Bubbles in the heart.

To the Editor: The image by Catapano et al1 gives misleading information concerning bubbles in the heart in patients with prosthetic valves. They speculated that “bright particles” seen in the left ventricular cavity are consistent with gas bubbles that occur in scuba divers after hypobaric decompression. We disagree with this speculation, because this phenomenon is well documented in patients with prosthetic valves. In their large series, Gencbay et al2 found a strong correlation between serum lactic dehydrogenase levels and quantity of bubbles. They suggested hemolysis as a cause of bubble formation. Moreover, Kaymaz et al3 determined the prevalence of bubble formation in 279 patients with valve replacement and found that none of the patients with bioprosthetic valves demonstrated bubble formation. Bubbles were present, however, in 128 of 227 (56.4%) prosthetic mitral valves (P 0.0001). Bubbles were documented in 75.4% of the normal bileaflet valves compared with 38.5% of the tilting-disk valves in their cases (P 0.0001). Also in their study, the bubble intensity score was also significantly higher in the bileaflet valves. The passage of bubbles in the aortic root was not documented in any cases in their study. They concluded that bubbles are normal echocardiographic findings depending on the type and function of the mechanical prosthetic mitral valve.