Influence of etiology on the functional result of aortic valve replacement.

The functional result of aortic valve replacement has been assessed in patients treated for isolated aortic incompetence. Using maximal oxygen uptake as an index of myocardial function, a significant difference (p less than .05) exists between the patients who had Q fever endocarditis on the one hand and those who had bacterial endocarditis or rheumatic fever on the other hand. We believe that permanent myocardial damage occurs as a result of bacterial endocarditis and rheumatic fever but because of the biological properties of Coxiella burnetii the myocardium is spared in Q fever endocarditis.