Introduction
Pulmonary valvar stenosis accounts for about one-tenth of congenital cardiac malformations and is usually recognised in infancy or early childhood. Balloon valvoplasty is established as first-line treatment, Reference Rao1 although a dysplastic valve is a well-recognised predictor of a poor response. Reference Marantz, Huhta and Mullins2,Reference Musewe, Robertson and Benson3 Hepatic injury is a familiar consequence of right heart failure, but rarely dictates the sequence of treatment. We describe an adolescent in whom severe pulmonary valvar stenosis was found incidentally, on a murmur elicited during attendance for an unrelated complaint, and in whom the liver then dictated the sequence of treatment.
Case report
A 17-year-old girl with type 1 diabetes mellitus presented to the emergency department with postcoital vaginal bleeding. Oxygen saturation was 94% in room air, blood pressure was 93/56 mmHg, and she was pale. A palpable systolic thrill and a grade 6/6 systolic ejection murmur were noted in the pulmonary area. Electrocardiography showed dominant R waves in leads V1 to V4 and P pulmonale, despite the absence of any cardiac complaint. She became hypotensive, and haemoglobin fell from 12.2 to 9.1 g/dL; fluid and red cell transfusion were given.
Echocardiography showed a thickened, dysplastic pulmonary valve with severely restricted opening and turbulent flow at valvar level (Figure 1 a ). Peak velocity on continuous wave Doppler was 9.43 m/s, giving a peak instantaneous gradient of 356 mmHg (Figure 1 c ). The right heart chambers were dilated, with right ventricular hypertrophy and leftward deviation of the ventricular septum (Figure 2). Tricuspid annular plane systolic excursion was 8.7 mm, indicating severe right ventricular systolic dysfunction. Left ventricular ejection fraction was 65%. No interatrial communication was identified.
Echocardiography before and after treatment. ( a ) Colour flow mapping across the right ventricular outflow tract before intervention, showing turbulent, aliased flow at valvar level. ( b ) The corresponding view one month after pulmonary valve replacement. ( c ) Continuous wave Doppler across the pulmonary valve before intervention. ( d ) Continuous wave Doppler across the bioprosthesis one month after replacement.
Figure 1. Long description
Panel A: A color Doppler echocardiogram image showing turbulent, aliased flow at the valvar level in the right ventricular outflow tract before intervention. The image is a color flow mapping with blue and red regions indicating flow direction and velocity. Panel B: A color Doppler echocardiogram image showing the corresponding view one month after pulmonary valve replacement. The image shows improved flow with less turbulence. Panel C: A continuous wave Doppler echocardiogram image showing the velocity of blood flow across the pulmonary valve before intervention. The graph displays high velocity peaks indicating severe stenosis. Panel D: A continuous wave Doppler echocardiogram image showing the velocity of blood flow across the bioprosthesis one month after replacement. The graph displays lower velocity peaks indicating improved flow.
Apical four-chamber view before intervention, showing right ventricular hypertrophy, dilatation of the right heart chambers and leftward deviation of the ventricular septum.
Liver function was normal on admission. Haemoglobin and the fluid deficit were replaced on the first day, and blood pressure normalised. Aminotransferases nevertheless rose over the following days, reaching 1280 U/L (aspartate aminotransferase) and 880 U/L (alanine aminotransferase). Lactate dehydrogenase was 976 U/L, the international normalised ratio 1.2 and total bilirubin 1.5 mg/dL. The ratio of alanine aminotransferase to lactate dehydrogenase was 0.9, consistent with hypoxic rather than viral or toxic injury. Viral serology and autoimmune liver markers were negative. Ultrasound showed hepatomegaly with dilatation of the inferior caval vein and hepatic veins. No gastroenterological cause was found, and the injury was attributed to the cardiac lesion, for which balloon valvoplasty—the established first-line treatment—was undertaken.
The catheter would not initially cross the valve; predilatation with a 7 × 20 mm Tyshak II balloon (NuMED, Hopkinton, New York, United States of America) was followed by 16 × 40 mm and 18 × 40 mm Z-Med balloons. The pulmonary annulus measured 14 mm, giving a balloon-to-annulus ratio of 1.28. Right ventricular systolic pressure fell from 141 to 110 mmHg. Within 48 hours the aminotransferases had fallen to between 269 and 492 U/L, and they were normal within 7 to 8 days.
Residual obstruction remained severe, and the patient underwent right ventricular outflow tract reconstruction with pulmonary valve replacement, using a 25 mm bioprosthesis. At review one month after surgery, peak velocity across the prosthesis was 2.54 m/s, giving a gradient of 26 mmHg, with turbulence but no regurgitation (Figure 1 b , d ); tricuspid annular plane systolic excursion had improved to 10.3 mm, aspartate aminotransferase was 25 U/L and alanine aminotransferase 19 U/L, and haemoglobin was 11.2 g/dL. She remained asymptomatic. Genetic evaluation for Noonan syndrome is ongoing.
Discussion
Three features merit comment.
First, severe obstruction had produced neither symptoms nor referral over 17 years, despite a thrill and a grade 6/6 murmur elicited only during attendance for an unrelated complaint. Adaptation to a slowly progressive lesion masked its cost until reserve was tested.
Second, that reserve was tested by an unrelated haemorrhage. Modest anaemia and hypotension, which a normal circulation would tolerate, produced aminotransferases twenty times normal. The haemorrhage was, however, only the trigger. Haemoglobin and blood pressure were restored on the first day, yet the aminotransferases went on rising and remained grossly elevated until the obstruction was relieved. What sustained the injury was not the bleeding but the heart: a right ventricle unable to deliver forward output across a critically narrowed valve, against a background of hepatic venous congestion. Reference Henrion4,Reference Xanthopoulos, Starling, Kitai and Triposkiadis5 Overt shock is absent in about half of such patients, and right heart failure is present in most. Reference Henrion4
Third, balloon valvoplasty was the appropriate first-line treatment, yet relieved the obstruction only partially, as is often the case with a dysplastic valve; Reference Marantz, Huhta and Mullins2,Reference Musewe, Robertson and Benson3 surgical reconstruction with valve replacement was therefore required. The procedure was not wasted, however. The biochemical course is striking: aminotransferases that had resisted otherwise adequate resuscitation fell by half or more within 48 hours of right ventricular pressure being lowered. Even the partial relief afforded by valvoplasty—a fall from 141 to 110 mmHg—sufficed to reverse the hepatic injury and bring the patient to surgery in better condition. Balloon valvoplasty may thus achieve worthwhile haemodynamic and biochemical improvement even where it cannot be definitive.
Limitations
The Doppler gradient greatly exceeded the peak-to-peak gradient measured invasively and implies a right ventricular pressure far above any recorded in this lesion; the velocity was probably overestimated, spectral broadening making the true envelope hard to define. Bernoulli overestimation, the instantaneous to peak-to-peak difference, and differing loading conditions all contribute. Reference Mullins, Ludomirsky and O’Laughlin7 Invasive data guided all decisions. A dynamic infundibular component was not excluded by catheter pull-back or angiography. Genetic testing for Noonan syndrome, the commonest syndromic association, is incomplete. Reference Roberts, Allanson, Tartaglia and Gelb6
Acknowledgements
None.
Financial support
This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
Competing interests
The authors declare none.
Ethical standards
The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national guidelines on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. Written informed consent for publication was obtained from the patient and her parent.
