[Dobutamine stress echocardiography in patients after an acute myocardial infarct: what is the significance of arterial patency related to the infarct?]. / Ecocardiografia de sobrecarga com dobutamina nos doentes pós-enfarte agudo do miocárdio: qual a importância da permeabilidade da artéria relacionada com o enfarte?

BACKGROUND: Dobutamine stress echocardiography is a very promising technique for assessing myocardial viability, ischemia and prognosis in patients with a recent acute myocardial infarction. Recent studies have shown that the type of perfusion in the infarct-related artery also plays a role in the prognosis of these patients. PURPOSE: To evaluated in patients with non complicated infarction the ability of low-dose and high-dose dobutamine stress echocardiography to assess the presence of both viability and inducible ischemia and correlate the results with the patency of the infarct related artery and the accuracy to predict cardiac events during one year follow-up. PATIENTS AND METHODS: Fifty one consecutive in-hospital patients (47 male and four female, mean age 52 +/- 11 years, range 31-75 years) with acute myocardial infarction were evaluated both by dobutamine stress echocardiography and by coronary angiography and followed-up for a mean of 12 +/- 8 months. RESULTS: With low-doses of dobutamine, the incidence of myocardial viability was 33% and with high-doses, the incidence of residual inducible ischemia was 41%. The patency of infarct-related artery showed significant correlation with score wall motion index for viability and for myocardial ischemia. Twenty four (47%) patients suffered cardiac events. Dobutamine stress echocardiography showed a positive predictive value of 67% and a negative of 70% and identified high and low risk patients. CONCLUSIONS: Dobutamine stress echocardiography in patients with acute myocardial infarction is a safe and well tolerated test, and provides in a single test useful information regarding viability, ischemia and prognosis.

[Stress echocardiography with dobutamine: the importance of adding atropine in inconclusive tests]. / Ecocardiografia de sobrecarga com dobutamina: a importância de adicionar atropina nas provas inconclusivas.

OBJECTIVES: To study the feasibility of adding atropine after dobutamine infusion in patients with known or suspected coronary artery disease not achieving 85% of predicted maximal heart rate. PATIENTS: We studied with dobutamine stress echocardiography 219 patients (174 men e 45 women; mean age +/- SD: 58 +/- 11 years), 126 patients with a previous myocardial infarction and 93 with angor. One hundred and thirty three (61%) also performed coronariography. METHODS: Dobutamine stress echocardiography protocol consisted of a step-wise infusion of dobutamine from 5 micrograms/kg/min to a maximal dose of 40 micrograms/kg/min or until a new or a worsening wall motion abnormality, 85% of predicted maximal heart rate or any indication for interruption. In patients not achieving any of these end points, intravenous atropine was administered up to 1 mg. Patients were divided in two groups: Group A: infusion of dobutamine alone and Group B: dobutamine plus atropine. RESULTS: With this protocol the test was interrupted in 41 patients (19%) because of adverse effects that were mild and short lived and resolved with discontinuation of the test. After dobutamine infusion 46% of the tests were nonconclusive, the majority were on beta blocker therapy. After atropine administration there was a significant reduction of the nonconclusive studies to 20% (p < 0.001). In patients with a normal rest echocardiogram the sensitivity and specificity of the test to diagnose significant coronary artery disease was respectively 89% e 100% after atropine. The capacity of the test to detect multivessel disease was also increased after atropine, allowing to reach a sensitivity of 85% and a specificity of 90%. CONCLUSIONS: Dobutamine stress echocardiogram supplemented with atropine is a safe and accurate method to diagnose significant coronary artery disease and to detect multivessel disease in patients with a previous myocardial infarction with rest wall motion abnormalities.

[Calcium antagonists in the treatment of congestive heart failure]. / Os antagonistas do cálcio no tratamento da insuficiência cardíaca congestiva.

The authors present a revision of the clinical studies using calcium antagonists to treat chronic heart failure. They analyse cases where calcium antagonists seem to be of no use (and can even have an adverse effect), particularly in patients with significant left ventricular systolic dysfunction, with normal afterload, high levels of renin, very high levels of right atrium pressure or low sodium. On the opposite, patients with increased afterload or valvular regurgitation can receive some benefit, although care must be taken in the administration of this kind of drugs. New calcium antagonists may show more benefit because they seem not to stimulate the adrenergic system and do not have significant negative inotropic effects. They conclude with a reference to the multiple situations that can be the basis for heart failure, suggesting that probably, in the future, therapy shall be more individually tailored and that in some cases calcium antagonists can be included in such therapy.

[The classic exercise test or by imaging? New applications of Doppler echocardiography]. / Prova de esforço clássica ou com imagem? Novas aplicações da ecocardiografia Doppler.

Classic electrocardiographic exercise test was for many years the only stress modality to exercise the heart, and remains the most widely performed method for provoking ischemia. ST segment deviation on the ECG is the most often utilized marker of abnormal regional myocardial perfusion. But it has traditionally been considered to possess unsatisfactory accuracy in certain categories of patients, namely those with baseline ECG changes that preclude the diagnosis of coronary artery disease. To overcome these limitations, other stress modalities have been introduced recently, namely the radionuclide techniques like stress thallium or MIBI scintigraphy, utilizing inhomogeneous uptake of the radionuclide as a marker of abnormal regional myocardial perfusion, and represents a major improvement in diagnostic accuracy compared with exercise ECG. But these stress modalities are very expensive, and need radiation exposure. More recently stress echocardiography has been introduced and recommended by the American College of Cardiology as a valid and clinically useful technique, presenting several advantages over the radionuclide techniques: a relatively inexpensive test, provides immediate results, no radiation exposure. Because many patients cannot perform dynamic exercise, pharmacological stress testing (dipyridamole, adenosine, dobutamine) coupled with imaging techniques, in particular echocardiography has become very popular with high sensitivity and specificity for the non invasive diagnosis of coronary artery disease. The analysis of the results obtained from several studies, showed that these new stress modalities, are ready for routine clinical use.

[Doppler echocardiography in the diagnosis of mechanic complications of acute myocardial infarction]. / Ecocardiografia/Doppler no diagnóstico das complicações mecânicas do enfarte agudo do miocárdio.

OBJECTIVES: To evaluate the ability of bedside emergency Doppler/Echocardiographic (ECOCG/DP) studies in the diagnosis of mechanic complications during acute myocardial infarction (AMI). DESIGN: Retrospective analysis of 44 fatal AMI cases, studied by ECOCG/DP and with diagnostic confirmation by surgery and/or necropsy. SETTING: Patients (pts) with AMI admitted to an Intensive Care Unit of a tertiary Hospital (UCIM), Hospital de Santa Maria. PATIENTS: 44 fatal AMI cases were analysed (24 men and 20 women; mean age +/- SD: 72 +/- 9 years) and were divided in two groups according to Killip classification in Group 1 (III/IV): 35 pts and Group 2 (I/II): 9 pts. METHODS: ECOCG/DP was performed in a routine basis at admission, using all standard views and by subcostal view when in an emergency scenario. RESULTS: In 20 pts with bad left ventricular function (LVF) (Group 1) at admission, ECOCG/DP monitoring showed that death was due to worsening of LVF, which was confirmed by necropsy. In the other 15 pts of this group, ECOCG/DP documented the clinical diagnosis of cardiac rupture (free wall: 4 pts; papillary muscle: 4 pts; interventricular septum: 7 pts) which was confirmed by surgery and/or necropsy. In the 9 pts of Group 2, ECOCG/DP disclosed, at admission, good LVF in all. In 5 pts there was a sudden worsening clinical status, and ECOCG/DP showed a severe pericardial effusion with right chambers collapse, highly suggestive of free wall rupture also confirmed at necropsy. In the other 4 pts, ECOCG/DP showed aggravation of wall motion abnormalities and of LVF without rupture, once again in agreement with necropsy. Five clinical cases are presented for illustration of this issue. CONCLUSION: In the 44 fatal AMI cases of our study there was complete agreement between the ECOCG/DP and necropsy studies. In AMI patients, ECOCG/DP monitoring can in a routine basis, evaluate wall motion abnormalities and LVF. In an emergency setting ECOCG/DP can diagnose all the mechanic complications with a great certainty.

[Thrombolysis in acute myocardial infarction in the aged. A greater risk of cardiac rupture?]. / Trombólise no enfarte agudo do miocárdio no idoso. Um risco acrescido de ruptura cardíaca?

OBJECTIVE: To evaluate age group and i.v. thrombolytic therapy (TT) influences on cardiac rupture complicating acute myocardial infarction (AMI). CONCEPTION: Retrospective analysis of patients (pts) admitted during 1988-89 to an Intensive Care Unit of a Terciary Hospital (UCIM) with AMI. POPULATION: 430 pts were admitted with AMI. During this period 89 pts were submitted to TT (25% age greater than or equal to 65 years). Eighty four pts died during hospital stay and 42 had autopsy study (50%). Only 7 of nonautopsied pts died of undetermined cause. Dead pts had age m +/- SD 72 +/- 11 years old (yo) (37% female, 63% male and 74% age greater than or equal to 65 yo). RESULTS: Nineteen pts died of cardiac rupture (CR) (23%). CR prevalence was 1.4% (3/218) in pts less than 65 yo and 7.5% (16/212) in pts greater than or equal to 65 yo (p less than 0.01). CR prevalence in pts submitted to TT (4.5%) 4/89, was similar to pts not submitted to TT (4.4%) 15/341 (n.s.). Pts less than 65 yo had nonsignificant differences in CR wether submitted or not to TT (0% vs 2%). Elderly pts (greater than or equal to 65 yo) CR prevalence was 18% (4/22) in those submitted to TT vs 6% (12/190) in those not submitted to TT (p less than 0.05). CONCLUSIONS: Thrombolytic therapy may carry an additional risk for cardiac rupture in elderly patients (greater than or equal to 65 yo).

[Thrombolysis in acute myocardial infarct. Experience at Santa Maria's Hospital]. / Trombólise no enfarte agudo do miocárdio Experiência no Hospital de Santa Maria.

OBJECTIVES: To evaluate the experience with i.v. streptokinase (SK) in the treatment of acute myocardial infarction (AMI) in two cardiac care units. Conception: Retrospective analysis of patients (pts) admitted either to UCIM or UTIC-AC with the diagnosis of AMI receiving SK. PATIENTS: 77 pts were treated, although one of them was later proved to be a false positive diagnosis of AMI. Of the other 76, there were 63 men and 13 women with age 55 +/- 12 (mean age +/- SD) years (limits of 20 and 82 years). AMIs were anterior in 42% of the pts, inferior in 51%, anterior and inferior in 4% and non Q wave in 1%; Killip classes (cl) were: cl I in 64%, cl II in 26%, cl III in 5% an cl IV in 5%. The time interval from the beginning of acute symptoms to the arrival at the hospital was 2.8 +/- 1.2 hours (1 to 15) and from that moment to administration of SK was 1.6 +/- 1.4 h. The whole interval to the administration of SK was 4.4 +/- 2.5 h. RESULTS: The 3 criteria of reperfusion (pain relief, ST changes resolution and less than 18 h maximum CK rise) were present in 36% of the pts, 2 of the criteria in 21%, and 41% of the pts had only one or no criteria. The time interval to the administration of SK in these 3 groups was 3.3 +/- 1.3 h, 4.8 +/- 3.1 h and 5.0 +/- 2.5 h respectively. Non fatal complications occurred in 16% of the pts (major bleeding in 2.6%, minor bleeding in 99% and minor anafilaxy in 4%. Mortality was 11.8% (9 pts). Two thirds of the deaths were due to cardiac rupture. In hospital residual ischemia was present in 9% (7 pts). CONCLUSION: Treatment of AMI with i.v. SK proved to be a safe and easy to apply therapeutic option, carrying a low morbidity and mortality, lower than that normally observed in our hospital with the conventional approach of AMI before the era of thrombolysis.