# Doing a double take: when transthoracic echocardiography fails for mitral valve annuloplasty ring endocarditis with Streptococcus pyogenes: a case report

## TL;DR

A rare case of Streptococcus pyogenes endocarditis on a mitral annuloplasty ring was missed by initial echocardiography but later diagnosed and successfully treated.

## Contribution

Highlights the diagnostic challenges and management of culture-negative endocarditis on cardiac prostheses.

## Key findings

- Transthoracic echocardiography failed to detect intra-atrial masses adherent to a mitral annuloplasty ring.
- Culture-negative endocarditis with Streptococcus pyogenes was diagnosed and treated surgically.
- Recurrent cardioembolic strokes were linked to undiagnosed endocarditis.

## Abstract

This case highlights several complications of a late and rare presentation of culture-negative Streptococcus pyogenes endocarditis of a previously repaired mitral valve with an annuloplasty ring including recurrent cardioembolic strokes, which was initially missed on transthoracic echocardiography.

A 66-year-old Caucasian female with prior mitral valve prolapse status post mitral valve annuloplasty and left atrial appendage occlusion, followed by two strokes, presented with supraventricular tachycardia that resolved spontaneously. During an inpatient admission, she developed symptoms of another stroke, and imaging studies were suggestive of recurrent cardioembolic phenomenon. Additional workup revealed two small intra-atrial masses adherent to the mitral annuloplasty ring missed on prior evaluation for recurrent stroke. She underwent surgical repair in the setting of a chronic culture-negative infectious endocarditis with Streptococcus pyogenes and recovered well with no further cardioembolic phenomenon.

This case serves to highlight the importance of having a higher index of suspicion in any cardiac prosthesis patient for endocarditis when presenting with symptoms such as recurrent stroke, arrhythmias, and abnormal cardiac lab work. It also demonstrates the need for appropriate imaging with transthoracic echocardiography followed by transesophageal echocardiography and reviews surgical indications to diagnose and treat culture-negative endocarditis.

The online version contains supplementary material available at 10.1186/s13256-024-04623-y.