Biomedical subjects
Publications and source records attributed to L Brandão.
Stress echocardiography is widely used in the investigation of coronary heart disease. Exercise stress echocardiography offers the advantage of visualizing myocardial motion abnormalities during physiological stress testing. The authors report the use of atropine, as an adjunct to exercise echocardiography, in risk stratification after myocardial infarction.
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In recent years, considerable progress has been achieved on the understanding of the mechanisms of the different supraventricular tachyarrhythmias. These advances have led to the development of rational procedures that can effectively cure most of the patients. Radiofrequency catheter ablation is highly effective in supraventricular tachycardia, with favorable cost-benefit analysis compared to lifelong antiarrhythmic drug therapy and should be considered as an initial option. In atrial fibrillation, only few patients are currently considered for non-pharmacologic therapeutic modalities, but this number should grow as this is the area of most promising research and the one expected to make more progress in the years to come.
Syncope is a frequent diagnosis, but the complete definition of its etiology is not uncommonly a difficult process, in which the physician sometimes needs to perform extensive diagnostic work-up, with low yield or inconclusive data. A thorough clinical evaluation allows, nevertheless, a definition of some criteria of great value in the choice of the most productive line of investigation, as well as in assessing a prognosis for the individual patient.
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The purpose of this study was to assess the results of the treatment of malignant ventricular tachyarrhythmias guided by electrophysiologic studies. Thirty patients with ventricular arrhythmias, aged 56.6 +/- 14.1 years, were submitted to EP testing. The clinical presentation of arrhythmia was sustained monomorphic ventricular tachycardia in 24 (80%), non-sustained ventricular tachycardia in three and another three were survivors of sudden cardiac death. Twenty five patients (83%) had evidence of structural heart disease and left ventricular ejection fraction was less than 40% in 16 (53%). Antiarrhythmic drugs were considered effective when sustained monomorphic ventricular tachycardia was noninducible or significantly slowed in serial EP testing. Sustained monomorphic VT was induced in 19 patients (63%) and an effective drug therapy was found in 13 (68%). In the other 11 patients sustained arrhythmias were not induced, although in six of them the study was done already under antiarrhythmic drugs, that were continued in the follow-up. In the six patients in which an effective drug regimen could not be found and in two sudden death survivors with primary ventricular fibrillation and negative EP testing, an Implantable Cardioverter-Defibrillator was implanted. After 17.8 +/- 10.5 months, there was recurrence of the arrhythmia in 4 (18%) of the 22 patients on antiarrhythmic drugs and half of the patients with ICDs received appropriate therapy from the device. Three patients (10%) died in the follow-up, of which only one due to sudden death. We conclude that selection of optimal antiarrhythmic treatment based on the results of EP testing, is associated with decreased episode recurrence and sudden death.
OBJECTIVE: To develop a Portuguese version of the Arthritis Impact Measurement Scales 2 (AIMS2) and to evaluate its measurement properties in Brazilian patients with rheumatoid arthritis (RA). METHODS: The BRASIL-AIMS2 was developed through the stages of initial translation, back translation, definition of the first Portuguese version, and committee review. Convergent validity was determined by administering the questionnaire to 32 patients with RA and correlating it with several clinical and laboratory variables. Twenty-five of the 32 patients were interviewed 3 times to evaluate test-retest and interobserver reliability. RESULTS: Six translated questions were replaced due to the lack of cultural equivalence. The mean time of administering the questionnaire was about 30 minutes. The test-retest and interobserver reliability were satisfactory, except for Health Perception, and correlation coefficients ranged from 0.87 to 0.98. The Physical, Symptom, and Role components were statistically correlated with Health Assessment Questionnaire, functional class, morning stiffness, and physician assessed disease activity. CONCLUSION: The Physical, Symptom, and Role subscales of the BRASIL-AIMS2 may be useful in the evaluation of quality of life in Brazilian patients with RA.
PURPOSE: To compare the utility of unipolar versus bipolar mapping to guide radiofrequency catheter ablation of manifest left-sided accessory pathways. SETTING: University Hospital PATIENTS AND INTERVENTIONS: We studied twelve patients with a mean age of 42 +/- 13 years, submitted to a successful left-sided accessory pathway ablation. Detailed mapping was performed with the ablation catheter, recording simultaneous unipolar (distal electrode) and bipolar electrograms, in sinus rhythm. Twenty-three recordings were analyzed, including twelve successful, and eleven unsuccessful sites. The following measurements were analyzed: atrial and ventricular amplitude; interval between atrial and ventricular electrogram onset; interval between onset of ventricular electrogram and delta wave; interval between ventricular electrogram activation and delta wave and; unipolar morphology, classified as P-rS, P-QS or PQS. MAIN RESULTS: Accessory pathway ablation required a mean of 6.3 +/- 7.9 (median of 2) energy applications. Analysis of the electrogram revealed that ventricular activation was significantly earlier in successful versus unsuccessful sites. Unipolar morphology was also different according to the ablation result: among unsuccessful applications the P-rS configuration occurred in one, and the P-QS in ten cases, while in successful sites, seven had P-QS, and five had PQS morphology. CONCLUSIONS: Unipolar recordings are useful to guide radiofrequency catheter ablation of manifest left-sided accessory pathways and should be used in association with bipolar electrograms.
OBJECTIVE: To describe the results of radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) by using a mixed electrophysiologic/anatomic mapping technique. DESIGN: Consecutive patients with AVNRT, submitted to AV node modification between November 1992 and March 1995. SETTING: Cardiology Department at an University Hospital. INTERVENTIONS: Twenty consecutive patients with AVNRT were submitted to AV node modification. The ablation technique included two sequential steps. Initially, a detailed electrophysiologic mapping was performed with the ablation catheter, positioned near the coronary sinus ostium, looking for a specific recording: fractionated atrial electrogram, suggestive "slow pathway" potential and a ratio of atrial: ventricular electrogram amplitude > 1. In case of failure, after 5 applications of radiofrequency energy, an anatomic technique was used. The fluoroscopic image, in left anterior oblique projection, was used to guide catheter progression, and the radiofrequency energy applied sequentially in the posterior (P), followed by medium (M) and anterior (A) septal areas if needed. Radiofrequency energy was applied a power of 16-36 watts for 30-60 sec. If a His bundle deflection > 0.0025 mV was recorded, energy was not applied. MEASUREMENTS AND RESULTS: Suppression of a AVNRT was initially obtained in 19 patients (95%). A mean of 8.3 +/- 6.1 energy application were required. Mean during of the entire procedure was 142 +/- 45 min and the fluoroscopy duration was 22 +/- 12 min. There were no complications. The location of successful ablation areas was: P in 15 patients, M in three and A in one. After a mean follow up of 10 +/- 6 months, two patients had recurrence of AVNRT. A second procedure was successful in the initially failed patient and in these two recurrences. CONCLUSIONS: A mixed electrophysiologic/anatomic mapping technique to perform radiofrequency catheter ablation of AVNRT was associated with high efficacy and no complications.
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OBJECTIVES: To assess the safety and efficacy of radiofrequency atrio-ventricular junctional ablation. DESIGN: Consecutive group of patients with refractory atrial tachyarrhythmias in whom catheter ablation of the atrio-ventricular junction was performed. SETTING: Cardiology Department at University Hospital. INTERVENTIONS: Atrio-ventricular junctional ablation was performed in 13 patients with a mean age of 53 +/- 13 years. Among six patients there was no evidence of organic heart disease, two had operated congenital heart disease, two had hypertensive heart disease, one had rheumatic heart disease with a prosthetic valve and the other had ischemic heart disease. The indication for ablation was drug-refractory atrial tachyarrhythmia in all patients: atrial fibrillation with uncontrolled rate in eight patients, atrial flutter in three, atrial tachycardia in one and inappropriate sinus tachycardia in one. An average of 3.7 +/- 0.9 anti-arrhythmia drugs was previously ineffective or associated with significant side-effects. Radiofrequency energy was applied between the distal pole of the ablation catheter and an indifferent cutaneous electrode with intensity of 40-65 volts for 30-60 secs. The ablation was initially performed utilizing the classical technique with the ablation catheter across the tricuspid valve. In the case of failure, an alternative method was used, with the ablation catheter positioned in the left ventricular septum. After the procedure a VVI-R permanent pacemaker was inserted in all patients. MEASUREMENTS AND RESULTS: Atrio-ventricular junctional ablation was successful in all patients after an average of 4.4 +/- 3.7 radiofrequency applications. The classical technique was successful in 11 patients (85%). The average amplitude of the His bundle electrogram recorded in the successful sites was not significantly different from the average maximum amplitude at unsuccessful sites (0.1 +/- 0.05 mV vs. 0.17 +/- 0.12 mV). There were no complications related to the procedures. During a mean follow-up of 7 +/- 4 months there was functional and symptomatic improvement in all patients. The only significant complication was an episode of sustained ventricular tachycardia that occurred three months after the ablation in a patient with Tetralogy of Fallot. CONCLUSIONS: In patients with refractory atrial tachyarrhythmias, atrio-ventricular junctional ablation is a safe and effective therapeutic option. The alternative technique should be reserved for cases of unsuccessful ablation with the classic method. Due to its potential significant side-effects, this therapy should be a last alternative option.
Our purpose was to assess the efficacy and safety of intravenous ATP for the acute termination of paroxysmal supraventricular tachycardia. There were 14 women and 10 men, aged 38 +/- 15 years. Three patients had evidence of structural heart disease (Ebstein's anomaly associated to atrial septal defect, operated mitral stenosis with insertion of a mechanical heart valve and CAD respectively). Twelve patients had Wolff-Parkinson-White syndrome and another had undergone surgical ablation of an accessory pathway. At the time of electrophysiologic testing, ATP was administered during episodes of paroxysmal supraventricular tachycardia, via a central vein, in incremental doses of 5, 10 and 20 mg followed by a flush of 10 c.c. of isotonic saline. The mechanism of the arrhythmia was orthodromic AV reentrant tachycardia in 19 (79%), AV nodal reentrant tachycardia in 4 (16.6%) and atrial tachycardia in one patient. The mean frequency of the tachycardia was 174 +/- 33 b.p.m. A dose of 5 mg was effective in 16 patients (66%), 5 required 10 mg and two required 20 mg for termination of the tachycardia. In the patient with atrial tachycardia ATP was not effective. The average time after injection to termination of the arrhythmia was 16 +/- 8 seconds. Orthodromic AV reentrant tachycardia was interrupted in the AV node limb in all but one patient and AV nodal reentry was terminated in the "slow-pathway" in three of the four patients. Nine patients had premature ventricular complexes, isolated or in couplets, after the termination of the SVT. Three patients had immediate recurrence of the SVT.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVE: To describe the experience and results in the diagnosis and catheter ablation of atrioventricular accessory (AP) pathways during the initial electrophysiologic study. DESIGN: We performed catheter ablation at the time of an initial electrophysiologic study in 22 consecutive patients (12 W and 10 M, mean age 42 +/- 15) with Wolff-Parkinson-White syndrome or supraventricular tachycardia. SETTING: Cardiology Department at University Hospital. INTERVENTIONS: The precise AP mapping was performed with the ablation catheter (4 mm distal electrode and deflectable tip) according to the earlier ventricular activation during sinus rhythm or the earlier atrial activation during ventricular pacing or orthodromic reentrant tachycardia. For left-sided pathways the ablation catheter was positioned on the mitral annulus retrogradely across the aortic valve, while for right-sided pathways it was positioned on the tricuspid annulus or near the coronary sinus os. Radiofrequency energy was applied for 20-60 segs with 55-65 Volts. MEASUREMENTS AND RESULTS: Seventeen AP were manifest and five were concealed. AP were left lateral in 11 patients (50%), left posterior in 5, and right postero-septal, right posterior or antero-septal in 2 patients each. The ablation was initially successful in 18/22 (82%), with 9 +/- 8 radiofrequency applications. Mean duration of the entire procedure was 145 +/- 59 min and the fluoroscopy duration was 39 +/- min. There were no major complications. During 2-9 months of follow-up AP conduction returned in two patients. CONCLUSIONS: Radiofrequency catheter ablation of AP is effective and safe and can be performed at the time of an initial electrophysiologic test, avoiding the need for long-term antiarrhythmic drug therapy or surgical ablation.
A total of 162 Duchenne (DMD) patients and two girls with a DMD phenotype were analysed for deletions in the central region of the dystrophin gene in order to determine if there was a correlation between mental retardation (MR) and the pattern of deletion. Approximately 43% of the patients studied had deletions with two dystrophin cDNAs, cf23a and cf56a, and among 148 patients who were mentally assessed, 50% were mentally retarded. The average IQ in the group of patients with DNA deletions did not differ significantly from those patients with no detectable deletions. However, six unrelated DMD boys with MR showed an identical pattern of deletion. Our observations in the group of patients who had detected DNA deletions suggest that exon 52 of the dystrophin gene may be functionally significant in the manifestation of MR: 70% (19/27) of patients with a deletion of this exon were mentally retarded, whereas only 38% (15/39) of MR patients had deletions not involving exon 52. This difference was statistically significant.
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