A 27-year-old G4P1021 African American woman presented at 9 weeks’ gestation with elevated blood pressure. The patient was otherwise asymptomatic, denying headache, vision changes, chest pain, shortness of breath, or neurologic symptoms. Her previous pregnancies were uncomplicated, with no history of hypertensive disorders of pregnancy. She had a 2-year history of chronic hypertension but had self-discontinued medications before presentation. She had no other chronic medical conditions. Family history was significant only for hypertension in both parents.
Assessment
Initial blood pressure was 192/115, with a heart rate of 95 beats per minute and respiratory rate of 18 breaths per minute. Height was 5 foot, 8 inches. She had a normal uvula and palate, no hypertelorism, and normal sclera. She did not have excessively velvety or soft skin, no elongated fingers or toes, and no pectus deformity. Cardiac examination revealed a short systolic ejection murmur with no diastolic murmur, and the pulse examination was normal. She had no features of a syndromic connective tissue disorder. Electrocardiogram revealed normal sinus rhythm with nonspecific T-wave abnormalities.
Initial laboratory evaluation revealed electrolytes and creatinine to be within normal limits. The aldosterone/renin ratio was normal. Renal ultrasound showed no evidence of renal artery stenosis. Transthoracic echocardiogram showed normal left ventricular systolic function with mild concentric left ventricular hypertrophy and a trileaflet aortic valve. Suprasternal notch views were suggestive of coarctation of the aorta, with continuous wave Doppler peak velocity of approximately 2.5 m/s and peak pressure gradient of 25 mm Hg in the proximal descending aorta, along with a narrow turbulent jet across this area. Subsequent magnetic resonance angiogram and follow-up contrast computed tomography of the aorta did not show evidence of aortic coarctation, but instead demonstrated a type B aortic dissection extending from just distal to the left subclavian artery to below the renal arteries, with aneurysmal enlargement of the proximal descending aorta measuring 5.0Â Ă— 5.8 cm. Fenestrations were present in the intimal flap, with the celiac and left renal arteries arising from the false lumen.
Diagnosis
The patient’s history and imaging were most consistent with chronic type B aortic dissection. On further questioning, the patient reported an episode of acute tearing chest and back pain that occurred during an argument 2 years before presentation. The pain was self-limited and was not evaluated at that time.
Aortic dissection in pregnancy is a rare but potentially life-threatening disease. In women of childbearing age, approximately 12%-50% of aortic dissections occur in the setting of pregnancy or the postpartum state, representing up to a 25-fold increase in the risk of dissection. The physiologic changes of pregnancy may increase risk for aortic dissection, owing to an increased hemodynamic load and hormonal-induced changes in aortic wall histology. During pregnancy, cardiac output is increased by up to 50%, owing to increase in plasma volume and heart rate, thus increasing hemodynamic stress on the walls of the aorta. Elevated estrogen levels during pregnancy may also remodel the vascular media, suppressing the synthesis of collagen and elastin. Aortic dissection is an established pregnancy-related risk for women with inherited or congenital aortopathies, such as Marfan syndrome, Loeys-Dietz syndrome, familial thoracic aortic aneurysm, coarctation of the aorta, and bicuspid aortic valve-associated aortopathy. The underlying aortopathies that predispose patients to aortic dissections are often related to mutations in genes associated with familial thoracic aortic aneurysms, including FBN1, TGFBR1, TGFBR2, ACTA2, COL3A1, MYH11, and others. However, this patient did not have clear evidence of a heritable or syndromic aortopathy by history, physical examination, or imaging. It was recommended that our patient undergo genetic testing, but she declined because of the expense. It has also been recommended that her first-degree family members be screened for thoracic aortic aneurysm.
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-Joyce Ji, MD, J. Trevor Posenau, MD, Kathryn J. Lindley, MD, Alan C. Braverman, MD
This article originally appeared in the May 2016 issue of The American Journal of Medicine.
