Isolated pulmonary valve endocarditis with pulmonary annular abscess in a patient of Noonan syndrome

INTRODUCTION

Infective endocarditis (IE) is associated with mortality, notwithstanding the use of appropriate antibiotic therapy and surgical intervention. Right-sided endocarditis is uncommon, with various series reporting an incidence of 5%–10%.¹ Among patients with right-sided IE, tricuspid valve (TV) involvement is seen in 90% of instances² and ‘isolated’ pulmonary valve endocarditis (PVE) is rare, affecting <2% of patients with IE.³ Early identification and prompt management are key to prevent long-term complications and reduce mortality in these patients.

THE CASE

A 50-year-old man with no history of intravenous (i.v.) drug abuse, alcoholism and surgery presented with the complaints of increased shortness of breath and fever for 1 month. His shortness of breath progressed from New York Heart Association (NYHA) class II to class III within 15 days. It was accompanied with fever, reduced appetite and myalgia. On examination, the patient was febrile (102 °F). Pallor and clubbing were present. He had tachycardia (pulse rate 120/minute) and hypotension (systolic blood pressure 90 mmHg). He had features of Noonan syndrome such as dysmorphic facies in the form of hypertelorism, low-set and backward rotated ears, small lower jaw, short neck and low hairline (Fig. 1a). On auscultation, Grade 4/6 ejection systolic murmur was present in the pulmonary area along with short diastolic murmur of pulmonary regurgitation in the third intercostal space in the left parasternal region. There were crepts in the left infra-axillary area. He also had splenomegaly. Blood investigations showed normocytic normochromic anaemia with haemoglobin of 8.4 g/dl, significantly elevated total leucocyte count of 42 800/cmm with 88% neutrophils, increased platelet count (700 000/ml), erythrocyte sedimentation rate of 50 mm in the 1st hour and C-reactive protein of 110 mg/L. Renal and liver function tests were normal. On chest X-ray, there was a patch in the left lower lobe. Transthoracic echocardiography (TTE) was done due to suspicion of endocarditis which showed dysplastic pulmonary valve (PV) (PV thick and dooming) with severe pulmonary stenosis (gradient 98 mmHg) and moderate pulmonary regurgitation (PR) with evidence of mobile vegetation on the PV. There was presence of pulmonary annulus (PA) abscess of 3 mm extending into the right ventricular outflow tract (RVOT) (Fig. 1b–d). Aortic, mitral and TVs were structurally and functionally normal. Blood cultures were sent, and he was started on ceftriaxone 2 g/24 hours i.v. and gentamycin 3 mg/kg/24 hour i.v. Blood culture grew Staphylococcus haemolyticus sensitive to ceftriaxone, hence gentamycin was discontinued. He received i.v. antibiotics for 4 weeks. The blood counts decreased to 24 000/cmm, but due to persistent fever, moderate PR and PA abscess formation, the patient was taken up for PV replacement (PVR). PVR was done with a 21-mm Hancock II porcine heart valve with excision of the aneurysmal anterior wall of the pulmonary artery with pericardial patch plasty of PA. PV showed multiple vegetations over the cusp and annulus with no subvalvular pathology. Subsequently, he was discharged and advised follow-up.

Close

FIG 1.

(a) Patient with dysmorphic facies in the form of hypertelorism, low-set and backward rotated ears, small lower jaw and having features of Noonan syndrome; (b) transthoracic echocardiography short-axis view showing evidence of pulmonary valve vegetation; (c) continuous-wave Doppler demonstrates severe pulmonary stenosis (gradient 98 mmHg) with moderate pulmonary regurgitation; (d) transthoracic echocardiography showing evidence of vegetation (marked with*) with evidence of pulmonary annular abscess extending into the right ventricular outflow tract (marked with arrow) of size 1.9 cm×1.0 cm

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DISCUSSION