[Evaluation of norepinephrine content in the myocardium in hypertensive patients with left ventricular hypertrophy].
The sympathetic nervous system seems to be a non hemodynamic factor involved in the development of hypertension and in left ventricular hypertrophy determinism. The aim of this study was to estimate the myocardial norepinephrine content in essential hypertensive patients, using a reliable radio-iodinated marker of norepinephrine: the 123I-meta-iodobenzylguanidine (123I-meta-iodobenzylguanidine). Eight male and female hypertensive patients with left ventricular hypertrophy and average age of 52 +/- 9 years underwent a resting, ambulatory and effort blood pressure measure. Echocardiographic parameters allowed measure of left ventricular mass index (according to Devereux, and we considered left ventricular hypertrophy as left ventricular mass index greater than 120g/m2. Plasma norepinephrine is measured at rest. Cardiac and mediastinal radioactivity is detected 4 h after a 4mCi i.v. injection of 123I-meta-iodobenzylguanidine and meta-iodobenzylguanidine myocardial uptake is definite as the cardiac/mediastinal ratio (N:1.78 +/- 0.19). Meta-iodobenzylguanidine-myocardial uptake average value of hypertensive patients was 1.89 +/- 0.19 (1.63 to 2.25) without statistical difference to control subjects. We found a significative correlation between meta-iodobenzylguanidine myocardial uptake and effort systolic blood pressure variation in one hand, and with heart rate increase with effort in the other hand. There is no correlation between meta-iodobenzylguanidine-myocardial uptake and left ventricular mass index or ambulatory blood pressure. In hypertensive patients with left ventricular hypertrophy, meta-iodobenzylguanidine myocardial uptake is normal or high, in agreement with experimental data in SHRs, model of human essential hypertension. Therefore myocardial scintigraphy with 123I-meta-iodobenzylguanidine can appreciate cardiac norepinephrine content in humans.
Schwebel
C
C
Service de médecine interne et cardiologie, CHRU, BP 217, Grenoble.
Fagret
D
D
Tremel
F
F
Siché
J P
JP
Boutelant
S
S
de Gaudemaris
R
R
Mallion
J M
JM
D019797:3-Iodobenzylguanidine; D000368:Aged; D005260:Female; D006801:Humans; D006973:Hypertension / Q000378:metabolism*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000378:metabolism; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D011877:Radionuclide Imaging
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine; D009638:Norepinephrine
Evaluation du contenu myocardique de noradrénaline chez l'hypertendu avec hypertrophie ventriculaire gauche.