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Biomedical subjects

L Botas

Publications and source records attributed to L Botas.

6 recordsLinked to original sources
PubMed1989

[Holter ECG in evaluating myocardial ischemia. Validation using the exercise test].

OBJECTIVES: Validation of ST-T ischemic changes in the Holter system by those recorded in the 12-lead ECG during the exercise test. DESIGN: The changes induced by the exercise test in the ST segment of the two Holter leads--aVF e V5 like--were compared with the changes simultaneously registered in the 12-lead ECG. SETTING: Exercise Test Laboratory and Holter Laboratory of the UTIC-Arsénio Cordeiro. Hospital de Santa Maria de Lisboa. PATIENTS: 31 patients, 23 male and 8 female, with a mean age of 55 +/- 7 years, 84% with ischemic heart disease. METHODS: The patients underwent a treadmill exercise test. 28 with the Bruce protocol and 3 with the Naugton protocol, during which the electrocardiogram was registered simultaneously with a 2-channel Holter recorder and by a conventional 12-lead system. The changes induced in the ST segment in the two systems were compared. RESULTS: The results of the two tests were concordant in 94% of the patients. In 4 patients (13%) there was not a good correlation between the inferior and anterior leads of the two methods, which diverged mainly between the Holter lead aVF and the inferior leads of the conventional ECG. The morphology of the ST depression was similar in both methods, and the severity of ST depression as judged by its amplitude showed an excellent positive linear correlation (r = 0.8542, p less than 0.001). CONCLUSIONS: The sensitivity and the specificity of the Holter system is similar to the conventional 12-lead ECG in detecting ischemic changes during exercise whenever they have electrocardiographic evidence.

Adult↗
PubMed1989

[Comparison of Holter electrocardiography and thallium 201 scintigraphy in the detection of myocardial ischemia].

OBJECTIVE OF THE STUDY: To compare ischemic changes (I) detected by Holter ECG (H ECG) to the myocardial perfusion defects found in 201 TI myocardial perfusion scintigraphy. DESIGN: 201 TI exercise test was made during the performance of a 24 hours H ECG. The validation of ST segment changes detected by H ECG during the exercise test was made on basis of reversible myocardial perfusion defects (RPD) detected on 201 TL and a relation between ST segment changes detected during the remaining 24 hours recording period and 201 TI (TI) RPD was established. SETTING: The patients (pt) included in the study have come from Cardiology and Heart Surgery Clinics of a Central teaching hospital. MATERIAL AND METHODS: 20 pt with a high coronary artery disease prevalence have been submitted to a two lead (V5 and aVF) 24 hour H ECG during which they have performed a symptom limited bicycle exercise test followed by an injection of 201 TI with acquisition 5 minutes later. Ischemic episodes detected on H ECG were quantified and their relation with heart rate and symptoms was established. As far as 201 TI studies are concerned the fixed and reversible perfusion defects as well as their location were evaluated. RESULTS: 1. H ECG: 6 pt (30%) presented ST changes on H ECG during the exercise test and a total of 9 pt (45%) had ST changes during exercise and during the remaining period of H ECG. 2. TI: 19 pt presented perfusion defects images (fixed in 7, reversible in 14, both kinds of defects in 7). 3. H ECG validation: H ECG during exercise presented I in 6 out of 14 pt with RPD on TI (sensitivity = 43%). Six of these 8 pt, with negative H and positive TI, had a chronic myocardial infarction. All the 6 pt with negative TI had negative H ECG (specificity = 100%). 4. H ECG TI comparison: 7 (50%) of the 14 pt with RPD had ST changes on 24 hrs H ECG. Seven of 11 pt with negative H ECG had RPD in TI. Two pt with negative TI had positive H ECG. These 2 pt had during H ECG a higher heart rate (HR) than the HR recorded during the exercise test. CONCLUSIONS: 1. In pt with known CAD, TI has a high sensitivity and specificity to show perfusion defects. 2. Considering TI as gold standard, H ECG showed to be a useful method to detect I in the studied population (sens. = 43%; spec. = 100%). 3. H ECG revealed to be an important diagnostic tool in detecting additional I episodes beyond the ones recorded during TI exercise test.

Adult↗
PubMed1989

[Significance of the exercise test in studying patients with heart insufficiency].

Assessment of functional capacity of patients with heart failure by means of exercise tests has recently become a new field of investigation for this diagnostic technique, constituting an incursion into an area so far out of its domains. It has been demonstrated that the functional capacity of these patients has a diagnostic and prognostic value, in addition to being the most accurate method to evaluate therapeutic effects. In patients with valvular disease, the performance of an exercise test, especially if other techniques are simultaneously being used, both invasive (catheterization) and non-invasive (respiratory parameters, isotopic angiography), yields very precise information, as regards for instance the determination of the correct timing for surgical repair, as well as prognostic information in some situations, such as aortic insufficiency.

Evaluation Studies as Topic↗