RESUMO
OBJECTIVES: The purpose of this study was to compare success rates, procedure and fluoroscopy times and complications for the transseptal and retrograde aortic approaches in a consecutive series of patients undergoing catheter ablation of left free wall accessory pathways. BACKGROUND: Radiofrequency catheter ablation of left-sided accessory pathways can be performed either by a retrograde, transaortic approach or by means of a transseptal puncture. METHODS: A total of 106 patients (mean age 33 years, range 4 to 79) underwent attempted catheter ablation of a single left-sided accessory pathway by either the retrograde or the transseptal approach, or both. In the first 65 patients, the retrograde aortic approach was the preferred initial method. In the most recent 51 patients, we first attempted the transseptal approach whenever a physician trained in the technique was available. Ultimately, 102 (96.2%) of 106 patients had successful ablation. RESULTS: Of 89 retrograde procedures, 85% resulted in elimination of accessory pathway conduction. Four retrograde procedures performed after failure of the transseptal approach were successful. Of the 13 patients with a failed retrograde procedure, 11 later underwent ablation using the transseptal approach. Twenty-six (85%) of 33 transseptal procedures were successful. All four patients with unsuccessful initial transseptal attempts were successfully treated with the retrograde method during the same session in the electrophysiology laboratory. Ten of 11 transseptal procedures after unsuccessful retrograde procedures were successful. Crossover from the retrograde to the transseptal approach was performed during a separate session in 9 of these 11. There was no difference in total procedure time (220 +/- 12.8 vs. 205 +/- 12.5 min) (mean +/- SEM) or fluoroscopy time (44.1 +/- 4.4 vs. 44.7 +/- 5.1 min) between the retrograde and transseptal methods. Ablation time was longer for the retrograde method (69.2 +/- 10.5 vs. 43.4 +/- 9.3 min) (p < 0.01). Of patients > or = 65 or < or = 16 years old, technical factors requiring crossover to the other technique or complications occurred in 7 (42%) of 17 patients undergoing the retrograde and 1 (11%) of 9 patients undergoing the transseptal approach (p < 0.01). The overall rate of complications was the same for both (6.7% for retrograde and 6.1% for transseptal). The most serious complication involved dissection of the left coronary artery with myocardial infarction during a retrograde procedure. CONCLUSIONS: The retrograde and transseptal approaches are complementary; if one method fails, the other should be attempted, yielding an overall success rate close to 100%. Because patients undergo heparinization immediately after the arterial system is entered during a retrograde procedure, failure of that approach requires crossover to the transseptal method during a separate session or reversal of heparin; if the transseptal method is tried first, crossover to the retrograde approach can be accomplished easily during the same session. To avoid complications related to access, the transseptal method should be the first used in children, the elderly and those with arterial disease or hypertrophic ventricles.
Assuntos
Ablação por Cateter/métodos , Sistema de Condução Cardíaco/cirurgia , Taquicardia Supraventricular/cirurgia , Adolescente , Adulto , Idoso , Ablação por Cateter/efeitos adversos , Criança , Pré-Escolar , Eletrocardiografia , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia Supraventricular/fisiopatologia , Resultado do TratamentoRESUMO
OBJECTIVES: We sought to determine the effect of inhomogeneous distribution of beam power produced by Doppler catheters on measurements of mean and peak velocity of coronary blood flow. BACKGROUND: Measurements of mean velocity of coronary blood flow by Doppler catheters have significant systematic errors that have not been completely characterized. We hypothesized that one error is the inhomogeneous distribution of the ultrasonic beam power and that this inhomogeneity makes measurements of mean, but not peak, velocity inaccurate. METHODS: We constructed a scaled-up model of a Doppler catheter to allow for accurate measurement of the distribution of beam power by miniature hydrophones. This catheter was placed in a model of coronary blood flow in which the fluid velocity was accurately measured by an external laser Doppler velocimeter. The laser Doppler measurements of mean velocity were compared with the measurements of mean velocity made by the catheter, using fast Fourier transform analysis, both without and with correction for inhomogeneous beam power distribution. Peak velocity measurements were also compared, as predicted from theory, without the need of correction for inhomogeneous beam power distribution. To investigate the clinical relevance of our results, we conducted studies using a clinical Doppler catheter both in a scaled model of coronary flow and in a series of eight patients. In the model and in each patient, we rotated the catheter without changing the axial position to systematically alter the relation of the beam power distribution to the local fluid dynamics. RESULTS: The measurement of beam power distribution revealed significant inhomogeneity. Comparison of the measured mean frequency shifts without correction for inhomogeneities in the distribution yielded a statistically significant difference. After correction for inhomogeneities, there was no statistically significant difference. Also, there was no significant difference for the peak frequency shifts. Rotation of the clinical catheter in the scaled model and in the patients changed the measured mean velocity (average change 18.8% and 20.6%, respectively), but not the measured peak velocity (average change 5.0% and 4.3%, respectively). CONCLUSIONS: For signal analysis using a fast Fourier transform, the inhomogeneous distribution of power of the ultrasonic beam produced by Doppler catheters makes measurements of mean, but not peak, velocity inaccurate. Measurements of peak velocity may therefore prove superior to measurements of mean velocity in estimating the response to pharmacologic intervention and in estimating stenosis severity.
Assuntos
Cateterismo Cardíaco , Circulação Coronária , Fluxometria por Laser-Doppler , Ultrassom , Adulto , Idoso , Velocidade do Fluxo Sanguíneo , Feminino , Análise de Fourier , Humanos , Masculino , Pessoa de Meia-Idade , TransdutoresRESUMO
OBJECTIVES: We evaluated a new technique for delineation of the vessel wall surface during intravascular ultrasound imaging using echogenic contrast agents. BACKGROUND: Intravascular ultrasound is used for detection of complex vessel wall structures after catheter-based interventions; however, differentiation between the lumen and these wall structures can be difficult. METHODS: In 12 anesthetized dogs, intracoronary ultrasound was performed during intracoronary bolus injection (3 and 6 ml) of different contrast agents (hand-agitated saline solution, standard iohexol, sonicated iohexol, hand-agitated iohexol, SHU 454, SHU 508). Contrast intensity was quantified by videodensitometry, and contrast homogeneity was assessed qualitatively (grade 0 to 3). RESULTS: Peak contrast intensities for SHU 454 and SHU 508 (mean [+/- SD] 48 +/- 9 and 36 +/- 6 U, respectively) were higher compared with standard, sonicated or agitated iohexol (16 +/- 3, 28 +/- 7 and 20 +/- 3 U, respectively) or with agitated saline solution (17 +/- 4 U); intensities were higher for 6 ml compared with that for 3 ml. Contrast homogeneity was higher for SHU 508 (mean [+/- SD] 3.0 +/- 0) and SHU 454 (2.7 +/- 0.5) compared with the other agents (standard iohexol 1.2 +/- 0.4, sonicated iohexol 2.0 +/- 0.5, agitated iohexol 1.8 +/- 0.6, agitated saline solution 1.0 +/- 0.4). Exact delineation of the vessel wall surface was possible in 100% of SHU 508 and in 88% of SHU 454 injections compared with 13% of agitated iohexol and 8% of sonicated iohexol injections. Accurate surface delineation was never achieved with standard iohexol or agitated saline solution. Shadowing of parts of the vessel wall by contrast material occurred at peak intensity of 75% of SHU 508 and 46% of SHU 454 injections but not with the other agents. No adverse physiologic reactions were noted, except for transient negative inotropic effects after 6 ml of SHU 508. CONCLUSIONS: This preliminary study shows that delineation of the vessel wall boundary using echogenic contrast agents during intravascular ultrasound is safe and feasible. Because of higher contrast intensity and homogeneity, SHU 454 and SHU 508 are superior to other agents.
Assuntos
Meios de Contraste , Vasos Coronários/diagnóstico por imagem , Ultrassonografia de Intervenção/métodos , Animais , Meios de Contraste/farmacologia , Cães , Hemodinâmica/efeitos dos fármacos , Iohexol/farmacologia , Polissacarídeos/farmacologia , Cloreto de Sódio/farmacologiaRESUMO
1. The American College of Cardiology acknowledges the continuum of changing societal, medical and economic perspectives affecting traditional medical ethics. Primacy of patient responsibility remains paramount to the cardiovascular specialist who at the same time should participate in the development of broader societal programs. 2. Medical decisions should be freely and jointly formulated by the patient and the cardiovascular specialist with appropriate sensitivity to such matters as mental competence, pertinent medical information and standards of care, sufficient time for contemplation, informed consent, patient right of refusal, physician right to refuse to provide inappropriate care and the right of patient, physician or third party payer to seek consultation or additional opinions. 3. The cardiovascular specialist should make a special effort to clarify and document patient preferences regarding end-of-life treatment through some form of advance directive. 4. The cardiovascular specialist bears a moral obligation to provide medical care to any patient who is HIV positive or has AIDS. 5. A conflict of interest occurs when a cardiovascular specialist places personal or financial interest ahead of the welfare and health of a patient. Professional accountability should be established through local or regional peer review. 6. The American College of Cardiology encourages and supports a renewed dedication to the principles of medical ethics, particularly in the field of cardiovascular disease. Cardiovascular specialists are encouraged to participate in the promulgation of medical ethics by teaching and by example, individually and with others.
Assuntos
Cardiologia , Ética Médica , Relações Médico-Paciente , Síndrome da Imunodeficiência Adquirida/prevenção & controle , Síndrome da Imunodeficiência Adquirida/terapia , Cardiologia/educação , Currículo , Atenção à Saúde/tendências , Revelação , Educação de Graduação em Medicina , Convênios Hospital-Médico/legislação & jurisprudência , Humanos , Educação de Pacientes como Assunto , Encaminhamento e Consulta , Responsabilidade Social , Estados UnidosRESUMO
OBJECTIVES: This study sought to evaluate the extent of atherosclerosis in coronary and iliac arteries in patients with heterozygous familial hypercholesterolemia or familial combined hyperlipidemia, using intravascular ultrasound imaging. BACKGROUND: Intravascular ultrasound imaging provides cross-sectional tomographic views of the vessel wall and allows quantitative assessment of atherosclerosis. METHODS: Forty-eight nonsmoking, asymptomatic patients with heterozygous familial hypercholesterolemia or familial combined hyperlipidemia underwent intravascular ultrasound imaging of the left anterior descending coronary, left main coronary and common iliac arteries. Angiography showed only minimal or no narrowing in these vessels. Intravascular ultrasound images obtained during catheter pullback underwent morphometric analysis. Plaque burden was expressed as the mean and maximal intimal index (ratio of plaque area and area within the internal elastic lamina) and as the percent of vessel surface covered by plaque. RESULTS: Intravascular ultrasound detected plaque more frequently than angiography in the left anterior descending (80% vs. 29%, respectively), left main (44% vs. 16%) and iliac arteries (33% vs. 27%). Plaque burden was higher in the left anterior descending (mean intimal index [+/- SD] 0.25 +/- 0.16) than in the left main (0.11 +/- 0.16, p < 0.001) and iliac arteries (0.02 +/- 0.04, p < 0.001). Angiography detected lumen narrowing only in coronary arteries with a maximal intimal index > or = 0.42 (left anterior descending artery) and > or = 0.43 (left main artery). The area within the internal elastic lamina increased with plaque area in the left anterior descending (r = 0.82, p < 0.001) and left main arteries (r = 0.53, p < 0.001). By stepwise multiple regression analysis, the strongest predictor for plaque burden in the left anterior descending artery was the level of high density lipoprotein (HDL) cholesterol and total/HDL cholesterol ratio for the left main artery. CONCLUSIONS: In patients with heterozygous familial hypercholesterolemia and familial combined hyperlipidemia, extensive coronary plaque is present despite minimal or no angiographic changes. Compensatory vessel enlargement and diffuse involvement with eccentric plaque may account for the lack of angiographic changes. Levels of HDL cholesterol and total/HDL cholesterol ratio are far more powerful predictors of coronary plaque burden than are low density lipoprotein cholesterol levels in these patients with early, asymptomatic disease.
Assuntos
Arteriosclerose/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Hiperlipidemia Familiar Combinada/complicações , Hiperlipoproteinemia Tipo II/complicações , Ultrassonografia de Intervenção , Adulto , Idoso , Arteriosclerose/complicações , HDL-Colesterol/sangue , Angiografia Coronária , Doença da Artéria Coronariana/complicações , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Artéria Ilíaca/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de RiscoRESUMO
In 10 patients with severe chronic congestive heart failure, changes in hemodynamic and cardiac performance at rest and during exercise were evaluated following short-term oral prazosin therapy. The median total dose of prazosin was 43 mg (range 23 to 95 mg) and the median duration of therapy was 47 hours (range 18 to 92 hours). Prazosin increased cardiac output and stroke volume significantly during exercise (both p less than 0.05) but not at rest (both p greater than 0.10). The magnitude of the increase in pulmonary capillary wedge pressure during exercise with the addition of prazosin was also significantly less than that during conventional therapy, suggesting improved cardiac performance during exercise. Peak oxygen consumption, peak lactate concentration and rate of disappearance of the increased concentration of lactate induced by exercise, however, remained unchanged following prazosin therapy. These findings suggest that short-term prazosin therapy, as other vasodilators, improves cardiac performance during exercise but may not necessarily influence oxygen consumption.
Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Hemodinâmica/efeitos dos fármacos , Esforço Físico , Prazosina/administração & dosagem , Quinazolinas/administração & dosagem , Vasodilatadores/administração & dosagem , Administração Oral , Coração/efeitos dos fármacos , Insuficiência Cardíaca/fisiopatologia , Humanos , Lactatos/metabolismo , Miocárdio/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Prazosina/uso terapêutico , Vasodilatadores/uso terapêuticoRESUMO
Valvular heart disease is rare in patients with juvenile chronic arthritis. We describe a 27-year-old woman with the systemic-onset form of juvenile chronic arthritis in whom aortic insufficiency necessitated valve replacement. Nodules were seen on both the aortic and anterior mitral leaflets at surgery, and histopathologic evaluation of the excised aortic leaflets demonstrated nonspecific changes similar to those described in rheumatoid valve disease causing aortic insufficiency in adults with rheumatoid arthritis. We believe that this is the first reported case of aortic insufficiency in systemic-onset juvenile chronic arthritis in which the pathologic condition of the valve can be attributed to the underlying disease.
Assuntos
Insuficiência da Valva Aórtica/etiologia , Artrite Juvenil/complicações , Adulto , Valva Aórtica/patologia , Insuficiência da Valva Aórtica/patologia , Insuficiência da Valva Aórtica/cirurgia , Feminino , HumanosRESUMO
Increased left ventricular filling pressure and reduced cardiac output are two major hemodynamic deficits in pump failure. In patients with chronic heart failure, consequences of these hemodynamic deficits and diminished cardiac reserve are manifested initially during stress and eventually at rest. The purpose of therapeutic interventions include reduction of ventricular filling pressure increase in cardiac output and improvement in cardiac reserve. To achieve these goals, the hemodynamic effects of predominantly venodilators (nitrates), predominantly arteriolar dilators (hydralazine) and the combination of nitrates and hydralazine were evaluated in patients with chronic heart failure at rest: left ventricular filling pressure (mm Hg) control 28, nitrates 17, hydralazine 25, nitrates plus hydralazine 18; cardiac output (liters/min/m2) control 2.1, nitrates 2.1, hydralazine 3.2, nitrates plus hydralazine 3.3; mean blood pressure (mm Hg) control 87, nitrates 85, hydralazine 83, nitrates plus hydralazine 85. These data suggest improved left ventricular performance with a combination of nitrates and hydralazine. Exercise hemodynamics improved in some patients, suggesting that such vasodilator therapy may be beneficial in chronic heart failure.
Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Vasodilatadores/uso terapêutico , Doença Crônica , Quimioterapia Combinada , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Hidralazina/farmacologia , Dinitrato de Isossorbida/farmacologia , Lúpus Eritematoso Sistêmico/induzido quimicamente , Nitroglicerina/farmacologia , Esforço Físico , Prazosina/farmacologia , Pressão , Descanso , Fatores de Tempo , Vasodilatadores/efeitos adversos , Vasodilatadores/farmacologiaRESUMO
Changes in cardiac performance and coronary hemodynamics were evaluated during dobutamine infusion in patients with chronic heart failure associated with ischemic heart disease. At the maximal administered dose (10 micrograms/kg per min) cardiac index increased by 54 percent and stroke work index by 65 percent, indicating improved left ventricular function. Coronary sinus flow and myocardial oxygen consumption increased concomitantly, but myocardial lactate production occurred in only one of eight patients. These findings suggest that improved left ventricular function with dobutamine is associated with increased myocardial oxygen consumption; however, overt myocardial ischemia occurs infrequently.
Assuntos
Catecolaminas/uso terapêutico , Doença das Coronárias/tratamento farmacológico , Dobutamina/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Idoso , Circulação Coronária/efeitos dos fármacos , Feminino , Humanos , Lactatos/metabolismo , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Pressão Propulsora Pulmonar/efeitos dos fármacos , Volume Sistólico/efeitos dos fármacosRESUMO
Contrast-enhanced computed tomography (CT) was compared with 2-dimensional echocardiography (2-D echo) for evaluation of left ventricular (LV) thrombus. Thirteen patients with coronary artery disease who had LV thrombus initially documented by 1 of the 2 techniques were then studied with the other technique. The findings of the studies were concordant in 8 of 13 patients, with a similar description of the presence, location and size of the LV thrombus and associated regional LV wall abnormalities. In 5 of 13 patients, the 2 techniques produced discordant data. Of these, 2 patients had false-negative results on 2-D echo owing to poor visualization of the LV apex; 1 patient had a false-positive result on 2-D echo related to misinterpretation of a prominent papillary muscle; 2 patients had false-negative CT results, 1 related to insufficient contrast infusion. The findings demonstrate that CT is a useful technique for evaluating LV thrombus, and may be particularly helpful when 2-D echo is technically limited or equivocal.
Assuntos
Doença das Coronárias/diagnóstico , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico por imagem , Erros de Diagnóstico , Ecocardiografia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
The hospital charts and billing records of 250 consecutive admissions for percutaneous transluminal coronary angioplasty (PTCA) at a university hospital were reviewed. Clinical characteristics, performing physician, angiographic features of the dilated lesion, procedural outcome, length of stay, and total and departmental hospital costs were recorded for each patient. We identified several independent predictors of hospital cost, including the physician ($4,400 increase from highest- to lowest-cost physician, p=0.004), age ($790 increase per 10-year increase in age, p=0.002), urgency of the procedure ($4,100 increase for urgent vs elective, p < 0.001), and combined angiography and PTCA ($850 increase vs separate angiography, p=0.04). Independent predictors of catheterization laboratory cost included the physician ($1,280 increase from highest- to lowest-cost physician, p=0.03), American College of Cardiology/American Heart Association lesion type B2 or C ($320 increase, p=0.03), and combined angiography and PTCA ($430 increase, p=0.003). Expensive operators used more catheterization laboratory resources than inexpensive operators; however, there are no significant differences in success rate or need for emergent bypass surgery between physicians. PTCA cost is determined by both patient characteristics and the performing physician. The increase in cost due to the physician was not explained by patient variables, lesions characteristics, success rate, or complications.
Assuntos
Angioplastia Coronária com Balão/economia , Cardiologia/economia , Doença das Coronárias/terapia , Padrões de Prática Médica/economia , Doença das Coronárias/economia , Custos e Análise de Custo , Feminino , Humanos , Masculino , Análise Multivariada , Estudos Retrospectivos , Estados UnidosRESUMO
During a multicenter study 57 patients with exercise-induced angina were evaluated with serial exercise testing to assess the efficacy of diltiazem, a calcium slow channel blocking agent, compared with a placebo. The study consisted of a 1 week single-blind placebo stabilization period followed by a double-blind triple crossover between diltiazem and placebo. Three dose levels were tested (120, 180 and 240 mg/day) in each patient. For the three time-related variables there was a significant dose-related response, with 240 mg/day being the most effective. The increases, over the washout placebo stabilization values, of the time-related variables for the 240 mg/day week compared with the corresponding placebo week were total duration of exercise 1.87 versus 1.05 minutes (p less than 0.002), time to onset of angina 1.81 versus 1.17 minutes (p less than 0.01) and time to appearance of 1 mm S-T segment depression 1.81 versus 1.01 minutes (p less than 0.002). Analysis of exercise variables indicated a significant reduction in heart rate, diastolic blood pressure, and pressure-rate product at submaximal exercise after administration of diltiazem. Diastolic blood pressure was significantly reduced at maximal exercise. Heart rate and pressure-rate product were unchanged at rest during submaximal or maximal exercise. Submaximal and maximal exercise S-T depression was not significantly altered by diltiazem. The reduction in pressure-rate product at submaximal exercise was a possible mechanism for the drug's beneficial effect in enhancing the three time-related variables.
Assuntos
Angina Pectoris/tratamento farmacológico , Benzazepinas/uso terapêutico , Diltiazem/uso terapêutico , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Ensaios Clínicos como Assunto , Doença das Coronárias/tratamento farmacológico , Diltiazem/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Eletrocardiografia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico , Distribuição AleatóriaRESUMO
In patients with chronic heart failure exercise allows the simultaneous observation of the cardiovascular pathophysiology and the symptoms of these patients. We administered short-term, oral prazosin to 10 patients with severe chronic heart failure. Prazosin increased cardiac output and stroke volume significantly during exercise (both P less than 0.05) but not at rest (both P greater than 0.10). Prazosin decreased the arteriovenous oxygen difference and left ventricular filling pressure significantly during exercise (both P less than 0.05) but not at rest (both P greater than 0.10). There was no significant correlation between prazosin-induced changes at rest and during exercise in cardiac output (r = 0.12), stroke volume (r = 0.02), arteriovenous oxygen difference (r = 0.33) or left ventricular filling pressure (r = 0.43). Prazosin predominantly affects hemodynamics during exercise because its pharmacologic activity as an alpha-adrenergic blocking agent is most prominent during exercise. The full evaluation of prazosin-induced changes in the hemodynamics of patients of patients with chronic heart failure requires evaluation during exercise.
Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Hemodinâmica/efeitos dos fármacos , Prazosina/uso terapêutico , Quinazolinas/uso terapêutico , Idoso , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Consumo de Oxigênio/efeitos dos fármacos , Fatores de Tempo , Resistência Vascular/efeitos dos fármacosRESUMO
Hemodynamic changes during exercise were evaluated in 20 patients with severe, chronic congestive heart failure. Two groups were identified by their stroke work response to maximal exercise. Group I (eight patients) showed an increase in stroke work index. This occurred because the stroke volume increased and the difference between mean systolic pressure and left ventricular filling pressure increased. Group II (12 patients) showed a decrease in stroke work index. This occurred because stroke volume decreased while the difference between mean systolic pressure and left ventricular filling pressure did not change. Despite hemodynamic differences, the groups could not be distinguished by the usual clinical criteria for heart failure including etiology, New York Heart Association functional class, heart size on chest X-ray film or duration of heart failure. Clinical criteria are relatively insensitive in predicting the exercise hemodynamics of any given patient with chronic severe heart failure. Determining the exercise hemodynamics may be helpful as a means of assessing left ventricular functional reserve in heart failure. Prognostic implications, drug therapy and prescription of activities may require adjustment based on this spectrum of hemodynamic response to exercise in patients with chronic heart failure.
Assuntos
Insuficiência Cardíaca/fisiopatologia , Hemodinâmica , Contração Miocárdica , Adulto , Idoso , Pressão Sanguínea , Débito Cardíaco , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Circulação Pulmonar , Volume SistólicoRESUMO
Changes in left ventricular performance were evaluated in 14 patients with functional New York Heart Association class III or IV chronic heart failure before and after the addition of oral hydralazine to conventional therapy. With conventional therapy, cardiac output increased from 3.4 +/- 0.8 (mean +/- 1 standard deviation) at rest to 4.7 +/- 1.4 liters/min during exercise. This increase in cardiac output on exercise during conventional therapy was mainly due to an increase in heart rate. After the addition of hydralazine, cardiac output at rest increased to 5.0 +/- 1.4 liters/min. The increase in cardiac output was essentially due to an increase in stroke volume. This enhanced stroke volume after hydralazine therapy was maintained during exercise. Hydralazine therapy did not change either the left ventricular filling pressure at rest or the magnitude of increase in left ventricular filling pressure during exercise. Nevertheless, increased cardiac output and stroke volume with similar changes in left ventricular filling pressure during exercise indicated improved left ventricular performance after hydralazine therapy. After short-term hydralazine therapy, symptom-limited peak exercise work load, duration of exercise and maximal oxygen consumption during exercise did not increase. Clinical follow-up at 2 months after long-term therapy revealed subjective improvement in exercise tolerance in 13 of the 14 patients.
Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Hemodinâmica/efeitos dos fármacos , Hidralazina/uso terapêutico , Administração Oral , Idoso , Débito Cardíaco/efeitos dos fármacos , Avaliação de Medicamentos , Quimioterapia Combinada , Insuficiência Cardíaca/fisiopatologia , Humanos , Hidralazina/administração & dosagem , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Esforço Físico , Volume Sistólico/efeitos dos fármacosRESUMO
The supply of oxygen to the myocardium is determined by coronary blood flow and oxygen carrying capacity. Coronary blood flow is a dynamic process modulated via multiple parameters. Cardiac metabolism is also affected by several factors. Under normal physiologic conditions, the demand is easily met by the supply of oxygen. In fact, there is a significant reserve on the supply side. Under certain pathologic states such as coronary artery disease, the supply of oxygen may be exhausted and an imbalance between supply and demand occurs which is translated into ischemia. The area of myocardium most susceptible to ischemia is the subendocardium due to mechanical and metabolic forces. In therapy of coronary artery disease, attention should be directed to directional changes in factors influencing supply and demand to improve blood flow to the most susceptible area.
Assuntos
Miocárdio/metabolismo , Consumo de Oxigênio , Circulação Coronária/fisiologia , Doença das Coronárias/metabolismo , Doença das Coronárias/fisiopatologia , HumanosRESUMO
Echocardiographic studies provide information useful in determining the etiology and location of aortic valvular lesions, but assessment of their severity remains difficult. We report the findings in two patients with surgically confirmed right (case 1) and noncoronary (case 2) flail aortic leaflets in whom dense echoes filled the aortic root in systole, only to move from this position into the left ventricular outflow tract during diastole. This echocardiographic finding is a clinically useful noninvasive indicator of rupture of the right or noncoronary aortic cusp and dictates a need for early surgery.
Assuntos
Insuficiência da Valva Aórtica/diagnóstico , Ecocardiografia , Endocardite Bacteriana/complicações , Adulto , Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/etiologia , Insuficiência da Valva Aórtica/cirurgia , Diástole , Endocardite Bacteriana Subaguda/diagnóstico , Infecções por Enterobacteriaceae/complicações , Humanos , Masculino , Serratia marcescens , Infecções Estreptocócicas/complicações , SístoleRESUMO
To examine whether the hemodynamic responses to halothane or morphine-nitrous oxide anesthesia produce different patterns of myocardial ischemia in patients undergoing myocardial revascularization, we studied 26 patients anesthetized with nitrous oxide (50%) and either halothane (0.2% to 1.0% end-tidal concentration) or morphine (2 mg/kg, given intravenously). We measured systemic and coronary hemodynamics and took blood samples to measure blood gases, oxygen content, and lactate and norepinephrine concentrations. Systemic blood pressure, rate-pressure produce, systemic vascular resistance, cardiac output, and stroke work were elevated following sternotomy in patients anesthetized with morphine, whereas halothane obtunded these hemodynamic responses to surgical stress. Intraoperative myocardial ischemia occurred in both patient groups. Ten of 14 patients receiving halothane and eight of 12 receiving morphine had at least one episode of either ST-segment depression or myocardial lactate production. The difference between these groups was not statistically significant. Only patients anesthetized with morphine had a significantly elevated rate-pressure product when ischemia occurred. In this selected series of patients subjected to myocardial revascularization, two sustained a myocardial infarction and four died in the postoperative period. The incidence of these and other indices of postoperative morbidity was not related to choice of primary anesthetic and did not differ between the patients who sustained ischemia and those who did not.
Assuntos
Anestesia Geral/efeitos adversos , Ponte de Artéria Coronária , Circulação Coronária/efeitos dos fármacos , Halotano/efeitos adversos , Morfina/efeitos adversos , Óxido Nitroso/efeitos adversos , Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Humanos , Complicações Intraoperatórias , Miocárdio/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacosRESUMO
The evaluation, surgical repair, and follow-up are described in an asymptomatic 27-year-old man with unilateral total anomalous pulmonary venous return from the left lung through an innominate vein and a patent foramen ovale. The anomalous vein was divided and anastomosed directly to the left atrium using a vascular technique that produced an orifice larger than the vein diameter. Radionuclide scanning accurately identified the anomaly before operation and allows periodic noninvasive reevaluation after operation. Correction is recommended in all patients with unilateral anomalous pulmonary venous return because disease in the one normal lung could be fatal.
Assuntos
Átrios do Coração/cirurgia , Cardiopatias Congênitas/cirurgia , Veias Pulmonares/anormalidades , Adulto , Seguimentos , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Masculino , Métodos , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/cirurgia , Radiografia , CintilografiaRESUMO
This report highlights our experience in 5 patients with severe aortic stenosis and multiple organ failure undergoing balloon aortic valvuloplasty as a bridge to conventional aortic valve replacement. Balloon aortic valvuloplasty successfully stabilized the condition of these patients, improved organ function, and decreased their baseline risk profile. Elective aortic valve replacement was then performed without complications. Short-term palliation with balloon aortic valvuloplasty should be considered as a bridge to aortic valve replacement in selected patients with critical aortic stenosis and multiple organ failure.