Microbubbles Mimicking Prosthetic Mitral Valve Thrombosis

J INVASIVE CARDIOL 2021;33(4):E317. doi:10.25270/jic/20.00199

Key words: microbubbles formation, prosthetic mitral valve

A 36-year-old woman with a history of redo mitral valve replacement (bileaflet mechanical mitral valve prosthesis) in 2002 for prosthetic mitral valve endocarditis presented to the emergency department with a history of recurrent palpitations. Her systemic examination was unremarkable, with a blood pressure of 110/76 mm Hg and oxygen saturation of 100% at room air. A 12-lead electrocardiogram showed atrial flutter with 3:1 atrioventricular conduction. Her complete blood count showed microcytic hypochromic anemia with hemoglobin of 8.8 mg/dL. Thyroid function tests were normal and international normalized ratio was in a therapeutic range of 3.5 on 2 mg of warfarin. She was treated with intravenous amiodarone and heart rate was normalized to sinus rhythm. A transthoracic echocardiogram was performed and falsely indicated a diagnosis of prosthetic mitral valve thrombosis. However, review of the echocardiogram by an experienced echocardiologist revised the diagnosis to microbubbles formation phenomenon with mechanical mitral prosthesis (Figure 1 and Video 1). A transesophageal echocardiogram performed on the same day demonstrated a normal-functioning prosthetic mitral valve and diagnosis of microbubbles formation was confirmed. Frame-by-frame analysis or reducing the frame rate of the recorded echocardiographic loop is vital to demonstrate the growing or dissipation of microbubbles and hence to avoid inadvertent thrombolytic therapy or surgical intervention. The patient remained asymptomatic and persistence of microbubbles formation continued to be observed in a transthoracic echocardiogram at 6-month follow-up.

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From Sultan Qaboos University Hospital, Muscat, Oman.

Disclosure: The author has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The author reports no conflicts of interest regarding the content herein.

The author reports that patient consent was provided for publication of the images used herein.

Manuscript accepted April 21, 2020.

Address for correspondence: Muhammad Athar Sadiq, Assistant Prof/Consultant Interventional Cardiologist, Sultan Qaboos University Hospital, Muscat, Oman. Email: matharsadiq@gmail.com