Material and Method: Between January 2010 and December 2012, 150 patients diagnosed with infective endocarditis by the modified Duke criteria treated at Srinagarind Hospital and Queen Sirikit Heart Center, Khon Kaen University were included. The transthoracic echocardiography (TTE) was performed on every patient.

Results: Four patients with S. agalactiae endocarditis were identified. The TTE features included one patient with a huge, highly mobile vegetation at the mitral position and patient presented with acute embolic stroke. Two patients with highly mobile vegetations at the aortic position and destroyed aortic cusps, both patients presented with congestive heart failure. One patient with vegetation at mechanical valve, mitral position and patient presented with congestive heart failure. All four patients underwent a combined medical and surgical therapy. A correlation between the echocardiographic features and surgical findings in all but two patients, fewer abscesses were found by surgery.

Conclusion: In the setting of acute endocarditis, the detection of large vegetation and severely destroyed valve by echocardiography is an argument in favor of S. agalactiae endocarditis and may warrant early surgical intervention.

Keywords: Streptococcus agalactiae, Infective endocarditis, Echocardiography