Cavitation phenomenon in mechanical prosthetic valves: Not only microbubbles

Area of Science:

• Cardiology
• Medical Imaging
• Vascular Surgery

Background:

• Microbubbles (MBs) or cavitation are echo-bright findings during mechanical valve operation.
• Gas emboli formation is less frequently described but can occur.
• Understanding gas emboli is crucial for accurate diagnosis post-valve replacement.

Purpose of the Study:

• To evaluate hemodynamic parameters associated with gas emboli formation.
• To assess the impact of gas emboli on the need for additional diagnostic investigations.
• To determine the clinical significance of gas emboli after mechanical valve surgery.

Main Methods:

• Retrospective analysis of transthoracic echocardiographic (TTE) studies in 57 patients with gas emboli post-heart valve replacement.
• Comparison of hemodynamic data (BP, HR, gradients, ejection fraction) between TTEs with and without gas emboli.
• Review of subsequent investigations (TEE, brain CT) prompted by gas emboli findings.

Main Results:

• Gas emboli were frequently observed, particularly with mitral or combined mitral/aortic mechanical valve prostheses.
• Patients with gas emboli showed a significantly higher heart rate (HR) compared to those without.
• Additional investigations like transesophageal echocardiography (TEE) and brain CT were frequently requested due to gas emboli, though often yielding negative results for thrombus or stroke.

Conclusions:

• Gas emboli are a frequent finding after mechanical valve replacement and are associated with an elevated heart rate.
• Gas emboli can mimic serious conditions like endocarditis or thrombus, leading to unnecessary diagnostic workups.
• Accurate interpretation of echocardiographic findings is essential to avoid misdiagnosis and excessive testing.