700 Letters to the Editor Figure 1 Immunohistochemical up- regulation of utrophin in all the car- diomyocytes of the carrier biopsy. the cytoplasm of some cardiomyo- cytes (Fig. 1). This finding suggests that utrophin may compensate, at least partially, for the dystrophin de- ficiency in more than 50% of the car- diomyocytes in this patient, as has been described in human skeletal and cardiac muscle of MDX mice' 51 . In conjunction with the remaining dys- trophin, the utrophin-positive myo- cytes are able to maintain sarcolemmal integrity and normal myocardial func- tion. Thus, upregulation of utrophin in the myocardium may prevent, or at least postpone, the development of dystrophin deficient cardiomyopathy in this DMD carrier patient. T. M. BEHR P. FISCHER H. MUDRA K. THEISEN C. SPES P. UBERFUHR* W. MULLER-FELBER D. E. PONGRATZ C. ANGERMANN Medizinische Klinik, Kiinikum Innenstadt and * Kiinikum Grosshadern, University of Munich, Germany References [1] Love DR, Hill DF, Dickson G. An autosomal transcript in skeletal muscle with homology to dystrophin. Nature 1989; 339: 55-8. [2] Pons F, Robert A. Fabbrizio E et al. Utrophin localization in normal and dystrophin deficient heart. Circulation 1994; 90. 369-74. [3] Schmid-Achert M, Fischer P, Pongratz D. Myocardial evidence of dystrophin mosaic in a Duchenne muscular dystro- phy carrier. Lancet 1992:340: 1235-6 [4] Schmid-Achert M, Fischer P, Muller Felber W, Mudra H, Pongratz D. Heterozygotic gene expression in en- domyocardial biopsies: a new diagnos- tic tool confirms the Duchenne carrier status. Clin Invest 1993; 71: 247-53. [5] Tinsley JM, Davies KE. Utrophin: a potential replacement for dystrophin? Neuromusc Disord 1993: 3: 537-9. Percutaneous stent implantation in an adult with left pulmonary artery stenosis and absent right pulmonary artery We encountered a rare case of progres- sive dyspnoea of 3 years duration in a middle aged woman. Tricuspid regur- gitation (TR) was grade 2/3 with a right ventricular systolic pressure of 70 mmHg at two-dimensional echo- cardiography and Doppler study. There was significant narrowing of the proxi- mal left pulmonary artery (LPA) and the right pulmonary artery (RPA) could not be seen. A radionuclide perfusion scan with 99m-Technetium showed no perfusion of the right lung and a first pass gated blood pool study revealed a RV ejection fraction (EF) of 33% and a left ventricular (LV) EF of 60%. Cardiac catheterization revealed a mean right atrial pressure of 12 mmHg; RV pressure was 70/12 mmHg with a gradient of 45 mmHg across the LPA stenosis. A pulmonary artery angio- gram revealed a 15 mm long 70% con- centric stenosis of the proximal LPA, absent RPA and poor RV contractility. The patient was therefore sub- jected to balloon dilatation and poss- ible stenting of the LPA stenosis. With a 7 F Judkins right coronary catheter as a guide, a 0035 inch angled glide wire (Terumo Corporation, Tokyo, Japan) was used to cross the stenosis and the catheter was then tracked dis- tally into the left pulmonary artery. A 0038 inch double length Amplatz extra stiff exchange guide wire (Cook Inc., Bloomington, Indiana) was positioned in the left lower lobe pulmonary artery. A 18 mm x 3 cm balloon catheter (Mansfield Inc., Boston) was positioned at the stenosis. The balloon was hand- inflated across the stenotic segment un- til disappearance of the waist. A repeat RV angiogram revealed only marginal improvement in the minimal internal diameter of the LPA (6 mm pre-dilation to 7 mm post dilatation). Since the lesion was stretchable with an elastic recoil, we decided to implant a stent to maintain dilatation of the LPA sten- osis. A 14 F Mullins sheath was intro- duced over the guide wire and past the stenosis. A Palmaz iliac stent, which is 0076 mm thick with a deflated profile of 3-4 mm and length of 30 cm was manually crimped on a 18 mm x 40 cm 8-5 F balloon (Cook Inc., Bloomington, Indiana) and the whole assembly was advanced into the Mullins sheath. The balloon-mounted stent was advanced up to the LPA stenosis and then hand inflated to deploy the stent. After successfully implanting the stent, RV angiograms (Fig. 1), taken in various projections showed a marked improve- ment in the minimal internal diameter (15 mm post stent implantation) and a minimal residual lesion. There was a significant improvement in RV contrac- tility. Ten thousand units of heparin were given during the procedure and heparin was continued for 24 h. Subse- quently she was advised to take aspirin orally 75 mg . day ~ ' for 3 months. Pre- discharge Doppler study showed no TR and a gradient of 10 mmHg across the LPA. Figure 1 Eur Heart J, Vol. 18, April 1997 Downloaded from https://academic.oup.com/eurheartj/article-abstract/18/4/700/528663 by guest on 16 June 2020