European Journal of Cardiovascular Medicine

Infective endocarditis (IE) is characterized by inflammation of the endocardium, primarily caused by infectious agents affecting cardiac valves and other extracardiac locations. Despite advancements in the management of IE, it remains an extremely difficult condition for clinicians to diagnose, resulting in significant morbidity and mortality ¹. Predisposing factors for infective endocarditis include underlying anatomical cardiac conditions such as valvular and congenital heart diseases, as well as the presence of prosthetic valves and intravenous drug abuse. The spectrum of infective endocarditis (IE) in India has evolved over the past decade due to a decrease in rheumatic heart disease incidence, a rise in intravenous drug abuse, improved survival rates among congenital heart disease patients, and the availability of diagnostic tools such as echocardiography^2-4. Gram-positive cocci, particularly Staphylococcus aureus, are the predominant infecting organisms, affecting each native and prosthetic valve infective endocarditis.

A 19-year-old man had intermittent fever for 4 months, NYHA class III shortness of breath for 3 weeks, and bilateral lower limb oedema for 2 weeks. Diabetes, high-risk conduct, or intravenous drug misuse were not present. Upon examination, the patient presented with fever (oral temperature 38.8°C), tachypnea (respiratory rate 30/min), and a heart rate of 118/min. Blood pressure was measured at 114/70 mm Hg, with elevated jugular venous pressure (JVP) at 10 cm above the sternal angle (v waves > waves). A palpable systolic thrill was noted in the left second intercostal space (ICS), accompanied by an ejection systolic murmur (ESM) graded 5/6 with delayed peaking in the left third ICS. Additionally, diffuse crepitations were observed in bilateral lung fields. The patient was admitted with a suspected diagnosis of infective endocarditis. Further investigation revealed cardiomegaly on his chest x-ray (figure 1).

Transthoracic echocardiography assessment (figure 2) demonstrated multiple vegetations affecting the tricuspid, pulmonary, aortic valves, and distal right ventricular outflow tract (RVOT). A prominent oscillating vegetation was observed on the tricuspid valve, measuring 21 mm x 9 mm. Another significant oscillating vegetation was noted on the pulmonary valve, measuring 8 mm x 6 mm, along with a distal RVOT vegetation measuring 11 mm x 6 mm, and an aortic vegetation measuring 11 mm x 5 mm. The right ventricle exhibited muscle bands obstructing the mid-cavity, resulting in the division of the RV into two chambers (figure 2-F): a proximal high-pressure chamber and a distal low-pressure chamber. The gradient across the obstruction measured 84 mm Hg, indicative of a double-chambered right ventricle, as verified by transoesophageal echocardiography (figure 2-H). Moderate aortic regurgitation was observed, characterized by a pressure half-time (PHT) of 305 ms, alongside severe tricuspid regurgitation.

A left-to-right shunt and restrictive perimembranous ventricular septal defect (4mm) were seen on transoesophageal echocardiography (figure 2 D). Three sets of blood cultures led to the patient being given intravenous ceftriaxone 2g/day, gentamycin (3 mg/kg/day), furosemide 40mg twice a day, and heart failure medications. The fever resolved after three days of initiating antibiotic therapy, and symptoms of heart failure gradually improved. Hematological investigations revealed no significant findings, except anemia (haemoglobin level of 7.9 g/dl). Blood cultures (BACT/ALERT and VITEK-2 BIOMERIUX) returned negative results following 5 days of incubation. Antibiotic therapy resulted in a reduction in the size of pulmonary and RVOT vegetations; however, other vegetations did not exhibit a decrease in size. The patient was therefore referred for surgical treatment.

Double-chambered right ventricle (DCRV) constitutes approximately 0.5-2% of all congenital heart diseases⁵. DCRV is commonly linked with additional anomalies such as peri-membranous VSD, aortic obstruction, or pulmonary valve stenosis ⁶. Limited cases of DCRV leading to infective endocarditis have been documented in the literature, while triple valve endocarditis remains exceedingly uncommon. Because of the strong turbulent jets in the outflow tracts, DCRV is sometimes mistaken as restricted VSD, making diagnosis difficult ⁷.

Chaurasia et al.⁷ described a case of a 16-year-old boy with a high-grade fever, cough, shortness of breath (NYHA class II), and weight loss that persisted for a month. The cardiovascular examination revealed a grade 4/6 ejection systolic murmur in the left third intercostal area. Transthoracic echocardiography revealed a 13 mm × 8 mm oscillating echogenic mass near the pulmonary valve and a double-chambered right ventricle with hypertrophied muscular bands connecting the septal tricuspid valve to the anterior wall. Transthoracic echocardiography revealed a 13 mm × 8 mm oscillating echogenic mass near the pulmonary valve and a double-chambered right ventricle with hypertrophied muscular bands connecting the septal tricuspid valve to the anterior wall. Although the other valves work generally, the right ventricular outflow tract's systolic gradient reached 141 mmHg. The improved subcostal and parasternal short-axis images showed a few hypertrophied muscle bands dividing the right ventricle into proximal and distal chambers. Since heart failure and repeated imaging showed no vegetation size change after antibiotics, the patient was recommended for surgery. 3D-transthoracic imaging verified the results.

A 37-year-old woman who had been experiencing shortness of breath and haemoptysis for a month was described by Myeong et al.⁸ as having NYHA class II symptoms. Examining the patient revealed a grade 4/6 ejection systolic murmur at the third left lower sternal border, fever, and pallor. Transthoracic echocardiography revealed tricuspid valve (6 x 6 mm on the anterior leaflet and 11 x 8 mm on the septal leaflet) and pulmonary valve (20 x 12 mm) oscillating vegetations, together with hypertrophy of the right ventricular septal and parietal band. Aneurysm formation occurred in the peri membranous region of the ventricular septum, with no associated shunt present. Transoesophageal imaging confirmed the findings. The patient received intravenous antibiotics for two weeks before being referred for surgical intervention.

A 21-year-old man who had no history of intravenous drug misuse or high-risk conduct presented with intermittent fever for one month and intermittent chest pain for six months in a case documented by Armyn et al. ⁹. Physical examination revealed fever and a grade 3/6 lower left sternal border pansystolic murmur. Echocardiography revealed a perimembranous ventricular septal defect, including a left-to-right shunt, a 14 mm × 12 mm aortic valve mass, two 7 mm × 13 mm and 9 mm × 12 mm pulmonary valve masses, mild aortic regurgitation (pressure half-time of 578 ms), and moderate tricuspid regurgitation. The patient was recommended for surgery after three weeks of intravenous antibiotics, but the vegetation did not shrink.

According to Kauffman et al.¹⁰, a 55-year-old woman was diagnosed with VSD and pulmonary stenosis as a child. Despite having no history of intravenous drug use, she had been suffering from increasing dyspnoea, fatigue, lower extremity edema, and weight loss for several of months. The exam showed a left lower sternal border systolic murmur, bilateral pedal oedema, and elevated jugular venous pulsation. Transesophageal echocardiography indicated a hypertrophied RV and significant subpulmonic stenosis in a double-chambered right ventricle (DCRV) pattern. Cardiovascular magnetic resonance imaging confirmed proximal RV hypertrophy and DCRV related to sub infundibular stenosis. The patient was advised to replace aortic and pulmonary valves, close ventricular septal defect, and remove right ventricular sub infundibular obstruction in addition to intravenous antibiotics.

The patient had a four-month-long fever, three weeks of NYHA III shortness of breath, two weeks of bilateral lower limb edema, and a grade 4/6 ejection systolic murmur in the left third intercostal region. A restricted perimembranous ventricular septal defect, mild aortic regurgitation, and several big vegetations on the tricuspid, pulmonary, and aortic valves as well as the distal right ventricular outflow tract were all seen on echocardiography. In this case, the jet of perimembranous VSD most likely caused infective endocarditis over the tricuspid, pulmonary, distal RVOT, and aortic valve. The patient was referred for surgical care after three weeks of intravenous antibiotics because the pulmonary valve vegetation shrank in size while the others stayed the same. Because of the large number of lesions, many cases are challenging to diagnose and manage. Due to the higher risk of embolism, instances with enormous oscillating vegetations and substantial valvular involvement should be treated surgically.

The double-chambered right ventricle is often associated with rare congenital abnormalities like pulmonary stenosis, VSD, and aortic obstruction. DCRV seldom causes infective endocarditis, which affects the pulmonary valves when the jet damages the endothelium. It is rare for DCRV to affect the distal RVOT, tricuspid, pulmonary, and aortic valves. Diagnosing significant involvement is difficult, and surgery is usually needed.

Figure 1. The posterior-anterior (PA) view of a chest x-ray

Figure 2. 2D- echocardiography showing A. Large vegetation attached to tricuspid valve, B. Vegetations attached to aortic valve, C. Vegetations attached to pulmonary valve and RVOT,

D,E. TEE showing restrictive perimembranous ventricular septal defect (VSD) and gradient across VSD. F,G,H. Showing obstruction in mid cavity of right ventricle (double chambered RV) with gradient across obstruction confirmed by TEE, I. Moderate aortic regurgitation.

Table 1. Hematological investigations

(Hb- hemoglobin, TLC-total leukocyte count, RBS- random blood sugar, AST- aspartate amino transferase, ALT- alanine transaminase, ALP- alkaline phosphatase, ESR- erythrocyte sedimentation rate)

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