Brief communication

Acquired left ventricular-right atrial and right ventricular communication due to infective endocarditis after aortic valve replacement

We report a case of aortic prosthetic valve endocarditis presenting with subaortic stenosis without perivalvular leakage and vegetations in the left ventricular outflow and right atrium, the latter being attached to the atrioventricular septum. Intraoperatively, an abscess that had formed on the aortic annulus and perforated to the right atrium was unexpectedly found, the fistula being occluded by vegetations. Even when no left-to-right shunts are detected by imaging, vegetations adjacent to the atrioventricular septum may conceal a left ventricle–right atrium fistula, resulting in prosthetic valve endocarditis presenting clinically as subaortic stenosis without perivalvular leakage.

Gerbode type defects are rare left ventricular outflow tract–right atrial communications in people that may be congenital or acquired; they have been reported only once previously in dogs. Acquired forms in humans have been reported secondary to bacterial endocarditis, trauma, and valve replacement surgery, among other causes. We report a case of left ventricular outflow tract to right atrium and right ventricle communications (Gerbode type defect) in association with aortic and tricuspid valve bacterial endocarditis in a geriatric dog. The dog also developed third degree atrioventricular block and had underlying subaortic stenosis. The authors hypothesize that the Gerbode type defect in this case was acquired secondary to invasion and destruction of the membranous interventricular septum due to bacterial endocarditis.

Left ventricular to right atrial communications are rare types of ventricular septal defects usually of congenital origin. A case of an iatrogenic shunt between the left ventricle and the right atrium as a rare complication of mitral valve replacement is reported.

Les communications du ventricule gauche à l’oreillette droite sont des types rares de malformation congénitale du septum interventriculaire, qui sont généralement d’origine congénitale. On présente un cas de shunt iatrogène entre le ventricule gauche et l’oreillette droite, une rare complication après le remplacement de la valvule mitrale.

Fistulas between the aorta and left atrium, invariably a complication of aortic valvular endocarditis, are rare and infrequently diagnosed premortem. We describe a patient who presented with this entity and review the reports of five other patients for whom a diagnosis was made premortem. A number of causative organisms have been identified. The clinical course is characteristically one of rapidly progressive heart failure. Notably, only half of these fistulas were detected by transthoracic echocardiography, whereas all were identified by transesophageal echocardiography when utilized. Once the diagnosis is made, prompt surgical repair is required to avert the high mortality from rapidly developing refractory congestive heart failure.

Rupture of the membranous interventricular septum resulting in a left ventricular to right atrial shunt is a rare complication of endocarditis. Early recognition of this complication is essential because these patients require early surgical intervention. We report a case of a left ventricular-right atrial shunt complicating aortic valve endocarditis in which transesophageal echocardiography was used to accurately diagnose the lesion before surgery. We will discuss the role of transesophageal echocardiography in the diagnosis of this lesion and will review the existing literature pertaining to this rare complication.

The causes of valvular emergencies, including infectious, inflammatory, ischemic, traumatic, degenerative, and iatrogenic causes, are reviewed. Recent developments in the diagnosis and treatment of valvular emergencies are discussed, such as color Doppler, transesophageal echocardiography, and the use of thrombolytic therapy for thrombosed prosthetic valves. Rapid diagnosis and aggressive management of valvular emergencies can produce excellent short- and long-term outcomes.