Luis Henrique Weitzel

The effects of early administration of atropine during dobutamine stress echocardiography: advantages and disadvantages of early dobutamine-atropine protocol.

BackgroundThe conventional dobutamine protocol for the investigation of induced myocardial ischemia is well established. Our objective was to evaluate the effects of early administration of atropine during the dobutamine stress echocardiogram, as compared to its conventional use.MethodsOne hundred and twenty-one patients were referred to the dobutamine stress echocardiogram, for the investigation of myocardial ischemia and the administration of atropine was randomized into three groups (A, B, C at 10, 20 and 40 mcg/kg/min of dobutamine, respectively).ResultsThe mean level of the double product was significantly lower in the group C patients when compared to group B patients (p = 0.002). The mean test time (12.8 ± 3.1 and 18.7 ± 3.4 p= 0.0001) and the mean total dose of dobutamine (14 × 18 × 25 mg p = 0.008) were significantly higher in group C patients than in group A & B patients. The mean test time was reduced in 6 minutes (31%) with the early administration of atropine in relation to the standard protocol. The atropine dose used in the different groups was similar. Complications were uniform in all cases.ConclusionThe early administration of atropine during the dobutamine-atropine stress echocardiography significantly reduces duration of the test and the dose of amine without increasing the number of complications, the total dose of atropine or the number of diagnostic tests.

The effects of beta-blockers on dobutamine-atropine stress echocardiography: early protocol versus standard protocol

BackgroundTo study the effects of Beta-blockers during Dobutamine Stress Echocardiography (DSE) comparing the hemodynamic benefits of an early administration of atropine in patients taking or not Beta-blockers.MethodsOne hundred and twenty-one patients were submitted to dobutamine stress echocardiography for the investigation of myocardial ischemia. The administration of atropine was randomized into two groups: A or B (early protocol when atropine was administered at 10 and 20 mcg/kg/min of dobutamine, respectively) and C (standard protocol with atropine at 40 mcg/kg/min of dobutamine). Analysis of the effects of Beta-blockers was done regarding the behavior pattern of heart rate and blood pressure, test time, number of conclusive and inconclusive (negative sub-maximum test) results, total doses of atropine and dobutamine, and general complications.ResultsBeta-blocked patients who received early atropine (Group A&B) had a significantly lower double product (p = 0.008), a higher mean test time (p = 0.010) and required a higher dose of atropine (p = 0.0005) when compared to the patients in this group who were not Beta-blocked. The same findings occurred in the standard protocol (Group C), however the early administration of atropine reduced test time both in the presence and absence of this therapy (p = 0.0001). The patients with Beta-blockers in Group A&B had a lower rate of inconclusive tests (26%) compared to those in Group C (40%). Complications were similar in both groups.ConclusionThe chronotropic response during dobutamine stress echocardiography was significantly reduced with the use of Beta-blockers. The early administration of atropine optimized the hemodynamic response, reduced test time in patients with or without Beta-blockers and reduced the number of inconclusive tests in the early protocol.

212 Analysis of intraventricular and aortic gradient during dobutamine stress echocardiogram: correlation with complications

RESUMO Fundamento: A interpretação do ecocardiograma de estresse com dobutamina-atropina é baseada no aumento do espessamento sistólico, onde o contrário disto é considerado indicativo de doença arterial coronariana (DAC). Porém, a condição hiperdinâmica induzida pela dobutamina pode repercutir em sintomas que não decorrem da DAC obstrutiva. Objetivo: Avaliar a associação entre o gradiente na via de saída do ventrículo esquerdo(VSVE) e aórtico(AO) e a presença de sintomas, durante a ecocardiografia de estresse com dobutamina (DOB);e as diferenças na hemodinâmica desses fluxos entre os protocolos precoce e padrão(PR e PD). Material e Métodos: Estudados 75pt com função sistólica normal. Os pt foram randomizados aleatoriamente para PD(Atr em 40mcg de DOB) ou PR(Atr iniciando em 20mcg de DOB).Os gradientes na VSVE e AO foram obtidos em repouso e em cada estágio do teste e foram analisados evolutivamente. Presença de complicações foram consideradas e alterações hemodinâmicas registradas. O teste de Wilcoxon, t de Student e de Mann-Whitney foram utilizados para análise estatística. Resultados: Dos 75 pt estudados,a média de idade foi de 61anos, 71% tinham história de HAS e HVE foi identificada em 36% dos casos. Variações dos gradientes entre os PD e PR não ocorreram junto ao basal, mas os gradientes foram maiores no PD a partir de 20mcg DOB, e em todos os estágios do teste os gradientes aumentam gradativa e significativamente (p<0,0001). No pico do teste os gradientes foram maiores no PD em relação ao PR (p<0,05), considerando um delta (pico basal) >20mmHg (p=0,022). Dor precordial ocorreu em 8,6%(em testes negativos), arritmias em 15,5%, e hipotensão 5,2% dos casos. A presença de complicações se relacionou mais com a elevação dos gradientes durante o teste, e mais no PD (60%x22%) em relação ao PR, p=0,002. Conclusão: Os gradientes em VSVE e AO apresentaram aumentos progressivos seguindo as doses de DOB. O PD resultou em gradientes significativamente mais elevados, que relacionou-se com maior sintomatologia e complicações expressa pelos pacientes.