Case report

A 11-year-old girl presented with low grade fever, dyspnoea on exertion NYHA class II and multiple episodes of haemoptysis for 2 days. She had rheumatic heart disease with severe mitral regurgitation and mild mitral stenosis, for which she underwent mitral valve replacement 2 months back with a 27 mm SJM mechanical mitral valve. There was no history of cough with expectoration or thromboembolic manifestation. On examination she was tachypnoeic, tachycardic and had bilateral crepitations on auscultation. Based on the initial clinical evaluation by the paediatric medicine team, a working diagnosis of lower respiratory tract infection and infective endocarditis was made and started investigating in those lines. Electrocardiogram revealed left ventricular hypertrophy and sinus tachycardia (Fig 1a). Chest X ray revealed features suggestive of pulmonary venous hypertension. However, there was no features of pneumonic patch, pleural effusion or any cavitary lesion in the X ray (Fig 1b). Screening echocardiography showed a gradient of 8 mm Hg across mitral valve at a heart rate of 130 bpm. She was referred to us for a detailed echocardiographic evaluation to rule out infective endocarditis.

Figure 1. (a) Electrocardiogram on presentation showing sinus tachycardia and left ventricular hypertrophy (b) Chest X ray posteroanterior view showing features suggestive of pulmonary venous hypertension (c) Colour doppler across the mitral valve in apical 4 chamber view (d) Colour doppler across the mitral valve in parasternal long axis view showing eccentric turbulent jet towards the ventricular septum.

Patient was not willing to undergo transoesophageal echocardiography; hence transthoracic echocardiography was done. The mean diastolic gradient across mitral valve was 9 mmHg at heart rate of 126 bpm, which is not too much given the presence of tachycardia. On first glance there was no turbulence in colour doppler across the mitral valve in apical four chamber view. However, in the parasternal long axis view an eccentric turbulent jet could be seen directed towards the interventricular septum (Figure 1c and d). Mobility of the leaflets could not be clearly ascertained. On analysis of the mitral inflow continuous wave doppler, pressure half time was more than 200 m/second, which suggested obstruction across prosthetic valve. Left ventricle was dilated with left ventricular ejection fraction of 35%. We did cine fluoroscopy, which revealed mobility of one leaflet was completely restricted, while the other one was partially restricted (supplementary video 1). Her complete blood count and antistreptolysin O titres were normal, blood culture was sterile and serum procalcitonin was negative. She had sub therapeutic international normalised ratio levels (1.3), which was probably the cause for prosthetic heart valve thrombosis.

Since patient had ongoing haemoptysis, we were initially sceptical about going ahead with thrombolytic therapy. Cardiac surgeons were also in favour of managing the patient medically. Warfarin was discontinued and was started on heparin since the day of admission. Since there was no evidence to suggest pneumonia or infective endocarditis, we hypothesised that the haemoptysis was due to rupture of bronchial veins as a consequence of acute elevation of left atrial pressure secondary to obstructive prosthetic heart valve thrombosis. She was already on heparin for 2 days without any improvement in symptoms and continuation of heparin might aggravate haemoptysis. Hence, we decided to administer low dose slow infusion of thrombolytic, in an effort to improve the success of thrombolysis and reduce bleeding. She was started on tenecteplase 7.5 mg (0.25 mg/kg) over 6 hours. However, after administration of half the dosage, she had a bout of haemoptysis. The infusion was discontinued, and echocardiography was repeated. The mean diastolic gradient reduced from 9 to 4 mmHg (Fig 2b). But the mobility of one of the leaflets was still completely restricted. Over the next 24 hours the frequency and volume of haemoptysis had reduced and so we decided to give a repeat dose of tenecteplase 7.5 mg over 6 hours.

Figure 2. (a) Continuous wave doppler across the mitral valve on presentation (b) Continuous wave doppler across the mitral valve after initial Tenecteplase infusion (c) Final Continuous wave doppler across the mitral valve showing E & A waves and normal gradient.

Repeat fluoroscopy showed normal mobility of both the leaflets (Supplementary video 2). The mean diastolic gradient reduced even further to 1.5 mmHg (Fig 2c). Tachycardia and haemoptysis resolved in the next 24 hours. She was started on warfarin, aspirin, beta blockers, angiotensin converting enzyme inhibitor and spironolactone. On 2 weeks follow up she is doing well and international normalised ratio in therapeutic range.