In vivo quantification of myocardial muscarinic receptors in heart transplant patients.

Background: Decreased myocardial adenylate cyclase activity in response to guanine nucleotide stimulation has been recently demonstrated in denervated myocardium of transplant patients, suggesting that changes in left ventricular muscarinic receptors may occur.

Methods And Results: The concentration and affinity constants of myocardial muscarinic receptors were determined by positron emission tomography with 11C-labeled methylquinuclidinyl benzilate (MQNB), a specific hydrophilic antagonist, in six transplant patients 4.7 +/- 2.

[Cardiac and extracardiac abscesses in bacterial endocarditis].

Cardiac abscesses are observed in 20 to 30% of cases of infective endocarditis and in at least 60% of prosthetic valve endocarditis. The aortic valve ring is more frequently affected than the mitral valve ring. A cavity contiguous with a cardiac chamber forming a pseudo-aneurysm or a closed purulent collection, the abscess may extend to the neighbouring cardiac structures or to the ascending aorta.