Purulent pericarditis-induced intracardiac perforation and infective endocarditis due to Parvimonas micra: a case report

Abstract

Background: Purulent pericarditis, a rare disease with a high associated mortality rate in patients without adequate treatment, can cause serious complications, such as perforation of the surrounding tissue and organs. Parvimonas micra is a very rare cause of purulent pericarditis.

Case summary: A 70-year-old male patient presented to our emergency room with chest pain of 10 days' duration. An electrocardiogram showed ST-segment elevation and PR-segment depression on multiple leads. A transthoracic echocardiogram showed normal left ventricular function and a large amount of pericardial effusion. Acute pericarditis was diagnosed, and anti-inflammatory drug therapy was initiated. Due to the lack of improvement in the symptoms, pericardiocentesis was performed on Day 8 and revealed about 800 cc of the bloody fluid. Parvimonas micra was detected in a culture of the pericardial effusion and blood. Although intravenous antibiotic therapy was initiated for purulent pericarditis, his fever persisted. Computed tomography of the chest performed on Day 14 showed an abscess cavity in the pericardial space around the right atrium (RA). Furthermore, transoesophageal echocardiography revealed vegetation in the RA. Emergency surgery confirmed the presence of vegetation and minor perforation of the RA with communication to the abscess cavity. After surgical therapy, the patient clinically improved and was discharged on Day 51.

Discussion: In cases of acute pericarditis, purulent pericarditis should be considered if clinical improvement is not observed after initial treatment with anti-inflammatory drugs. Once the diagnosis of purulent pericarditis is made, aggressive source control is necessary for improved clinical outcomes.

Keywords: Case report; Infective endocarditis; Intracardiac perforation; Parvimonas micra; Purulent pericarditis.

Figure 1

Electrocardiography at admission showing ST-segment elevation and PR- segment depression on the II, III, aVF, and V2 to V6 leads.

Figure 2

Transthoracic echocardiogram of apical four-chamber view at admission showing a large amount of pericardial effusion (asterisk) without compression of right side of the heart. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

Figure 3

Computed tomography of chest showing abscess cavity in the pericardial space around the right atrium (asterisk) and trabecular shadow in the right atrium (arrow). Ao, ascending aorta; LA, left atrium; LV, left ventricle; PA, pulmonary artery; RA, right atrium; RV, right ventricle.

Figure 4

Transoesophageal echocardiographic mid-oesophageal 135˚ view of the right side of the heart. Vegetation with severe mobility (19.2 mm × 9.2 mm) was observed in the right atrium (arrow) near the abscess cavity in the pericardial space. AC, abscess cavity; LA, left atrium; RA, right atrium; RV, right ventricle.

Figure 5

Intraoperative photos. (A) An abscess cavity was observed around the right side of the heart (white arrows). (B) Pus was removed from the abscess cavity. (C) After abscess cavity removal, subsidence in the right atrium and minor bleeding were observed (yellow arrow). (D) The vegetation (22 mm × 12 mm × 2 mm) removed from the right atrium. Ao, ascending aorta; RA, right atrium; RV, right ventricle.