Estratificando o risco na angina instável com a ecocardiografia sob estresse com dobutamina / Stratifying the risk in unstable angina with dobutamine stress echocardiography / Stratifying the risk in unstable angina with dobutamine stress echocardiography

OBJETIVO: Avaliar a importância da ecocardiografia sob estresse pela dobutamina (EED) na estratificação de risco de pacientes com angina instável (AI) de baixo a moderado risco, quanto à capacidade de predizer os eventos clínicos combinados (morte de causa cardiovascular, infarto agudo do miocárdio (IAM), AI recorrente, necessidade de revascularização miocárdica) no seguimento de 6 meses. MÉTODOS: Estudo prospectivo, multicêntrico. Os pacientes incluídos estavam internados, assintomáticos havia 24 horas e a medicação em uso não era suspensa para a realização do exame. O EED era realizado preferencialmente até 72 horas da chegada ao hospital. RESULTADOS: Foram avaliados 95 pacientes consecutivos. O EED foi positivo para isquemia em 40 pacientes (42,1 por cento) e em 55 (57,9 por cento), foi negativo. Eventos ocorreram em 28 pacientes, 26 dos quais tinham o EED positivo para isquemia miocárdica. Os outros 67 pacientes não tiveram eventos; desses, 53 tinham o EED negativo. A sensibilidade, especificidade, acurácia, valor preditivo positivo e negativo do teste frente aos desfechos foram: 92,9 por cento, 79,1 por cento, 83,2 por cento, 65 por cento e 96,4 por cento, respectivamente. Sobrevida livre de eventos após 6 meses para os pacientes com EED negativo foi de 96 por cento, comparada com 35 por cento nos que tiveram o EED positivo (p<0,001). A análise univariada identificou classificação da AI, fração de ejeção do VE, índice de movimentação parietal do VE pré e pico, resultado do EED e antecedentes de IAM prévio como fatores prognósticos associados com os desfechos. Somente a variável resultado do EED permaneceu com uma associação significativa com o desfecho através da análise multivariada (p<0,01). CONCLUSÃO: O EED apresentou excelente valor preditivo negativo, permitindo alta hospitalar precoce dos pacientes, sem necessidade de exames adicionais. O resultado do exame foi o único fator prognóstico independente para os eventos.

OBJECTIVE: To evaluate the role of dobutamine stress echocardiography (DSE) in the risk stratification of low to moderate risk unstable angina (UA) patients, to predict the combined clinical outcome of cardiovascular death, myocardial infarction (MI), recurrent UA and the need of revascularization procedures in a 6 month period. METHODS: Multicenter prospective study. Patients should be admitted to the hospital and asymptomatic in the last 24 hours. The exam was performed up to 72 hours from the hospital admission and no medication was stopped prior to the test. RESULTS: Ninety-five consecutive patients were evaluated by DSE. Forty patients (42,1 percent) had a positive ischemic test and fifty five (57,9 percent) had a negative one. Clinical events occurred in twenty eight patients, twenty six of whom had a positive test. The rest of the patients (67) did not have clinical events and fifty three of them, had a negative test. The sensibility, specificity, accuracy, positive predictive value and negative predictive value of the test related to the clinical events were: 92,9 percent, 79,1 percent, 83,2 percent, 65 percent and 96,4 percent, respectively. Event-free survival after 6 months for pacients with a negative DSE was 96 percent compared to 35 percent for those with a positive DSE (p<0,001). The UA classification, left ventricular ejection fraction, rest and peak wall motion score index, DSE result and history of previous MI were associated with the combined end point by univariate analysis. The test result was the only independent predictor of cardiac events by multivariate analysis (p<0.001). CONCLUSION: O DSE has shown an excellent negative predictive value allowing for early hospital discharge without further exams. The positive test result was the only independent predictor for adverse cardiac events.

Existe um comportamento circadiano da isquemia miocárdica ao longo de 48 horas em pacientes com angina instável? / Does a circadian variation occur in myocardial ischemia over 48 hours in patients with unstable angina?

OBJECTIVE: To study the incidence of and variation in myocardial ischemia over 48 hours in patients with unstable angina. METHODS: Thirty-nine patients with unstable angina underwent long-term electrocardiography for 48 hours. The number of events and the period of time of ischemia (in minutes) were analyzed for the 48 hours, in two periods of 24 hours, and in periods of 4 hours. RESULTS: We analyzed 1755.8 hours of monitoring tapes, and ischemic episodes were detected in 18 (46.2 percent) patients, corresponding to 173 ischemic episodes, allowing the evaluation of 1304 minutes of ischemia.only 4 of which were (2.2 percent) symptomatic, Considering the entire period of time of recording and the predetermined time intervals, we observed a higher number of ischemic episodes (38) and a longer duration of ischemia (315.4 minutes) between 11:00 am and 3:00 pm. However, no significant differences occurred among the values in the different intervals. CONCLUSION: Long-term electrocardiography over 48 hours showed a high incidence (97.8 percent) of silent ischemic episodes in patients with unstable angina. No evidence of a circadian variation of myocardial ischemia in unstable angina was observed

Farmacologia cardiovascular em emergências / Cardiovascular pharmacology in emergency room

Todo socorrista deve ser hábil na arte de identificar situaçöes de emergências e seus possíveis diagnósticos. Ele também näo pode perder tempo quando tem de escolher e administrar a terapêutica mais adequada. Para isso, deve treinar e conhecer muito bem as condutas e normas preestabelecidas. Fazem parte desse conhecimento a manipulaçäo de drogas. Com relaçäo a essas , devem ter efeito rápido, ter meia-vida curta, ser administradas por via que näo dependa da colaboraçäo do paciente e que as permitam chegar rapidamente a seu local de açäo ser bem conhecidas por quem as manipula e estar acessíveis para serem prontamente utilizadas. Baseado nesses princípios e nas suas indicaçöes, podemos separar as drogas de acordo com sua preferencial utilizaçäo: na parada cardiorrespiratória, nas arritmias, na hipertensäo, nos quadros isquêmicos, no choque e na sedaçäo.

Quando interromper, na sala de emergência, as manobras de ressuscitação cardiopulmonar na parada cardiorrespiratória sem atendimento pré-hospitalar? / When Should we Stop Cardiopulmonary Resuscitation in Patients Brought to the Emergency Room in Cardiac Arrest with no Out-ofHospital Care

PURPOSE: The decision of stopping cardiopulmonary resuscitation (CPR) in patients brought to emergency room in arrest remains a challenge. Such decision is even more difficult when someone is brought by bystanders, after an acute loss of consciousness without any out-of-hospital care. To evaluate the probability of survival of these patients we reviewed retrospectively charts in our institution, during a period of five years. METHODS: One hundred and one patients that fulfilled these characteristics came to our emergency in arrest. The time to arrival since symptoms started, cardiac rhythm at first electrocardiogram (EKG), age, gender, initial CPR success, late outcomes and previous diseases were obtained. Patients were divided in two groups regarding which cardiac rhythms they had at first EKG: A-patients arriving in asystole; and VF-patients arriving in ventricular fibrillation. To evaluate time to arrival, we arbitrarily choose 15 min as a reference point. RESULTS: In these 101 subjects the mean age was 62 +/- 13.7 years and 63 (62.3) were men. Previous heart disease was documented in 74 [dilated cardiomyopathy in 22 (21.7), coronary heart disease in 41 (40.6), arterial hypertension in 25 (24.7) and others in 6 (5.6)]. In 66 episodes we were sure of the time patients spent before arrival (mean 2.5 +/- 11 min). Only in 63 subjects we had no doubts about the rhythm at entrance: VF in 37 (58.7), A in 22 (34.9) and an accelerated idioventricular rhythm (AIR) in four (6.3). Time to arrival was 18.6 +/- 10.6 in VF vs 32.5 +/- 11.7 min in A (p = 0.012). Fourteen (13.8) subjects resumed a supraventricular rhythm with systolic pressure > or = 90 mmHg after CPR and all of them were in VF (13) or AIR (one). Nine patients (8.9) evolved in coma. Only five (4.9) were discharged from the hospital without any neurological disturbance and their time to arrival ranged from one to 15 (9 +/- 5.8) min. CONCLUSION: Delayed arrival to the emergency room (> 15 min) associated with asystole were predictors of unsuccessful CPR, and both data are helpful in deciding when to stop CPR in subjects arriving at the emergency department with no out-of-hospital care.

Objetivo - Avaliar a chance de sobrevivência dos pacientes trazidos à emergência em parada cardiorrespiratória, sem atendimento pré-hospitalar, situação de difícil decisão quanto a se interromper as manobras de ressuscitação cardiopulmonar (RCP). Métodos - Retrospectivamente, analisamos os prontuários de 101 indivíduos trazidos à emergência em parada cardiorrespiratória (PCR) de janeiro/89 a dezembro/93. Avaliamos o tempo em minutos do início do sintomas até a chegada, o ritmo cardíaco ao eletrocardiograma (ECG), idade, sexo, taxa de sucesso inicial da RCP, evolução tardia e doenças pregressas. Dividimos os pacientes em 2 grupos, de acordo com o ritmo inicial: A - assistolia e FV -fibrilação ventricular. Na avaliação do tempo de chegada, consideramos arbitrariamente 15min como referência.Para avaliar diferenças entre os grupos realizamos os testes de Student e do X2 Resultados - A idade média foi de 62±13,7 anos e 63 (62,3%) eram homens. Pôde-se confirmar a existência de doença prévia em 74 casos [cardiomiopatia dilatada em 22 (21,7%), doença coronária em 41 (40,6%), hipertensão arterial em 25 (24,7%) e outras em seis (5,6%)]. Em 66 episódios tivemos certeza do tempo decorrido até a chegada à emergência (média de 22,5± 11 min.). Em 63 casos tivemos certeza do ritmo de chegada: FV em 37 (58,7%), A em 22 (34,9%) e ritmo idioventricular acelerado em quatro (6,3%). O tempo para a chegada foi de 18,6±10,6 no grupo FV vs 32,5±11,7min. no grupo A (p= 0,012). Quatorze (13,8%) indivíduos, nenhum do grupo A, reassumiram ritmo supraventricular com pressão arterial sistólica>90mmHg após a RCP. Desses, nove (8,9%) evoluíram em coma e somente cinco (4,9%) tiveram alta hospitalar, todos sem distúrbios neurológicos e do grupo FV. O tempo de chegada nesses cinco sobreviventes variou de 1 a 15 (9±5,8)min.Conclusão - Um tempo de chegada >15min associado a assistolia pode ajudar na decisão de se terminar os esforços de RCP em indivíduos que chegam à emergência sem atendimento pré-hospitalar

Relação entre o ECG convencional e a artéria coronária responsável no infarto agudo do miocárdio / The relationship between conventional ECG and the culprit coronary artery in acute myocardial infarct

PURPOSE--To evaluate electrocardiogram (ECG) in detecting acute myocardial infarction (AMI) during the first 12 hours of symptoms and its relationship to the culprit coronary artery. METHODS--We studied 68 patients aged 55.6 (30 to 76) years, 61 males, with AMI confirmed by elevated CKMB isoenzyme and cinecoronariography (CINE). In all of them we obtained two ECG: first (i), with < 12 hours of symptoms and a second, > or = 5 days during evolution. ECG were analyzed in order to disclose up and downward ST-T segments > or = 1 mm, new Q waves > or = 0.04 s and R/S > or = 1 plus downward ST-T segment in leads V1 and V2. Then we have done correlation between these and the culprit coronary lesions at CINE. RESULTS--The culprit coronary lesions were: right coronary artery (RCA) in 16, left circumflex (LC) in 26 and left anterior descending (LAD) in 31 cases. According to the ECG, the RCA determined inferior AMI in all patients and the LC only in 62 por cento of cases. Posterior AMI due to LC was seen in 81 por cento of cases at ECG and, associated with lateral AMI, in 52 por cento . Lone lateral AMI was seen in 5 por cento and true posterior in 14 por cento of cases, all of them due to LC. CONCLUSION--False negative ECG (i) in AMI is in fact due to LC occlusion which, frequently, causes posterior wall more then inferior wall myocardial infarction at ECG

Pontes miocárdicas múltiplas / Multiple myocardial coronary bridges

White woman, 31 years old, complaint pain in the left arm, at rest, and few months later she had pain in the precordial region with dyspnea, diaphoresis and dizziness without any inducing factor. One hour later, symptoms ceased spontaneously, remaining daily precordial pain. Subsidiary examinations as cineangiocoronariography revealed 100 per cent of arterial lumen constriction in the middle portion of the descending coronary artery, during systole, as well as in the diagnoalis and marginal branches. Multiple myocardial coronary bridges has been described in necropsy, but during cinecoronarioangiography, this case appeared to be the first one