Assessment of coronary reserve in man using intravenous bolus 15O-water and positron emission tomography (PET): A comparison with intra coronary doppler study

J Mol Cell Cardiol 23 (Supplement IV) (1991)

124 ASSESSMENT

OF CORONARY RESERVE IN MAN USING MTRAVENOUS WATER AND POSITRON EMISSION TOMOGRAPHY 0 : A COMPARISON CGRONARY DOPPLER STUDY. P. Merlet, B. Mar&x, j.L. DuboisRand6, &~t~~~rouzcl, A. Castaigne, A. Symta. SI-IFJ, CEA. Orsay, and Cardiology

BOLUS *50WITH INTRA L. Raynaud, L. CHU Mondor,

;he purpose of this study was to evaluate the ability of intravenous (IV) bolus l50-water PET study to measure the coronary reserve (CR) in patients with significant stenosis of the left anterior descending artery (LAD). Using a ‘IOF-PET camera, 9 patients underwent 1) an IV bolus of 25 mCi of H215O at baseline and 4 to 6 minutes after an intravenous injection of 0.56 mg/kg of dipyridamole ; 2) a 18F Fluorodeoxyglucose (FIX) cardiac imaging. An anterior myocardium re ‘on of interest was manually drawn on the 20 minute static FDG image obtained 40 minutes after F&a mjection. Regional myocardial blood flow (rMBF) was obtained by fitting a 2 compartment model (rMBF = kl), including a vascular component, to kinetic PET tissue data and using the left ventricular chamber time-activity curve as an input function. Direct ultrasonic measurement of CR has been performed the day after the PET study : a 3Fr intra coronary doppler catheter was placed into the proximal LAD and mean velocity has been registucd at baseline and after dipyridamole IV injection using the same method as for PET study. Results : CR measured by PET study (1.9 +. 0.6) correlated with CR measured by intra coronary doppler study (2 + 0.6) : (r = 0.96, p c 0.001, n = 9). Thus IV bolus l50-water PET method represents an accurate mean to measure coronary resetve non invasively in ischemic patients.

125

coNs~~OFORTH(mlPICHEARI~US~-~?~AA’IRULNATRIUREIIC PEPTIDE (ANP), RENIN, ALDOSTBRONB AND VASOPRRSSIN PWSMA LBVBLSSM. Mmtes, N. De Talanc6, B. Peiffert. J.L. Retownart, M. Clavey. I.P. Haberer. C. Btulet. J.P. Villemot, M. Boulmg6. Labor&k d’Bxplomtions IJoncticmn~llcs R&ales et M&.sboliques. Chimqie Cardiaque et Transplant&ms Ckdio-dmrxklum. CHU BRABOIS. 54511 VANDOEUVRB-LBS-NANCY The aim of this study was to compare the immediate postopaativc (lnt (Dl) to 8th (D8) days) effects of human orthotopic heart and heart-hmg bansplanution on tlx release of the major hamones mgulsting fluid and electrolyte homeostasis. Over the 8 day postapemtive study period, alpha ANP. rain, aldostemne and vuo~essin serum levels were determined by radio-immunoassay in 10 heart (group 1: Gl) and 5 heart-lung recipients (group 2 : 02). Alpha ANP kvels wem slightly increased (25.1 i 2.2 fmolfml) on Dl and rapidly rose to 35.4 f 5.5 fmol/ml (DE, Gl). Results concerning group 2 patienU were similu (27 f 3.0 fmol/ml on Dl to 45.6 f 5.5 final/ml on DE). With exception to a peak in vuopressin on D 1 (87.7 f 18.8 pghnl for Gl snd 84.2 + 23.0 pg/ml for 02) postopmtive levels of this hormone were near normal in both group. A peak in ahiosterone level was also found on Dl(l303 f 301 pm&l for Gl and 2781 i 941 pmol/l for 02). These peaks in vuoprmsin ud aldosterot~e levels csn probably bc attributed to the surgical stress undergone by the patients. Rain levels on Dl were increased (264.1 f96.6 rig/l for Gl and S31.5 f 62.5 nfl for G2) but dropped significantly over the course of the study. This drop in ratin kds was related to improved p&em hemodynamic status. No significant correlation was found bmween changes in alpha ANP levels. rain aldostemne or vasopressin levels. patient hemodynamic status m admiitered drugs. In conclusion, grafted heart tissw wu found to be capable of sustained h&h levels of ANP release in both groups euly on. Comomitan:ly. vasopressbt levels md the renbt-aldostemne level retllmed to more normal levels. This disturbance in the hormonal regulation of fluid awl electrolyte homeostasis could be the result of primary hypersecretion of alpha ANP by both host and QIIIX atria1 USSUC. However, since the dative increase in the atrial tissue mass is less important in heart-lung recipients. hi8b levels of alpha ANP observed in this group might bc attributable to a possible modul&ttg mle of cardiac innervation upon the release of this hormone.

126

CONSEQUENCES OF HUMAN ORTHOTOPIC HEART TRANSPLANTATION ON RRNAL ELJZClXOLYl’E EXCR!Zl-ION AND HORMONAL REGULATION. P.M. Mates. N. De Talaw6, G. pbwJli. M.P. Mattei. J.P. Cateutx. E. Hottier, J.P. Viiemos C. Buries M. BoulangC. Explomtions Fonctimmellu R&mles et M6taboliques. Chimrgie Cudique et Tmnsplantations Cardio-thoraciques - CHV BRABOIS 54511 VANDOEUVRE-LES-NANCY The aim of this study was to evaluate the respective roles of the major hormones regulming fluid and electrolyte homeostasis in modulating electrolyte renal excretion during the acute postopnative period after human orthotopic heart transplantation. Ten heart transplant recipients WCTC studied from the fvst (Dl) to the ninth (IX) postoperative days. Fractional sodium (FeNa). potassium (FeK), osmole (FeOsm) and water (FeH20) excretion u well u cmatinii (Ccr) and osmolu clearance (COsm) were determined daily. Atial nakimetic peptide (ANP). plasma Vasopwsin @ADH). Renin and Aldostemne @Aldo) aa well as 24 hour urinary Vasopmssin (uAHD) and Aldostcmnc @Al&) wue assayed by radioiiouuy. Cmainine clearance was found to be significantly reduced in all patients (52 f 7 ml/mitt on Dl. 5.0 f 7 ml/min on D9) with initial polywia gradually returning to more nonnd levels (2.1 f 03 mUmin on D9). FeN l ~~~~(5.7f0,9%~Dl)udnpidlydroppad(22fO,9%onD9)@< 0.01). This drop was parallel to decreased renin serum snd al&staone urinary levels. as well as with decreased administration of fumsemide. No conelation WM found with ANP plasma levels. FeK was elev&d (76 f 8 & on Dl) and rapidly drop@ m 35 -f 10 R on D9. This decrease was related to decreased ahi~stemne urinary le.vels as well aa dccrxased fmoumide admiitmtiat. C&m (5.04 f 0.04 mmoUmin), Fe Osm (10.5 f 1.0 %) and F&20 (10.9 i 1.0 %) were increased on Dl snd rapidly deuascd during the study period @ < 0.02). in rel&m with an initial therapeaic osmotic dimesis. In camzhtsion, a significant dccrase in Ccr was observed in all patients. Orthotopic heart tianspllmt was followed by increased urinary excretion in relation with thempwticdly induced osmotic dime&s. However. d ccreasel in both reni” plasma levels atxl fmumnide 8dmbdsUUion were followed by L drop in FeNa. Finally. ANP release did not seem to be dimctly related to sodium urinary excretion. S.42