RESUMO
Background and Objectives: Atrioventricular (AV) dyssynchrony as well as atrial and ventricular pacing affect left atrial (LA) function. We conducted a study evaluating the effect of atrial and ventricular pacing on LA morphological and functional changes after dual-chamber pacemaker implantation. Materials and Methods: The study prospectively enrolled 121 subjects who had a dual-chamber pacemaker implanted due to sinus node disease (SND) or atrioventricular block (AVB). Subjects were divided into three groups based on indication and pacemaker programming: (1) SND DDDR 60; (2) AVB DDD 60 and (3) AVB DDD 40. Subjects were invited to one- and three-month follow-up visits. Three subsets based on pacing burden were analyzed: (1) high atrial (A) low ventricular (V); (2) high A, high V and (3) low A, high V. LA function was assessed from volumetric parameters and measured strains from echocardiography. Results: The high A, low V group consisted of 38 subjects; while high A, high V had 26 and low A, high V had 23. A significant decrease in reservoir and contractile LA strain parameters were only observed in the high A, low V pacing group after three months (reservoir 25.9 ± 10.3% vs. 21.1 ± 9.9%, p = 0.003, contractile -14.0 ± 9.0% vs. -11.1 ± 7.8, p = 0.018). While the re-established atrioventricular synchrony in the low A, high V group maintained reservoir LA strain at the baseline level after three months (21.4 ± 10.4% vs. 22.5 ± 10.4%, p = 0.975); in the high A, high V group, a further trend to decrease was noted (20.3 ± 8.9% vs. 18.7 ± 8.3%, p = 0.231). Conclusions: High atrial pacing burden independently of atrioventricular dyssynchrony and ventricular pacing impairs LA functional and morphological parameters. Changes appear soon after pacemaker implantation and are maintained.
Assuntos
Bloqueio Atrioventricular , Marca-Passo Artificial , Humanos , Estimulação Cardíaca Artificial/efeitos adversos , Átrios do Coração , Síndrome do Nó Sinusal/terapia , Bloqueio Atrioventricular/terapiaRESUMO
Background and Objectives: Chronic atrial stimulation might impair left atrial (LA) function. We aimed to assess the impact of atrial pacing burden on LA volumetric and functional parameters after implantation of a dual-chamber pacemaker. Materials and Methods: The prospective study included 121 subjects with sinus node disease (SND) or atrioventricular block (AVB) that received a dual-chamber pacemaker. After device implantation, the subjects were divided into three groups: (1) SND with a lower rate (LR) set to 60 bpm and rate response enabled; (2) AVB with an LR set to 60 bpm and no rate response; and (3) AVB with an LR set to 40 bpm and no rate response. Subjects were followed at one and three months. Two subsets of patients with high and low atrial pacing burdens accompanied by low ventricular pacing percentage were analyzed. LA function was evaluated with volumetric and strain parameters from transthoracic echocardiography. Results: The high atrial low ventricular pacing group consisted of 38 subjects, and the low atrial low ventricular group consisted of 22 subjects. When looking at the change in volumetric parameters, we observed a tendency for volumes to increase in both groups; however, only minimal LA volume reached statistical significance at three months in the high atrial pacing group. A trend towards the lowering of an active emptying fraction at one month (p = 0.076) became significant at three months (p = 0.043), and was also only observed in the same group. Moreover, a decrease in the tendency to reach statistical significance at three months for reservoir and contractile strain parameters and stiffness index was only observed in the high atrial pacing group. Meanwhile, in the low atrial pacing burden group, all parameters remained significantly unchanged. Conclusions: The burden of right atrial pacing in patients with preserved left ventricular function negatively influences functional and morphologic LA parameters. Moreover, negative effects take place soon after pacemaker implantation and appear to be sustained.
Assuntos
Bloqueio Atrioventricular , Marca-Passo Artificial , Bloqueio Atrioventricular/terapia , Estimulação Cardíaca Artificial/efeitos adversos , Átrios do Coração , Humanos , Estudos Prospectivos , Síndrome do Nó Sinusal/terapiaRESUMO
Background and objectives: To identify clinical, echocardiographic, and laboratory parameters that affect the early recurrence of atrial fibrillation (AF) after restoring sinus rhythm (SR) by electrical cardioversion (ECV), and to determine whether left atrial (LA) strain, as a noninvasive indicator reflecting fibrosis, is associated with laboratory indicators affecting the development of fibrosis, interleukin 6 (IL-6) or tumor necrosis factor α (TNF-α). Materials and Methods: The study included 92 persistent AF patients who underwent elective ECV. The effective maintenance of SR was evaluated after 40 ± 10 days of ECV. Echocardiography, inflammatory markers (high-sensitivity c-reactive protein (hs-CRP), IL-6, and TNF-α), and natriuretic peptides (N-terminal pro b-type natriuretic peptide (NT-proBNP) and N-terminal pro a-type natriuretic peptide (NT-proANP)) were assessed. Results: After a 40 ± 10 days observation period, 51 patients (55.4%) were in SR. Patients with AF recurrence had a significantly longer duration of AF (p = 0.008) and of arterial hypertension (p = 0.035), lower LA ejection fraction (p = 0.009), lower LA strain (p < 0.0001), higher left ventricular global longitudinal strain (p = 0.001), and a higher E/e' ratio (p < 0.0001). LA strain was an independent predictor of early AF recurrence (OR: 0.65; 95% Cl 0.5−0.9, p = 0.004). LA strain < 11.85% predicted AF recurrence with 70% sensitivity and 88% specificity (AUC 0.855, 95% CI 0.77−0.94, p < 0.0001). LA strain demonstrated the association with NT-proBNP (r = −0.489, p < 0.0001) and NT-proANP (r = −0.378, p = 0.002), as well as with hs-CRP (r = −0.243, p = 0.04). Conclusions: LA strain appeared to be the most accurate predictor of early AF recurrence after ECV in patients with persistent AF. LA strain inversely correlated with NT-proBNP and NT-proANP, but no significant association with any of the inflammatory markers was identified.
Assuntos
Fibrilação Atrial , Cardioversão Elétrica , Fibrilação Atrial/terapia , Biomarcadores , Proteína C-Reativa/análise , Fibrose , Humanos , Interleucina-6 , Peptídeos Natriuréticos , Recidiva , Fatores de Risco , Volume Sistólico , Fator de Necrose Tumoral alfa , Função Ventricular EsquerdaRESUMO
PURPOSE: Spectral tissue Doppler-derived E/e' ratio has been proposed as the best parameter for prediction of atrial fibrillation (AF). Relaxation and contraction are equivalent parts of a continuous cardiac cycle, where systolic and diastolic abnormalities have a variable contribution to the left ventricle (LV) failure. The aim of this study was to investigate whether the E/(e'xs') ratio is a better index than E/e' to predict AF recurrence and to determine the changes of spectral tissue Doppler indices 1 month after the electrical cardioversion (ECV). PATIENTS AND METHODS: The study included 77 persistent AF patients with restored sinus rhythm (SR) after ECV. Only patients with normal LV ejection fraction (EF) were included. Echocardiography and NT-proBNP laboratory findings were performed. A primary outcome was the early (within 1 month) recurrence of AF. RESULTS: After a 1 month follow-up period, 39 patients (50.6%) were in SR. E/e' (HR=1.74, P=0.001) and E/(e'×s') ratios (HR=8.17, P=0.01) were significant predictors of AF recurrence. E/(e'×s') in combination with LV end-diastolic diameter >49.3 mm and NT-proBNP >2000 ng/L demonstrated a higher contribution in the model to predict AF recurrence compared to the E/e' ratio (18.94, P=0.005 vs 1.95, P=0.001). On ROC analysis, E/(e'×s') and E/e' showed similar diagnostic accuracy (E/(e'×s'), AUC=0.71, P=0.002 and E/e', AUC=0.75, P<0.0001). Average e' value significantly decreased after 1 month in SR (from 10.76±1.24 to 8.96±1.47 cm/s, P=0.01), E wave did not change significantly and E/e' ratio tended to improve. A decrease of average e' and an increase of average s' values led to significant improvement of E/(e'xs') ratio. CONCLUSION: E/(e'xs') and E/e' ratios are comparable to predict early AF recurrence after ECV in patients with persistent AF. The e' value decreased significantly after 1 month follow-up period after ECV for persistent AF patients.
Assuntos
Fibrilação Atrial/diagnóstico por imagem , Ecocardiografia Doppler/métodos , Cardioversão Elétrica/estatística & dados numéricos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Idoso , Fibrilação Atrial/prevenção & controle , Ecocardiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Recidiva , Volume Sistólico , Disfunção Ventricular Esquerda/prevenção & controleRESUMO
Background and Objectives: Cardiac resynchronization therapy (CRT) is a successful treatment option for appropriately selected patients. However, one-third of recipients do not experience any positive outcome or their condition even declines. We aimed to assess preimplantation factors associated with worse survival after the CRT. Materials and Methods: This was a retrospective unicenter trial. The study cohort included 183 consecutive CRT-treated patients. Baseline demographic, clinical, electrocardiographic, and echocardiographic characteristics were analyzed. Results: After the median follow-up of 15.6 months (9.3-26.3), 20 patients had died (11%). In multivariate Cox regression analysis, ischemic origin of heart failure (HF) was a significant predictor of poor survival (adjusted hazard ratio (aHR) 15.235, 95% confidence interval (CI) (1.999-116.1), p = 0.009). In univariate Cox regression, tricuspid annular plane systolic excursion (TAPSE) <15.5 mm (sensitivity 0.824, specificity 0.526; HR 5.019, 95% CI (1.436-17.539), p = 0.012), post-implantation prescribed antiplatelet agents (HR 2.569, 95% CI (1.060-6.226), p = 0.037), statins (HR 2.983, 95% CI (1.146-7.764), p = 0.025), and nitrates (HR 3.694, 95% CI (1.342-10.171), p = 0.011) appeared to be related with adverse outcome. Conclusions: ischemic etiology of HF is a significant factor associated with worse survival after the CRT. Decreased TAPSE is also related to poor survival.
Assuntos
Terapia de Ressincronização Cardíaca/mortalidade , Insuficiência Cardíaca/mortalidade , Idoso , Ecocardiografia , Feminino , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Lituânia/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
Atrial fibrillation (AF) despite the absence of heart failure is related to increased levels of natriuretic peptides (NPs). NPs have not been widely investigated in relation to left atrium (LA) function after sinus rhythm (SR) restoration and duration of AF. The aim of the study was to determine the changes of NPs levels and to define their relation with LA phasic function after electrical cardioversion (ECV). Methods. The study included 48 persistent AF patients with restored SR after ECV. NT-proANP and NT-proBNP were measured for all patients before the ECV. LA phasic function (reservoir, conduit, and pump phases) was assessed using echocardiographic volumetric analysis within the first 24 hours after ECV. Patients were repeatedly tested after 1 month in case of SR maintenance. Results. After 1 month, SR was maintained in 26 (54%) patients. For those patients, NT-proBNP decreased significantly (p=0.0001), whereas NT-proANP tended to decrease (p=0.13). Following 1 month after SR restoration, LA indexed volume decreased (p=0.0001) and all phases of LA function improved (p=<0.01). Patients with AF duration < 3 months had lower NT-proANP compared to patients with AF duration from 6 to 12 months (p = 0.005). Higher NT-proANP concentration before ECV was associated with lower LA reservoir function during the first day after SR restoration (R=-0.456, p=0.005), whereas higher NT-proBNP concentration after 1 month in SR was significantly related to lower LA reservoir function (R=-0.429, p=0.047). Conclusions. LA indexed volume, all phases of LA function, and NT-proBNP levels improved significantly following 1 month of SR restoration. Preliminary results suggest that higher baseline NT-proANP levels and higher NT-proBNP for patients with maintained SR for 1 month are related to lower LA reservoir function. The longer duration of persistent AF is associated with higher NT-proANP concentration.
Assuntos
Fibrilação Atrial/terapia , Função do Átrio Esquerdo , Insuficiência Cardíaca/terapia , Peptídeos Natriuréticos/genética , Idoso , Fibrilação Atrial/genética , Fibrilação Atrial/fisiopatologia , Biomarcadores/metabolismo , Ecocardiografia , Cardioversão Elétrica , Feminino , Átrios do Coração/fisiopatologia , Átrios do Coração/ultraestrutura , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos Natriuréticos/metabolismoRESUMO
BACKGROUND: Ganglionated plexuses (GP) are terminal parts of cardiac autonomous nervous system (ANS). Radiofrequency ablation (RFA) for atrial fibrillation (AF) possibly affects GP. Changes in heart rate variability (HRV) after RFA can reflect ANS modulation. METHODS: Epicardial RFA of GP on the left atrium (LA) was performed under the general anesthesia in 15 mature Romanov sheep. HRV was used to assess the alterations in autonomic regulation of the heart. A 24 - hour ECG monitoring was performed before the ablation, 2 days after it and at each of the 12 following months. Ablation sites were evaluated histologically. RESULTS: There was an instant change in HRV parameters after the ablation. A standard deviation of all intervals between normal QRS (SDNN), a square root of the mean of the squared differences between successive normal QRS intervals (RMSSD) along with HRV triangular index (TI), low frequency (LF) power and high frequency (HF) power decreased, while LF/HF ratio increased. Both the SDNN, LF power and the HF power changes persisted throughout the 12 - month follow - up. Significant decrease in RMSSD persisted only for 3 months, HRV TI for 6 months and increase in LF/HF ratio for 7 months of the follow - up. Afterwards these three parameters were not different from the preprocedural values. CONCLUSIONS: Epicardial RFA of GP's on the ovine left atrium has lasting effect on the main HRV parameters (SDNN, HF power and LF power). The normalization of RMSSD, HRV TI and LF/HF suggests that HRV after epicardial RFA of GPs on the left atrium might restore over time.
Assuntos
Função do Átrio Esquerdo , Denervação Autônoma/métodos , Ablação por Cateter , Gânglios Autônomos/cirurgia , Átrios do Coração/inervação , Frequência Cardíaca , Animais , Eletrocardiografia Ambulatorial , Feminino , Gânglios Autônomos/fisiopatologia , Masculino , Carneiro Doméstico , Fatores de TempoRESUMO
OBJECTIVE: The aim of this study to investigate the most frequent risk factors of atrial fibrillation (AF), co-morbidities, complications associated with AF and the use of anticoagulants and other medications in patients who were referred to university hospitals in Lithuania. MATERIALS AND METHODS: This cross-sectional study enrolled consecutive inpatients and outpatients with AF presenting to cardiologists in the two biggest Lithuanian university hospitals from November 2013 to May 2014. AF diagnosis was confirmed by a 12-lead ECG or 24-h Holter with an episode duration of >30s. RESULTS: A total number of 575 patients were recruited, and complete data on clinical subtype were available for 515 patients (mean age of 70.7 years; 48.5% of women). Permanent AF was the most frequent type of AF (46.6%). Common comorbidities were hypertension (85.8%), heart failure (77.9%) and coronary artery disease (51.8%). Amiodarone was the most common antiarrhythmic agent used in 14.6% of the patients, while beta-blockers and digoxin were the most often used rate control drugs (59.6% and 10.7%, respectively). Oral anticoagulants were used by 53.3% of the patients; of them, 95.6% used vitamin K antagonists, while non-vitamin K antagonist were used by only 4.4%. The INR within a therapeutic range (2.0-3.0) was documented in 19.2% of the patients. Other antithrombotic drugs such as aspirin and clopidogrel were used in 13.7% and 2.0% of the patients, respectively; dual antiplatelet treatment was administered in 6.2% of the patients. Of the entire cohort, the mean CHA2DS2-VASc score was 3.97±1.6 and the mean HAS-BLED score was 2.25±1.0. CONCLUSIONS: Compliance with the treatment guidelines remains suboptimal and further patient education is needed.
Assuntos
Antiarrítmicos/uso terapêutico , Anticoagulantes/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/epidemiologia , Fibrinolíticos/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Comorbidade , Doença da Artéria Coronariana/tratamento farmacológico , Doença da Artéria Coronariana/epidemiologia , Estudos Transversais , Feminino , Fibrinolíticos/administração & dosagem , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/epidemiologia , Hemorragia/tratamento farmacológico , Hemorragia/patologia , Hospitais Universitários , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Lituânia/epidemiologia , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND AND OBJECTIVE: To evaluate left ventricular (LV) longitudinal function and dyssynchrony mechanisms after dual chamber pacemaker implantation. MATERIALS AND METHODS: The speckle tracking imaging technique was used for quantification of global longitudinal function of the left ventricle and for dyssynchrony evaluation before pacemaker implantation and after 3-month follow-up. The study group consisted of 98 patients with conventional indications for dual chamber pacemaker implantation. RESULTS: Speckle tracking echocardiographic methods and image postprocessing revealed impairment of global longitudinal strain and significant LV dyssynchrony derived from 12 basal and mid-septum segments usually untraceable with conventional echocardiographic methods. Despite good physical performance and ejection fraction, global longitudinal strain significantly decreased in all patients from -15.08±0.46 to -13.56±0.5 (P<0.05) as well as mitral annulus movement decreased from 11.57±2.41 to 8.46±1.74cm/s (P<0.001) and from 12.55±2.75 to 10.78±2.82mm (P<0.001). It was expected that patients with dual chamber pacemaker will develop inter- and intraventricular dyssynchrony, but our study showed that pacing lead position did not prevent from LV dysynchronisation and only changed the mechanism. CONCLUSIONS: Global longitudinal strain and LV dyssynchrony assessment enables us to detect early signs of LV dysfunction. Mechanisms of dyssynchrony development will be useful for pacemaker programing choices in order to prevent further dyssynchronisation.
Assuntos
Bloqueio Atrioventricular/cirurgia , Dispositivos de Terapia de Ressincronização Cardíaca , Síndrome do Nó Sinusal/cirurgia , Disfunção Ventricular Esquerda/fisiopatologia , Remodelação Ventricular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia , Feminino , Humanos , Masculino , Implantação de PróteseRESUMO
BACKGROUND: Approximately 30% of patients treated with cardiac resynchronization therapy (CRT) do not achieve favourable response. The purpose of the present study was to identify echocardiographic and clinical predictors of a positive response to CRT. METHODS: The study included 82 consecutive heart failure (HF) patients in New York Heart Association (NYHA) functional class III or IV with left bundle branch block (LBBB), QRS duration ≥ 120 ms and left ventricular ejection fraction (LVEF) ≤ 35%. Statistical analysis was performed using IBM SPSS statistical software (SPSS v.21.0 for Mac OS X). A p value < 0.05 was considered statistically significant. RESULTS: Echocardiographic response was established in 81.6% and clinical response was achieved in 82.9% of patients. Significant univariate predictors of favourable echocardiographic response after 12 months were smaller left ventricular end-diastolic diameter (LVEDD) (odds ratio [OR] 0.89; 95% confidence interval [CI] 0.82 - 0.97, p = 0.01), and smaller left ventricular end-systolic diameter (LVESD) (OR 0.91; 95% CI 0.85 - 0.98, p = 0.01). Lower uric acid concentration was associated with better echocardiographic response (OR 0.99; 95% CI 0.99 - 1.0, p = 0.01). Non-ischemic HF etiology (OR 4.89; 95% CI 1.39 - 17.15, p = 0.01) independently predicted positive clinical response. Multiple stepwise regression analysis demonstrated that LVEDD lower than 75 mm (OR 5.60; 95% confidence interval [CI] 1.36 - 18.61, p = 0.01) was the strongest independent predictor of favourable echocardiographic response. CONCLUSIONS: Smaller left ventricular end-diastolic and end-systolic diameters and lower serum uric acid concentration were associated with better response to CRT. Left ventricular end-diastolic diameter and non-ischemic heart failure etiology were the strongest independent predictors of positive response to CRT.
Assuntos
Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca/terapia , Idoso , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Ecocardiografia Doppler , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Seleção de Pacientes , Valor Preditivo dos Testes , Fatores de Risco , Volume Sistólico , Resultado do Tratamento , Ácido Úrico/sangue , Função Ventricular EsquerdaRESUMO
BACKGROUND: In treatment of atrial fibrillations (AF), radiofrequency ablation (RFA) at the pulmonary vein (PV) roots isolates AF triggers in the myocardial sleeves, but also can destroy PV ganglia and branches of the intrinsic cardiac nerve plexus. AIM: To determine the long-term impact of RFA at the PV roots on the structure of epicardial nerves located distally from the RFA site. METHODS: Five black-faced sheep underwent epicardial RFA of the left and middle PV roots. Two to 3 months after RFA, we obtained samples of epicardial nerves from remote locations of the left dorsal (LD) neural subplexus that extends along the roots of the superior PVs toward the coronary sinus (CS) and dorsal left ventricle (LV). Right atrial epicardial nerves from the right ventral (RV) neural subplexus of the ablated animals and epicardial nerves from LD neural subplexus of five additional intact sheep were used as control. Nerve morphology was examined using histochemical, immunohistochemical and transmission electron microscopy. RESULTS: Histochemical acetylcholinesterase staining did not reveal any epicardial nerve alterations. However, tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) staining showed clearly the reduced numbers of TH and ChAT immunoreactive (IR) nerve fibers within epicardial nerves derived from the remote LD subplexus; control samples from all examined animals were full of evenly distributed TH-IR and ChAT-IR nerve fibers. In sharp contrast to control nerves, numerous swollen or disintegrated axons and Schwann cells with pyknotic nuclei inside unmyelinated and myelinated nerve fibers were identified by electron microscopy of ultrathin sections of epicardial nerves from the CS and LV regions in all ablated animals. CONCLUSIONS: Degeneration of remote atrial and ventricular epicardial nerves is evident 2-3 months after epicardial RFA at the PV roots. Such nerves are likely to be non-functional. Therefore, long-term autonomic dysfunction is a potential risk of PV isolation by RFA.
Assuntos
Axônios/patologia , Ablação por Cateter/efeitos adversos , Degeneração Neural/patologia , Pericárdio/inervação , Veias Pulmonares/patologia , Veias Pulmonares/cirurgia , Acetilcolinesterase/metabolismo , Animais , Axônios/ultraestrutura , Colina O-Acetiltransferase/metabolismo , Feminino , Imuno-Histoquímica , Masculino , Microscopia Eletrônica de Transmissão , Fibras Nervosas/patologia , Fibras Nervosas/ultraestrutura , Fibras Nervosas Mielinizadas/patologia , Veias Pulmonares/inervação , Células de Schwann/patologia , Células de Schwann/ultraestrutura , Ovinos , Toracotomia , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
UNLABELLED: Idiopathic ventricular tachycardia is a rare condition, and there is a lack of clear guidelines for the necessity and indications for prophylactic antiarrhythmic or curative treatment. The aim of this study was to review the clinical picture of idiopathic ventricular tachycardia and evaluate the efficacy and safety of radiofrequency ablation therapy in children. MATERIAL AND METHODS: The subjects of this study were 16 children with idiopathic ventricular tachycardia. The mean age at onset of idiopathic ventricular tachycardia was 12 years. All patients underwent electrophysiological examination. Nonfluoroscopic mapping technology (Carto) was used in one case. Radiofrequency ablation was performed in all children (mean duration of follow-up was 46 months). RESULTS: Six children with idiopathic ventricular tachycardia were free of symptoms. Palpitation was the only complain in four patients, and six patients presented with symptoms of circulatory disorder (the tendency of the higher rate of ventricular tachycardia and more premature contractions and episodes of ventricular tachycardia in one day were noticed in five of them). All children after radiofrequency ablation were alive, and only one complication (complete right bundle branch block) occurred. Success at last follow-up included five children with left and six with right idiopathic ventricular tachycardia. CONCLUSIONS: Catheter ablation seems a promising therapeutic option with the outlook possible of the idiopathic ventricular tachycardia in children. It is safe enough and should be considered as the therapy of choice even in children without of symptoms if they wish to live active social and physical life.
Assuntos
Ablação por Cateter , Taquicardia Ventricular/cirurgia , Adolescente , Fatores Etários , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/fisiopatologia , Criança , Pré-Escolar , Ecocardiografia , Eletrocardiografia , Eletrofisiologia , Feminino , Seguimentos , Humanos , Masculino , Segurança , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
The objective of this article was to find out how radiofrequency catheter ablation (RFA) influences platelet aggregation (PA), and the dependence on the total energy (TE) of RFA used and the cause of arrhythmia. We investigated 97 patients. PA was analyzed before, after, and in 24 hours after RFA. ADP- and epinephrine-induced PA significantly decreased after RFA by 5% and 8.9% (P < .001), respectively, and increased in 24 hours close to baseline. PA induced by ADP and collagen did not radically depend on the TE. Epinephrine-induced PA decreased after RFA by 0%, 8% (P < .05), and 16.9% (P < .01) in groups of patients where the TEs used were <4000 J, 4000 to 15,000 J, and >15,000 J, respectively. There were no significant differences in PA between groups based on the cause of arrhythmia. ADP- and epinephrine-induced PA significantly decreased after RFA and returned close to baseline in 24 hours. Epinephrine-induced PA was inversely associated with the TE used for RFA.
Assuntos
Arritmias Cardíacas/sangue , Arritmias Cardíacas/terapia , Ablação por Cateter/efeitos adversos , Agregação Plaquetária , Difosfato de Adenosina/farmacologia , Adulto , Idoso , Colágeno/farmacologia , Epinefrina/farmacologia , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacos , Tromboembolia/etiologiaRESUMO
OBJECTIVES: The aim of the study was to study some anatomic and electrophysiological features of the right atrium, related to the presence of atrial flutter. MATERIALS AND METHODS: A total 23 patients with type I atrial flutter and 22 patients without atrial flutter were studied. Right atrium size was assessed using echocardiography before intracardiac examination and radiofrequency ablation. RESULTS: Effective refractory periods of coronary sinus, high right atrium, low right atrium were different comparing with the control group (P<0.05). A stimulus-response time between high right atrium and low right atrium positions in anterograde and retrograde ways, an impulse propagation speed along the lateral wall of the right atrium were statistically different comparing both groups (P<0.05). There was a significant correlation among effective refractory periods measured in different sites of the right atrium (r2=0.64, 0.44, 0.44, respectively). All measured effective refractory periods also correlated with stimulus-response time in anterograde way (P<0.05) and impulse propagation speed (P<0.05). Right atrium dimensions were significantly larger in atrial flutter group. There was no correlation between the right atrium dimensions and measured electrophysiological parameters in both groups. CONCLUSIONS: The presence of atrial flutter associates with diffuse alterations of the right atrium, but not the focal or single changes of refractoriness.
Assuntos
Flutter Atrial/fisiopatologia , Átrios do Coração/fisiopatologia , Idoso , Flutter Atrial/diagnóstico por imagem , Flutter Atrial/cirurgia , Ablação por Cateter , Interpretação Estatística de Dados , Ecocardiografia , Eletrocardiografia , Eletrofisiologia , Feminino , Átrios do Coração/anatomia & histologia , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Período Refratário EletrofisiológicoRESUMO
OBJECTIVE: To find out if radiofrequency ablation as method of treatment of cardiac arrhythmia influences platelet aggregation and if intensity of this process depends on the number of radiofrequency ablation episodes for one patient. MATERIAL AND METHODS: We analyzed platelet aggregation before, right after and in 24 hours after radiofrequency ablation in whole blood and platelet rich plasma in 39 cases with cardiac arrhythmias. Adenosine diphosphate and adrenaline were used for aggregation induction. Three groups of patients were formed based on the number of radiofrequency ablation episodes: A-- <10, B--10-20, C-- >20 for one patient. RESULTS: We detected a decrease in spontaneous, adenosine diphosphate and adrenaline induced platelet aggregation in plasma right after radiofrequency ablation, and also the same tendency was noted in adenosine diphosphate induced aggregation in whole blood. In 24 hours after radiofrequency ablation platelet aggregation tended to return to pre-radiofrequency ablation levels. Based on the number of radiofrequency ablation episodes we detected significant changes in spontaneous and adrenaline-induced aggregation in plasma. In group A adrenaline induced aggregation after radiofrequency ablation increased by 0.4%, in group B it decreased by 15.7% and in group C it decreased by 19.4% from pre-radiofrequency ablation level (p<0.05, between groups A and C). Spontaneous platelet aggregation after radiofrequency ablation decreased in group A 41.9%, in group B--20.8% and in group C--18.4% from pre-radiofrequency ablation level (p<0.05 between groups A and C). The greater decrease in adenosine diphosphate induced aggregation in plasma and in whole blood was detected in the group with larger number of radiofrequency ablation episodes. CONCLUSIONS: This study found that platelet aggregation decreased in plasma and in whole blood after radiofrequency ablation. And this alteration was significant in groups B and C, when the number of radiofrequency ablation episodes were >10. In 24 hours platelet aggregation increased again to pre- radiofrequency ablation level.