RESUMO
BACKGROUND AND PURPOSE: Little is known about associations between spontaneous coronary artery dissection and cervical artery abnormalities. This study sought to assess the prevalence of cervical artery abnormalities among patients with spontaneous coronary artery dissection. MATERIALS AND METHODS: A retrospective analysis was completed of patients who underwent CTA neck imaging as part of arterial assessment following the diagnosis of spontaneous coronary artery dissection. The internal carotid and vertebral arteries were evaluated for the presence of fibromuscular dysplasia, dissection and/or pseudoaneurysm, ectasia and/or aneurysmal dilation, atherosclerosis, and webs. Carotid tortuosity was categorized into kinks, loops, coils, and retrojugular and/or retropharyngeal carotid courses; vertebral tortuosity was classified by subjective analysis of severity. RESULTS: Two hundred fourteen patients were included in the final cohort, of whom 205 (95.8%) were women; the average age was 54.4 years. Fibromuscular dysplasia was the most frequently observed abnormality (83 patients; 38.8%), followed by dissections and/or pseudoaneurysms (n = 28; 13.1%), ectasia and/or aneurysmal dilation (n = 22; 10.3%), and carotid webs (n = 10; 4.7%). At least 1 type of carotid tortuosity was present in 99 patients (46.3%). The majority (n = 185; 86.4%) of patients had no carotid atherosclerosis; and 26 (12.2%) had mild; 3 (1.4%), moderate; and 0, severe carotid atherosclerosis. CONCLUSIONS: The most common abnormality in the cervical artery vasculature of patients with spontaneous coronary artery dissection is fibromuscular dysplasia. Cervical dissections were higher than previously reported but were not observed in most patients.
Assuntos
Aneurisma , Displasia Fibromuscular , Vasos Coronários , Dissecação , Feminino , Displasia Fibromuscular/diagnóstico por imagem , Displasia Fibromuscular/epidemiologia , Humanos , Pessoa de Meia-Idade , Prevalência , Estudos RetrospectivosRESUMO
OBJECTIVES: In a double-blind, randomized, crossover trial we sought to evaluate the effect of dual-chamber pacing in patients with severe symptoms of hypertrophic obstructive cardiomyopathy. BACKGROUND: Recently, several cohort trials showed that implantation of a dual-chamber pacemaker in patients with severely symptomatic hypertrophic obstructive cardiomyopathy can relieve symptoms and decrease the severity of the left ventricular outflow tract gradient. However, the outcome of dual-chamber pacing has not been compared with that of standard therapy in a randomized, double-blind trial. METHODS: Twenty-one patients with severely symptomatic hypertrophic obstructive cardiomyopathy were entered into this trial after baseline studies consisting of Minnesota quality-of-life assessment, two-dimensional and Doppler echocardiography and cardiopulmonary exercise tests. Nineteen patients completed the protocol and underwent double-blind randomization to either DDD pacing for 3 months followed by backup AAI pacing for 3 months, or the same study arms in reverse order. RESULTS: Left ventricular outflow tract gradient decreased significantly to 55 +/- 38 mm Hg after DDD pacing compared with the baseline gradient of 76 +/- 61 mm Hg (p < 0.05) and the gradient of 83 +/- 59 mm Hg after AAI pacing (p < 0.05). Quality-of-life score and exercise duration were significantly improved from the baseline state after the DDD arm but were not significantly different between the DDD arm and the backup AAI arm. Peak oxygen consumption did not significantly differ among the three periods. Overall, 63% of patients had symptomatic improvement during the DDD arm, but 42% also had symptomatic improvement during the AAI backup arm. In addition, 31% had no change and 5% had deterioration of symptoms during the DDD pacing arm. CONCLUSIONS: Dual-chamber pacing may relieve symptoms and decrease gradient in patients with hypertrophic obstructive cardiomyopathy. In some patients, however, symptoms do not change or even become worse with dual-chamber pacing. Subjective symptomatic improvement can also occur from implantation of the pacemaker without its hemodynamic benefit, suggesting the role of a placebo effect. Long-term follow-up of a large number of patients in randomized trials is necessary before dual-chamber pacing can be recommended for all patients with severely symptomatic hypertrophic obstructive cardiomyopathy.
Assuntos
Estimulação Cardíaca Artificial/métodos , Cardiomiopatia Hipertrófica/terapia , Adulto , Idoso , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Estudos Cross-Over , Método Duplo-Cego , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
OBJECTIVES: We attempted to determine the accuracy and pitfalls of calculating the mitral regurgitant orifice area with the proximal isovelocity surface area method in a clinical series that included patients with valvular prolapse and eccentric jets. BACKGROUND: The effective regurgitant orifice area, a measure of lesion severity of mitral regurgitation, can be calculated by the proximal isovelocity surface area method, the accuracy and pitfalls of which have not been established. METHODS: In 119 consecutive patients with isolated mitral regurgitation, effective regurgitant orifice area was measured by the proximal isovelocity surface area method and compared with measurements simultaneously obtained by quantitative Doppler and quantitative two-dimensional echocardiography. RESULTS: The effective mitral regurgitant orifice area measured by the proximal isovelocity surface area method tended to be overestimated compared with that measured by quantitative Doppler and quantitative two-dimensional echocardiography (38 +/- 39 vs. 36 +/- 33 mm2 [p = 0.09] and 34 +/- 32 mm2 [p = 0.02], respectively). Overestimation was limited to patients with prolapse (61 +/- 43 vs. 56 +/- 35 mm2 [p = 0.05] and 54 +/- 34 mm2 [p = 0.014]) and was restricted to patients with nonoptimal flow convergence (n = 7; 137 +/- 35 vs. 84 +/- 34 mm2 [p = 0.002] and 79 +/- 33 mm2 [p = 0.002]). In patients with optimal flow convergence (n = 112), excellent correlations with both reference methods were obtained (r = 0.97, SEE 6 mm2 and r = 0.97, SEE 7 mm2, p < 0.0001). CONCLUSIONS: In calculating the mitral effective regurgitant orifice area with the proximal isovelocity surface area method, the observed pitfall (overestimation due to nonoptimal flow convergence) is rare. Otherwise, the method is reliable and can be used clinically in large numbers of patients.
Assuntos
Insuficiência da Valva Mitral/patologia , Valva Mitral/patologia , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/diagnóstico por imagem , Estudos ProspectivosRESUMO
High blood pressure is a major individual and public-health issue because of its wide prevalence and associated complications. More women than men have hypertension, but until recently, women have been relatively underrepresented in clinical trials. Gender differences in the physiology, genetics, and treatment benefit of hypertension have been noted in several studies that have included women. These findings have raised concerns about the generalizability of the results of previous investigations to women. The currently available information regarding gender differences and similarities and the results of hypertension treatment trials in women are reviewed herein. These studies suggest that, although gender differences exist, women benefit significantly when they receive therapy to normalize blood pressure.
Assuntos
Hipertensão , Saúde da Mulher , Terapia de Reposição de Estrogênios , Feminino , Humanos , Hipertensão/complicações , Hipertensão/epidemiologia , Hipertensão/etiologia , Hipertensão/fisiopatologia , Hipertensão/terapia , Masculino , Fatores SexuaisRESUMO
The population of older individuals in the United States is growing rapidly. Because women generally live longer than men and make up the majority of this aging population, the elucidation of health issues related to older women is important. Cardiovascular disease is the leading cause of death and disability for women and claims the lives of more women than the next 14 causes combined. The majority of these deaths are due to atherosclerotic coronary heart disease, with nearly 250,000 women dying of myocardial infarction each year. There is evidence that women with suspected or established cardiovascular disease have not benefited fully from recent advances in the detection and management of coronary heart disease. Regardless of the mechanism and extent of the effect that sex differences have on approaches to cardiovascular disease, women appear to benefit from proven efficacious therapies, and the longer-term outcomes associated with these treatments are positive. The data regarding women and coronary heart disease are rapidly evolving and sometimes conflicting. The intent of this article is to summarize the most current understanding of coronary heart disease risks in women, highlighting the impact of prevention, and to discuss the latest novel findings that may become important in our armamentarium for prevention of coronary heart disease.
Assuntos
Doença das Coronárias/prevenção & controle , Saúde da Mulher , Adulto , Fatores Etários , Idoso , Fármacos Cardiovasculares/uso terapêutico , Doença das Coronárias/epidemiologia , Terapia de Reposição de Estrogênios , Feminino , Humanos , Estilo de Vida , Pessoa de Meia-Idade , Fatores de Risco , Estados Unidos/epidemiologiaRESUMO
Percutaneous aortic balloon valvuloplasty (PABV) is useful in palliating symptoms of severe aortic stenosis in patients who are not candidates for aortic valve replacement. In 15 patients who had severe aortic stenosis and a contraindication to aortic valve replacement, PABV was performed before a noncardiac procedure, in an attempt to improve their hemodynamics and reduce the risks associated with the operation or preoperative diagnostic test. The mean aortic gradient was reduced from 58.1 +/- 6.0 mm Hg to 32.2 +/- 4.0 mm Hg (P less than 0.0002), and the aortic valve area was increased from 0.49 +/- 0.04 cm2 to 0.85 +/- 0.10 cm2 (P less than 0.0002). Complications associated with PABV included left ventricular perforation in three patients (which resulted in death in one of them), transient congestive heart failure in one, and development of femoral pseudoaneurysms in one. After PABV, nine patients underwent the planned surgical procedure under general anesthesia without complications. Five patients underwent surgical diagnostic procedures after PABV that resulted in a change in treatment strategy. Three of these patients required no further treatment, and two required resection of the colon for bleeding, which was preceded by aortic valve replacement. This study demonstrates that PABV may be useful in reducing the risks of noncardiac procedures in selected patients with severe aortic stenosis who are otherwise not candidates for aortic valve replacement.
Assuntos
Estenose da Valva Aórtica/terapia , Cateterismo/métodos , Cuidados Paliativos/métodos , Cuidados Pré-Operatórios/métodos , Procedimentos Cirúrgicos Operatórios , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/fisiopatologia , Cateterismo/efeitos adversos , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente/métodos , Fatores de RiscoRESUMO
OBJECTIVE: To evaluate the treatment strategies for primary and secondary management of malignancy-related pericardial effusions. PATIENTS AND METHODS: Retrospective review of Mayo Clinic Rochester charts and external records of patients with pericardial effusion associated with malignant disease who required treatment between February 1979 and June 1998 was performed. Telephone interviews with patients, their families, or their physicians were conducted to determine the outcomes of treatment. Recurrence of pericardial effusion and survival were the main outcome measures. RESULTS: Of 1002 consecutive pericardiocenteses performed during the period under study, 341 were performed in 275 patients with confirmed malignant disease. Patients were followed up for a minimum of 190 days, unless death occurred first. Of 275 patients, recurrence of pericardial effusion or persistent drainage necessitated secondary management in 59 (43 of 118 simple pericardiocenteses, 16 of 139 pericardiocenteses with extended catheter drainage, and 0 of 18 pericardial surgery following temporizing pericardiocentesis). Recurrence was strongly and independently predicted by absence of pericardial catheter for extended drainage, large effusion size, and emergency procedures. Recurrence after secondary management occurred in 12 patients: 11 underwent successful pericardiocentesis with extended catheter drainage, and 1 had pericardial surgery. Median survival of the cohort was 135 days, and 26% survived the first year after diagnosis of pericardial effusion. Male sex, positive fluid cytology for malignant cells, lung cancer, and clinical presentation of tamponade or hemodynamic collapse were independently associated with poor survival. CONCLUSION: Echocardiographically guided pericardiocentesis with extended catheter drainage appears to be safe and effective for both primary and secondary management of pericardial effusion in patients with malignancy.
Assuntos
Neoplasias/complicações , Derrame Pericárdico/terapia , Adulto , Idoso , Cateteres de Demora , Fatores de Confusão Epidemiológicos , Árvores de Decisões , Drenagem , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/etiologia , Pericardiocentese/métodos , Recidiva , Estudos Retrospectivos , Escleroterapia , Análise de Sobrevida , Resultado do TratamentoRESUMO
OBJECTIVE: To examine the use of Doppler echocardiography in preoperative assessment of aortic stenosis and to determine its effect on subsequent use of hemodynamic cardiac catheterization. MATERIAL AND METHODS: We retrospectively reviewed a consecutive series of 574 adult patients who underwent aortic valve replacement for aortic stenosis between 1990 and 1992 at our institution. The use of Doppler echocardiography and cardiac catheterization and the predictive factors for use of hemodynamic catheterization were analyzed. RESULTS: After Doppler echocardiography in 423 patients, invasive hemodynamic assessment of the severity of aortic stenosis was performed in only 42% (179 patients). The use of cardiac catheterization declined over time (54% in 1990, 40% in 1991, and 35% in 1992) (P = 0.003), whereas no significant change in the baseline clinical characteristics of the population or in severity of stenosis as determined by Doppler echocardiography occurred during that time. Multivariate analysis identified the following variables as independent predictors of use of cardiac catheterization after Doppler echocardiography: clinically not severe aortic stenosis, mean gradient of less than 50 mm Hg determined by Doppler echocardiography, Doppler-determined aortic valve area of more than 0.8 cm2 or not calculated, attending cardiologist not specialized in echocardiography, and earlier year of assessment. CONCLUSION: After Doppler echocardiography, less than 50% of our patients undergoing aortic valve replacement for aortic stenosis have cardiac catheterization preoperatively. The use of cardiac catheterization after Doppler echocardiography--thus, duplication of hemodynamic assessment--declined significantly over time during the study period. Decline in the use of catheterization is related to the degree of diagnostic certainty provided by Doppler echocardiography and to the level of familiarity of the attending cardiologist with the technique.
Assuntos
Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Cateterismo Cardíaco , Ecocardiografia Doppler , Cuidados Pré-Operatórios , Adulto , Feminino , Próteses Valvulares Cardíacas , Hemodinâmica , Humanos , Masculino , Estudos Retrospectivos , Resultado do TratamentoRESUMO
OBJECTIVE: To determine the attitudes of Olmsted County, Minnesota, adults about environmental tobacco smoke in restaurants, bars, and nightclubs. SUBJECTS AND METHODS: In this population survey,2014 adults were contacted by random digit dial methods between February 28 and May 5, 2000, and asked to participate in a telephone survey; 1224 (61%) consented. RESULTS: For the 57% (95% confidence interval [CI], 54%-60%) of the study population that reported exposure to environmental tobacco smoke, the most frequently reported sites of exposure were restaurants (44% [95% CI, 41%-48%]), work (21% [95% CI, 18%-24%]), and bars (19% [95% CI, 16%-22%]). Seventy-two percent (95% CI, 69%-74%) of respondents said that they would select a smoke-free restaurant over one where smoking is permitted, and 70% (95% CI, 67%-72%) said that they would select a smoke-free bar over one where smoking is permitted. The majority of respondents said that they would not dine out or visit bars or nightclubs more often or less often if all restaurants, bars, and nightclubs were smoke-free. CONCLUSIONS: Olmsted County residents prefer smoke-free restaurants, bars, and nightclubs.
Assuntos
Atitude Frente a Saúde , Restaurantes , Poluição por Fumaça de Tabaco , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Minnesota , Política PúblicaRESUMO
OBJECTIVE: To establish baseline data for the CardioVision 2020 program, a collaborative project in Olmsted County, Minnesota, organized to reduce cardiovascular disease rates by altering 5 health-related items: (1) eliminating tobacco use and exposure, (2) improving nutrition, (3) increasing physical activity, (4) lowering serum cholesterol level, and (5) controlling blood pressure. SUBJECTS AND METHODS: Data about tobacco use, diet, and physical activity were collected by random digit dial interview and follow-up questionnaire from a sample of the population. Blood pressure data were collected from medical records at Mayo Clinic, and serum cholesterol data were derived from the Mayo Clinic laboratory database. Data were stratified into 6 age groups. RESULTS: A total of 624 women and 608 men responded to the questionnaire. Population blood pressure data were available for 1,956 women and 1,084 men. Population serum cholesterol data were available for 17,042 women and 12,511 men. Except for women in the 30- to 39-year-old age group, less than 10% of the population sampled met 4 or 5 goals. Conversely, about 90% of the population met at least 1 goal, and about 80% met 1, 2, or 3 of the goals. CONCLUSION: The data from the Olmsted County population indicate considerable opportunity to reduce this population's burden of cardiovascular disease.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Comportamentos Relacionados com a Saúde , Inquéritos Epidemiológicos , Adulto , Idoso , Pressão Sanguínea , Colesterol/sangue , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Minnesota , Assunção de RiscosRESUMO
OBJECTIVE: This study of surgical aortic stenosis characterized sex differences in left ventricular (LV) geometry and outcome. MATERIALS AND METHODS: We examined 92 women and 82 men who underwent echocardiography before valve replacement for aortic stenosis. RESULTS: Women had a smaller cavity size (LV end-diastolic diameter 48.2 +/- 7 mm in women vs 53.6 +/- 7.6 mm in men; p = 0.0001) and higher ejection fraction (59% in women vs 54% in men; p = 0.02). LV mass was greater in men than women (300.4 +/- 88 g in men vs 250.6 +/- 85.8 g in women; p = 0.0055) but when corrected for body surface area, the difference was not significant. The prevalence of LV hypertrophy was similar in both sexes (51% in women vs 49% in men; p = 0.62). The 5-year survival was 82% in women and 79% in men (p = 0. 9). CONCLUSION: Several descriptors of LV geometry differed between men and women. These differences were largely eliminated after normalizing for body surface area. No differences in surgical mortality or long-term outcome were noted.
Assuntos
Estenose da Valva Aórtica/diagnóstico por imagem , Implante de Prótese de Valva Cardíaca , Ventrículos do Coração/diagnóstico por imagem , Caracteres Sexuais , Idoso , Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/cirurgia , Ecocardiografia Doppler , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/epidemiologia , Hipertrofia Ventricular Esquerda/etiologia , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Prevalência , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Função Ventricular EsquerdaRESUMO
STUDY OBJECTIVES: This study assessed the clinical features, timing of presentation, and echocardiographic characteristics associated with clinically significant pericardial effusions after cardiothoracic surgery. The outcomes of echocardiographically (echo-) guided pericardiocentesis for the management of these effusions were evaluated. DESIGN: From the prospective Mayo Clinic Registry of Echo-guided Pericardiocentesis (February 1979 to June 1998), 245 procedures performed for clinically significant postoperative effusions were identified. Clinical features, effusion causes, echocardiographic findings, and management outcomes were studied and analyzed. Cross-referencing the registry with the Mayo Clinic surgical database provided an estimate of the incidence of significant postoperative effusions and the number of cases in which primary surgical management was chosen instead of pericardiocentesis. RESULTS: Use of anticoagulant therapy was considered a significant contributing factor in 86% and 65% of early effusions (< or =7 days after surgery) and late effusions (>7 days after surgery), respectively. Postpericardiotomy syndrome was an important factor in the development of late effusions (34%). Common presenting symptoms included malaise (90%), dyspnea (65%), and chest pain (33%). Tachycardia, fever, elevated jugular venous pressure, hypotension, and pulsus paradoxus were found in 53%, 40%, 39%, 27%, and 17% of cases, respectively. Transthoracic echocardiography permitted rapid diagnosis and hemodynamic assessment of all effusions except for three cases that required transesophageal echocardiography for confirmation. Echo-guided pericardiocentesis was successful in 97% of all cases and in 96% of all loculated effusions. Major complications (2%), including chamber lacerations (n = 2) and pneumothoraces (n = 3), were successfully treated by surgical repair and chest tube reexpansion, respectively. Median follow-up duration for the study population was 3.8 years (range, 190 days to 16.4 years). The use of extended catheter drainage was associated with reduction in recurrence for early and late postoperative effusions by 46% and 50%, respectively. CONCLUSIONS: The symptoms and physical findings of clinically significant postoperative pericardial effusions are frequently nonspecific and may be inadequate for a decision regarding intervention. Echocardiography can quickly confirm the presence of an effusion, and pericardiocentesis under echocardiographic guidance is safe and effective. The use of a pericardial catheter for extended drainage is associated with lower recurrence rates, and the majority of patients so treated do not require further intervention.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Drenagem , Derrame Pericárdico/diagnóstico por imagem , Derrame Pericárdico/terapia , Procedimentos Cirúrgicos Torácicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Drenagem/métodos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Resultado do Tratamento , UltrassonografiaRESUMO
Two-dimensional echocardiography-guided pericardiocentesis is an accepted, safe, and cost-effective procedure. Carefully selected patients can be treated with this technique in an outpatient setting. A consecutive series of outpatient echocardiography-directed pericardiocentesis performed for diagnostic or therapeutic indications is described. Appropriate technique and precautions are discussed.
Assuntos
Assistência Ambulatorial , Drenagem/métodos , Ecocardiografia , Derrame Pericárdico/diagnóstico por imagem , Derrame Pericárdico/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/diagnóstico , Punções/métodosRESUMO
Ethanol produces in vitro vasoconstriction of coronary arteries and can precipitate angina in patients with coronary obstructive disease. To demonstrate the in vivo effect of ethanol on coronary dynamics, baseline measurements of left anterior descending (LAD) coronary artery dimension by quantitative angiography, hemodynamics, arterial and coronary sinus blood gases, and blood ethanol levels were obtained in 14 closed-chest mongrel dogs. Three ethanol levels were established by intravenous bolus followed by 1-hour maintenance infusions. All measurements made at baseline were recorded every 30 minutes. Phentolamine (5 mg i.v.) and nicardipine (0.15 mg/kg i.v.) were given to evaluate constrictor mechanisms. Blood ethanol levels achieved at 60, 120, and 180 minutes were 649 +/- 48, 1,285 +/- 81, and 2,546 +/- 130 micrograms/ml, respectively. LAD cross-sectional area was reduced significantly from control at the end of each of the three dosing periods (-24 +/- 5%, -40 +/- 3%, and -53 +/- 3%; p less than 0.004). alpha-Adrenergic blockade had no effect on LAD cross-sectional area, while nicardipine partially reversed the ethanol-induced vasoconstriction. No significant change in vessel cross-sectional area took place in control dogs. These data suggest that ethanol induces epicardial coronary artery vasoconstriction in dogs at clinically important blood levels. alpha-Adrenergic blockade does not alter or reverse ethanol-induced vasoconstriction, while calcium channel blockade appears to be an effective vasodilator of ethanol-constricted vessels.
Assuntos
Vasos Coronários/efeitos dos fármacos , Etanol/farmacologia , Vasoconstrição/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Vasos Coronários/fisiologia , Cães , Etanol/antagonistas & inibidores , Etanol/sangue , Frequência Cardíaca/efeitos dos fármacos , Masculino , Nicardipino/farmacologia , Oxigênio/sangue , Fentolamina/farmacologiaRESUMO
A case of low pressure cardiac tamponade is reported in which hypovolaemia altered the clinical findings of tamponade and complicated the diagnosis. Venous pressure was not raised and there was no pulsus paradoxus. In this patient, a man of 67, characteristic variations in diastolic inflow signals and the isovolumic relaxation period throughout the respiratory cycle were shown by Doppler echocardiography and led to the diagnosis of cardiac tamponade in the absence of characteristic signs and symptoms.
Assuntos
Tamponamento Cardíaco/diagnóstico , Idoso , Volume Sanguíneo , Tamponamento Cardíaco/fisiopatologia , Tamponamento Cardíaco/cirurgia , Ecocardiografia Doppler , Humanos , MasculinoRESUMO
The effect of intravenous cocaine on coronary artery dynamics in 23 closed-chest dogs was examined. To determine dose-related effects, intravenous cocaine was administered in doses of 1, 3, 6, and 9 mg/kg; saline solution was used in control dogs. Heart rate, aortic pressure, and left anterior descending coronary artery cross-sectional area were measured before and for 60 minutes after each injection. Myocardial blood flow was measured with 15 microns radioactive microspheres at baseline and 30 minutes after administration of cocaine or saline solution. Plasma cocaine, benzoyl ecgonine, and norepinephrine concentrations were measured and correlated with physiologic changes. Cocaine caused sustained dose-dependent vasoconstriction of the left anterior descending coronary artery, which was significant at 15 minutes and maximum at 60 minutes (control = 2 +/- 10%; cocaine, 9 mg/kg = 46 +/- 10% cross-sectional area reduction). There was an immediate but transient reduction in aortic pressure and an elevation of heart rate after the 6 and 9 mg/kg doses and no hemodynamic changes with lower doses. Coronary blood flow was reduced 30 minutes after the 3, 6, and 9 mg/kg doses. Two dogs had refractory ventricular tachycardia after injection of cocaine and were not included in the analysis. Results of this investigation demonstrate angiographic evidence of dose-dependent, cocaine-induced epicardial coronary vasoconstriction and deleterious hemodynamic abnormalities at commonly used doses of cocaine. These results demonstrate a mechanism for the development of angina and myocardial infarction associated with cocaine use.