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Editor,—We read with interest this report of peripheral pulmonary artery stenosis in congenital generalised lipodystrophy but query the physical findings, particularly in case 1.1 Furthermore, the term ‘pulmonary hypertension’ is used imprecisely. Pulmonary hypertension implies a pulmonary artery pressure higher than normal but whether this is systolic, diastolic, or mean has different connotations. The intensity of the pulmonary component of the second heart sound depends primarily on the pulmonary artery diastolic pressure dependent in turn on pulmonary vascular resistance. In peripheral pulmonary artery stenosis, both are low, analogous to the situation after pulmonary artery banding to reduce pulmonary blood flow in certain congenital cardiac defects. If the pulmonary artery diastolic pressure is high, the pulmonary component of the second sound is likely to be accentuated. In case 1 of the above paper, the child is alleged to have both peripheral pulmonary artery stenosis and ‘a loud pulmonary second heart sound’. This would indeed be unique. We would be interested to know the authors’ explanation.
Dr Uzun comments:
We were surprised at Drs Carvalho and Shinebourne’s comments on clinical signs in patients with peripheral pulmonary stenosis—they state that pulmonary artery diastolic pressure is low in these patients and that the pulmonary component of the second heart sound is, therefore, not accentuated (as it was in one of our cases). This may indeed be the case in some patients with a limited number of discrete pulmonary artery stenoses (diastolic pressure being low because of flow occurring through the low resistance vessels which are unaffected by the disease). In contrast, when there are multiple severe peripheral pulmonary artery stenoses and a paucity of low resistance vessels remaining then diastolic pressure in the proximal pulmonary arteries rises and the pulmonary second sound may be accentuated, as described in our report1-1 (our patient’s pressure was 85/30 with mean of 55 mm Hg). These clinical findings are not unique and are clearly described in the highly regarded reference text1-2 edited by Dr Shinebourne himself!