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ABSTRACT: Radiofrequency ablation (RFA) in children is an increasingly common practice.
To evaluate, in our institution, the results of RFA in children younger than 15 years.
A total of 125 children submitted to RFA between May 1991 and May 2010 were analyzed.
Sixty-seven (53.6%) children were males, aged between 44 days and 15 years (mean 8.6 ± 3.3 years) with median weight of 31 kg. Heart disease was present in 21 (16.8%) patients. The RFA of accessory pathways (AP) was the most common procedure (62 children - 49.6%). The RFA of nodal reentrant tachycardia (NRT) was the second most common arrhythmia in 27 (21.6%), followed by atrial tachycardia (AT) in 16 (12.8%) and ventricular tachycardias (VT) in 8 (6.4%) children. The success criteria were achieved in 86.9%, 96.1%, 80% and 62.5% of patients undergoing RFA of AP, NRT, AT and VT, respectively. Transient AVB occurred during RFA in 4 (3.2%) and LBBB in 7 (5.6%) children. Twenty-five children underwent a new RFA due to initial failure or recurrence. During the mean follow up of 5.5 ± 3.4 years, 107 (88.4%) remained without recurrence. There was no statistical difference regarding the results and the age at which the patient underwent the procedure. No child had persistent AVB or required a permanent pacemaker.
Catheter ablation is a safe and effective alternative therapy in children with recurrent tachycardias refractory to medical treatment.
Arquivos brasileiros de cardiologia 05/2012; 98(6):514-8. · 1.32 Impact Factor
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Arquivos brasileiros de cardiologia 01/2011; 96(1):e3-6. · 1.32 Impact Factor
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ABSTRACT: Cardiac resynchronization therapy (CRT) is an efficient treatment for patients with heart failure (HF), severe ventricular dysfunction and intraventricular block. Conventional pacemakers (CPM) implanted in the right ventricular apical area cause alterations in the normal sequence of cardiac activation similar to those induced by LBBB (left bundle-branch block). Therefore, patients with CPM and advanced HF could be candidates to undergo CRT, but as only small numbers of patients have been evaluated so far, definitive conclusions are lacking.
To assess the clinical and functional outcome of cardiac resynchronization therapy (CRT) in patients with conventional pacemakers.
Patients with CPM, who were in NYHA HF functional class III/IV class refractory to drug therapy, and left ventricular ejection fraction (LVEF) ) <35% underwent CRT. Patients clinical-functional behavior was assessed prospectively six months after the procedure. The improvement of one HF-functional class was set as an effective response to the procedure. The following was assessed: QRS duration (ECG), diastolic diameter (LVDd), left ventricular systolic diameter (LVSd) and LVEF seen on the echocardiogram. For the statistical analysis, Students paired t test and Spearmans correlation were used.
Twenty-nine patients (mean age 61.5) were evaluated. Of these, six were females, and chagasic cardiomyopathy was predominant. During the clinical follow-up of 22.7+/-13 months, 86.2% of the patients benefited from CRT. Within this group, the mean LVEF increased by 18% (p=0.013), QRS duration dropped by 11.8% (p=0.002) and no significant reduction in left ventricular intracavitary diameters was observed.
CRT is effective for patients with CPM and advanced HF as it yields a high rate of response (86.2%), significantly improves LVEF and reduces QRS duration.
Arquivos brasileiros de cardiologia 02/2008; 90(2):138-43. · 1.32 Impact Factor
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ABSTRACT: Our objective was to study the anatomic relations of the human left atrial oblique vein (Marshall vein), particularly of its ostium opening into the coronary sinus, in order to guide ablation procedures related to that vein.
The study was carried out in 23 heart-specimens (mean weight 446 +/- 204 g) of individuals whose mean ages were 43 +/- 21 years, 20 males. The coronary sinus was opened longitudinally, exposing the ostium of the tributary veins; the Vieussens valve was looked for, as well as its relationship to the left atrial oblique vein. The diameters of the left atrial oblique vein and the coronary sinus ostia were measured and the distance between them was determined. The left atrial oblique vein could be identified in 20 (87%) of the hearts, while the Vieussens valve was present in 17 (74%) of the specimens (in 16 of which the left atrial oblique vein was identified). In such condition, the vein was adjacent to the Vieussens valve and proximally positioned relative to the coronary sinus ostium in most of them (14/16 cases). The mean diameters of the left atrial oblique vein and of the coronary sinus ostia were, respectively, 1.23 +/- 0.38 and 8.22 +/- 1.88 mm. The mean distance between both ostia was 30.9 +/- 10.2 mm.
When present, the left atrial oblique vein can be easily recognized, adjacent to the Vieussens valve. The mean distance between the coronary sinus opening and left atrial oblique vein ostium was around 30 mm, independently of the heart weight and the presence of cardiomegaly.
Europace 11/2007; 9(10):915-9. · 1.98 Impact Factor
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ABSTRACT: To determine ventricular remodeling (VR) and the role of clinical and functional variables in patients with normal cardiac function who underwent right ventricular apical pacing (RVAP).
Among the 268 consecutive patients with standard pacemaker due to complete atrioventricular block (CAVB), those with left ventricular ejection fraction (LVEF) < 55% and left ventricular end-diastolic diameter (LVEDD) > 53 mm on Doppler echocardiography were excluded. Ventricular remodeling was defined as echocardiographic changes documented at least six months after implantation, namely, a >10% increase in LVEDD and a > 20% decrease in LVEF. The following variables were analyzed: underlying heart disease, NYHA functional class of heart failure (HF), time of ventricular stimulation, and QRS duration. Statistical analysis included likelihood ratio test, Fishers exact test, and Wilcoxon rank-sum test. A p value < 0.05 was considered statistically significant.
The study included 75 patients, mean age 70.9 +/- 14, of whom 22.6% were male. Mean time between both evaluations was 80.2 months. Before implantation, mean LVEF was 72% and LVEDD was 46 mm; after implantation this values were 69.7% (p = 0.0025) and 48.5 mm (p = 0.0001), respectively. Mean QRS duration after implantation was 156 ms. Ventricular remodeling was observed only in four patients (5.3%), and no exploratory variable specified this behavior.
In a long-term follow-up, patients without ventricular dysfunction who underwent RV apical pacing (RVAP) showed low VR rate, and no analyzed variable was associated with its occurrence.
Arquivos brasileiros de cardiologia 03/2007; 88(2):131-6. · 1.32 Impact Factor
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ABSTRACT: Study the prevalence of neurocardiogenic etiology in patients with unexplained syncope and ventricular premature beats, with right ventricle outflow tract morphology (RVOT) and no apparent structural cardiopathy.
Ninety patients (66 women, mean age 40.2 +/- 16.95 years of age) with monomorphic premature beats originated at RVOT were evaluated prospectively. Fifty-four patients reported syncopes or near-syncopes associated to palpitations or not; twenty-seven presented palpitations with no pre-syncope or syncope, and nine were asymptomatic. All patients were submitted to echocardiogram, high resolution ECG and cardiac MRI to rule out structural cardiopathy, to exertion test to rule out adrenergic dependent ventricular tachycardia, and ECG prolonged outpatient monitoring (Holter and symptomatic events monitor) to correlate symptoms and ventricular arrhythmias. Investigation on the susceptibility to neurocardiogenic syncope was evaluated by Tilt Table Test (TTT). Groups were compared regarding gender, age, premature beats frequency and complexity, at exertion or not, TTT results and clinical course.
In the syncope and pre-syncope groups, TTT was positive for 38% of cases, and in groups with palpitations and assymptomatics, it was positive for 11% (p = 0.0257). After recommendations and treatment of neurocardiogenic syncope, 85% of syncope and pre-syncope patients and positive TTT was asymptomatic along the 40-month follow-up. Two patients with syncope and negative TTT presented spontaneous, sustained ventricular tachycardia during clinic course.
The prevalence of neurocardiogenic syncope in patients with idiopathic RVOT premature beats is high. Patients with recurrent, unexplained syncope and idiopathic VE must be kept under investigation.
Arquivos brasileiros de cardiologia 12/2006; 87(5):570-4. · 1.32 Impact Factor
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ABSTRACT: To determine the effectiveness of surgical isolation of the left atrial posterior wall encompassing the ostia of the pulmonary veins for the treatment of atrial fibrillation of rheumatic etiology.
Prospective and randomized study of patients with rheumatic mitral valve disease, persistent atrial fibrillation for 6 months or longer, age < or = 60 years, and left atrial diameter < or = 65 mm. The patients were randomly distributed into 2 groups as follows: surgical valvular treatment (control group) and surgical valvular treatment associated with isolation of the left atrial posterior wall according to the "cut-and-sew" technique (treated group).
Twenty-nine individuals were operated upon, 27 of whom (13 in the control group and 14 in the treated group) were regularly followed up. The patients of both groups did not differ in regard to their basal characteristics. The mean follow-up time was 11.5 months in the control group and 10.3 months in the treated group. The cumulative frequencies of the patients without atrial fibrillation were significantly greater in the treated group both in the perioperative (P = 0.0035) and late (P = 0.0430) phases.
Surgical isolation of the left atrial posterior wall encompassing the ostia of the pulmonary veins is an effective form of treating atrial fibrillation in rheumatic mitral valve disease.
Arquivos Brasileiros de Cardiologia 10/2004; 83(3):211-8; 203-10. · 0.88 Impact Factor