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Biomedical subjects

M G Lopes

Publications and source records attributed to M G Lopes.

At least 19 recordsLinked to original sources
PubMed1999

Dynamic three-dimensional reconstruction of the heart by transesophageal echocardiography.

OBJECTIVE: To evaluate echocardiography accuracy in performing and obtaining images for dynamical three-dimensional (3D) reconstruction. METHODS: Three-dimensional (3D) image reconstruction was obtained in 20 consecutive patients who underwent transesophageal echocardiography. A multiplanar 5 MHz transducer was used for 3D reconstruction. RESULTS: Twenty patients were studied consecutively. The following cardiac diseases were present: valvar prostheses--6 (2 mitral, 2 aortic and 2 mitral and aortic); mitral valve prolapse--3; mitral and aortic disease--2; aortic valve disease--5; congenital heart disease--3 (2 atrial septal defect--ASD- and 1 transposition of the great arteries-TGA); arteriovenous fistula--1. In 7 patients, color Doppler was also obtained and used for 3D flow reconstruction. Twenty five cardiac structures were acquired and 60 reconstructions generated (28 of mitral valves, 14 of aortic valves, 4 of mitral prostheses, 7 of aortic prostheses and 7 of the ASD). Fifty five of 60 (91.6%) reconstructions were considered of good quality by 2 independent observers. The 11 reconstructed mitral valves/prostheses and the 2 reconstructed ASDs provided more anatomical information than two dimensional echocardiography (2DE) alone. CONCLUSION: 3D echocardiography using a transesophageal transducer is a feasible technique, which improves detection of anatomical details of cardiac structures, particularly of the mitral valve and atrial septum.

Adult↗
PubMed1999

[The Internet as a solution facilitating the identification of patients with a suspected acute myocardial infarct].

The current steps for diagnosing heart disease are very time consuming, delaying the correct identification of the problem, therefore, delaying the right treatment. In this study we have developed an experimental method using e-mail in order to identify patients with "rule out myocardial" condition and reduce the time lag for thrombolysis or coronary angioplasty in this clinical setting. Three different locations linked to the Internet by ISDN lines were used. Each line was connected with a computer. A pager and a dedicated phone line were also used. The following steps were performed for each situation: filling out of a questionnaire, ECG recording, questionnaire mailing and ECG by e-mail as attachment, pager warning that an urgent cardiology consultation was requested, including the doctor and patient's phone number, time to open the message and reply by e-mail, phone call for additional comments. A total of 24 attempts of interactive communication were performed. In 22 of those, an answer was obtained in less than 30 minutes. Two failures were recorded. One was due to a delay in the pager message, which did not arrive within the first hour; the second was due to a computer break down. This report shows that it is possible to establish a fast communication between the out patient clinic and the hospital (less than 30 minutes in most cases) at a very low cost and in a simple manner.

Costs and Cost Analysis↗
PubMed1997

[The digital image archive--its clinical applications and importance in cardiology consulting by telemedicine].

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.

Cardiology↗
PubMed1997

[Incessant atrial tachycardia and peripartum cardiomyopathy--a therapeutic challenge].

Peripartum cardiomyopathy is an uncommon cause of heart failure but with serious prognosis. We report the case of a patient with peripartum cardiomyopathy presenting acute heart failure (severe biventricular systolic failure) and incessant atrial tachycardia, a rare arrhythmia difficult to control, that was responsible for cardiogenic shock, fetus death and multiple organ failure: renal failure (hemodialysis during 17 days), respiratory and hepatic failure and ischemic acute cholecystitis (treated surgically). After emergency cesarean section, heart rate control was obtained only after administering verapamil. Progressive clinical improvement with total recovery of hepatic and renal functions followed under treatment with vigorous multiple organ support. Six months after referral, the patients is doing well with normal daily life controlled with conventional therapy for heart failure, in stable sinus rhythm. Echocardiography shows a dilated left ventricle with partial resolution of systolic dysfunction rhythm. Echocardiography shows a dilated left ventricle with partial resolution of systolic dysfunction. The use of verapamil in severe biventricular systolic failure is discussed.

Cardiomyopathies↗
PubMed1997

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.

Cardiovascular Diseases↗
PubMed1997

[Rational distribution of resources in intensive medicine. Analysis of admission and discharge criteria at intensive care units].

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.

Critical Care↗
PubMed1997

[Risk stratification and prognosis in critical surgical patients using the Acute Physiology, Age and Chronic Health III System (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.

APACHE↗
PubMed1996

[Thrombolytic therapy in acute myocardial infarct--is it being used to the fullest?].

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.

Aged↗
PubMed1994

[Stress echocardiography with dobutamine: the importance of adding atropine in inconclusive tests].

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.

Aged↗
PubMed1993

[Calcium antagonists in the treatment of congestive heart failure].

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.

Calcium Channel Blockers↗
PubMed1993

[The classic exercise test or by imaging? New applications of Doppler echocardiography].

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.

Contrast Media↗
PubMed1993

[Prognostic systems in intensive care: general principles, development, and clinical applications].

In this review article, we present the need for prognostic scoring in clinical medicine, specially in Intensive Care Medicine (ICM). The general principles of prognostication in ICM are discussed, and three general scoring systems are presented: ACUTE PHYSIOLOGY AND CHRONIC HEALTH EVALUATION (APACHE) in its 3 versions, SIMPLIFIED ACUTE PHYSIOLOGY SCORE (SAPS) and MORTALITY PREDICTION MODEL (MPM). The use of these prognostic systems is then evaluated not only as a support for medical decision-making, and resource allocation, but also as a tool for clinical studies in terms of patient randomization. Finally, the future developments and clinical application of these risk stratification systems are presented and discussed.

Critical Care↗
PubMed1989

[Role of echocardiography in cardiac insufficiency].

Several clinical cases are presented showing that Echocardiography (M-mode, 2D and Doppler) may give us a complete picture of the heart anatomy and the physiopathology associated with heart failure, as well as the functional status of the left ventricle. With this useful information (presence, location and degree of the abnormality) that can be obtained at bedside in a non-invasive way, the cardiologist may take, without delay, the most correct therapeutic choice (surgical and/or medical). Echocardiography should be used as a first line diagnostic test (after ECG and Chest X Ray) in all patients presenting with heart failure.

Echocardiography↗