RESUMEN
BACKGROUND: The results from studies of coronary angioplasty after failed thrombolysis (rescue-PTCA) in acute myocardial infarction are contradictory. Long-term results were not presented till now. Therefore we analyzed the data from our registry of those patients whose acute and long-term results were available. PATIENTS AND METHODS: Data of 49 patients were analyzed who had been admitted for rescue-PTCA from other hospitals. Thrombolysis had to be started < 6 hours (mean 2.7 hours) from onset of symptoms. Rescue-PTCA had to be completed within < 24 hours (mean 10.5 hours). 37 patients received streptokinase, seven rt-PA, three urokinase and two prourokinase. Electrocardiographic and clinical criteria were used to define failure of thrombolysis. The data of the acute results were from a prospective registry and the long-term results came from clinical follow-up visits and a questionnaire sent to the patients. RESULTS: Mean age of the patients was 48.5 years (38-78 years), 45 male, nine patients in cardiogenic shock (18%), infarct related artery (IRA): RCA 22x, LAD 21x, LCX 5x, CABG 1x, single vessel disease 27x, multiple vessel disease 22x. Acute results: Initial IRA-TIMI flow 0 in 28 patients, 1 in twelve patients, 2 in 9 patients; after rescue-PTCA TIMI flow 1 in one patient, 2 in two patients, 3 in 46 patients (procedural success 94%). Hospital mortality 8.2% (four patients), all in cardiogenic shock. Early reocclusion rate 10%. Bleeding complications 14%, no fatal complications. Long-term results: Observation period 2.5 years in 42 patients (0.5-6.5 years). Three more deaths. Total mortality 14% (7/49). Angiographic follow-up: Ejection fraction initially 50%; 53% after 3 months. Repeat revascularization in 43% (15/35): Re-PTCA in 8/35, surgery in 6/35 patients, 1x transplantation. 80% of the patients were free from angina or heart failure. CONCLUSIONS: Rescue-PTCA in acute myocardial infarction has a high procedural success rate with a low hospital mortality. It is the treatment of choice for patients in cardiogenic shock. Transportation to an interventional center is safe. The reintervention rate is comparably high. The long-term results are good.
Asunto(s)
Angioplastia Coronaria con Balón , Infarto del Miocardio/terapia , Derivación y Consulta , Terapia Trombolítica , Adulto , Anciano , Femenino , Estudios de Seguimiento , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Retratamiento , Análisis de Supervivencia , Insuficiencia del TratamientoRESUMEN
Dobutamine is a synthetic catecholamine with predominant beta-stimulation. Its half-life is approximately 2 min. The positive chronotropic and inotropic effects of dobutamine induce myocardial ischaemia if significant coronary artery obstruction is present. Regional ischaemia produces regional wall motion abnormalities which can be detected by echocardiography. Most dobutamine stress protocols start at an infusion rate of 5 micrograms.kg-1.min-1 and increase to a peak dose of 40 or 50 micrograms.kg-1.min-1; to further increase heart rate, a bolus injection of 0.25-1.0 mg atropine is added. Test endpoints are the detection of new wall motion abnormalities, the occurrence of severe complications or achievement of the target heart rate. Viable myocardial regions have a positive inotropic reserve, which can be stimulated by dobutamine and detected by echocardiography. Indications for the use of dobutamine stress echocardiography are to prove stress-inducible myocardial ischaemia and to detect myocardial viability. The test should only be performed for the detection of stress-induced myocardial ischaemia if patients are unable to undergo exercise echocardiography, or if patients fail to reach their required test level in exercise echocardiography.
Asunto(s)
Antagonistas Adrenérgicos beta , Enfermedad Coronaria/diagnóstico , Dobutamina , Ecocardiografía/métodos , Antagonistas Adrenérgicos beta/efectos adversos , Diagnóstico Diferencial , Dobutamina/efectos adversos , Ecocardiografía/efectos adversos , Electrocardiografía , Prueba de Esfuerzo/efectos adversos , Prueba de Esfuerzo/métodos , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Humanos , Sensibilidad y EspecificidadRESUMEN
Arbutamine, a new potent non-selective beta-adrenoceptor agonist with mild alpha 1-sympathomimetic activity, has been developed specifically for pharmacological stress testing. The drug acts like physical exercise, increasing both heart rate and myocardial contractility. Sensitivity, specificity and accuracy in detecting significant stenotic coronary artery disease are 76%, 96%, and 82%, respectively, again similar to those of exercise echocardiography. The drug is delivered by a computerized drug delivery and monitoring device (GenESA) which adjusts the infusion rate according to the patient's heart rate data feedback. The drug is generally well tolerated and has an acceptable safety profile. This article describes recent clinical experience with arbutamine and presents preliminary results of a multicentre multinational study which evaluates the clinical utility and safety of the GenESA system in diagnosing coronary artery disease.
Asunto(s)
Agonistas Adrenérgicos beta , Catecolaminas , Enfermedad Coronaria/diagnóstico , Ecocardiografía/métodos , Prueba de Esfuerzo/métodos , Agonistas Adrenérgicos beta/administración & dosificación , Animales , Catecolaminas/administración & dosificación , Ensayos Clínicos como Asunto , Sistemas de Liberación de Medicamentos/instrumentación , Quimioterapia Asistida por Computador/instrumentación , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Humanos , Sensibilidad y EspecificidadRESUMEN
In recent years, stress echocardiography has gained broad acceptance as a non-invasive method for the diagnosis of coronary artery disease. Facing different protocols, dosages and instrumentation, official guidelines for the performance, standardization and quality control of stress echocardiograms are needed; however, so far they are not available. This paper recommends the type of personnel and technical equipment needed for stress echocardiography laboratories, based on experience gained during more than 2000 stress echocardiographic procedures. To perform stress echocardiography, a cardiologist and a technical assistant--both well trained over a large number of tests--should be involved. The laboratory must have basic equipment such as a 12-lead ECG, blood pressure monitoring capacity, a treadmill or bicycle for ergometry, a precision intravenous delivery system for pharmacological stress testing as well as an adequate echo table; additionally, emergency equipment is mandatory. The ultrasound machine should contain transducers with high 2-D resolution; most important is a digital image acquisition system which facilitates performance and interpretation through side-by-side display of synchronized rest and stress images. Finally, there is a need for proper patient preparation and the obtaining of informed consent.
Asunto(s)
Ecocardiografía/instrumentación , Prueba de Esfuerzo/instrumentación , Laboratorios de Hospital , Personal de Laboratorio Clínico/normas , Enfermedades Cardiovasculares/diagnóstico por imagen , Competencia Clínica , Ecocardiografía/métodos , Prueba de Esfuerzo/métodos , Alemania , Humanos , Laboratorios de Hospital/normas , Recursos HumanosRESUMEN
Asynergic myocardial regions in patients with coronary artery disease can be viable. They may have the ability to improve their function after restoring coronary blood flow. Asynergic but viable myocardial regions have a positive inotropic reserve which can be stimulated by catecholamines. Because echocardiography is an established method for evaluating regional left ventricular function, it has the potential to detect the inotropic response of asynergic myocardial regions. In the clinical setting, prediction of left ventricular functional improvement after revascularization is particularly important. Dobutamine stress echocardiography is the most frequently used stress echocardiographic test for detection of myocardial viability. Dobutamine is infused at low rates of 2.5 to 20 micrograms.kg-1.min-1 to detect myocardial viability. This paper reports on the sensitivity and specificity of the method for the detection of viability and its usefulness for prediction of left ventricular functional improvement after revascularization.
Asunto(s)
Cardiotónicos , Dobutamina , Ecocardiografía/métodos , Prueba de Esfuerzo/métodos , Infarto del Miocardio/diagnóstico , Aturdimiento Miocárdico/diagnóstico , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miocardio/patología , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Función Ventricular Izquierda/fisiologíaRESUMEN
Accurate heparin anticoagulation assessment is important to prevent complications (hemorrhage, thrombotic coronary occlusion) during and after coronary angioplasty (PTCA). Paired ACT-, aPTT- and prothrombin time (PT) measurements have not been studied after PTCA using a high dose heparin management. For that reason we analyzed in 150 consecutive patients (115 m., 35 f., 61 +/- 10 y.) immediately after PTCA and at the time of arterial sheath removal aPTT-(Neothromtin, Behring), PT- (Thromborel S, Behring) and ACT-(HR-ACT, HemoTec) values after application of 20,000 U of heparin (5,000 U intravenous, 15,000 U intracoronary) followed by a heparin-infusion (15,000-25,000 U/24 h). Immediately after PTCA in all patients a aPTT above the upper limit of >180 s was found. The average postprocedural ACT was 330 +/- 82 s. Only 9 patients showed an ACT below 200 s. All coronary reocclusions (n = 3) immediately after PTCA occurred in this group. Arterial sheaths were removed 13 +/- 3 h after PTCA. The incidence of minor peripheral bleeding complications at that time was 21% and was related to the anticoagulation level. Major bleeding complications requiring transfusion were noted in only one case. Our findings suggest that after high dose heparinization for PTCA the ACT test provides a reliable and broad range for the assessment of heparin anticoagulation. In contrast to the aPTT the ACT is ideally suited to determine the dosage of heparin infusion and the time of arterial sheath removal after PTCA. ACT measurements are superior to aPTT measurements in heparin anticoagulation assessment during and direct after PTCA.
Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad de la Arteria Coronaria/terapia , Heparina/administración & dosificación , Tiempo de Tromboplastina Parcial , Tiempo de Coagulación de la Sangre Total , Anciano , Enfermedad de la Arteria Coronaria/sangre , Trombosis Coronaria/sangre , Trombosis Coronaria/prevención & control , Relación Dosis-Respuesta a Droga , Femenino , Hemorragia/sangre , Hemorragia/inducido químicamente , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Recurrencia , Valores de ReferenciaRESUMEN
Calcium antagonists such as verapamil/diltiazem predominantly delay av-nodal conduction. Thus, the most important clinical indications for their application are the av-nodal-reentrant-tachycardia as well as the slowing of rapid ventricular response in intraatrial tachyarrhythmias. To reestablish sinus rhythm in atrial fibrillation, verapamil should be combined with chinidin. Usually, ventricular arrhythmias cannot be suppressed by calcium antagonists, but they may be indicated in exercise-induced ventricular arrhythmias and tachycardias arising from the right ventricular outflow tract. Verapamil/diltiazem are effective in ischemia-induced tachyarrhythmias, especially ventricular fibrillation, because of the reduction of ischemia-related conduction delay in the ischemic zone. The effectiveness of calcium antagonists in the secondary prevention of myocardial infarction can not yet be definitively defined.
Asunto(s)
Arritmias Cardíacas/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/uso terapéutico , Electrocardiografía/efectos de los fármacos , Sistema de Conducción Cardíaco/efectos de los fármacos , Ventrículos Cardíacos/efectos de los fármacos , Humanos , Taquicardia/tratamiento farmacológicoRESUMEN
Acute thrombosis of highly stenosed coronary arteries often results in acute myocardial infarction. The rationale for thrombolytic therapy is to restore blood flow before irreversible myocardial cell damage develops. In this review the results of more than 60 interventional studies in which reperfusion or "patency" rates, left ventricular function, infarct size, as well as intrahospital and long-term mortality following thrombolytic therapy were assessed, are reported and analyzed with respect to the patterns of applying thrombolytic therapy (different thrombotic agents and percutaneous transluminal coronary angioplasty). The results show that a significant reduction in infarct size, improvement in left ventricular function, and decrease in early- as well as late-mortality can be achieved when successful recanalization is established within four hours after onset of symptoms. Thrombolytic efficacy with respect to patency rates is highest after intravenous application of so-called fibrin-selective thrombolytic agents (rt-PA) and APSAC (71% and 73%), intracoronary application of streptokinase (69%), and primary percutaneous transluminal coronary angioplasty (88%). By contrast, intravenous infusion of streptokinase results in recanalization of only 56% of occluded vessels. However, the improved reperfusion rates after treatment with rt-PA or intracoronary application of streptokinase are associated with a relatively high incidence of reocclusion (up to 20%). Patients' prognosis after successful initial thrombolysis is essentially influenced by additional interventions, e.g., percutaneous transluminal coronary angioplasty and surgical revascularisation. At present, several questions about the ideal thrombolytic agents or the optimal timing of additional interventions need to be clarified. Further studies are necessary to answer these questions.