[Acute effects of tobacco and vascular risk modulated by genetic factors]. / Acções agudas do tabaco e risco vascular modulado por factores genéticos.

Most studies regarding the acute effects of cigarette smoking refer to the higher sympathetic and adrenomedullary activity as a result of sympathetic ganglia and adrenal medulla nicotinic receptor activation. Although it is reasonable to suppose that the renin-angiotensin system might be activated, this possible effect of nicotine has not been studied. We have studied the effects of cigarette smoking on blood pressure, cardiac output, pulse pressure, renin-angiotensin system, kinins-NO, oxidative stress and insulin. Also, we have investigated if the variability of the biochemical parameters was dependent on genetic polymorphisms of the angiotensin converting enzyme and the acute phase protein haptoglobin. 39 normotensive individuals, 18 males and 21 females, of mean age 35.4 +/- 8.9 years were included in this study. Oxidative stress was dependent on the ACE I/D and Hp1/2 polymorphisms, with the ACE DD genotype and the Hp2-2 phenotype not showing variation in the anti-oxidant defense systems, and the ACE II-ID genotypes and Hp1-1 + 2-2 phenotypes showing a higher anti-oxidant response, hence a lower cardiovascular risk being predictable in the latter individuals.

[The successes and failures in the primary prevention of coronary disease]. / Sucessos e insucessos da prevenção primária da doença coronária.

The modification of major behavioural and environmental risk factors has helped reduce coronary heart disease. It seems, however, that prevention results were not so good as expected. It is assumed that the major cause of this apparent unsuccessful data is basically due to world population ageing, as it is known that coronary heart disease is much more frequent in older people. Therefore the current life expectancy shows that the preventive measures have indeed been successful. From the analysis and discussion of the preventive epidemiological recommendations and the identification of new risk factors, the Authors suggest new strategies for health promotion and particularly for coronary heart disease reduction.

Comparison between dobutamine echocardiography and thallium-201 scintigraphy in detecting residual stenosis, ischemia, and necrosis in patients with prior myocardial infarction.

BACKGROUND: Following the first attempts to detect myocardial ischemia with two-dimensional echocardiography stress testing, pharmacologic stress using dobutamine infusion has become an alternative to echocardiography exercise testing for evaluation of coronary artery disease. It has been shown that stress echocardiography has a diagnostic accuracy similar to that of an exercise thallium test. Other studies, however, indicated that radionuclide myocardial perfusion imaging was more sensitive than exercise or pharmacologic stress echocardiography for detection of ischemia or jeopardized myocardium. HYPOTHESIS: The aim of the present study was to determine the ability of dobutamine stress echocardiography in comparison with thallium-201 scintigraphy to identify multivessel disease and the presence of myocardial scar and ischemia in 60 consecutive patients who suffered a first myocardial infarction (MI). METHODS: Patients were evaluated by coronary angiography and ventriculography, thallium-201 (201TI) tomographic scintigraphy, and dobutamine echocardiography within 3 months of a first MI. Forty-seven had Q-wave MI and 13 had non-Q-wave MI. Eleven patients were excluded from final analysis-7 because of failure to achieve target heart rate in spite of the use of atropine, and 4 because of high blood pressure following the infusion of dobutamine. RESULTS: Dobutamine echocardiography showed an overall sensitivity of 43% for detection of coronary artery lesions of 50-74% diameter stenosis and 201TI scintigraphy showed a sensitivity of 71%. For detection of lesions of > or = 75% diameter stenosis, dobutamine echocardiography showed a sensitivity of 52% and 201TI a sensitivity of 70%. Overall agreement between wall motion and myocardial perfusion for detection of necrosis and/or ischemia in the infarct area was 40.4% with a kappa coefficient of 0.09 (p = 0.13). For detection of ischemic myocardium outside the infarct zone, overall agreement was 78.6% with a kappa coefficient of 0.49 (p < 0.0001). CONCLUSION: Dobutamine echocardiography results showed a lower sensitivity than myocardial perfusion images in predicting multivessel coronary artery disease, and there was poor agreement between both methods in identifying necrosis or ischemia.

[Coronary artery disease, myocardial perfusion and ventricular function in Q-wave and non-Q-wave myocardial infarcts]. / Doença arterial coronária, perfusão miocárdica e função ventricular em enfartes do miocárdio com onda Q e sem onda Q.

Controversy remains in considering non-Q wave myocardial infarction (NQMI) a distinct pathophysiological entity of Q wave myocardial infarction (QMI). In order to analyze the severity of coronary artery disease, extension of myocardial scar or myocardial ischemia and ventricular function, 78 consecutive patients with QMI and 32 with NQMI, mean age 55.4 +/- 8.5, not submitted to thrombolytic therapy, were studied. Coronary angiography, exercise thallium scintigraphy and radionuclide ventriculography were performed in all at least within 3 months of a prior myocardial infarction. In the present study the occurrence of QMI was significantly more frequent in older patients than NQMI. There was no prevalence of occlusion either in the right, left circumflex or left anterior descending coronary arteries in both groups. Ejection fraction, degree of occlusion and presence of collateral circulation showed an equal prevalence in QMI and NQMI patients. A higher incidence of multivessel disease was found in NQMI that had less necrosis than QMI patients. The prevalence of exercise induced thallium-201 redistribution defects within the infarct zone was substantially higher and involved more scar segments in NQMI patients. Physiological and clinical consequences of coronary thrombosis depends on the size and the number of diseased arteries, the approach the pathophysiologic consequences of coronary disease in terms of fractal structure has been suggested. A pronounced heterogeneity in regional myocardial blood flow in a fractal branching arterial network may be responsible for the pathophysiologic differences of coronary thrombosis between Q-wave and non Q-wave infarction.

[The digital image archive--its clinical applications and importance in cardiology consulting by telemedicine]. / Arquivo digital de imagens--aplicações clínicas e sua importância na consultoria cardiológica por telemedicina.

The revolution in digital technology is rapidly changing the world of telecommunications. Its applications to Medicine, and in particular to Cardiology, offer enormous benefits since communication is an essential part of medical practice. The need to improve the management of medical information is critical because of the explosion of medical knowledge, and the need to provide comprehensive documentation on patient care. The availability of a network offers many possibilities for clinical, research and teaching activities. Relevant, up-to-date scientific information is instantly available for analysis and interaction. The authors review the issue of digital communications as well as its potential application to Telemedicine, and present their preliminary experience with digital analysis and storage of echocardiographic images.

Dynamic three-dimensional echocardiography: a new era in ultrasound technology.

The use of noninvasive methods to visualise the heart has had an extraordinary development over the last decade, with echocardiography demonstrating a particularly fast growth. Despite its unquestionable role in the diagnosis of heart disease and in the management of cardiac patients, it does have some limitations, both in the morphological visualisation, as well as in the functional assessment of the heart, such as blood flow, quantification of intracardiac volumes, etc. The recent development of dynamic three-dimensional (3D) echocardiography from two dimensional images has opened new perspectives in the study of cardiac pathophysiology. There are basically two methods of displaying three dimensional data sets: (1) a two-dimensional display from individual selected cut planes (any-plane echocardiography) or from parallel short axis cuts; (2) a volume rendered technique: from any defined cut plane, different algorithms are applied to represent the information in space. There are several potential clinical applications of 3D such as the measurement and serial follow-up of left ventricular volumes; in valvular heart disease (the abnormalities can be delineated more precisely and in greater detail than conventional imaging, including a detailed definition of mitral apparatus in mitral stenosis), in mitral valve prolapse both leaflets can be seen from the left atrial view and in endocarditis it can aid in deciding when and how to intervene; in complex congenital heart disease, such as reconstruction of double outlet right ventricle, left-sided obstructive and regurgitant lesions and subaortic obstructive cases, in atrial and ventricular septal defects, displaying size, geometry and relationships to other structures; another expression of cardiac disorders are blood flow disturbances (visualisation of flows in 3D could allow a better qualitative and quantitative assessment of their size and severity; the pictures so far generated allow a good perception of the size and shape of mitral, aortic and tricuspid regurgitation jets, by examining them from a new perspective, it also has the potential to display the flow convergence zone and quantify the regurgitant volume). Recent studies have clearly demonstrated the feasibility of performing three-dimensional imaging in a variety of cardiac diseases, but continued development of ultrasound technology must be made to improve better image resolution. The prolonged acquisition time is the most important limiting factor that currently restricts the routine use of 3D echocardiography. The development of faster computers will shorten the time needed for image acquisition, postprocessing, and data analysis, contributing to the goal of easy access and wide use. With improvements in computer technology and production of interactive software, 3D echocardiography will provide a dynamic view of the surgical anatomy of the heart. Thus, the three-dimensional reconstruction concept has the potential to and diagnostic assessment of cardiac pathology in every facet.

[Risk stratification and prognosis in critical surgical patients using the Acute Physiology, Age and Chronic Health III System (APACHE III)]. / Estratificação de risco e prognóstico em doentes cirúrgicos críticos utilizando o Sistema Acute Physiology, Age and Chronic Health III (APACHE III).

INTRODUCTION: Outcome prediction in critical surgical patients admitted to intensive care units (ICU) has been established using several scoring systems. To evaluate the predictive performance of the Acute Physiology, Age and Chronic Health Evaluation (APACHE III) scoring system in these patients, we studied a population admitted to a surgical ICU in our University Hospital. METHODS: We collected prospective data on 220 consecutive patients admitted over a period of 12 months. APACHE III (A3) scores were obtained over the first 24 hours of ICU admission (APACHE II scores were also calculated); data also included age, sex, acute and chronic diseases, ICU and hospital length of stay (LOS), patient location prior to ICU admission and outcome. The relationship of hospital mortality with A3 scores was analyzed using logistic regression, with the discriminatory power of these systems being assessed by the area under the ROC curve and percentage of correct classification. RESULTS: Patient's mean age was 57 +/- 17 years and 44% were male; 53.6% were elective and 46.4% were emergency postoperative patients; 5% of patients had co-morbidities; ICU mortality rate was 10% and in-hospital mortality rate (HMR) was 15%; mean ICU LOS was 3.9 +/- 5.6 days and mean hospital LOS was 9.4 +/- 8.2 days; mean scores were: APACHE III = 33 +/- 2 and APACHE II = 9 +/- 6 points. There was a significant relationship between ascending A3 scores and HMR. APACHE III had a correct classification rate of 87.3% and an area under the ROC curve of 0.830. CONCLUSIONS: In a population of critical surgical patients admitted to our ICU the APACHE III scoring system demonstrated an excellent prognostic performance as measured by contingency tables and areas under the ROC curve; this system can be a useful tool for outcome prediction in critical surgical patients.

[Rational distribution of resources in intensive medicine. Analysis of admission and discharge criteria at intensive care units]. / Distribuição racional de recursos em medicina intensiva. Análise de critérios de admissão e alta de unidades de cuidados intensivos.

Cost-containment in health care has become a major issue in today's practice of medicine. With its needs in advanced technologies and skilled personnel, intensive care is among the most expensive of all hospital activities. This fact makes the analysis of indications for intensive care unit admission, as well as early discharge, of paramount importance: patients who are not likely to benefit from intensive care are at the extremes of disease severity, since low-risk patients are not ill enough to need ICU admission and high-risk patients have a very high mortality, irrespective of intensive care treatment. In this paper we discuss, based on published evidence, the formulation of recommendations for admission and early discharge from ICUs, and also present the Society of Critical Care Medicine guidelines, on this subject.

[Thrombolytic therapy in acute myocardial infarct--is it being used to the fullest?]. / Terapêutica trombolítica no enfarte agudo do miocárdio--estará a ser utilizada em pleno?

OBJECTIVE: To evaluate the experience with thrombolytic therapy (TT) in the treatment of patients with the discharge diagnosis of acute myocardial infarction (AMI). DESIGN: Retrospective analysis of the clinical records of patients with the discharge diagnosis of AMI, between May 1988 and December 1995. SETTING: Intensive Cardiac Care Unit (UCIM-Medicina IV) of Santa Maria University Hospital, Lisbon, Portugal. PATIENTS: 1319 patients, 958 men (73%) and 361 women, mean age 64 +/- 12 years. MAIN RESULTS: Thrombolytic therapy was administered in 391 patients (30%). Female patients received less thrombolytic therapy compared with male (17% vs. 34%; p < 0.001). Anterior wall infarction was more frequent (38%). Patients in Killip class I-II (77%) received more thrombolytic therapy than class III-IV (33% vs. 17%). The utilization rate of thrombolytic therapy increased from 25% in 1988 to 34% in 1995. Two major categories of patients were not treated with thrombolysis: 1) patients presented more than 12 hours after pain onset (38%); 2) patients without ST segment elevation or LBBB on the ECG presented (37%). Overall hospital mortality was 15.6%. The mortality in patients receiving thrombolytic therapy was significantly lower than in those excluded (9.4% vs. 18.2%; p < 0.001). CONCLUSION: Only 30% of patients with AMI receive TT. Of those excluded from this important therapeutic intervention, 75% had no ECG criteria or were outside the standard therapeutic "window". This significant group of patients need new diagnostic and intervention strategies.

[Electrocardiographic changes after coronary angiography: effect of the contrast media used]. / Alterações electrocardiográficas após coronariografia: influência do contraste utilizado.

UNLABELLED: Prospective study to evaluate the influence of 2 different iodine contrasts (used in coronariography) on the electrocardiographic changes recorded after intra-coronary injection. MATERIAL AND METHODS: Sixty-six patients (pts) - 50 men and 16 women - 59 +/- 4 years underwent coronariography to confirm and/or evaluate coronary artery disease (CAD). Group I (33 pts) received a hyperosmolar contrast; group II received a low osmolarity contrast. The electrocardiograms were recorded during and until 20 seconds after intra-coronary injection, in standard leads and V5. Tracings were analysed regarding the development of: arhythmias, mean axis deviation and QRS enlargement - type A abnormalities; ventricular repolarization (ST/T) changes - type B abnormalities. ECG changes were compared with: 1. contrast used; 2. presence (or absence) of CAD; 3. correlation between type B abnormalities and the arteries affected. RESULTS: 1. a) Twenty nine pts (88%) of group I had A and/or B electrocardiographic changes, compared with 16 (48%) of group II (p < 0.01). b) There were type A changes in 13 pts of group I (39%) versus 3 pts (9%) of group II (p < 0.01). c) Type B changes were present in 25 pts (76%) of group I and in 20 pts (60%) of group II (p-NS). 2. a) Type A abnormalities were recorded in 13 of 48 pts with CAD (27%) against 3 of 18 (17%) cases with normal coronariography (p-NS). b) Type B abnormalities were present in 30 of 48 pts (63%) with CAD and in 10 of 18 cases (56%) of people with normal coronariography (p-NS). 3. In 21 pts with isolated right (or left) CAD, contrast injection in the right coronary artery induced type B ECG changes on the homo-lateral supplied territory in 14 cases, no change at all in 4 cases and changes in the contra-lateral area in only 3 pts. Injections in the left coronary artery produced similar results. CONCLUSIONS: 1. Hyperosmolar contrast produced significantly more electrocardiographic abnormalities, mainly type A, than low osmolarity contrast. This one may be, therefore, preferable. 2. Both types of electrocardiographic changes were equally recorded in pts with CAD and in people with normal coronariography. 3. Type B changes seem to be related with the location of the injection, irrespective of the presence or absence of coronary artery disease.

[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.

Community-based stroke prevention: a Portuguese challenge.

Stroke is the leading cause of death in Portugal, accounting for about 20% of total mortality, despite a 25% decline in death rates from cerebrovascular diseases between 1980 and 1989. Epidemiological observations demonstrating that the high rates of cerebrovascular disease are accompanied by high levels of blood pressure have raised considerable interest concerning the primary prevention of hypertension. Excess salt consumption is considered to have an important role in the pathogenesis of hypertension. Since salt is widely consumed by the Portuguese population, priority has been given to salt reduction for the primary prevention of hypertension. Community-based programs have demonstrated that it is possible to improve lifestyles, for instance by reducing high salt intake. Integrated and multifactorial interventions have promoted health and better treatment of hypertension as well as better control of concomitant risk factors. As a consequence of the population aging, there is a high probability of an increase in stroke occurrence. The present and future number of stroke survivors, requiring both acute and long-term care, will increase the social and economic burden. It is important to raise the awareness of politicians and the public so that both the prevention and management of patients with stroke will be given high priority.

Minimal residual coronary obstructions in patients who suffered a first myocardial infarction. A prospective study comparing coronary angiography and exercise thallium scintigraphy.

The purpose of the present study was to correlate the presence of minimal coronary obstruction (< or = 50%) assessed by coronary angiography with the presence of myocardial scar and ischemia detected by thallium-201 myocardial perfusion imaging. The study included 83 consecutive patients (74 men and 9 women) with a mean age 55.4 +/- 8.5 years who suffered a first myocardial infarction and did not undergo thrombolytic therapy. In all patients, coronary angiography, left ventriculography, and exercise thallium-201 tomographic scintigraphy were performed within 3 to 5 months of the myocardial infarction. Coronary arteriograms showed minimal residual obstructions in 37 (45%) patients. Of a total of 54 patients with < or = 50% obstruction, 18 showed persistent defects and 22 reversible defects on thallium scintigrams. The present study showing estimated angiographic stenosis of < or = 50% as being responsible either for myocardial scar or myocardial ischemia on postexercise thallium scintigrams leads us to conclude that percent value of stenosis does not accurately predict the pathophysiologic significance of coronary atherosclerotic lesions in patients who suffer a myocardial infarction. After a first myocardial infarction, coronary angiographies and thallium-201 scintigrams are complementary for an optimal treatment strategy for selected subsets of patients.

[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.