Significance of an Atrial Gallop Sound in Mitral Regurgitation

The incidence of atrial gallop sounds was studied in 51 patients with pure mitral regurgitation of sufficient severity to require operative treatment. Seventeen patients were in sinus rhythm. Nine of them had atrial gallop sounds and mitral regurgitation secondary to ruptured chordae tendineae, while six without atrial gallop sounds had primary valvular disease. The degrees of disability or the hemodynamic findings did not differ among the patients with ruptured chordae tendineae and those with primary valvular disease and sinus rhythm. However, the duration of symptoms and the history of a heart murmur were much shorter and the left atrium tended to be smaller in patients with ruptured chordae tendineae than in those with primary valvular disease. Sinus rhythm in a symptomatic patient with severe mitral regurgitation, therefore, should suggest the diagnosis of ruptured chordae tendineae. If, in addition, an atrial gallop sound is found the diagnosis of ruptured chordae tendineae is even more likely.