OBJETIVOS: Avaliar se a ablação com radiofreqüência é um procedimento eficiente para o tratamento das extra-sístoles da via de saída do ventrículo direito (EVSVD), e se resulta em melhora dos sintomas. MÉTODOS: Estudo prospectivo, com 30 pacientes consecutivos (idade média de 40±13 anos, 25 do sexo feminino), sem cardiopatia estrutural aparente, com EVSVD, muito freqüentes (densidade média de 1.263±593/h), sintomáticos por mais de 1 ano (média =74 meses) e refratários aos fármacos antiarrítmicos (3±1,7, incluindo os beta-bloqueadores), que foram submetidos à ablação com radiofreqüência. RESULTADOS: Após o primeiro procedimento, houve 23 sucessos iniciais (76,6%) e 7 iniciais insucessos (23,4%). Quatro pacientes tiveram recorrências, sendo que dois desses não se submeteram ao segundo procedimento. O segundo procedimento foi realizado em 9 pacientes (7 insucessos iniciais e 2 recorrências), e o sucesso ocorreu em 5 pacientes adicionais, sendo 1 caso por acesso epicárdico. A taxa de sucesso final foi de 80% (24/30), e nenhuma complicação maior ocorreu. Após um seguimento médio de 14±6 meses, no grupo de sucesso final houve uma redução de mais de 90% na densidade das extra-sístoles(24/24; p<0,0001) e resultante ausência de sintomas na maioria dos pacientes (23/24; p<0,001). CONCLUSÃO: A ablação com radiofreqüência é um tratamento seguro e eficaz para os pacientes com extra-sístoles persistentes e sintomáticas com morfologia do trato de saída do ventrículo direito.

OBJECTIVES: To evaluate if radiofrequency catheter ablation is an effective procedure for the treatment of right ventricular outflow tract premature ventricular contractions (RVOT-PVC) and ascertain if it results in an improvement of symptoms. METHODS: A prospective study with 30 consecutive patients (mean age 40 ± 13 years, 25 females), with no apparent structural cardiopathy, with very frequent (mean density of 1,263 ± 593/h) RVOT-PVC, symptomatic for more than one year (mean = 74 months) and resistant to antiarrhythmic drugs (3 ± 1.7, including beta-blockers), who underwent radiofrequency catheter ablation. RESULTS: After the first procedure, there were 23 initial successful cases (76.6%) and 7 initial failures (23.4%). Four patients experienced relapses, two of whom did not undergo the second procedure. The second procedure was carried out in 9 patients (7 initial failures and 2 relapses), and there was success in 5 additional patients, one of them by epicardial access. The final success rate was 80% (24/30), and there were no major complications. After a mean follow-up of 14 ± 6 months, in the successful group there was a reduction greater than 90% in density of premature ventricular contractions (PVC) (24/24; p<0.0001) and a resulting absence of symptoms in the majority of patients (23/24; p<0.001). CONCLUSION: Radiofrequency catheter ablation is a safe and effective treatment for patients with persistent and symptomatic PVC with RVOT morphology.

OBJECTIVE: To compare single-photon-emission computed tomography (SPECT) imaging scans using 201Tl and 99mTc-MIBI in detection of viable myocardium, in regions compromised by infarction. METHODS: Thirty-two (59.3±9.8 years old and 87% male) myocardial infarction patients were studied. All had Q waves on the ECG and left ventricle ejection fraction of <50%. They underwent coronary and left ventricle angiographies and SPECT before (including 201Tl reinjection) and after coronary artery bypass surgery (CABG). Improvement in perfusion observed after surgery was considered the gold standard for myocardial viability. RESULTS: Among 102 studied regions of the heart, there were 40 (39.2%) areas of transient perfusion defects in the conventional protocol with 201Tl and 52 (51.0%) after reinjection. Therefore, 12/62 (19.4%) more viable regions were identified by reinjection. Using 99mTc-MIBI, only 14 (13.7%) regions with transient defects were identified, all of which were seen also in 201Tl protocols. After surgery, 49 of a total of 93 regions analyzed (52.7%) were viable. Sensitivity, specificity, accuracy, positive and negative prediction values were, respectively, 201Tl SPECT scans - 65.3%, 90.9%, 77.4%, 88.9% and 70.2%, reinjection protocol with 201Tl scans - 81.6%, 81.8%, 81.7%, 83.3% and 80.0%; 99mTc-MIBI SPECT scans - 20.4%, 90.9%, 53.8%, 71.4% and 50.6%. Logistic regression demonstrated that the reinjection protocol with 201Tl was the best predictor of viability (P<0.001). CONCLUSION: Our data suggest the election of 201Tl for viability studies, especially when using the reinjection protocol.

OBJETIVO: Avaliar o poder de contribuição do monitor de eventos sintomáticos no esclarecimento de sintomas. MÉTODOS: Foram estudados 64 pacientes encaminhados para esclarecimento de sintomas e que já haviam sido submetidos à gravação com Holter. Foram monitorizados, durante 15 dias, com gravador com memória circular com capacidade de registrar uma derivação do ECG (CM5), antes e após ativado pelo paciente. Na vigência de sintomas, o paciente acionava um comando do gravador que provocava a retenção do sinal do ECG, que era, posteriormente, transmitido a uma central via telefone. RESULTADOS: Em dois pacientes não foi possível a realização completa da monitorização, nos restantes, sintomas que motivaram a indicação do exame foram: palpitações (67,7%), tonturas (32,3%), síncopes (29%) e outros (30,6%). Em 85,5% dos pacientes houve relato de sintomas, sendo que em 62,2% houve registro de alterações eletrocardiográficas, relacionadas aos sintomas: taquicardia sinusal, 45,5%; extra-sístoles, 30,3%; taquiarritmia supraventricular, 21,2%; taquicardia ventricular, 3% e bloqueio atrioventricular, 3%. A 1ª transmissão motivada por sintoma ocorreu: 35,5% no 1º dia, 33,9% do 2° ao 5º, 12,9% do 6º ao 10º e 3,2% do 11º ao 15º. Nos pacientes onde a gravação com Holter não permitiu esclarecimento, o gravador de eventos registrou sintomas em 35,5%. CONCLUSÃO: Trata-se de método bem aceito pelos pacientes e capaz de produzir aumento significativo no esclarecimento de sintomas em relação ao Holter.

PURPOSE: To evaluate the contribution of the loop memory recorder in improving the diagnosis of symptoms related to cardiac arrhythmias. METHODS: The study population was 64 patients whose Holter monitorization was inconclusive as to the diagnosis of symptoms related to cardiac arrhythmias. Each wore a patient-activated ambulatory electrocardiogram device for 15 days. The ECG recordings during the occurrence of symptoms were sent to the ECG receiving center by phone. RESULTS: Two patients did not conclude the study. The majority of the patients (85.5%) experienced symptoms in the fifteen days of monitorization, and in 62.2% of these patients electrocardiographic events were observed. The main symptoms experienced by these patients were: palpitation (67.7%), dizziness (32.3%), and syncope (29%). Other symptoms like breast pain, fatigue, indisposition and dyspnea were also noted in 30.6% of the patients. The main electrocardiographic disturbances observed were: sinus tachycardia (45.5%), isolated premature beats (30.3%), supraventricular tachycardia (21.2%), ventricular tachycardia (3%) and third degree AV block (3%). We also observed that the first symptomatic recording occurred mainly in the initial days of monitorization (69.4% in the first 5 days). The percentage of diagnoses was 35.5% in patients whose Holter monitoring had been inconclusive. CONCLUSION: The cardiac loop ECG recorder therefore achieved an important incremental diagnostic yield.