Aortic dissection and third-degree atrioventricular block in a patient with ahypertensive crisis

Abstract

A 55-year-old man with a history of uncontrolledhypertension was admitted because of an episodeof severely elevated blood pressure. An electrocardiogramrevealed complete atrioventricular blockwhile imaging showed a dissecting aneurysm ofthe descending thoracic and abdominal aorta, type B according to the Stanford classification.Laboratory tests revealed significant increases inserum C-reactive protein. Coronary arteriographywas performed and was negative for coronaryartery disease. A VDD pacemaker was placed, and a combination of 4 antihypertensive agentswas used as treatment. Type B aortic dissectionmay present with a wide range of manifestations.The authors suggest that measurement ofC-reactive protein may be used in hypertensivepatients to help reflect vascular injury and itsdegree, progression, and prognosis. Disorders ofintraventricular conductivity are rarely seen inboth types of dissection of the aorta (type A, B).Atrioventricular conductivity disorders that resultin complete atrioventricular block have beenreported only in patients with type A dissection(before the bifurcation of the subclavian artery).In this particular case, however, the authors diagnosedan atrioventricular conductivity disordercausing atrioventricular block in a patient withtype B dissection. Consequently, the authorsspeculate that myocardial fibrosis, as a result oflong-standing hypertension, could be the mainpathogenetic mechanism leading to the developmentof such phenomena, resulting from a potentialexpanding of the fibrotic process to the atrioventricularconduction system. © 2008 Le Jacq.