Biomedical subjects
Publications and source records attributed to R Seabra-Gomes.
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AIMS: To evaluate the usefulness of three-dimensional (3D) electroanatomical mapping of the pulmonary veins (PV) for guiding radiofrequency (RF) ablation of focal atrial fibrillation (AF) in a single session and to correlate the electrophysiological results with the six month clinical outcome. METHODS AND RESULTS: Sixteen consecutive patients with idiopathic paroxysmal AF (more than 1 episode/month) were studied. A non-fluoroscopic mapping system was used to generate 3D electroanatomic maps of the left atrium and deliver RF energy. In patients with frequent ectopies, mapping was performed using the 'hot-cold' approach (looking for the earliest electrogram in the 3D reconstruction). In patients with infrequent/no ectopies, double/ multiple potentials recorded at the PV were tagged. Pacing at these sites to test for inducibility of ectopy or atrial fibrillation was used to define PV foci. The therapeutic endpoint was defined as suppression of premature beats, dissociation of PV potentials and inability to induce AF. Twenty-five foci were identified (multiple foci in 38%). In the 4 pts with frequent ectopies, Group A, these were suppressed by 4 +/- 4.7 applications. In the 12 pts with infrequent/no ectopies, Group B, an average 4.7 +/- 1.8 applications were delivered per focus; the endpoint was achieved in eight of the patients (13 of 21 foci). By 180 days follow-up, 11 patients were free of symptoms and in sinus rhythm, two had paroxysmal AF episodes and 3 have symptomatic ectopies and are receiving antiarrhythmic drugs. The overall success rate at six months was thus 69%, 100% for group A and 58% for group B. CONCLUSION: Electroanatomic guided RF ablation of paroxysmal AF was highly successful in patients with frequent ectopies. The use of electroanatomical mapping for precise anatomical localization of multiple potentials and for guiding the PV ostia isolation allowed successful RF ablation in 50% of pts with infrequent/no ectopies.
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The initial experience with percutaneous transluminal coronary angioplasty (PTCA) at Santa Cruz Hospital is presented. Between May and November 1984, ten patients with single significant (> 75%) coronary artery obstructions, 8 of the left anterior descending (LAD), 1 of the circumflex (Cx) and one of the right coronary artery (RCA), underwent coronary angioplasty using Gruentzig's technique and steerable catheters. Five patients were cases of chronic stable angina and 5 patients were cases of unstable angina, one of them of acute coronary insufficiency previously treated with intracoronary streptokinase. In every case was possible to cross the lesions which were proximal in 9 cases (7 of the LAD, 1 of the Cx and 1 of the RCA) and distal (LAD) in one case. Primary failure to dilate was seen in 2 cases of unstable angina due to pain and reversible ECG changes. In only 1 case there was occlusion at 9 hours after angioplasty which required emergency bypass operation. Although with a short follow-up, six patients are well and free of symptoms and in only 1 case there was recurrence of angina at four and a half months after PTCA. These results which represent the beginning of the learning curve are considered satisfactory and rewarding.
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AIM: After ST elevation myocardial infarction, ST segment and T wave changes generally resolve, but in some patients T waves keep their negative components for a long time. The aim of this study is to evaluate the pathophysiological implications of persistent negative T waves and restored positive T waves in the chronic stage of Q wave myocardial infarction. METHODS: We studied 30 patients with a previous anterior wall ST elevation myocardial infarction (more than one year follow-up) and presenting Q waves in at least three consecutive precordial leads in the standard 12-lead electrocardiogram at rest. Patients were divided into two groups according to the T wave pattern in leads with Q waves: positive T group consisting of patients in whom all T wave components showed an upright configuration; and a negative T group consisting of patients in whom T waves were are least partly inverted. We used echocardiography to measure systolic thickening of the interventricular septum within the infarction area. Systolic thickening was considered significant when end-systolic thickness was greater than end-diastolic thickness by > 25% in proportion and > 1 mm in absolute value. RESULTS: Significant systolic thickening was demonstrated in 14 (74%) of the 19 positive T patients and in one (9%) of the 11 negative T patients (odds ratio 8.1; 95% CI, 1.2 to 53.5; p = 0.002). CONCLUSION: In the chronic stage of a myocardial infarction, restored T wave positivity predicts preserved systolic thickening, suggesting the presence of viable and normally contracting myocytes within the infarction area. Further studies are needed to establish the prognostic value of T wave characteristics in patients with a past history of myocardial infarction.
INTRODUCTION: Stents are being used with increasing frequency in percutaneous transluminal coronary angioplasty (PTCA) but their use in small vessels is still controversial, due to the possibility of excessively high rates of adverse events and restenosis. OBJECTIVE: To assess the safety and clinical efficacy of ACS RX Multi-Link (ML) 2.5 mm stents, in "de novo" coronary stenosis. DESIGN: Prospective Registry, with 6 months clinical follow-up, involving all Portuguese centers of Interventional Cardiology. POPULATION: Between April 7 and November 20 1998, 102 patients were enrolled, 82 male and with ages ranging from 30 to 86 years (average 58 +/- 11). Clinical presentation for PTCA was stable angina in 53%, unstable angina in 36% and silent ischemia in 11%. There was a history of previous myocardial infarction in 29% of patients. The main risk factors were hypertension (58%), hyperlipidemia (57%), smoking (25%) and diabetes (20%). Multivessel coronary artery disease was present in 46% of patients and left ventricular function was normal in 89%. Of the 217 existing lesions, 188 (87%) were treated: 35 with balloon angioplasty and 153 with stent implantation, 114 of which were ML 2.5 mm: 79 of 15 mm in length and 35 of 25 mm. METHODS: Angiographic success with ML stent implantation and major adverse cardiac events (MACE)--myocardial infarction (MI), coronary artery bypass graft (CABG), new target vessel revascularizations and death--were evaluated during hospital stay, and at 1 and 6 months clinical follow-up. RESULTS: Angiographic success was 97.4%. In one patient it was not possible to cross the lesion, in another there was stent migration and in a third distal coronary flow after stenting was TIMI grade 1. Clinical success was 96.1% and there were no cases of death, Q-wave MI or urgent CABG. Two patients had non-Q wave MI and two required urgent repeat angioplasty. Subacute stent thrombosis occurred in 1 patient. There were no additional MACE at 1 month follow-up. At 6-month follow-up (in 97% of patients) MACE had occurred in 14.1%: 2 deaths (one non-cardiac), 3 MI (one non-Q) and 14 new PTCA (one in a non-ML stent). There was no need for CABG in any patient. Six-month survival rate was 97.9%, 94.9% were free of infarction and 84.8% were free of infarction and new revascularization. CONCLUSIONS: Multi-Link 2.5 mm stent implantation appears to be safe and efficient with a low incidence of immediate and 6-month adverse events in the range of centers and operators of the Registry.
INTRODUCTION: The restenosis rate of stents implanted into small coronary arteries is considered higher than that of stents in arteries > or = 3 mm, but could be influenced by clinical parameters and by the type and length of the stents. OBJECTIVE: To assess the incidence of angiographic restenosis at 6 months after implantation of 2.5 mm ACS RX Multi-Link (ML) stents, 15 and 25 mm length, in de novo coronary stenosis. DESIGN: Angiographic substudy of the Portuguese Multi-Link 2.5 Registry, which included Interventional Cardiology centers with facilities for coronary angiographic recordings allowing quantitative analysis. POPULATION: Between April 7 and November 20 1998 and in the 5 hospitals that agreed to participate, 61 patients were enrolled and 40 selected as having procedural and 6-month angiographies of sufficient quality for quantitative analysis. The only significant differences in the demographic, clinical and angiographic characteristics of the patients relative to those of the Registry were the lower prevalence of unstable angina and smoking in the angiographic substudy. There were 43 lesions and 46 ML stents were implanted. In 37% the lesions were located in the LAD, in 37% in the LCx and 26% in the RCA. 29 stents of 15 mm length and 17 stents of 25 mm were used. METHODS: The morphologic characteristics of the lesions were analyzed subjectively using the AHA/ACC classification. Quantitative coronary analysis (QCA) was performed, in an independent laboratory using the CAAS 2 system, for reference vessel diameter, lesion length, percentage of stenosis, minimum lumen diameter (MLD) and related parameters. Restenosis was defined as > or = 50% lumen obstruction at 6-month angiography. RESULTS: In the subjective analysis, 2 lesions were type B1, 27 type B2 and 14 type C. The overall restenosis rate was 32.6%. Restenosis was 27.7% for 15 mm stents and 36% for 25 mm stents (p = 0.4). For the QCA parameters analyzed, only MLD at the end of stent implantation was a predictor of 6-month restenosis (2.19 +/- 0.30 without vs. 2.03 +/- 0.18 with restenosis, p = 0.048). CONCLUSIONS: The restenosis rate of the Multi-Link 2.5 mm stents, of 15 and 25 mm length, was similar to that described with other types of stents in small coronary arteries. Minimum lumen diameter after stenting was found to be the best predictor of 6-month restenosis.
OBJECTIVES: The introduction of the implantable cardioverter-defibrillator was a very important advance in the treatment of malignant ventricular arrhythmias. However, its use is associated with some possible adverse events, which should be taken into consideration when a patient is proposed for implantation. These complications may occur early after implantation and be associated with the procedure itself, or they may be late complications, usually associated with the device or the arrhythmia. It was our objective to assess the incidence of these complications in our population of patients. POPULATION AND METHODS: We describe the complications found in 98 patients (55.9 +/- 13.9 years, 89% male) with an implantable cardioverter-defibrillator and compare our results with the incidence of complications described by other authors. RESULTS: We found complications associated with the presence of the implantable cardioverter-defibrillator in 32% of patients. The most frequent complication was inappropriate shocks in 13%. The presence of infection was detected in 4%, lead insulation faults in 5%, need for lead extraction in 2%, repositioning in 1% and re-establishment of the connection with the generator in 2%. In 5% of patients, there was inefficacy of the device, 3% due to non-detected ventricular tachycardias (slow tachycardias) and 2% due to electrical storms. There was syncope in 2% of patients. The total mortality in a 2.9 +/- 1.9 year follow-up was 13% (sudden death in 3%). CONCLUSIONS: Major complications associated with implantable cardioverter-defibrillators were in our experience relatively rare, our results agreeing with those of other centers.
The authors report a case study of a 73-year-old male, with signs of right-sided heart failure with 6 months of evolution. It was constrictive pericarditis, without radiologic, echocardiographic and magnetic resonance imaging manifestations, diagnosed on the basis of the clinical situation and hemodynamic evaluation during cardiac catheterization. The authors suggest that the lack of imagiologic manifestations might have been the result of an early diagnosis, before the development of the classic picture. Pericardiectomy, performed with success, was followed by resolution of the heart failure. It was not possible, histologically, to draw conclusions about the etiology. The development of mitral regurgitation after pericardiectomy has enriched this case with an unusual, but previously described, complication of this type of surgery.
We describe a 33-years-old male patient, presenting with progressive right heart failure. After evaluation, the hypothesis of effusive-constrictive pericarditis was considered. Medical therapy was initiated with no clinical benefit. On the 15th day after admission he was proposed for surgical intervention. The intraoperatory examination revealed a thick pericardium adhering to the epicardium without a clear separation between them. Complete resection was technically impossible. The postoperative course evolved with worsening heart failure and development of renal failure requiring hemodialysis. A diagnosis of primary pericardial mesothelioma was made after histological evaluation. The patient died 8 days after surgery despite all efforts at hemodynamic compensation. Despite its rarity, this diagnosis should be considered in cases with rapid evolution of constrictive or effusive-constrictive pericarditis. The prognosis for pericardial mesothelioma is poor due to its late diagnosis, the difficulty of surgical excision and poor response to radio- or chemotherapy.
BACKGROUND: Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may have other disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive. METHODS AND RESULTS: To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is "optimal." An optimal result was defined as a flow reserve >2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; P:=0.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P:=0. 066). CONCLUSIONS: After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.
BACKGROUND: In addition to its known properties as a competitive, nonselective beta and alpha-1 receptor blocker, carvedilol directly inhibits vascular myocyte migration and proliferation and exerts antioxidant effects that are considerably greater than those of vitamin E or probucol. This provides the basis for an evaluation of carvedilol for the prevention of coronary restenosis. METHODS AND RESULTS: In a prospective, double-blind, randomized, placebo-controlled trial, 25 mg of carvedilol was given twice daily, starting 24 hours before scheduled directional coronary atherectomy and continuing for 5 months after a successful procedure. The primary end point was the minimal luminal diameter as determined during follow-up angiography 26+/-2 weeks after the procedure. Of 406 randomized patients, 377 underwent attempted atherectomy, and in 324 (88.9%), a </=50% diameter stenosis was achieved without the use of a stent. Evaluable follow-up angiography was available in 292 eligible patients (90%). No differences in minimal luminal diameter (1.99+/-0.73 mm versus 2.00+/-0.74 mm), angiographic restenosis rate (23.4% versus 23.9%), target lesion revascularization (16.2 versus 14.5), or event-free survival (79.2% versus 79.7%) between the placebo and carvedilol groups were observed at 7 months. CONCLUSIONS: The maximum recommended daily dose of the antioxidant and beta-blocker carvedilol failed to reduce restenosis after successful atherectomy. These findings are in contrast to those of the Multivitamins and Probucol Trial, which raises doubts regarding the validity of the interpretation that restenosis reduction by probucol was via antioxidant effects. The relationship between antioxidant agents and restenosis remains to be elucidated.
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