Exercise supplementation to dipyridamole prevents hypotension, improves electrocardiogram sensitivity, and increases heart-to-liver activity ratio on Tc-99m sestamibi imaging.

BACKGROUND: Myocardial perfusion imaging with dipyridamole is an alternative with which to evaluate patients who are unable to exercise. Many patients who undergo dipyridamole testing are limited in their ability, but are not completely unable, to exercise. There are benefits from adding low workload exercise to dipyridamole testing, including a reduction of thallium 201 concentration in the liver, leading to a higher heart-to-liver activity ratio and better image quality. This prospective study was designed to evaluate a protocol of exercise supplementation during dipyridamole technetium 99m sestamibi imaging and to verify whether a higher heart-to-liver activity ratio could be obtained. We also evaluated the potential of this combined protocol to prevent hypotension and induce ischemic changes on the electrocardiogram (ECG). METHODS AND RESULTS: Ninety consecutive patients who were not completely disabled for exercise underwent dipyridamole Tc-99m sestamibi cardiac single photon emission computed tomography with a protocol of exercise supplementation (DipEx). The heart-to-liver activity ratio, hemodynamics, and electrocardiographic changes were studied. The findings were compared with those of a control group (Dip) composed of 99 patients who underwent dipyridamole infusion alone. Patients with left bundle branch block, pacemaker, and atrial fibrillation were excluded. The DipEx patients tolerated the protocol, exercising 4.2 +/- 1.3 minutes on the treadmill (Bruce protocol). Compared with Dip, patients in the DipEx group had a higher heart-to-liver activity ratio (1.3 +/- 0.4 vs 1.6 +/- 0.5, respectively; P =.00001), had no incidence of hypotension (6% vs 0%, respectively; P =.03), and had a higher sensitivity of the ECG to detect ischemia (6% vs 34%, respectively; P =.003). The increase in sensitivity seen in the DipEx group was accompanied by a significant decrease in specificity compared with the Dip group (67% vs 100%, P =.000001). CONCLUSIONS: Our data show that the addition of limited exercise to dipyridamole results in benefits during Tc-99m sestamibi imaging, increasing heart-to-liver activity ratio, preventing vasodilator-induced hypotension, and improving ECG sensitivity for the detection of ischemia. Furthermore, this protocol also provides an estimation of the patient's physical capacity and could be used as an alternative for patients undergoing dipyridamole infusion who are not completely unable to exercise.

Early infarct artery collateral flow does not improve long-term survival following thrombolytic therapy for acute myocardial infarction.

It is known that acutely developed collaterals can prevent the onset of acute myocardial infarction (AMI) in the presence of a total coronary occlusion. However, there still is controversy concerning long-term follow-up of coronary collateral circulation to the infarct-related artery. In this study we analyze the prognostic role of collateral flow (degrees 0 to 3) as well as anterograde flow (degrees 0 to 3) in patients with AMI treated with thrombolytic therapy. Four hundred twenty-two patients (median age 57 years, 355 men) with AMI were treated with intravenous streptokinase and followed prospectively for up to 8 years. At the end of the study period, patients with collateral coronary flow 3 (n = 30) and those with flow <3 (n = 392) at in-hospital coronary arteriography had survival rates of 66% and 85%, respectively (p <0.12). Meanwhile, patients with coronary anterograde flow 3 (n = 189) and those with flow <3 (n = 233) had survival rates of 89% and 80%, respectively (p <0.04). By censored regression analysis, a negative correlation was found between coronary collateral flow degree and survival (p = 0.0498) and, inversely, a positive correlation was found between coronary anterograde flow degree and survival (p = 0.0053). By Cox multivariate analysis, the following variables showed significant correlations with long-term survival: global left ventricular ejection fraction (p = 0.0003), anterograde flow degree (p = 0.0006), collateral flow degree (negative correlation, p = 0.0179), and medical treatment (negative correlation, p = 0.0464). Thus, patients treated with intravenous streptokinase during AMI and with adequate coronary collateral circulation had a worse prognosis than those who developed adequate anterograde flow, probably because of residual myocardial ischemia. Such patients may benefit from coronary revascularization (angioplasty or surgery) to restore anterograde blood flow and minimize myocardium at risk.

Arritmias no infarto agudo do miocárdio / Arrhythmias in acute myocardial infarction

Há alta incidência de arritmias no pós-infarto agudo do miocárdio. Distúrbios no ritmo e na condução estão entre as primeiras complicaçöes descritas. Embora eses distúrbios sejam claramente menos comuns em pacientes tratados com terapia fibrinolítica, permanecem uma contínua fonte de problemas para os clínicos que cuidam de pacientes com infarto agudo do miocárdio. Além disso, incertezas acerca da utilização de medidas terapêuticas, medidas profiláticas e prognóstico a curto e longo prazos têm estimulado a realização de vários estudos no sentido de definição de prognóstico a curto e longo prazos têm estimulado a realização de vários estudos no sentido de definição de prognóstico, prevenção e tratamento das arritmias no infarto agudo do miocárdio. Neste artigo, os autores abordam o manuseio clínico das arritmias no infarto agudo do miocárdio, com ênfase na incidência, no prognóstico, na prevenção e no tratamento.

The role of antegrade and collateral flow in relation to left ventricular function post-thrombolysis.

UNLABELLED: The aim of the study was to analyze the relationship between antegrade and collateral flow degree to the "culprit" coronary artery, and between both variables and left ventricular systolic function. We analyzed five hundred patients with acute myocardial infarction, treated prospectively and consecutively within 6 h of evolution with intravenous streptokinase. The degree of antegrade (0-3) and collateral blood flow (0-3) were correlated with 18 other variables. RESULTS: (a) By simple regression analysis, antegrade flow degree correlated positively (p < 0.0001), and collateral flow degree negatively (p = 0.0073) with left ventricular ejection fraction; (b) By multiple regression analysis, antegrade flow degree (p = 0.0032), but not collateral flow degree (p > 0.1), correlated independently with left ventricular ejection fraction; (c) In the subgroup of patients with occluded "culprit" coronary artery, the mean ejection fraction was significantly higher for those with collateral flow 3 (60.2% +/- 13.3 in relation to those with collateral flow < 3 (53.9% +/- 13.1, p = 0.032, 95% CI. 11.96 to (0.53%). In conclusion, antegrade coronary flow degree, but not collateral flow degree, correlated significantly and independently with left ventricular ejection fraction. However, in the subgroup of patients with occluded "culprit" coronary artery, collateral flow 3 led to better left ventricular systolic function, in relation to collateral flow < 3.

Diltiazem improves left ventricular systolic function following acute myocardial infarction treated with streptokinase. The Calcium Antagonist in Reperfusion Study (CARES) Group.

The role of diltiazem on left ventricular systolic function was analyzed in 101 patients with acute myocardial infarction treated with streptokinase, being obtained, for the total of the population, higher LV global ejection fraction (p = 0.022), LV regional shortening (p = 0.046) and LV global shortening (p = 0.064) for the treated group, relative to the placebo group; the p values were, respectively, 0.005, 0.009, and 0.012, for patients that achieved TIMI-3 antegrade coronary flow. It is concluded that diltiazem is useful as adjuvant to streptokinase, especially when antegrade coronary blood flow TIMI-3 is obtained.

[Left ventricular function in the acute phase of patients with myocardial infarction randomly treated with 750,000 or 1.5 million units of streptokinase]. / Função ventricular esquerda na fase aguda de infartados submetidos aleatoriamente a 750,000 ou 1.5 milhão de unidades de estreptoquinase.

PURPOSE: To compare the doses of 750,000 and 1.5 million units (U) of streptokinase (SK), relatively to the left ventricular (LV) systolic function analyzed through contrasted ventriculography. METHODS: We included 110 patients with acute myocardial infarction (AMI) within 6h of the onset (mean-age 60 years, 83.6% men), that were randomized to receive 750,000U of SK in 15 min (55 patients), or 1.5 million U in 30 min (55 patients). The study main goal was the comparison between the groups relatively to LV ejection fraction, global and regional shortening, obtained at the fifth day of the AMI. RESULTS: The 750,000 and 1.5 million groups were homogeneous relatively to 15 analyzed variables. Relatively to the main goal of the study, it was found respectively: a) ejection fraction analysis (median): 64% and 60.5% for the total population (p = 0.25, 95% CI -2.7 to 10), 64% and 57.5% for anterior AMI (p = 0.2, 95% CI -3.6 to 16.3), 65% and 65% for inferior AMI (p = 0.99, 95% CI -8.4 to 8.4); b) global shortening analysis: -2.53 and -2.66 for the total population (p = 0.3, 95% CI -0.47 to 0.87), -2.27 and -2.53 for anterior AMI (p = 0.18, 95% CI -0.3 to 1.4), -1.82 and 1.72 for inferior AMI (p = 0.9, 95% CI -0.82 to 0.75); c) regional shortening analysis: anterior AMI -2.6 and -2.67 (p = 0.47, 95% CI -0.7 to 1.5), inferior AMI -2.3 and -2.32 (p = 0.9, 95% CI -0.82 to 0.75). CONCLUSION: The dose of 750,000U was as efficacious as the 1.5 million relatively to LV systolic function, one of the best survival predictors of short-medium and long-term survival post AMI.

[Rupture of the left ventricular free wall. A lethal entity that can be surgically treated with success]. / Ruptura da parede livre do ventrículo esquerdo. Uma entidade letal que pode ser tratada cirurgicamente com sucesso.

We present three patients with left ventricular free wall rupture post acute myocardial infarction, all three treated successfully through surgery. Two of them were submitted to streptokinase IV. In all cases the diagnosis were based on clinical and echocardiographic features. The authors conclude that the diagnostic suspicion can be done easily, the echocardiogram is very useful, and the surgical treatment may led to a good short- and long-term survival.

Surgical revascularization after fibrinolysis in acute myocardial infarction. Long-term follow-up.

One hundred twenty-eight patients with myocardial infarction who underwent operation for myocardial revascularization and 147 patients who received medical therapy were followed up for up to 6 years: all patients had received treatment with intravenous streptokinase. In the surgical group, 91.5% of the patients had the region related to the infarction revascularized, and in 82.8% of them the mammary artery was used. Statistically significant differences were not detected between the groups according to infarct size, clinical features, and left ventricular ejection fraction. However, there was a higher risk in the surgical group, as compared with that in the medical group, in terms of anatomic characteristics: 99.2% versus 77.1% of the patients showed more than 70% residual obstruction at the "culprit" coronary artery (p < 0.001, 95% confidence interval 14.1% to 30.1%) and 76.8% versus 40.7% showed multivessel coronary disease (p < 0.001, 95% confidence interval 23.7% to 48.5%). In-hospital survival was 95.3% in the surgical group and 89.1% in the medical group (p = 0.096, 95% confidence interval -0.2% to 12.6%). Significantly higher survivals were obtained for the surgical group both during the first (93% +/- 2.3% versus 80.3% +/- 3.3%, p = 0.005) and the sixth (86.4% +/- 3.4% versus 68.4% +/- 4.3%, p = 0.003) year of follow-up. Statistically significant differences were also obtained when in-hospital deaths were excluded. A Cox regression model with 13 variables showed that only age (p = 0.0422) and medical treatment (p = 0.0194) correlated independently with mortality. It is concluded that in this nonrandomized study, operation led to a significantly higher survival both on a medium- and long-term basis, when compared with that obtained for patients receiving medical therapy.

[In-hospital survival predictors in infarction patients undergoing fibrinolytic therapy]. / Preditores da sobrevida intra-hospitalar em pacientes infartados submetidos à terapêutica fibrinolítica.

PURPOSE: To analyze the in-hospital predictors of survival in a population of infarcted patients submitted to the same therapeutic protocol that included IV streptokinase (SK) in the dose of 750,000 units. METHODS: Three hundred and thirty two patients (mean age 55.6 +/- 10 years, 82.3% men) with acute myocardial infarction (AMI) were studied within six hours of onset of symptoms in a prospective and consecutive protocol. Using simple and multiple regression analysis, the following variables were selected for correlation with survival: LV ejection fraction by contrast ventriculography > 50%; CK-MB peak < or = 100 UI/1; male sex; invasive treatment (surgery or angioplasty); patent "culprit" coronary on cineangiography; age < or = 65 years; time interval between the onset of pain and the beginning of SK infusion < 3 hours; residual obstruction < 70% at the "culprit" coronary; inferior AMI location on ECG; absence of hypotension per-peri SK infusion, previous AMI, multivessel coronary artery disease and reinfarction. RESULTS: By simple regression analysis, ejection fraction > 50% (p < 0.001), CK-MB peak < or = 100 UI/1 (p = 0.003), and the absence of hypotension (p < 0.001), previous AMI (p = 0.009), multivessel coronary artery disease (p = 0.02) and reinfarction (p = 0.049), correlated significantly with survival. By multiple regression analysis ejection fraction > 50% (p = 0.017) and the absence of hypotension (p < 0.01), multivessel coronary artery disease (p = 0.032) and reinfarction (p = 0.037) correlated independently with survival. CONCLUSION: The data presented strongly support the concept of preventing atherosclerosis and maintaining myocardial viability using either direct measures such as recanalization, or indirect measures such prevention of hypotension and reinfarction.

Acute myocardial infarction treated with intravenous streptokinase: 6-year follow-up.

Our objective was to investigate variables which, although occurring during the acute period, could influence the medium (1st year) and long-term (6th year) survival of infarcted patients. Of a total of 332 patients treated consecutively and prospectively according to the same protocol which included intravenous streptokinase, 305 survived the hospital phase and represent the study population. Mean patient age was 55.6 +/- 10 years and mean follow-up time was 3.33 years, with 1008.59 patient-years. The clinical course of the group was analyzed according to the following variables: left ventricle ejection fraction, hypotension per/peri streptokinase infusion, CK-MB peak, previous myocardial infarction, number of obstructed coronaries, reinfarction, sex, 'definitive' treatment, residual obstruction, age, pain/streptokinase infusion interval, patency of the 'culprit' coronary and infarct location. Overall, patient survival was 93.8 +/- 1.4% during the 1st year and 83.7 +/- 2.6% at the 6th. The following groups showed significantly different (log-rank) survivals: (a) 1st year: 94.6% for absence and 82.6% for presence of reinfarction (P = 0.0451); 97.9% for inferior and 91.4% for anterior infarct location (P = 0.044); 96.4% for ejection fraction > 50% and 90.6% for ejection fraction < or = 50% (P = 0.0187); 96.5% for angioplasty/surgery and 90.1% for clinical treatment (P = 0.0028); 95.5% for absence and 80.6% for presence of previous infarct (P = 0.0001). (b) 6th year: 88.3% for ejection fraction > 50% and 73.9% for ejection fraction < or = 50% (P = 0.028); 87.4% for < or = 65 and 66.4% for > 65 years (P = 0.0114); 89.6% for aggressive and 76.8% for conservative treatment (P = 0.013); 86.6% for absence and 60.7% for presence of previous infarct (P = 0.0009).

Estudo do calcio total plasmatico nas primeiras 72 horas de vida em recemnascidos a termo e sadios. / Study of plasma total calcium during the first 72 hours of life in healthy at term newborn infants

Foram estudados 73 recem-nascidos a termo e sadios, subdivididos em quatro grupos de acordo com o periodo de colheita do sangue: sangue do cordao, de 0 a 24 horas, de 24 a 48 horas e de 48 a 72 horas de vida.Analisaram-se as concentracoes plasmaticas de calcio total, magnesio, fosforo e proteinas totais. Foi estudada a evolucao do calcio total plasmatico nas primeiras 72 horas de vida, comparando-se os valores obtidos com os da literatura. Estudou-se a correlacao entre calcio total plasmatico e magnesio, fosforo e proteinas totais nas primeiras 72 horas de vida