Nilson Araújo

Atrial-oesophageal fistula following percutaneous radiofrequency catheter ablation of atrial fibrillation: the risk still persists

Aims Atrial‐oesophageal fistula is a serious complication related to ablation of atrial fibrillation. As its occurrence is rare, there is a great lack of information about their mechanisms, incidence, presentations, and treatment. The objective of this manuscript is to present a series of cases of atrial‐oesophageal fistula in Brazil, focusing on incidence, clinical presentation, and follow‐up. Methods and results This is a retrospective multicentre registry of atrial‐oesophageal fistula cases that occurred in eight Brazilian centres from 2003 to 2015. Ten cases (0.113%) of atrial‐oesophageal fistula were reported in 8863 ablation procedures in the period. Most of the subjects were male (70%) with age 59.6 ± 9.3 years. Eight centres were reference units in atrial fibrillation ablation with an experience over than 200 procedures at the time of fistula occurrence. Oesophageal temperature monitoring was performed in eight cases using coated sensors in six. The first atrial‐oesophageal fistula clinical manifestation was typically fever (in six patients), with a median onset time of 16.5 (12‐43) days after ablation. There was a delay of 7.8 ± 3.3 days between the first manifestation and the diagnosis in five patients. The treatment was surgical in six cases, clinical in three and stenting in one. Seven patients died (70%) and two developed permanent neurological sequelae. Conclusion Atrial‐oesophageal fistula remains a serious complication following AF ablation despite the incorporation of protective measures and increased technical experience of the groups. The high morbidity and mortality despite the treatment indicates the need to develop adequate preventive strategies.

Prognostic criteria of success and recurrence in circumferential ablation for the treatment of atrial fibrillation

OBJECTIVES To analyze the success of circumferential ablation of atrial fibrillation and to investigate possible clinical and electroanatomic predictors of recurrence of cardiac arrhythmia. METHODS 104 consecutive patients free of structural heart disease and refractory to at least two antiarrhythmic drugs, and undergoing circumferential ablation for the treatment of paroxysmal/persistent atrial fibrillation were analyzed. Seventy two patients were males and the mean age of the group was 58.6 + 10.9 years. The procedure consisted of a single transseptal puncture and three-dimension mapping using the CARTO system to acquire points in the left atrium and pulmonary veins. Radiofrequency applications were performed encircling the pulmonary vein ostea, up to a > or = 80% reduction of the atrial potential amplitude. One additional line was created in the mitral isthmus and another in the cavotricuspid isthmus. Total left atrium volume, area ablated around the pulmonary veins, and completeness of the ablation line (complete or incomplete line) were analyzed. A line was considered complete when the distance between two contiguous radiofrequency application points was lower than 10mm. RESULTS In a mean 18-month follow-up, 87 patients were in sinus rhythm (84%), and 17 patients presented recurrence (16%). In the multivariate analysis, only the left atrial volume (p<0.0001) and complete ablation (p<0.05) were independent predictors of recurrence. CONCLUSION The results suggest that the left atrial volume and the presence of complete ablation are predictive of recurrence of atrial fibrillation.

Acompanhamento clínico de pacientes portadores de cardioversor-desfibrilador implantável

OBJECTIVE: To report appropriate (AT) and inappropriate (IT) ICD therapies in patients with ischemic and nonischemic heart disease, as well as early and late procedure-related complications. METHODS: One hundred and fifty-five patients (119 male and 36 female), mean age 47 years (21-88), who underwent ICD implantation between 1994 and March 2003 were analyzed. Patients were divided into the following groups: Group I--Post-AMI patients (n = 80); Group II--Patients with nonischemic heart disease and LV ejection fraction < 40% (n = 45), Chagas disease (n = 18), idiopathic dilated cardiomyopathy (n= 12), hypertensive disease (n = 8), hypertrophic cardiomyopathy (n = 4) and valvular heart disease (n = 3); Group III--Patients with arrhythmogenic right ventricular dysplasia (n = 13); and Group IV--Patients with channelopathies: Brugada Syndrome (n = 8) and idiopathic ventricular arrhythmias (n = 9). All patients underwent electrophysiological study (EPS) with induction of sustained ventricular arrhythmia ICD implantation. RESULTS: During the 26-month mean follow up, a high rate of appropriate ICD therapies (antitachycardia pacing and/or shock) was observed (46%) in the four groups, with no statistically significant difference. The four groups did not differ in either overall (8.4%) or arrhythmic mortality (1.3%). There was no correlation between appropriate ICD therapies and initial clinical presentation or inducible ventricular arrhythmia at EPS, and a 4% incidence of early and late procedure-related complications was found. CONCLUSION: The high incidence of appropriate ICD therapy and low rate of sudden death in the patients studied suggest that ICD is a valuable strategy in the management of ischemic and nonischemic patients previously selected by means of EPS.

305 TRANSCATHETER RENAL DENERVATION IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND RESISTANT HYPERTENSION: FIRST EXPERIENCE IN BRAZIL

Background: Recently, the transcatheter renal denervation procedure (TRD) has proved effective in lowering blood pressure (BP), in cases of refractory hypertension (RHTN). This study evaluated the safety and efficacy of TRD as well as its impact on glomerular filtration and proteinuria in patients with RHTN and chronic kidney disease (CKD). Methods: 4 patients with CKD (stages 3 and 4) and RHTN underwent bilateral TRD with standard cardiac irrigated catheter ablation. Ambulatory blood pressure monitoring for 24 hours, office BP measurements, estimated glomerular filtration rate (eGFR), plasma creatinine and urinary total protein/ microalbumin were obtained at baseline and 1 month after the procedure. Renal Duplex ultrasound was also performed before the procedure. Measurements of plasma catecholamines, renin and angiotensin were made before the intervention, immediately after and 30 days after the procedure. Results: The means and standard errors of baseline BP was 188.5 ± 8.9 / 104.4 ± 4.3 mmHg; baseline eGFR was 42.4 ± 12.2 ml/min/1.73m2. BP values 7 and 30 days after the procedure were reduced to 126 ± 5.4 / 82.2 ± 2.9 and 128.7 ± 6.1 / 81.8 ± 3.8, respectively (P <0.05 for all comparisons). There was an average reduction of 1.8 antihypertensive drugs (P <0.05) per patient. There were no complications and no significant change in eGFR or in all substances measured. Conclusions: TRD may be performed safely and effectively in patients with RHTN and CKD, using standard irrigated ablation catheter, resulting in reduction in the number of antihypertensive drugs used without impaired renal function.