RESUMO
Following a week of racemic mexiletine HCl at 200 mg tid (2x100 mg capsules), stereoselective aliphatic hydroxylation was studied in eight Chagasic women with chronic ventricular arrhythmias (52-67 yrs) with no history of renal or hepatic diseases. Blood samples were collected at dose interval up to 24 h of drug administration. Plasma concentrations of R(-) and S(+) mexiletine (MEX) and its metabolite hydroxymethylmexiletine (HMM) were determined by HPLC after derivatization with chiral reagent. The differences between R(-) and S(+) enantiomers were compared by paired t-test. Results are mean (95% CI). The following differences (p < 0.05) between R(-) and S(+) enantiomers, respectively, were found: MEX AUCss(0-8) 2.34 (1.84-2.85) vs 2.55 (1.97-3.13) microg.ml(-1) x h(-1); MEX CL/f 11.27 (7.77-14.77) vs 10.46 (7.18-13.74)ml.min(-1).Kg(-1); HMM Cmax 38.26 (24.3-52.22) vs 16.73 (10.1-23.29)ng.ml(-1); HMM Tmax 4.71 (2.67-6.76) vs 3.29 (1.24-5.33) h and HMM AUCss(0-8) 253.50 (165.39-341.61) vs 103.70 (69.51-137.90)ng.ml(-1).h(-1). The AUCss(0-8) ratio R(-)/S(+) for MEX was 0.93 (0.87-0.98) while for HMM was 2.50 (2.16-2.85). Distribution of MEX and HMM enantiomers were not significantly different. In this study we demonstrate that kinetic disposition of mexiletine exhibits stereoselectivity in vivo and that aliphatic hydroxylation is favored for R(-) mexiletine in Chagasic women with ventricular arrhythmias.
Assuntos
Antiarrítmicos/sangue , Arritmias Cardíacas/metabolismo , Doença de Chagas/metabolismo , Mexiletina/sangue , Antiarrítmicos/farmacocinética , Arritmias Cardíacas/complicações , Doença de Chagas/complicações , Feminino , Ventrículos do Coração , Humanos , Taxa de Depuração Metabólica , Mexiletina/farmacocinética , Pessoa de Meia-Idade , EstereoisomerismoRESUMO
Congenital coronary fistula is a rare heart defect, which consists of a communication between a coronary artery and a cardiac chamber of coronary vessel. Most such fistulae drain into a right heart chamber or into the pulmonary artery. Congenital left coronary artery-left ventricle fistula is even more uncommon. In a search of the literature, we were able to find only 15 other cases of congenital left coronary artery-left ventricle fistula. We describe here the clinical picture of a patient with left circumflex coronary artery draining into the left ventricle, and the successful surgical repair of the lesion. As far as we know, such a case has never before been reported in detail.
Assuntos
Anomalias dos Vasos Coronários/cirurgia , Fístula/congênito , Fístula/cirurgia , Ventrículos do Coração/anormalidades , Ventrículos do Coração/cirurgia , Adolescente , Anomalias dos Vasos Coronários/diagnóstico por imagem , Fístula/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , RadiografiaRESUMO
The superior vena cava syndrome that causes difficulties on venous return to the heart is a uncommon clinical entity and actually, more than 90% of the cases are secondary to a malignant intrathoracic process, rather than the intrinsic diseases of the aorta that is a rare etiology of the compression. The present report documents an aortic ascending atherosclerotic aneurysm that developed a superior vena cava compression syndrome. The literature was reviewed, stressing some important aspects about the etiology, physiopathology, diagnostic procedures, prognostic and treatment of this syndrome.
Assuntos
Aneurisma Aórtico/complicações , Síndrome da Veia Cava Superior/etiologia , Aorta Torácica/diagnóstico por imagem , Aneurisma Aórtico/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Síndrome da Veia Cava Superior/diagnóstico por imagemRESUMO
PURPOSE: To show the initial experience of this service with the technique of percutaneous transluminal coronary angioplasty. PATIENTS AND METHODS: Between january 1988 and december 1989, 305 coronary angioplasties were performed in 280 patients with age range of 33 to 82 years (being 49% above 60 years old) and 71% male. Among those, 212 (75%) experienced clinical picture of stable angina and 68 (25%) of unstable angina or myocardial infarction. Patients were divided in three groups: group A--those with lesions of 70% or worse in more than one vessel or in the same vessel with or without any other vessel total occlusion (multiple lesions or multiple vessels: 36 patients; group B--those with lesions of 70% or worse in one vessel with at least one occluded vessel: 64 patients; group C--those with lesions of 70% or worse isolated in a single vessel: 180 patients. RESULTS: Of the 280 treated patients, 229 were considered successful (75%). There has been 22 complications (7%) and 9 deaths (3%). The late follow-up (from 1 to 24 months), displayed 28 new procedures based on clinical suspicion of restenosis. Obstruction or occlusion were present in 16 of the later, with 10 being selected to undergo new procedure, one of those twice. The remaining 12 patients received clinical or surgical treatment. CONCLUSION: Aside from the fact that early and midterm results indeed are promising, the procedure is not safe from immediate risks, and limiting late restenosis. Nevertheless, the lesions might be redilated by the same technique, with success rates comparable to the initial one.