Bacterial Endocarditis and Atrial Rupture

Clinical History

This 60 year old male attended Outpatients 7 months prior to death, with hypertensive heart disease and normochromic anaemia. He was admitted for investigation of the anaemia. On admission the blood pressure that had been 200/105 was now 125/60. Clinically it was thought he had endocarditis but repeated blood cultures were negative. No explanation was found for the anaemia so the patient was transfused and discharged. He was re-admitted a month or so later following anorexia and vomiting. Examination at this stage showed congestive cardiac failure and anaemia once again. A mitral diastolic murmur was heard in the apex in addition to a loud systolic bruit which has been present all the time. There was a rapid deterioration and death.

Pathology

The specimen is of a heart sliced to display the left atrial and ventricular cavities. The heart is enlarged and the left ventricle is hypertrophied. A split is present in the posterior wall of the left atrium 5 cm in length and situated 5 mm above the posterior cusp of the mitral valve. The split appears to be of recent origin and can also be seen extending through on the posterior aspect of the specimen. There is a large pale vegetation 1 cm in diameter with some adherent clot present on the posterior cusp of the mitral valve. The chordae tendinae of the cusp have ruptured and the cusp has prolapsed into the atrium. Smaller vegetations are present on the same valve and chordae. At necropsy the pericardial sac contained over one litre of fresh blood and clot. Smear and Gram stain of vegetation showed Streptococcus viridans. This, then, is an example of subacute bacterial endocarditis with atrial rupture leading to cardiac tamponade.