Implante de Stent dentro de Stent recém implantado em ponte de veia safena para otimizaçäo do resultado angiográfico / Stenting a Stent in saphenous vein graft to optimize the angiogrphic result

Mulher de 60 anos, com angina progressiva e revascularizaçäo do miocárdio, há oito anos, com ponte de veia safena para coronária direita e anastomose de artéria mamaria esquerda para artéria descendente anterior. Submetida a implante de stent Gianturco-Roubin II em terço proximal da ponte de veia safena para artéria coronária direita, com resultado insatisfatório pela persistência de lesäo residual, provavelmente, decorrente de prolapso para dentro da luz de material aterosclerótico através dos coils. Foi implantado outro stent (Palmaz-Schatz biliar) dentro do stent GRII com sucesso e ótimo resultado angiográfico. Um 2§ stent Palmaz-Schatz biliar foi implantado em lesäo distal no corpo da ponte, ultrapassando os dois stents, anteriormente implantados, com sucesso. Em algumas situaçöes, implante de stent dentro de outro stent é recurso útil para otimizaçäo de resultado angiográfico do implante de um stent.

A perda precoce do diâmetro luminal após angioplastia coronária e sua influência no fenômeno da reestenose / Early luminal diameter loss after percutaneous transluminal coronary angioplasty and its relation to the restenosis phenomenon

OBJETIVO - Analisar a perda do diâmetro luminal mínimo (DLM) nos primeiros 15 min após angioplastia coronária por balão (AC), quantificando sua influência na reestenose coronária. MÉTODOS - Foram estudadas, prospectivamente, 86 AC em 86 pacientes. Os pacientes foram divididos em dois subgrupos de acordo com apresença ou ausência de reestenose; o 1o. grupo compreendendo as 31 lesöes com reestenose e o 2o. as 55 lesöes sem reestenose. RESULTADOS - A análise univariada mostrou que a relação balão/artéria foi menor no grupo com reestenose (0,92ñ0,01 vs 1,00ñ0,11, P=.003). O grupo com reestenose apresentou maior recolhimento elástico absoluto e relativo no 1o. min (0,79ñ0,54 vs 0,68ñ0,59mm; P=0,007 e 32,04ñ14,27 vs 22,15ñ16,25 por cento; P=0,006.) e no controle angiográfico do 15o. min (1,25ñ0,59 vs 0,90ñ0,65mm, P=0,017 e 46,75ñ15,69 vs 29,18ñ17,84 por cento , P<0,00001)do que o grupo sem reestenose. O DLM no 1o. min foi menor no grupo com reestenose (2,15ñ0,42 vs 2,43ñ0,58mm; P=0,002). O grupo com reestenose apresentou uma maior perda precoce no DLM (0,46ñ0,34 vs 0,22ñ0,35mm, P=0,004). Este decréscimo na luz do vaso determinou que o DLM do 15o. min fosse ainda menor no grupo com reestenose (1,69ñ0,48 vs 2,20ñ0,61; P=0,0001). Da análise multivariada, entretanto, identificou-se apenas a relação balão/artéria e o DLM do 15o. min como os dois fatores independentes mais relacionados à reestenose. CONCLUSÄO - O recolhimento elástico e a perda do DLM ao longo dos 15 min são fatoes diretamente relacionados à reestenose.Entretanto, a análise multivariada mostrou que a relação balão/artéria e o DLM de 15 min são os dois fatores independentes mais fortemente preditores de reestenose.

Slow coronary run-off in patients with angina pectoris: clinical significance and thallium-201 scintigraphic study

To determine whether or not slow coronary flow (SF) depends on hemodynamic variables, we studied 17 patients (15 men, mean age = 47.8 years) with SF at coronariography. Exercise thallium-201 myocardial scintigraphy revealed perfusion abnormalities in 13 (76.4 per cent) patients. We then selected 89 individuais submitted to cinecoronariography for comparison: 15 were normal and 74 had heart disease. The coronary flow velocity was evaluated by the number of heart beats (HB) needed for coronary artery dye filling. The patients in the SF group had normal hemodynamic variables which were significantly different from those of patients with heart disease (P = 0.001). Patients with heart disease needed no more than 4 HB to fill their arteries, in contrast to 6.88 ñ 1.68 (5 to 11) in the SF group (P<0.OOO1). Thus, in our patients with myocardial scintigraphy suggesting ischemia, SF was found to be an event which did not depend on hemodynamic factors.

Infecções bacterianas em 100 pacientes submetidos a transplante cardíaco / Bacterial Infections in 100 Patients Submitted to Heart Transplantation

Objetivo - analisar as ocorrências, os agentes etiológicos e a apresentaçäo clínica referentes às infecçöes bacterianas diagnosticadas em grupo de pacientes submetidos a transplante (Tx) cardíaco. Métodos - foram considerados 100 doentes, observados consecutivamente, após Tx cardíaco. O período de seguimento variou de 3 a 90 (média 25,38 + ou - 25,96) meses. O reconhecimento das infecçöes bacterianas levou em conta os critérios estabelecidos pelos Centers for Disease Control. Resultados - as infecçs pulmonares bacterianas comparecem em maior número, havendo dificuldade para diagnosticá-las depois do Tx. Ocorreram comprometimentos motivados por bactérias em pele, mucosas, partes moles, ferida operatória, pericárdio, pleura, loja do marcapasso e vias urinárias, tendo também sido constatadas bacteremias e endocardites. Os agentes etiológicos, quando reconhecidos, ficaram devidamente especificados. Conclusäo - o período pós-operatório inicial é crítico, pois nos 30 dias subsequentes a ele as infecçöe acterianas surgem com maior frequência. Elas também suscitam maior preocupaçäo nas fases de tratamento dos episódios de rejeiçöes. Diagnóstico precoce e rápida adoçäo de medidas coercitivas podem evitar gravidade e evoluçäo para óbito

Purpose - To evaluate clinical findings and etiology of bacterial infections diagnosed in 100 consecutive heart transplantations. Methods - One hundred consecutive heart transplant patients were studied. Follow-up after heart transplantation varied from 3 to 90 (mean 25.38± SD 25.97) months. Etiology of bacterial infection was established using the Centers for Disease Control criteria. Results - Bacterial infection was the most common cause of infection after heart transplantation; diagnosis was difficult. Infection sites were skin, mucous, membranes, soft tissue, surgical scar, pericardial and pleural spaces, soft tissue around heart pacing devices, urinary tract; bacteremias and endocarditis were also found. All bacterial agents recovered were fully identified Conclusion - Bacterial infections are the most common infections in the first month after heart transplantation. They are important and also common after the treatment of the rejection episodes. Rapid diagnosis and adequate treatment are essential to prevent morbidity and death

Infecções fúngicas em 100 pacientes submetidos a transplante cardíaco / Fungal Infections in 100 Patients Submitted to Heart Transplantation

Objetivo - analisar as ocorrências, agentes etiológicos, aspectos clínicos, topografias e números de óbtios referentes às infecçöes fúngicas diagnósticas em grupo de pacientes submetidos a transplante cardíaco (TX). Métodos - foram considerados 100 pacientes, observados consecutivamente, após TX. O período de seguimento variou de 3 a 90 (média 25,38 +/- 25,97) meses. O reconhecimento das infecçöes fúngicas levou em conta os critérios os estabelecidos pelos Centers for Disease Control. Resultados -ouve reconhecimentos de 47 infecçöes, com 3 óbitos atribuíveis diretamente a elas, Acremonium sp, Aspergillus sp, Candida albicans, C.tropicalis, Histoplasma capsulatum e Pneumocystis carinii constituíram os fungos responsáveis. Candidíase da cavidade oral devida à candida albicans representou o acometimento mais comumente comprovado. Conclusäo - as infecçöes fúngicas no grupo avaliado foram responsáveis por 3 óbitos e devem suscitar proprostas profiláticas e terapêuticas

Purpose - To evaluate prevalence, causes, clinicalaspects, topography and deaths due to fungal infections diagnosed in a series of patients submitted to heart transplantation. Methods -100 consecutive patients submitted to heart transplantation were studied Follow-up was three to 90 (mean 25.38±25.97) months. Fungal infections were diagnosed by the Centers for Disease Control criteria. Results - Forty seven fungal infections were found, with three deaths caused mainly by fungal infection. The most common infection in this series was oral infection by Candida albicans, Acremonium sp, Aspergillus sp, Candida tropicalis, Histoplasma capsulatum and Pneumocystis carinii were also responsible for infections in this patient population. Conclusion - Fungal infections caused three deaths in this series, and were responsiblefor increased morbidity. The authors suggest prophylactic and therapeutic recommencations

Valor do precondicionamento isquêmico na circulaçäo colateral, funçäo ventrícular e evoluçäo clínica no infarto agudo do miocárdio / The effecft of ischemic preconditioning on collateral circulation, ventricular function and clinical outcomes after acute

Objetivo - Avaliar a influência do precondicionamento isquêmico no fenômeno do desenvolvimento de circulaçäo colateral (CC), na funçäo ventrícular precoce e na evoluçäo hospitalar de pacientes com infarto agudo do miocárdio (IAM). Métodos - Foram estudados 97 pacientes com IAM anterior nas primeiras 6h, com oclusäo proximal da artéria coronária descendente anterior e divididos em 2 grupos na dependência da presença (GA) ou ausência (GB) de angina precedendo o IAM. Coronariografia e ventriculografiaoram realizadas nas primeiras 6h , antes de qualquer tentativa de reperfusäo. A fraçäo de ejeçäo global do ventrículo esquerdo (FEVE), foi obtida através do método de áreas e a funçäo regional da parede anterior anterior através da linha do centro. Resultados - Os grupos foram superponíveis em relaçäo ao sexo, idade, pico de CKMB, tratamento instituído (perfusäo química ou mecânica) e sucesso na reperfusäo. A média da FEVE e a mobilidade da parede anterior foram similares nos 2 gupos, respectivamente, 3+_9 por cento e -2,55+/_1,17 dp/corda no GA e 37 por cento+/_8 por cento e -2,75+/_0,79 dp/corda no GB (p=ns). A CC esteve presente em 6 pacientes do GA e em 8 do GB (p=ns). A evoluçäo clínica foi melhor no GA (todos Killip classe 1) em comparçäo ao GB (8 pacientes Killip > ou igual a 2) p=0,007. Conclusäo - Embora näo exista diferença entre os grupos em relaçäo a presença de CC, funçäo ventricular e regional do ventrículo esquerdo, a presença de angina precedendo o infarto associado à melhor evoluçäo hsptalar, a qual poderia em parte ser explicada pelo fenômeno denominado precondicionamento esquêmico.

Análise da retração elástica nos primeiros 15 minutos após angioplastia coronária por cateter balão / Elastic recoil in the firt 15 minutes following a successfull balloon angioplasty

Objetivo - Determinar angiograficamente a retraçäo elástica (RE) nos primeiros 15 minutos após angioplastia coronária (AC) por cateter baläo. Métodos - E um estudo prospectivo, 154 pacientes, portadores de angina estável, foram submetidos a AC com sucesso. Realizaram-se angiografias imediatamente após a última insuflaçäo com sucesso e aos 5,10 e 15 min. Na análise quantitativa utilizou-se caliper eletrônico. Quantificaram-se o diâmetro luminal mínimo (DLM) e a RE no controle imediato, aos 5, 10 e 1min. Relacionaram-se a magnitude da RE e o DLM com as características angiográficas da lesäo tratada, com o diâmetro do baläo e com o grau de lesäo residual imediatamente após a AC. Resultados - O diâmetro de referência médio do vaso foi de 3,09+/_0,61 mm e o diâmetro do baläo de 2,95+/_0,52 mm. O DLM mínimo pré dilataçäo foi de 0,65+/_0,42 mm, atingindo 2,23+/_0,55 mm após a dilataçäo (p<0,0001), decrescendo para 2,09+/_0,47 mm e 5 min (p<0,0001), 2,01+/_0,47 mm em 10 min (p<0,0001) e para1,91+/_0,56 mem 15 min. (p<0,0001). A RE aumentou progressivamente, atingindo 34,29+/_20,40 por cento aos 15 min. Nos vaso tratados onde a relaçäo baläo/artéria < ou igual a 1 a RE foi de 0,90+/_0,74 mm em 15 min. e de 1,20+/_0,50 mm quando a relaçäo foi >1 (p<0,0001). Identificou-se maior RE nos primeiros 15 min. no grupo de pacientes onde a lesäo residual no controle imediato situou-se entre 30 a 50 por cento do que no grupo onde a lesäo residual foi < 30 por cento. Conclusäo - A RE é um fenômeno dinâmico e progrssvo que ocorre dentro de 15 min. após a AC com sucesso. Determinou reduçäo média de 34,29+/_20,40 por cento no diâmetro do vaso em 15 min. e é maior quando a relaçäo baläo/artéria é >1. A lesäo residual que situa entre 30 e 50 por cento no controle angiográfico imediato é fator preditor de maior RE ao longo dos 15 min.

Endocardite infecciosa em 100 pacientes submetidos a transplante cardíaco / Inectious endocarditis in 100 patients after heart transplantation

Objetivo - analisar ocorrências, agentes etiológicos, aspectos clínico e taxa de óbitos referentes à endocardite infecciosa (EI) diagnosticada em pacientes submetidos a transplante cardíaco. Métodos - cem doentes foram observados consecutivamente após transplante cardíaco. O período de seguimento variou de 3 a 90 (média 25,38 +/- 25,97) meses. O reconhecimento da EI levou em conta critérios usados no Serviço de Epidemiologia e Desenvolvimento de Qualidade do INCOR da FMUSP, tendo como bases as defiçöes estipuladas pelo Center for Disease Control. Cooperaram para estabelecer o diangóstico, fundamentalmente, hemocultura, ecocardiograma transtorácico ou esofágico e necrópsia. Resultados - houve reconhecimento de 6 casos, com 4 óbitos, estando presentes em 3 processos sistêmicos generalizados. Febre compareceu como manifestaçäo clínica habitual. Conclusäo - o número de óbitos afigurou-se elevado, tendo em conta a natureza das bactérias causadores, a associaçäo com afecçöes graves e o uso de fármacos mnodepressores. Considerou-se importante adotar adequados cuidados em relaçäo aos fatores de risco, efetuar precocemente o diagnóstico e institutir rapidamente o tratamento.

Myocardial protection in the occlusion/reperfusion dog model: the role of ischemic necrosis vs reperfusion injury

The present study was designed to assess the possbility of maximizing the effects of reperfusion by the association of the calcium channel blocker, verapamil and the iron chelator deferoxamine, to delay necrosis and avoid reperfusion injury. Sixty-four mongrel dogs (15 ñ 1.1 (SD)Kg) were successfully subjected to 24 h of reperfusion following 90-min occlusion of the left anterior coronary artery. ECG and arterial presure were monitored. The risk area (RA; percent left ventricle (LV)) was determined by the infusion of Evans blue into the aortic root and the area of necrosis (AN; per cent RA) by triphenyltetrazolium chloride staining. Myocardial presevation was defined as per cent RA not necrosed calculated as (RA - AN)/RA x 100.RA was similar in all dogs, i.e., 33 ñ 2 per cent LV (SD). There were no differences in arterial pressure, heart rate or double product among groups. Myocardial preservation was 60 ñ 13 per cent RA in 9 control dogs submitted to reperfusion only (group C), and 58 ñ 18 per cent RA in 17 dogs treated with deferoxamine (500 mg, iv), 30 min before reperfusion (group DF). Verapamil (0.2 mg/Kg, iv) was given alone 15 min after occlusion to 15 dogs (group VP), followed by prereperfusion deferoxamine to 16 dogs (goup VP + DF) and in two doses after occlusion and 15 min before reperfusion in 7 dogs (group VP + VP). Myocardial preservation was greater in the latter groups when compared to controls, namely 76 ñ 13 per cent RA in group VP, 74 ñ 11 per cent in group VP + DF and 73 ñ 9 per cent in group VP + VP (P = 0.04 vs group C., ANOVA). The data suggest that mechanism underlying this beneficial effect is mainly related to the retardation of nectosis progression. O2 free radicals or Ca2+-induced reperfusion injury do not play a major role

Beneficial effect of long-term use of a beta-blocker in patients before acute myocardial infarction

The outcome of 38 beta-blocker users (group BB, 28 men and 10 women with a mean age of 56 ñ 4 years) was compared to that of 100 non-users (group NU, 69 men and 31 women with mean age of 57 ñ 8 years) after acute myocardial infarction (AMI). The two groups were compared in terms of electrocardiographic (EKG) location of the AMI (anterior, inferior and lateral), EKG Q and non-Q wave infarction, clincial functional class of Forrester, serum cratine phosphokinase MB fraction (CKMB) peak release and intrahospital mortality.There were no differences between groups concerning sex or severity of coronary artery disease bath arterial hypertension was 3-fold more prevalent group BB. The EKG location of the AMI was similar int he two groups. Non-Q infarction was significantly more prevalent in group BB (37 percent) than in group NU (5 percent). The incidence of clinical functional class IV of Forrester and the serum CKMB peaks were significantly lower in goup BB (2.6 percent vs 16.0 percent and 53 ñ 3 vs 68 ñ 9 UI/1, respectively. Intrahospital mortality was also significantly lower in group BB (2.6 percent) than in group NU (10 percent). These data suggest the beneficial effect of previous long-term use of beta-blockers as indicated by a lower incidence of cardiogenic shock and a significant decrease in intrahospital mortality after AMI

Clearance of a chylomicron-like emulsion from plasma is delayed in patients with coronary artery disease

To determine whether the metabolism of chylomicrons and their remmants is related to atherogenesis, a triglyceride-rich emulsion known to mimic chylomicron behavior in plasma and labeled with 1-14C-cholesteryl oleate was injected intravenously into 11 normolipidemic patients (triglycerides: 133 + or - 60 mg/dl; total cholesterol: 207 + or - 20 mg/dl; LDL: 143 + or - 20 mg/dl; VLDL: 27 + or - 13 mg/dl; and HDL cholesterol: 41 + or - 11 mg/dl; apo AI: 1.27 + or - 0.54 g/l and apo B: 1.42 + or - 0.31 gl) with atherosclerotic coronary artery disease and into 11 control subjects (triglycerides: 109 + or - 32 mg/dl; total cholesterol: 190 + or - 38 mg/dl; LDL: 125 + or - 29 mg/dl; VLDL: 22 + or - 6 mg/dl; and HDL cholesterol: 44 + or - 9 mg/dl; apo AI: 1.09 + or - 0.28 g/land apo B: 1.09 + or - 028 g/l) without the disease. The emulsion (69 percent triolein, 23 percent lecithin, 6 percent cholesteryl oleate and 2 percent cholesterol) was injected intravenously at approximately 9:00 a.m., after a 12-h fast. The clearance of the emulsion label from plasma, expressed as fractional clearance rate (FCR), was lower in coronary artery disease compared to controls (0.019 + or - 0.005/min vs 0.036 + or - 0.018/min, respectively, P<0.05). These results indicate that the rate of removal of chylomicron remmants is slower in patients with coronary artery disease

Lipoprotein (a) in subjects with or without coronary artery disease: relation to clinical history and risk factors

Lipoprotein (a) [Lp(a)] is an atherogenic lipoprotein resembling low-density lipoprotein (LDL) but with an additional apoprotein (apo), apo(a). To determine whether plasma Lp(a) levels can influence the clinical presentation and extent of coronary artery disease (CAD), Lp(a), plasma lipids and apolipoproteins were determined in 203 Caucasian subjects with CAD and in 66 subjects without CAD, all confirmed by cinecoronariography. CAD patients were divided into groups according to their clinical history. The extent of the disease was evaluated by a scoring system. Lp(a) was elevated in CAD patients compared to subjects without CAD. However, there was no difference between patients that had myocardial infarction as the first manifestation of the disease and those who had only angina pectoris for at least two years. Plasma lp(a) levels were correlated with extent of the disease. Among patients with CAD, Lp(a) was higher in females. Lp(a) was also studied separately in 29 Black subjects, Lp(a) was higher than in Caucasians but there was no difference between subjects with and without CAD. Among the other risk factors studied, only plasma apo B levels and smoking were correlated with CAD

Antagonizing the hydroxyl ion free radical (HO.) does not abolish reperfusion ventricular fibrillation in anesthetized dogs

1. The hypothesis that the hydroxyl ion free radical, HO; derived from O2 plays a pivotal role in the development of reperfusion ventricular fibrillation was tested in 63 anesthetized mongrel dogs of either sex weighing 14 +/- 7 kg submitted to 90-min coronary occlusion followed by 60-min reperfusion. 2. OH. was blocked by the iron chelator deferoxamine (DF, 500 mg) and by dimethylthiourea (DMTU, 500 mg/kg), a HO. scavenger both given iv over 30 min before reperfusion. 3. The frequency of reperfusion ventricular fibrillation was similar in all animals, i.e., 7/27 (26 per cent ) control dogs, 7/23 (30 per cent ) DF-treated dogs and 3/13 (23 per cent ) DMTU-treated dogs. Arterial pressure, heart rate and double product were not significantly different among the three groups during occlusion or reperfusion. The hemodynamic variables were also similar among dogs that fibrillated and those that did not. Likewise, extent of ischemic areas and necrosis was similar among the three experimental groups, with the control values being 34 +/- 4 per cent and 14 +/- 5 per cent , respectively. 4. We conclude that OH. does not play a major role in the induction of reperfusion ventricular fibrillation in the anesthetized dog with ischemia/necrosis

Evoluçäo do ciclo gravídico-puerperal em portadoras de estenose mitral / Course of pregnancy and puerperium in women with mitral valve stenosis

Objetivo. Estudar a evoluçäo do ciclo gravídico-pleural (CGP) e das características dos recém-nascidos, em portadoras de estenose mitral, que iniciaram a gravidez assintomáticas ou oligossintomáticas. Métodos. Sessenta e duas gestantes divididas em grupo GE 30 portadoras de estenose mitral GN - 32 sem cardiopatia. Resultados. No grupo GE, 16(53,3//) pacientes evoluíram para classe funcional (CF) III e 10(33//) para CF IV no decorrer da gestäo. No grupo GN, 18(56,2//) evoluíram para CF II. No grupo GE o parto foi vaginal em 70,0// e aplicado o bloqueio regional em 56,6// dos casos, sem diferença significativa (P > 0,1) entre os grupos. Prematuridade (20,0//) e recêm-nascidos pequenos para a idade gestacional (PIG) (36,7//) foram significativamente (p < 0,001) mais freqüentes no grupo GE. Näo houve mortalidade materno-fetal. Conclusäo. A maioria (86,7//) das gestantes do grupo GE evoluiu para CF III/CGP. Repouso, farmacoterapia e, em um caso, a valvoplastia por cateter-baläo contribuíram para que todas as pacients alcançassem a viabilidade fetal. Entretanto, freqüência expressiva de recém-nascidos prematuros (20,0// e PIG (36,7//) foi registrada

Increased plasma removal of microemulsions resembling the lipid phase of low-density lipoproteins (LDL) in patients with acute myeloid leukemia: a possible new strategy for the treatment of the disease

A microemulsion of lipid composition resembling low-density lipoprotein (LDL), but devoid of apolipoproteins and labeled with [14C]-cholesteryl oleate was injected into 16 healthy subjects and into 15 patients with acute myeloid leukemia (AML). Removal from plasma of the lipid label was higher in the leukemic group compared to healthy subjects in terms of fractional clearance rate (0.185 +/- 0.205 and 0.080 +/- 0.030 h-1, respectively, P < 0.03). When the emulsion was again injected into 10 of the AML patients after complete hematological remission, the fractional clearance rate of cholesteryl ester was reduced to one third of the value observed prior to treatment (0.061 +/- 0.038 h-1) and was not different from that obtained for the healthy subjects. Also, in untreated AML patients, serum LDL-cholesterol levels inversely correlated with the values of fractional clearance rate of the microemulsion. This correlation was no longer observed after treatment. These data suggest that the LDL-like microemulsion was selectively taken up by the neoplastic cells presumably by interaction with LDL receptors. Therefore, microemulsions may function as potential carriers for anticancer drugs that are targeted to tumor cells for patients with acute myeloid leukemia. Unlike native LDL, microemulsions are suitable for utilization in routine clinical practice

The antiadrenergic effects of hypermagnesemia: an experimental study

The circulatory effects of norepinephrine (4 * g/kg) and phenylephrine (20 */kg) were determined in anesthetized dogs withnormal plasma magnesium and with induced hypermagnesemia. Norepinephrine caused a 24% increased in heart rate by 103% increase in the systemic vascular, resistance index in normomagnesemic dogs, while with hypermagnesemia the variations were of 13% and 1%, respectively. Isoproterenol increased heart rate by 485 and 185 in dogs with normo- and hypermagnesemia, respectively.Phenylephrine increased the systemic vascular resistance index (74%) only in the normomagnesemic state.The effects of all the drugs were significantly defferent (P<0.01), without and with the simultaneous administration of magnesium sulfate (plasma magnesium, 1.3ñ0.2mEq/l and 6.8ñ1.1 mEq/l, respectively).We conclude that acute induced hypermagnesemia antagonizes the circulatory effects of adrenergic stimulation, a fact that may explain its antiarrhythmic and hemodynamic effects during acute myocardial ischemia

Acute effects of dobutamine and dopamine on renal and respiratory functions in patients on prolonged mechanical ventilation

Its is known that positive pressure mechanical ventilation (PPMV) decreases diuresis and increases extravascular water, thereby impairing pulmonary gas exhange. Sympathomimetic amines are commonly used to relieve these effects. To compare the effects of dobutamine (DT) and dopamine (DP) on renal and pulmonary function, we studied 30 patients submitted to continuous PPMV for a least 72 h. All were in stable hemodynamic conditions.patients had pulmonary insufficiency of different etiology. The drugs were randomly administered by continuous intravenous infusion at the dose of 4 to 6 *g kg-1 min-1 for 3 h. An interval of 60 min was allowed to elapse between treatments. A significant increases in arterial pressure and heart rate occurred with both drugs (P,0.05). DP increased urinary flow by 93.7% (1.6ñ0.1 to 3.1 ñ0.4 ml/min; P,0.05) and Na excretion fraction (NaEF) by 35.5% (P,0.05).In contrast, DT reduced NaEF by 58.9%(P,0.05) and had effect on urinary flow. Neither drug altered cretinine clearance.The alveolo-arterial O2 difference (a-aO2D), which was 370ñ20 mmHg during the control period, increased to 394 ñ 20 mmHg after DP and decreased to 355 ñ 22 mmHg after DT, the difference being statistically significant (P,0.05). Pulmonary shunt (%) and the venous pO2 (mmHg) did not change during the infusion of DP or DT.In conclusion, an acute increase in salt and water excretion does not necessarily lead to an immediate reduction in pulmonary "shunt". DT deserves further investigation since it may increase paO2 in the absence of ventricular failure

Mycrocardial protection by verapamil and reperfusion following coronary occlusion

The hypothesis that early verapamil (VP) treatment in acute myocardial ischemia can enhance the effects of subsequent reperfusion was tested in open-chest dogs submitted to 3h of left anterior descending artery occlusion and 2 h of reperfusion. 2. Arterial pressure and heart rate were monitored continuosusly. The area at risk (AR) was deteminede by left injection of99 technetium-labeled microspheres soon after occlusion. The area of necrossis (AN) was indentified histologically with triphenyl tetrazolium chloride and calculated as percent of Ar. Myocardial preservation is reported as percent of AR spared from necrosis (AR-An) x 100/AR). 3. Fouteen dogs received 0.2 mg VP, iv, 15 min after occlusion and 9 untreated dogs served as controls. Verapamil signficantly reduced heart rate but did not affect blood pressure or the pressure or the pressure-heart rate product. 4. Myocardial preservation was significantly greater in verapamil-treated dogs than in control animals (51ñ20 vs 31 ñ 19%, mean ñ SD). However, area at risk (%) in the left ventricle was not significantly different in treated and control animals (31 ñ 12 vs 32 ñ 4%). 5. These data indicate that verapamil protects the ischemic myocardium in this occlusion/reperfusion model and that the mecanism of protection is probably related to a non-hemodynamic, metabolic activity of verapamil .

Infarct-sparing effect of propranolol in an occlusion-reperfusion dog model

To test the hypothesis that early pharmacological protection of the ischemic myocardium can enhance the effects of late reperfusion, 32 mongrel dogs were submitted to 6 h of left anterior descending coronary (LAD) occlusion and 18 h of reperfusion. Arterial pressure and ECG were monitored. Area at risk was determined with methylene blue during coronary occlusion. Myocardial infarct size, measured with triphenyl tetrazolium chloride and by planimetry, was reported as percent of the area at risk of necrosis. Ten dogs received no treatment and were used as controls (Group I); Group II (9 dogs) and Group III (13 dogs) received 2.0 and 4.0 mg/kg propranolol, iv, respectively, 30 min after LAD occlusion. The hemodynamic effects of propranolol were not significantly different among groups during ischemia or reperfusion. Area at risk was similar in the 3 groups. Following reperfusion, salvage of ischemic myocardium was 13 + or - 3% of area at risk in Group I, and 18 + or - 8% (Group II) and 25 + or - 5% (Group III) in propranolol-treated animals. The differences between Groups I and II or II and III were not significant. However, preservation was significantly greater in Group III than in Group I (P<0.05). Therefore, early propranolol administration during ischemia improves the effects of subsequent reperfusion