesophageal echocardiographyc.Esophagogastroduodenoscopyd.Aortographye.Coronary angiography Because of the hemodynamic instability of the patient, initial testing should be rapid, accurate, and portable (performed at the bedside), if possible. Transthoracic echocardiography (TTE) can accurately detect regional wall motion abnormalities, valvular heart disease, pericardial effusion, cardiac tamponade, and ascending aortic dilatation. Transesophageal echocardiography (TEE) provides excellent visualization of the heart and thoracic aorta because of the close proximity of the esophagus to these structures. 1Cigarroa JE Isselbacher EM DeSanctis RW Eagle KA Diagnostic imaging in the evaluation of suspected aortic dissection: old standards and new directions.N Engl J Med. 1993; 328: 35-43Crossref PubMed Scopus (338) Google Scholar TEE, because it is noninvasive, rapid, and accurate and can be performed at the bedside, is preferred for the emergent diagnosis of thoracic aortic dissection. Furthermore, TEE can quantify aortic regurgitation, left ventricular function, and regional wall motion abnormalities. Esophagogastroduodenoscopy (EGD) can be quickly performed at the bedside to rule out a bleeding or perforated ulcer, although signs of an acute gastrointestinal hemorrhage other than hypotension and decreased hemoglobin level were not present. Aortography is useful in detecting aortic dissection or penetrating aortic ulcer; however, it is invasive and cannot be performed as rapidly as TEE. 2Chirillo F Cavallini C Longhini C Ius P Totis O Cavarzerani A et al.Comparative diagnostic value of transesophageal echocardiog-raphy and retrograde aortography in the evaluation of thoracic aortic dissection.Am J Cardiol. 1994; 74: 590-595Abstract Full Text PDF PubMed Scopus (41) Google Scholar Coronary angiography would help exclude appreciable coronary artery disease and provide information on left ventricular function and associated aortic and mitral valve disease; however, the normal ECG and CK-MB fraction make myocardial infarction a less likely diagnosis. Because of the sudden onset of severe chest pain associated with a normal ECG and CK-MB fraction, as well as the widened mediastinum on a chest roentgenogram, the attending physician was concerned about aortic dissection. Other signs and symptoms that suggested aortic dissection and possible cardiac tamponade were presyncope, a diastolic murmur, and hypotension. 3Which one of the following tests is least likely to help confirm the clinical diagnosis? a.Aortographyb.Computed tomographyc.Magnetic resonance imagingd.Transesophageal echocardiographye.Transthoracic echocardiography In the past, aortography was considered the “gold standard” for evaluation of suspected aortic dissection. More recently, computed tomography (CT), magnetic resonance imaging (MRI), and TEE have proved extremely useful for this assessment 1Cigarroa JE Isselbacher EM DeSanctis RW Eagle KA Diagnostic imaging in the evaluation of suspected aortic dissection: old standards and new directions.N Engl J Med. 1993; 328: 35-43Crossref PubMed Scopus (338) Google Scholar TTE images may be suboptimal because of obesity, emphysema, or chest wall abnormalities; therefore, it has a lower sensitivity for detecting aortic dissection. TTE sensitivity is highest for dissection that involves the ascending aorta, ranging from 78 to 100%, whereas the sensitivity for detection of dissection in the descending aorta is as low as 31%. 1Cigarroa JE Isselbacher EM DeSanctis RW Eagle KA Diagnostic imaging in the evaluation of suspected aortic dissection: old standards and new directions.N Engl J Med. 1993; 328: 35-43Crossref PubMed Scopus (338) Google Scholar Before referral, the patient underwent biplane thoracic aortography, which demonstrated aneurysmal dilatation of the aortic root in conjunction with moderate aortic insufficiency. No evidence of aortic dissection was noted. The descending thoracic aorta was mildly ectatic. TEE and MRI of the heart and aorta also did not reveal dissection. During her hospital stay, the AST, hemoglobin, and creatinine normalized after blood transfusions and resolution of shock. Because of persistent back and chest pain and the suspicion of aortic dissection, the patient was transferred to our institution for further assessment. Physical examination revealed blood pressure of 152/50 mm Hg in the right arm and 156/42 mm Hg in the left arm. Peripheral pulses were normal. A grade 3 systolic ejection murmur and a grade 2 decrescendo diastolic murmur (both on a scale of 1 to 6) along the upper right and left sternal borders, respectively, were detected. Repeated studies of creatine kinase, serum transaminases, creatinine, and hemoglobin all showed normal results. ECG and chest roentgenographic findings were unchanged, and results of EGO were normal. TTE and TEE (multiplane) disclosed a dilated ascending aorta with a maximal dimension of 52 mm. The aortic arch and descending thoracic aorta were of normal caliber. Moderate eccentric aortic regurgitation was present, but an intimal flap was not detected. Left ventricular function was normal, and a small circumferential pericardial effusion was present. Coronary and aortic root angiograms confirmed the findings seen on the TEE and revealed mild coronary artery disease. 4Which one of the following treatments is the most appropriate in the initial management of this patient? a.Sodium nitroprusside onlyb.Intravenously administered [3-adrenergic blocker and sodium nitroprussidec.Sublingually administered nifedipined.Hydralazinee.Digoxin With a presumptive clinical diagnosis of aortic dissection, the most important factors promoting continued propagation of the dissection are hypertension and the velocity of left ventricular ejection.' Intravenous administration of sodium nitroprusside should be initiated immediately to decrease the systolic pressure to 100 to 120 mm Hg or to a level at which urine output is maintained. Concomitantly, an intravenously administered β-adrenergic blocker such as esmolol hydrochloride should be infused to reduce the velocity of left ventricular ejection. Arterial vasodilators, such as nifedipine administered sublingually or hydralazine, will result in a compensatory tachycardia and subsequent increase in the pulsatile load. Digoxin increases heart contractility and is therefore contraindicated for treatment of aortic dissection. 3Fuster V Halperin JL Aortic dissection: a medical perspective.J Card Surg. 1994; 9: 713-728Crossref PubMed Scopus (54) Google Scholar With dissection of the ascending aorta (type A), emergent surgical repair is the preferred treatment. Patients with uncomplicated dissection of the descending thoracic aorta (type B) are most often treated medically, unless pain persists, hypertension cannot be controlled, or progressive aortic dilatation is noted on follow-up. 3Fuster V Halperin JL Aortic dissection: a medical perspective.J Card Surg. 1994; 9: 713-728Crossref PubMed Scopus (54) Google Scholar Intravenous administration of esmolol and sodium nitroprusside was initiated to maintain the systolic blood pressure below 120 mm Hg. With a presumptive clinical diagnosis of aortic dissection, the patient was taken to the operating room. After median sternotomy, 150 mL of clotted blood was removed from the pericardial space, and a hematoma was seen extending over the proximal portion of the ascending aorta. A transverse tear in the aorta immediately above the left coronary ostium extended circumferentially to the right coronary ostium. This localized dissection did not extend beyond the sinotubular junction. The patient had annuloaortic ectasia and associated central insufficiency of the aortic valve. The aortic valve and ascending aorta were replaced with a composite St. Jude aortic valve prosthesis and ascending aortic graft. The coronary arteries required reimplantation. Pathologic examination of the aorta revealed grade IV cystic medial degeneration. After an uneventful postoperative course, the patient was dismissed. 5Which one of the following is not a risk factor in persons with our patient's diagnosis? a.Pregnancyb.Cystic medial degenerationc.Hypertensiond.Bicuspid aortic valvee.Mitral valve prolapse An association between aortic dissection and pregnancy has been documented in case reports, most often involving patients in the third trimester. Factors thought to contribute to aortic dissection during pregnancy include the stress and strain of labor, hormonal changes, and presence of associated diseases (such as hypertension). 4Slater EE Aortic dissection: presentation and diagnosis.in: Doroghazi RM Slater EE Aortic Dissection. McGraw-Hill, New York1983: 61-70Google Scholar Congenital and acquired defects in connective tissue, such as occur in the Marfan syndrome and cystic medial degeneration, weaken the aortic wall and predispose it to dissection. 4Slater EE Aortic dissection: presentation and diagnosis.in: Doroghazi RM Slater EE Aortic Dissection. McGraw-Hill, New York1983: 61-70Google Scholar The aorta dilates because of weakness in the medial layer. Luminal dilatation considerably increases shear stress, with the pulsatile load being greatest in areas of dilatation. Over time, increasing shear stress leads to the primary intimal tear, which serves as an entry point for dissection. 3Fuster V Halperin JL Aortic dissection: a medical perspective.J Card Surg. 1994; 9: 713-728Crossref PubMed Scopus (54) Google Scholar Hypertension and atherosclerosis accelerate this process. 3Fuster V Halperin JL Aortic dissection: a medical perspective.J Card Surg. 1994; 9: 713-728Crossref PubMed Scopus (54) Google Scholar In a clinical series reported by Spittell and associates, 5Spittell PC Spittell Jr, JA Joyce JW Tajik AJ Edwards WD Schaff HV et al.Clinical features and differential diagnosis of aortic dissection: experience with 236 cases (1980 through 1990).Mayo Clin Proc. 1993; 68: 642-651Abstract Full Text Full Text PDF PubMed Scopus (449) Google Scholar hypertension was the most common predisposing factor for dissection (78% of patients). Bicuspid aortic valve is associated with cystic medial degeneration in the ascending aorta and a resultant increased risk of aortic dissection. Mitral valve prolapse has not been associated with aortic dissection, except when it occurs in patients with the Marfan syndrome. 6Which one of the following complications is least likely to occur in persons with our patient's diagnosis? a.Cardiac tamponadeb.Aortic regurgitationc.Myocardial infarctiond.Complete heart blocke.Glomerulonephritis With rupture of a proximal aortic dissection into the pericardial space, cardiac tamponade can occur. 6Crawford ES The diagnosis and management of aortic dissection.JAMA. 1990; 264: 2537-2541Crossref PubMed Scopus (240) Google Scholar Aortic regurgitation is an important sign of proximal aortic dissection and is present in approximately two thirds of the affected patients. 4Slater EE Aortic dissection: presentation and diagnosis.in: Doroghazi RM Slater EE Aortic Dissection. McGraw-Hill, New York1983: 61-70Google Scholar Aortic regurgitation may be attributable to mechanical displacement of the valve leaflets or to disruption of the valve annulus. 4Slater EE Aortic dissection: presentation and diagnosis.in: Doroghazi RM Slater EE Aortic Dissection. McGraw-Hill, New York1983: 61-70Google Scholar Myocardial ischemia arising from acute coronary artery occlusion is a serious complication in a small number of patients. Coronary artery insufficiency is suggested by pericardial friction rub, pericardial effusion, and aortic insufficiency. 6Crawford ES The diagnosis and management of aortic dissection.JAMA. 1990; 264: 2537-2541Crossref PubMed Scopus (240) Google Scholar Complete heart block can result if the hematoma extends proximally into the area of the atrioventricular node. Renal artery occlusion may result from abdominal aortic dissection, but glomerulonephritis is not a recognized complication. Acute aortic dissection is a life-threatening condition; prompt diagnosis and treatment are needed for improvement of patient survival. Maintaining a high index of suspicion for aortic dissection is the most important aspect that will lead to a rapid and definitive diagnosis. Most patients with thoracic aortic dissection have acute onset of severe chest pain. In a retrospective clinical series of 124 patients, Slater and DeSanctis 7Slater EE DeSanctis RW The clinical recognition of dissecting aortic aneurysm.Am J Med. 1976; 60: 625-633Abstract Full Text PDF PubMed Scopus (267) Google Scholar found that only 5% of patients had painless dissection. A large number of patients with proximal dissection experienced pain in the anterior chest area, whereas those with distal dissection generally complained of posterior chest pain. Pain was migratory in 71 % of patients, the location of pain often corresponding to the portion of aorta involved in the dissection. Syncope was experienced in six patients, five of whom had an ascending aortic dissection with extension into the pericardial cavity that caused cardiac tamponade. In a series of 235 patients described by Spittell and colleagues, 5Spittell PC Spittell Jr, JA Joyce JW Tajik AJ Edwards WD Schaff HV et al.Clinical features and differential diagnosis of aortic dissection: experience with 236 cases (1980 through 1990).Mayo Clin Proc. 1993; 68: 642-651Abstract Full Text Full Text PDF PubMed Scopus (449) Google Scholar pain in the neck, throat, jaw, face, or earwas present in 43 patients, all but 2 of whom had proximal aortic dissection. On physical examination, many patients have hypertension even though they may appear to be in shock. Pulse deficits may be noted, the site of the dissecting hematoma determining the location and frequency of pulse loss. 4Slater EE Aortic dissection: presentation and diagnosis.in: Doroghazi RM Slater EE Aortic Dissection. McGraw-Hill, New York1983: 61-70Google Scholar Ascending aortic dissection may produce a murmur of aortic insufficiency and subsequently widened pulse pressure. 4Slater EE Aortic dissection: presentation and diagnosis.in: Doroghazi RM Slater EE Aortic Dissection. McGraw-Hill, New York1983: 61-70Google Scholar Less commonly, neurologic deficits can occur, resulting from obstruction of the blood supply to the brain, extremities, or spinal cord. For many years, aortography was the only imaging procedure available for detection of aortic dissection. In a study by Erbel and coworkers, 8Erbel R Engberding R Daniel W Roelandt J Visser C Rennollet H Echocardiography in diagnosis of aortic dissection.Lancet. 1989; 1: 457-461Abstract PubMed Scopus (505) Google Scholar the sensitivity and specificity of aortography in the detection of aortic dissection were 88% and 94%, respectively. Advantages of aortography in aortic dissection include the delineation of branch vessel involvement and the ability to outline the entry and exit points of intimal tears. It is accurate for imaging both the ascending and the descending thoracic aorta. 1Cigarroa JE Isselbacher EM DeSanctis RW Eagle KA Diagnostic imaging in the evaluation of suspected aortic dissection: old standards and new directions.N Engl J Med. 1993; 328: 35-43Crossref PubMed Scopus (338) Google Scholar Some disadvantages exist, however, such as test invasiveness, need for use of a contrast medium, nonportability, and subsequent delay in diagnosis. During the past 5 years, TEE has become the noninvasive imaging modality of choice for the emergent diagnosis of thoracic aortic dissection. TEE was demonstrated to be 99% sensitive and 98% specific by Erbel and associates 8Erbel R Engberding R Daniel W Roelandt J Visser C Rennollet H Echocardiography in diagnosis of aortic dissection.Lancet. 1989; 1: 457-461Abstract PubMed Scopus (505) Google Scholar in a prospective study of 164 patients with suspected thoracic aortic dissection. In that series, only one false-negative result occurred with both TEE and angiography in a patient with a localized dissection of the aortic root identified intraoperatively. Prior studies have noted false-positive TEE findings, especially in the ascending aorta. Such results may be due to extensive plaque formation, echo reverberations in the ascending aorta, or tracheal obstruction of the echo signals. 8Erbel R Engberding R Daniel W Roelandt J Visser C Rennollet H Echocardiography in diagnosis of aortic dissection.Lancet. 1989; 1: 457-461Abstract PubMed Scopus (505) Google Scholar The overall specificity of TEE in thoracic aortic dissection ranges from 68 to 98%. MRI is an excellent noninvasive test for diagnosing aortic dissection. In a study by Nienaber and colleagues, 9Nienaber CA Spielmann RP von Kodolitsch Y Siglow V Piepho A Jaup T et al.Diagnosis of thoracic aortic dissection: magnetic resonance imaging versus transesophageal echocardiography.Circulation. 1992; 85: 434-447Crossref PubMed Scopus (247) Google Scholar 53 consecutive patients with clinically suspected aortic dissection underwent MRI. Those investigators demonstrated 100% sensitivity and specificity for the detection of both type A and type B aortic dissection. The sensitivity for detecting the entry site of the dissection in the ascending aorta, however, was only 71 %, which was comparable to TEE findings. The major advantage of MRI stems from the high contrast among the blood pool, vascular wall, and adjacent soft tissues, in addition to the quality of images in multiple imaging planes. 1Cigarroa JE Isselbacher EM DeSanctis RW Eagle KA Diagnostic imaging in the evaluation of suspected aortic dissection: old standards and new directions.N Engl J Med. 1993; 328: 35-43Crossref PubMed Scopus (338) Google Scholar Disadvantages of MRI in the diagnosis of aortic dissection include cost, time delay in obtaining images, inability to detect intimal flaps if a thrombosis is in the false lumen, and nonportability, which limits its use in critically ill patients in an emergency setting. 1Cigarroa JE Isselbacher EM DeSanctis RW Eagle KA Diagnostic imaging in the evaluation of suspected aortic dissection: old standards and new directions.N Engl J Med. 1993; 328: 35-43Crossref PubMed Scopus (338) Google Scholar Ultrafast CT is another imaging technique for detecting aortic dissection. It allows rapid imaging of the thoracic aorta after a single intravenous bolus injection of contrast medium so that intimal flaps and dissection entry sites can be visualized. The study can be performed with breath holding in less than 5 minutes. In one study, Hamada and coworkers 10Hamada S Takamiya M Kimura K Imakita S Nakajima N Naito H Type A aortic dissection: evaluation with ultrafast CT.Radiology. 1992; 183: 155-158Crossref PubMed Scopus (32) Google Scholar used ultrafast CT to assess 17 patients with type A aortic dissection. Although dissection was diagnosed in all cases, one intimal tear in the aortic arch was not visualized. Conventional CT is also useful for diagnosing aortic dissection; sensitivities of 88 to 93% and specificities of 87 to 100% have been reported. Disadvantages of conventional CT in aortic dissection include inability to detect intimal tear entry sites, aortic regurgitation, or involvement of branch vessels. It also has limited applicability in hemodynamically unstable patients. 11Nienaber CA von Kodolitsch Y Nicolas V Siglow V Piepho A Brockhoff C et al.The diagnosis of thoracic aortic dissection by noninvasive imaging procedures.N Engl J Med. 1993; 328: 1-9Crossref PubMed Scopus (770) Google Scholar Our current case is notable in that the aortic dissection was diagnosed on clinical grounds, despite nondiagnostic results of aortography, TEE, TTE, and MRI. The dissection was small and localized to the sinus of Valsalva; therefore, these imaging studies were unable to detect the lesion preoperatively. In a recent study, Bansal and associates 12Bansal RC Chandrasekaran K Ayala K Smith DC Frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography.J Am Coll Cardiol. 1995; 25: 1393-1401Abstract Full Text PDF PubMed Scopus (104) Google Scholar discussed the frequency of and rationale for false-negative diagnoses of thoracic aortic dissection by aortography an TEE. Aortography revealed false-negative results in 15 patients (sensitivity, 77%). A false-negative diagnosis was thought to result primarily from an intramural hematoma, which cannot be easily visualized by aortography. Biplane TEE yielded false-negative results in two patients (sensitivity, 97%). The diagnosis was overlooked in small localized dissections of the upper portion of the ascending aorta because of image interference from the air-filled trachea. The sudden onset of anterior chest pain, hypotension, new aortic insufficiency, and a pericardial effusion in the setting of normal ECG findings strongly suggested proximal aortic dissection in our patient. Although new and highly accurate modes of imaging are available to diagnose aortic dissection, the clinician's high index of suspicion remains invaluable. The surgical expertise of Dr. Hartzell V. Schaff in the care of this patient is acknowledged.