RESUMO
A new miniaturized nonimaging radionuclide detector (Cardioscint, Oxford, England) was evaluated for the continuous on-line assessment of left ventricular function. This cesium iodide probe can be placed on the patient's chest and can be interfaced to an IBM compatible personal computer conveniently placed at the patient's bedside. This system can provide a beat-to-beat or gated determination of left ventricular ejection fraction and ST segment analysis. In 28 patients this miniaturized probe was correlated against a high resolution gamma camera study. Over a wide range of ejection fraction (31% to 76%) in patients with and without regional wall motion abnormalities, the correlation between the Cardioscint detector and the gamma camera was excellent (r = 0.94, SEE +/- 2.1). This detector system has high temporal (10 msec) resolution, and comparison of peak filling rate (PFR) and time to peak filling (TPFR) also showed close agreement with the gamma camera (PFR, r = 0.94, SEE +/- 0.17; TPFR, r = 0.92, SEE +/- 6.8). In 18 patients on bed rest the long-term stability of this system for measuring ejection fraction and ST segments was verified. During the monitoring period (108 +/- 28 minutes) only minor changes in ejection fraction occurred (coefficient of variation 0.035 +/- 0.016) and ST segment analysis showed no significant change from baseline. To determine whether continuous on-line measurement of ejection fraction would be useful after coronary angioplasty, 12 patients who had undergone a successful procedure were evaluated for 280 +/- 35 minutes with the Cardioscint system.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Angioplastia Coronária com Balão , Diagnóstico por Computador , Coração/diagnóstico por imagem , Monitorização Fisiológica/instrumentação , Função Ventricular Esquerda , Adulto , Idoso , Eletrocardiografia , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Cintilografia , Volume SistólicoRESUMO
The murine-derived monoclonal antibody OKT3 has been shown to be a useful immunosuppressive agent in transplant recipients; but it may cause cardiac instability and hemodynamic findings similar to those seen in septic shock after a first dose. Eight patients who received orthotopic heart transplants and were randomized to OKT3 therapy for immunosuppression were evaluated with serial hemodynamic and radionuclide monitoring for an 8-hour period during the first dose of OKT3. Cytokines including tumor necrosis factor-alpha, interleukin-1 and -2, and interferon-gamma were measured hourly to determine the potential mechanism of action of OKT3. All patients tolerated OKT3, although most had symptoms--pyrexia, chills, dyspnea, nausea and vomiting, and fever--within an hour after the dose. All patients exhibited a biphasic hemodynamic response to the first dose of OKT3. The initial hemodynamic response was characterized by a hyperdynamic phase with involvement in cardiac function as measured by cardiac output and ejection fraction. Left ventricular ejection fraction increased from 68% +/- 10% to 79 +/- 11% and was accompanied by increases in right ventricular ejection fraction and increases in cardiac index from 2.1 +/- 1.1 to 3.8 +/- 1.3 L/min/m2. The increase in ejection fraction was accompanied by a significant decrease in systemic vascular resistance index, from 2190 +/- 740 to 1608 +/- 573 dyne.sec.cm-5. The improvement in left ventricular ejection was caused by a significant decrease in end-systolic volume index (18 +/- 9.5 to 11 +/- 7 ml/m2). This occurred within the first 2 hours after OKT3 and was followed by cardiac index and ejection fraction returning to baseline in the next 2 to 3 hours.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Anticorpos Monoclonais/uso terapêutico , Transplante de Coração/fisiologia , Hemodinâmica/fisiologia , Terapia de Imunossupressão , Função Ventricular/fisiologia , Adulto , Feminino , Rejeição de Enxerto/imunologia , Coração/diagnóstico por imagem , Transplante de Coração/imunologia , Humanos , Masculino , Muromonab-CD3 , Cintilografia , Fator de Necrose Tumoral alfa/análiseRESUMO
Transient left ventricular dysfunction is commonly described in association with cardiopulmonary bypass (CPB). We evaluated changes in right ventricular (RV) function after elective cardiac surgery in 24 patients with normal preoperative cardiac function. In all, irrespective of distribution of coronary artery disease or use of pharmacologic support, a transient depression of RV systolic function with respect to both preinduction and initial postoperative (Postop) values occurred 262 +/- 116 min post-CPB as represented by a decrease in RV stroke volume index (25.0 +/- 1.7 vs. 33.4 +/- 1.9 ml/m2 Postop) and RV ejection fraction (31.0 +/- 2.2 vs. 45.6 +/- 2.5% Postop), and an increase in RV end-systolic and end-diastolic volume indices. This depression responded readily to pharmacologic therapy within 2 h, resolved within 24 h, and had no adverse consequences in these otherwise healthy patients. Further studies are needed to identify the cause of this phenomenon and its importance in patients with preexisting cardiac dysfunction.