RESUMEN
BACKGROUND: Obesity is associated with an increased risk of developing recurrent atrial fibrillation (AF) after catheter ablation (CA). However, the current data on weight loss interventions show inconsistent results in preventing the recurrence of AF after CA. METHODS: We conducted a systematic search in MEDLINE and EMBASE to identify studies that reported the outcome of recurrence of AF after CA in obese patients undergoing weight interventions. The subgroup analysis included: (1) Weight loss versus no weight loss, (2) >10% weight loss versus <10% weight loss, (3) <10% weight loss versus no weight loss, (4) Follow-up <12 months, and (5) Follow-up >12 months after CA. Mantel-Haenszel risk ratios with a 95% confidence interval (CI) were calculated using a random effects model and for heterogeneity, I2 statistics were reported. RESULTS: A total of 10 studies (one randomized controlled trial and nine observational studies) comprising 1851 patients were included. The recurrence of AF was numerically reduced in the weight loss group (34.5%) versus no weight loss group (58.2%), but no statistically significant difference was observed (risk ratio [RR] = 0.76; 95% CI: 0.49-1.18, p = .22). However, there was a statistically significant reduction in recurrence of AF with weight loss versus no weight loss at follow-up >12 months after CA (RR = 0.47; 95% CI: 0.32-0.68, p < .0001). At follow-up >12 months after CA, both >10% weight loss versus <10% weight loss (RR = 0.49; 95% CI: 0.31-0.80, p = .004) and <10% weight loss versus no weight loss (RR = 0.39; 95% CI: 0.31-0.49, p < .00001) were associated with a statistically significant reduction in recurrent AF. CONCLUSION: In patients with AF undergoing CA, weight loss is associated with reducing recurrent AF at > 12 months after ablation and these benefits are consistently seen with both >10% and <10% weight loss. The benefits of weight loss in preventing recurrent AF after CA should be examined in larger studies with extended follow-up duration.
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Fibrilación Atrial , Ablación por Catéter , Humanos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Fibrilación Atrial/etiología , Resultado del Tratamiento , Recurrencia , Obesidad/complicaciones , Obesidad/diagnóstico , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND AND AIMS: Colchicine is an anti-inflammatory drug that may prevent post-operative atrial fibrillation (POAF). The effect of this drug has been inconsistently shown in previous clinical trials. We aimed to compare the efficacy and safety of colchicine vs. placebo to prevent POAF in patients undergoing cardiac surgery. METHODS AND RESULTS: A systematic search of EMBASE, MEDLINE, SCOPUS, ClinicalTrials.gov, and the Cochrane Library for randomized controlled trials (RCTs) was conducted from inception till April 2023. The primary outcome was the incidence of POAF after any cardiac surgery. The secondary outcome was the rate of drug discontinuation due to adverse events and adverse gastrointestinal events. Risk ratios (RR) were reported using the Mantel Haenszel method. A total of eight RCTs comprising 1885 patients were included. There was a statistically significant lower risk of developing POAF with colchicine vs. placebo (RR: 0.70; 95% CI: 0.59-0.82; P < 0.01, I2 = 0%), and this effect persisted across different subgroups. There was a significantly higher risk of adverse gastrointestinal events (RR: 2.20; 95% CI: 1.38-3.51; P < 0.01, I2 = 55%) with no difference in the risk of drug discontinuation in patients receiving colchicine vs. placebo (RR: 1.33; 95% CI: 0.93-1.89; P = 0.11, I2 = 0%). CONCLUSION: This meta-analysis of eight RCTs shows that colchicine is effective at preventing POAF, with a significantly higher risk of adverse gastrointestinal events but no difference in the rate of drug discontinuation. Future studies are required to define the optimal duration and dose of colchicine for the prevention of POAF.
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Fibrilación Atrial , Procedimientos Quirúrgicos Cardíacos , Humanos , Colchicina/efectos adversos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Fibrilación Atrial/etiología , Ensayos Clínicos Controlados Aleatorios como Asunto , Procedimientos Quirúrgicos Cardíacos/efectos adversos , IncidenciaRESUMEN
BACKGROUND: Endocardial mapping for scars and abnormal electrograms forms the most essential component of ventricular tachycardia ablation. The utility of ultra-high resolution mapping of ventricular scar was assessed using a multielectrode contact mapping system in a chronic canine infarct model. METHODS: Chronic infarcts were created in five anesthetized dogs by ligating the left anterior descending coronary artery. Late gadolinium-enhanced magnetic resonance imaging (LGE MRI) was obtained 4.9 ± 0.9 months after infarction, with three-dimensional (3D) gadolinium enhancement signal intensity maps at 1-mm and 5-mm depths from the endocardium. Ultra-high resolution electroanatomical maps were created using a novel mapping system (Rhythmia Mapping System, Rhythmia Medical/Boston Scientific, Marlborough, MA, USA) Rhythmia Medical, Boston Scientific, Marlborough, MA, USA with an 8.5F catheter with mini-basket electrode array (64 tiny electrodes, 2.5-mm spacing, center-to-center). RESULTS: The maps contained 7,754 ± 1,960 electrograms per animal with a mean resolution of 2.8 ± 0.6 mm. Low bipolar voltage (<2 mV) correlated closely with scar on the LGE MRI and the 3D signal intensity map (1-mm depth). The scar areas between the MRI signal intensity map and electroanatomic map matched at 87.7% of sites. Bipolar and unipolar voltages, compared in 592 electrograms from four MRI-defined scar types (endocardial scar, epicardial scar, mottled transmural scar, and dense transmural scar) as well as normal tissue, were significantly different. A unipolar voltage of <13 mV correlated with transmural extension of scar in MRI. Electrograms exhibiting isolated late potentials (ILPs) were manually annotated and ILP maps were created showing ILP location and timing. ILPs were identified in 203 ± 159 electrograms per dog (within low-voltage areas) and ILP maps showed gradation in timing of ILPs at different locations in the scar. CONCLUSIONS: Ultra-high resolution contact electroanatomical mapping accurately localizes ventricular scar and abnormal myocardial tissue in this chronic canine infarct model. The high fidelity electrograms provided clear identification of the very low amplitude ILPs within the scar tissue and has the potential to quickly identify targets for ablation.
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Técnicas de Imagen Sincronizada Cardíacas/métodos , Cicatriz/fisiopatología , Imagen por Resonancia Magnética/métodos , Infarto del Miocardio/fisiopatología , Taquicardia Ventricular/fisiopatología , Animales , Medios de Contraste , Modelos Animales de Enfermedad , Perros , Electrocardiografía , Gadolinio DTPA , Procesamiento de Imagen Asistido por ComputadorRESUMEN
BACKGROUND: During pulsed field ablation (PFA), relationships between ablation parameters (contact force [CF], number of burst pulses, impedance decrease, and electrode temperature) and lesion size in beating hearts have not been well validated. METHODS: A 7.5F-catheter with a 3.5-mm ablation electrode and CF sensor (ThermoCool SmartTouch SF-Dual-Energy, Biosense Webster, Inc, Irwindale, CA) was connected to a PFA system (TRUPULSE2, Biosense Webster, Inc). In 11 closed-chest swine, biphasic PFA current was delivered between the ablation electrode and the skin patch at 219 sites in left ventricle and right ventricle using 12, 18, and 24 burst pulses with 4 different levels of CF: (1) low (n=57; CF, 4-15g; median, 10g); (2) moderate (n=60; CF, 16-30g; median, 22.5g); (3) high (n=68; CF, 32-65g; median, 40g); and (4) no electrode contact (n=34), 2 mm away from the endocardium. Swine were euthanized 2 hours after ablation, and lesion size was measured using triphenyl tetrazolium chloride staining. RESULTS: All PFA lesions with electrode-myocardium contact were well demarcated with triphenyl tetrazolium chloride staining, demonstrating (1) pale central zone (contraction band necrosis with minimal coagulation necrosis), (2) dark brown zone (contraction band necrosis with hemorrhage), and (3) hyperstained red zone by triphenyl tetrazolium chloride (unaffected normal myocardium with preserved mitochondrial activity, consistent with reversible zone). Lesion depth increased significantly with increasing CF and the number of PFA burst pulses. An exponential/logarithmic formula combined with CF and the number of PFA burst pulses correlated lesion depth with high accuracy: R=0.809, P<0.0001, ±1.0-mm accuracy in 128 of 163 (79%) lesions, and ±1.5-mm accuracy in 153 of 163 (94%) lesions. Impedance decrease and electrode temperature were poor predictors of lesion size. There were no detectable lesions resulting from ablation without electrode contact. CONCLUSIONS: Acute PFA ventricular lesions demonstrate irreversible and reversible lesion boundaries. Electrode-tissue contact is required for effective lesion formation. Lesion depth increases significantly with increasing CF and PFA burst pulses. A new exponential/logarithmic formula combined with CF and the number of PFA burst pulses correlates lesion depth with high accuracy.
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Ablación por Catéter , Animales , Ablación por Catéter/instrumentación , Ablación por Catéter/métodos , Porcinos , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Catéteres Cardíacos , Diseño de Equipo , Miocardio/patología , Modelos Animales , Impedancia Eléctrica , Necrosis , Sus scrofa , Temperatura , Factores de Tiempo , Frecuencia CardíacaAsunto(s)
Fibrilación Atrial/cirugía , Cateterismo Cardíaco/normas , Ablación por Catéter/normas , Criocirugía/normas , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Cateterismo Cardíaco/efectos adversos , Ablación por Catéter/efectos adversos , Consenso , Criocirugía/efectos adversos , Humanos , Factores de Riesgo , Resultado del TratamientoAsunto(s)
Fibrilación Atrial/cirugía , Cateterismo Cardíaco/normas , Ablación por Catéter/normas , Criocirugía/normas , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Cateterismo Cardíaco/efectos adversos , Ablación por Catéter/efectos adversos , Consenso , Criocirugía/efectos adversos , Humanos , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: In patients with atrial fibrillation (AF) and stable ischemic heart disease, recent guidelines recommend oral anticoagulant (OAC) monotherapy in preference to OAC + single antiplatelet agent (SAPT) dual therapy. However, these data are based on the results of only two randomized controlled trials (RCTs) and a relatively small group of patients. Thus, the safety and efficacy of this approach may be underpowered to detect a significant difference. We hypothesized that OAC monotherapy will have a reduced risk of bleeding, but similar all-cause mortality and ischemic outcomes as compared to dual therapy (OAC + SAPT). METHODS: A systematic search of PubMed/MEDLINE, EMBASE, and Scopus was conducted. Safety outcomes included total bleeding, major bleeding, and others. Efficacy outcomes included all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, and major adverse cardiovascular events (MACE). RCTs and observational studies were pooled separately (study design stratified meta-analysis). Subgroup analyses were performed for vitamin K antagonists and direct oral anticoagulants (DOACs). Pooled risk ratios (RR) with corresponding 95% confidence intervals (CI) were calculated using the Mantel-Haenszel method. RESULTS: Meta-analysis of 2 RCTs comprising a total of 2905 patients showed that dual therapy (OAC + SAPT) vs. OAC monotherapy was associated with a statistically significant increase in major bleeding (RR 1.51; 95% CI [1.10, 2.06]). There was no significant reduction in MACE (RR 1.10; [0.71, 1.72]), stroke (RR 1.29; [0.85, 1.95]), myocardial infarction (RR 0.57; [0.28, 1.16]), cardiovascular mortality (RR 1.22; [0.63, 2.35]), or all-cause mortality (RR 1.18 [0.52, 2.68]). Meta-analysis of 20 observational studies comprising 47,451 patients showed that dual therapy (OAC + SAPT) vs. OAC monotherapy was associated with a statistically significant higher total bleeding (RR 1.50; [1.20, 1.88]), major bleeding (RR = 1.49; [1.38, 1.61]), gastrointestinal bleeding (RR = 1.62; [1.15, 2.28]), and myocardial infarction (RR = 1.15; [1.05, 1.26]), without significantly lower MACE (RR 1.10; [0.97, 1.24]), stroke (RR 0.93; [0.73, 1.19]), cardiovascular mortality (RR 1.11; [0.95, 1.29]), or all-cause mortality (RR 0.93; [0.78, 1.11]). Subgroup analysis showed similar results for both vitamin K antagonists and DOACs, except a statistically significant higher intracranial bleeding with vitamin K antagonist + SAPT vs. vitamin K antagonist monotherapy (RR 1.89; [1.36-2.63]). CONCLUSIONS: In patients with AF and stable ischemic heart disease, OAC + SAPT as compared to OAC monotherapy is associated with a significant increase in bleeding events without a significant reduction in thrombotic events, cardiovascular mortality, and all-cause mortality.
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Fibrilación Atrial , Infarto del Miocardio , Isquemia Miocárdica , Accidente Cerebrovascular , Humanos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Fibrilación Atrial/diagnóstico , Resultado del Tratamiento , Isquemia Miocárdica/complicaciones , Anticoagulantes/uso terapéutico , Hemorragia/inducido químicamente , Infarto del Miocardio/complicaciones , Fibrinolíticos/efectos adversos , Vitamina K , Administración OralRESUMEN
BACKGROUND: Multiple randomized controlled trials (RCTs) have compared the success of antero-lateral vs. antero-posterior electrode position for cardioversion of atrial fibrillation (AF). However, due to small sample size and conflicting results of these RCTs, the optimal electrode positioning for successful cardioversion remains uncertain. METHODS: A systematic search of MEDLINE and EMBASE was conducted. Outcomes of interest included overall success of cardioversion with restoration of sinus rhythm, 1st shock success, 2nd shock success, mean shock energy required for successful cardioversion, mean number of shocks required for successful cardioversion, success of cardioversion at high energy (> 150 J) and success of cardioversion at low energy (< 150 J). Mantel-Haenszel risk ratios (RR) with 95% confidence intervals were calculated using random-effects model. RESULTS: A total of 14 RCTs comprising 2445 patients were included. There was no statistically significant difference between two cardioversion approaches in the overall success of cardioversion (RR 1.02; 95% CI [0.97-1.06]; p = 0.43), first shock success (RR 1.14; 95% CI [0.99-1.32]), second shock success (RR 1.08; 95% CI [0.94-1.23]), mean shock energy required (mean difference 6.49; 95% CI [-17.33-30.31], success at high energy > 150 J (RR 1.02; 95% CI [0.92-1.14] and success at low energy < 150 J (RR 1.09; 95% CI [0.97-1.22]). CONCLUSIONS: This meta-analysis of RCTs shows no significant difference in the success of cardioversion between antero-lateral vs. antero-posterior electrode position for cardioversion of AF. Large well-conducted and adequately powered randomized clinical trials are needed to definitively address this question.
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Fibrilación Atrial , Humanos , Cardioversión Eléctrica/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Electrodos , Oportunidad Relativa , Resultado del TratamientoRESUMEN
AIMS: Patients undergo ablation for focal atrial fibrillation (AF) as a result of failure of anti-arrhythmic drugs. Our basic studies have implicated cholinergic and adrenergic neurotransmitter release as the underlying mechanism for focal AF. Therefore, we tested the efficacy of a combination of sodium channel-blocking agents with additional vagolytic properties and a ß-blocker to terminate and prevent focal AF. METHODS AND RESULTS: In 18 Na-pentobarbital-anaesthetized dogs, after a right or left thoracotomy, acetylcholine (Ach, 0.5 cc, 100 mM) was injected into a fat pad containing ganglionated plexi (GP) or applied on an atrial appendage (AA) to induce focal firing at the pulmonary veins (PVs) or AA, respectively. Disopyramide (2-4 mg/kg, n= 6) or quinidine (3-6 mg/kg, n= 12) combined with esmolol or propranolol (1 mg/kg, n= 13 and 5, respectively) were slowly injected to terminate (Group I, n= 12) or prevent (Group II, n= 6) Ach-induced sustained focal AF. In another four dogs, only the sodium channel-blocking agents with additional vagolytic properties or only the ß-blocker was injected prior to or after the initiation of focal AF. At baseline, the mean duration of AF induced by Ach was 26 ± 4 min. Group I: After drugs, Ach-induced AF duration was 3 ± 1 min (P< 0.001). Group II: Prior to drugs, Ach-induced AF lasted for 19 ± 3 min. With the drug combination the duration of Ach-induced AF, decreased to 6 ± 1/min, P< 0.001. Either quinidine or propranolol alone did not change the duration of Ach-induced AF, mean 25 ± 10 min compared with Ach alone, 28 ± 16 min, P= 0.2. CONCLUSIONS: Type IA (cholinergic antagonist) plus Type II (ß-adrenergic antagonist) provides significant prevention and suppression of focal AF arising at PV and non-PV sites.
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Antiarrítmicos/uso terapéutico , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/prevención & control , Acetilcolina/administración & dosificación , Antagonistas Adrenérgicos beta/uso terapéutico , Animales , Apéndice Atrial/efectos de los fármacos , Disopiramida/uso terapéutico , Perros , Quimioterapia Combinada , Venas Pulmonares/efectos de los fármacos , Quinidina/uso terapéutico , Bloqueadores de los Canales de Sodio/uso terapéuticoRESUMEN
BACKGROUND: The open-irrigated catheter is used most frequently for atrial and ventricular radiofrequency ablation (RFA), and is often considered as the standard by which new ablation systems are compared. But few data have been published concerning its safety. This report provides a comprehensive safety analysis of the use of an open-irrigated catheter for RFA of atrial flutter, ventricular tachycardia, and atrial fibrillation in 1,275 patients in six rigorously monitored, prospective, multicenter studies. METHODS: This analysis is of data from six studies conducted as part of both Food and Drug Administration-mandated investigational device exemption studies and postapproval studies. The six studies span a period of more than 10 years. All serious RFA complications and vascular access complications that occurred within seven days postprocedure were included. RESULTS: The number of patients who experienced any acute serious RFA complication in these studies combined was 4.9% (63/1,275). The two earliest studies were conducted when the open-irrigated catheter was first introduced, and accounted for 55.6% of the complications. In the first atrial flutter ablation study, RFA complications decreased by 60% (15.4%-6.2%) after a proctoring program was initiated during the study. For all studies, vascular access complications ranged between from 0.5%-4.7%, and no stroke or transient ischemic attack was reported within 7 days postprocedure. No significant pulmonary vein stenosis was reported from the atrial fibrillation studies. CONCLUSION: A proctoring program, careful fluid management, and absence of char and coagulum contributed to the safe use of the open-irrigated RFA catheter.
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Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/cirugía , Ablación por Catéter/métodos , Ablación por Catéter/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Irrigación Terapéutica/estadística & datos numéricos , Anciano , Comorbilidad , Medicina Basada en la Evidencia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Medición de Riesgo , Resultado del TratamientoRESUMEN
INTRODUCTION: There has been a long-standing controversy regarding the mechanism(s) to explain the irregular ventricular response during atrial tachycardia (AT) or atrial fibrillation (AF) and where the site of block, if any, resides in the atrioventricular (AV) junction. METHODS: We studied 12 Langendorff preparations perfused with modified Tyrode's solution containing 5-10 mM diacetyl monoxime which suppressed contractility but allowed the use of intracellular action potential (AP) recordings. Octapolar catheters (2-mm rings, 2-mm spacing) were secured along the tricuspid annulus from the apex to the base of the triangle of Koch and along the anterior limbus of the fossa ovalis to record extracellular, slow pathway, fast pathway, His bundle (Hb) and AV nodal (AVN) extracellular potentials as well as intracellular action potentials. RESULTS: AT or AF induced by rapid atrial pacing showed a variety of irregular responses due to: (1) Wenckebach conduction showing decrement within the AVN and progressive diminution of extracellular AVN potentials (n = 5); (2) repetitive concealed conduction proximal to the AVN (n = 3); (3) ectopic beats arising within the AVN (n = 2); (4) ectopic beats arising at the Hb (n = 2). CONCLUSIONS: In this experimental preparation, extracellular and intracellular recordings provided presumptive evidence for the mechanisms causing the irregularities of the ventricular response such as repetitive concealed conduction, enhanced automaticity or electrotonically triggered activity. Also more definitive determinations of the site of block in the AV junction were also obtained.
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Potenciales de Acción , Fibrilación Atrial/fisiopatología , Nodo Atrioventricular/fisiopatología , Electrofisiología , Taquicardia Supraventricular/fisiopatología , Animales , Arritmias Cardíacas/fisiopatología , Perros , Sistema de Conducción Cardíaco/fisiopatología , Técnicas In VitroRESUMEN
BACKGROUND: Totally thoracoscopic epicardial pulmonary vein ablation is an emerging treatment of atrial fibrillation (AF). A hybrid surgical-electrophysiological procedure with periprocedural confirmation of conduction block might reduce recurrences of AF or atrial tachycardia and improve surgical success. METHODS AND RESULTS: We report our joint surgical-electrophysiological approach for confirmation of conduction block across pulmonary vein ablation lines and those compartmentalizing the left atrium during totally thoracoscopic surgery. A diagnostic electrophysiology (EP) catheter positioned under the left atrium is used as reference and a custom-made multi-electrode for recording. Determination of conduction block across the pulmonary vein (PV) ablation lines requires measurement of activation time differences of milliseconds. Second, a stable reference electrogram to which to relate local activation time is required. Third, the recording electrode terminals and the inter-electrode distance should be small to prevent recording of far field activity and to allow recording of very small electrograms. We confirm entry and exit block and determine conduction block across linear ablation lines with differential pacing. CONCLUSION: A joint surgical-electrophysiological protocol for confirmation of conduction block across PV isolation lines and left atrial ablation lines is feasible and might prevent recurrences and further improve the success of minimally invasive surgery for AF.
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Fibrilación Atrial/cirugía , Bloqueo Cardíaco , Pericardio/inervación , Toracoscopía/instrumentación , Ablación por Catéter/instrumentación , Ablación por Catéter/métodos , Electrodos , Electrofisiología/instrumentación , Electrofisiología/métodos , Atrios Cardíacos/inervación , Humanos , Venas Pulmonares/inervación , Toracoscopía/métodosRESUMEN
INTRODUCTION: We sought to extend the use of low-level vagal stimulation by applying it only to the right vagus nerve (LL-RVS) to suppress atrial fibrillation (AF). METHODS: In 10 pentobarbital anesthetized dogs, LL-RVS (20 Hz, 0.1 ms pulse width) was delivered to the right vagal trunk via wire electrodes at voltages 50% below that which slowed the sinus rate (SR) or atrio-ventricular conduction. Electrode catheters were sutured at multiple atrial and pulmonary vein (PV) sites to record electrograms. LL-RVS continued for 3 hours. At the end of each hour, 40 ms of high-frequency stimulation (HFS; 100 Hz, 0.01 ms pulse width) was delivered 2 ms after atrial pacing (during the refractory period) to determine the AF threshold (AF-TH) at each site. Other electrodes were attached to the superior left ganglionated plexi (SLGP) and right stellate ganglion (RSG) so that HFS (20 Hz, 0.1 ms pulse width) to these sites induced SR slowing and acceleration, respectively. Microelectrodes inserted into the anterior right ganglionated plexi (ARGP) recorded neural activity. RESULTS: (1) Three hours of LL-RVS induced a progressive increase in AF-TH at all sites (all P < 0.05). (2) The SR slowing and acceleration response induced by SLGP and RSG stimulation, respectively, was blunted by LL-RVS. (3) The frequency and amplitude of the neural activity recorded from the ARGP were markedly inhibited by LL-RVS. CONCLUSIONS: LL-RVS suppressed AF inducibility and the chronotropic responses to parasympathetic and sympathetic stimulation. Inhibition of neural activity in the GP may be a mechanism underlying these results.
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Fibras Adrenérgicas , Fibrilación Atrial/prevención & control , Fibras Colinérgicas , Ganglios Autónomos/fisiopatología , Estimulación del Nervio Vago , Animales , Fibrilación Atrial/etiología , Fibrilación Atrial/fisiopatología , Estimulación Cardíaca Artificial , Modelos Animales de Enfermedad , Perros , Estimulación Eléctrica , Técnicas Electrofisiológicas Cardíacas , Atrios Cardíacos/inervación , Venas Pulmonares/inervación , Factores de TiempoRESUMEN
INTRODUCTION: We hypothesized that low-level vagosympathetic stimulation (LL-VNS) can suppress atrial fibrillation (AF) by inhibiting the activity of the intrinsic cardiac autonomic nervous system (ICANS). METHODS AND RESULTS: Wire electrodes inserted into both vagosympathetic trunks allowed LL-VNS at 10% or 50% below the voltage required to slow the sinus rate or atrioventricular conduction. Multielectrode catheters were attached to atria, atrial appendages and all pulmonary veins. Electrical stimulation at the anterior right and superior left ganglionated plexi (ARGP, SLGP) was used to simulate a hyperactive state of the ICANS. Effective refractory period (ERP) and window of vulnerability (WOV) for AF were determined at baseline and during ARGP+SLGP stimulation in the presence or absence of LL-VNS. Neural activity was recorded from the ARGP or SLGP. ARGP+SLGP stimulation induced shortening of ERP, increase of ERP dispersion and increase of AF inducibility (WOV), all of which were suppressed by LL-VNS (10% or 50% below threshold) at all tested sites. Sham LL-VNS failed to induce these changes. The effects of LL-VNS were mediated by inhibition of the ICANS, as evidenced by (1) LL-VNS suppression of the ability of the ARGP stimulation to slow the sinus rate, (2) the frequency and amplitude of the neural activity recorded from the ARGP or SLGP was markedly suppressed by LL-VNS, and (3) the spatial gradient of the ERP and WOV from the PV-atrial junction toward the atrial appendage was eliminated by LL-VNS. CONCLUSIONS: LL-VNS suppressed AF inducibility by inhibiting the neural activity of major GP within the ICANS.
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Fibrilación Atrial/prevención & control , Fibrilación Atrial/fisiopatología , Ganglios Simpáticos/fisiología , Neuronas/fisiología , Estimulación del Nervio Vago/métodos , Nervio Vago/fisiología , Potenciales de Acción/fisiología , Animales , Perros , Estimulación Eléctrica/métodos , Sistema de Conducción Cardíaco/fisiologíaRESUMEN
BACKGROUND: Pulmonary vein (PV) antrum isolation with ganglionated plexi (GP) ablation is a novel atrial fibrillation (AF) ablation technique. The aim of this study was to evaluate acute changes in left atrial and PV flow velocities following PV antrum isolation with GP ablation using transesophageal echocardiography (TEE). METHODS: TEE was performed before and after PV antrum isolation with GP ablation in 88 consecutive patients. All four PVs, when possible, were analyzed with regard to peak systolic and diastolic pulsed-wave Doppler flow velocities. Left atrial appendage emptying velocities were also obtained. PV stenosis was defined as a peak PV Doppler flow velocity of ≥110 cm/sec with spectral broadening (turbulence). RESULTS: All but four right inferior and four left inferior PVs were visualized. Compared to preablation values, both PV systolic and diastolic velocities increased after ablation (P < 0.05 for each of the four PVs). However, the systolic to diastolic ratio decreased significantly after ablation in all PVs (1.3 ± 0.6 to 0.9 ± 0.4, P < 0.0001, 1.2 ± 0.7 to 0.9 ± 0.4, P < 0.0001, 1.2 ± 0.6 to 1.0 ± 0.6, P = 0.035 and 1.1 ± 0.5 to 0.9 ± 0.5, P = 0.0001, for left superior, left inferior, right superior and right inferior PV, respectively). Left atrial appendage emptying velocities showed a trend towards higher values following ablation (62.7 ± 26.1 cm/sec vs. 67.5 ± 23.2 cm/sec, P = 0.07). Asymptomatic PV stenosis occurred in seven patients (seven PVs). CONCLUSIONS: PV antrum isolation with GP ablation acutely increased PV flow velocities and altered the pattern of PV Doppler flow signal, likely correlating with increased left atrial pressures, but did not appear to adversely impact on left atrial appendage physiology.
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Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/cirugía , Ablación por Catéter/métodos , Ecocardiografía Transesofágica/métodos , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/cirugía , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/cirugía , Adulto , Anciano , Fibrilación Atrial/fisiopatología , Velocidad del Flujo Sanguíneo , Comorbilidad , Femenino , Atrios Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Venas Pulmonares/fisiopatología , ReoperaciónRESUMEN
In this review, we emphasize the unique value of recording the activation sequence of the His bundle or right bundle branch (RB) for diagnoses of various supraventricular and fascicular tachycardias. A close analysis of the His to RB (H-RB) activation sequence can help differentiate various forms of supraventricular tachycardias, namely atrioventricular nodal reentry tachycardia from concealed nodofascicular tachycardia, a common clinical dilemma. Furthermore, bundle branch reentry tachycardia and fascicular tachycardias often are included in the differential diagnosis of supraventricular tachycardia with aberrancy, and the use of this technique can help the operator make the distinction between supraventricular tachycardias and these other forms of ventricular tachycardias using the His-Purkinje system. We show that this technique is enhanced by the use of multipolar catheters placed to span the proximal His to RB position to record the activation sequence between proximal His potential to the distal RB potential. This allows the operator to fully analyze the activation sequence in sinus rhythm as compared to that during tachycardia and may help target ablation of these arrhythmias. We argue that 3 patterns of H-RB activation are commonly identified-the anterograde H-RB pattern, the retrograde H-RB (right bundle to His bundle) pattern, and the chevron H-RB pattern (simultaneous proximal His and proximal RB activation)-and specific arrhythmias tend to be associated with specific H-RB activation sequences. We show that being able to record and categorize this H-RB relationship can be instrumental to the operator, along with standard pacing maneuvers, to make an arrhythmia diagnosis in complex tachycardia circuits. We highlight the importance of H-RB activation patterns in these complex tachycardias by means of case illustrations from our groups as well as from prior reports.
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Fascículo Atrioventricular/fisiopatología , Estimulación Cardíaca Artificial/métodos , Electrocardiografía/métodos , Taquicardia Paroxística/diagnóstico , Taquicardia Ventricular/diagnóstico , Humanos , Taquicardia Paroxística/fisiopatología , Taquicardia Paroxística/terapia , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/terapiaRESUMEN
[Figure: see text].
Asunto(s)
Fibrilación Atrial/cirugía , Temperatura Corporal/fisiología , Atrios Cardíacos/fisiopatología , Miocardio/patología , Ablación por Radiofrecuencia/métodos , Animales , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Modelos Animales de Enfermedad , Perros , HumanosRESUMEN
Although several randomized clinical trials have demonstrated the safety and efficacy of catheter ablation of atrial fibrillation (AF) in experienced centers, the outcomes of this procedure in routine clinical practice and in patients with persistent and long-standing persistent AF remain uncertain. Brisk adoption of this therapy by physicians with diverse training and experience highlights potential concerns regarding the safety and effectiveness of this procedure. Some of these concerns could be addressed by a national registry of AF ablation procedures such as the Safety of Atrial Fibrillation Ablation Registry Initiative that was initially proposed at a Cardiac Safety Research Consortium Think Tank meeting in April 2009. In January 2010, the Cardiac Safety Research Consortium, in collaboration with the Duke Clinical Research Institute, the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, held a follow-up meeting of experts in the field to review the construct and progress to date. Other participants included the National Heart, Lung, and Blood Institute; the Centers for Medicare and Medicaid Services; the Agency for Healthcare Research and Quality; the AdvaMed AF working group; and additional industry representatives. This article summarizes the discussions that occurred at the meeting of the state of the Safety of Atrial Fibrillation Ablation Registry Initiative, the identification of a clear pathway for its implementation, and the exploration of solutions to potential issues in the execution of this registry.
Asunto(s)
Fibrilación Atrial/cirugía , Ablación por Catéter/normas , Vías Clínicas/organización & administración , Sistema de Registros , Administración de la Seguridad/organización & administración , Humanos , Relaciones Interprofesionales , Estados UnidosRESUMEN
Atrial fibrillation (AF) is a major public health problem in the United States that is associated with increased mortality and morbidity. Of the therapeutic modalities available to treat AF, the use of percutaneous catheter ablation of AF is expanding rapidly. Randomized clinical trials examining the efficacy and safety of AF ablation are currently underway; however, such trials can only partially determine the safety and durability of the effect of the procedure in routine clinical practice, in more complex patients, and over a broader range of techniques and operator experience. These limitations of randomized trials of AF ablation, particularly with regard to safety issues, could be addressed using a synergistically structured national registry, which is the intention of the SAFARI. To facilitate discussions about objectives, challenges, and steps for such a registry, the Cardiac Safety Research Consortium and the Duke Clinical Research Institute, Durham, NC, in collaboration with the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, organized a Think Tank meeting of experts in the field. Other participants included the National Heart, Lung and Blood Institute, the Centers for Medicare and Medicaid Services, the Agency for Healthcare Research and Quality, the Society of Thoracic Surgeons, the AdvaMed AF working group, and additional industry representatives. The meeting took place on April 27 to 28, 2009, at the US Food and Drug Administration headquarters in Silver Spring, MD. This article summarizes the issues and directions presented and discussed at the meeting.
Asunto(s)
Fibrilación Atrial/cirugía , Ablación por Catéter , Vías Clínicas , Sistema de Registros , Fibrilación Atrial/mortalidad , Femenino , Humanos , Relaciones Interprofesionales , Masculino , Administración de la Seguridad , Estados UnidosRESUMEN
INTRODUCTION: the mechanism underlying spontaneous rapid superior vena cava (SVC) firing that initiates atrial fibrillation (AF) remains poorly understood. We investigated the role of the SVC-aorta-ganglionated plexus (SVC-Ao-GP) in AF initiated by rapid firing from the SVC. METHODS AND RESULTS: in 42 dogs, a circular catheter was positioned above the SVC-atrial junction. Multielectrode catheters were sutured on atria, atrial appendages and pulmonary veins. The effective refractory period (ERP) and window of vulnerability (WOV) for AF were measured at all sites in the baseline state, during cervical vagosympathetic trunk stimulation and during SVC-Ao-GP stimulation, before and after SVC-Ao-GP ablation. AF inducibility was also assessed by delivering high-frequency stimulation (HFS) within myocardial refractory period to the SVC before and after SVC-Ao-GP ablation. HFS applied to the SVC-Ao-GP slowed the sinus rate and/or atrioventricular conduction. HFS of the SVC-Ao-GP induced more significant shortening of ERP and a greater increase in WOV at the SVC than other sites. Ablation of the SVC-Ao-GP significantly increased the baseline ERP and decreased the baseline WOV only at the SVC. AF induced at the SVC by HFS during refractoriness was eliminated by ablation of the SVC-Ao-GP but was not altered by ablation of the 4 major atrial GP. Direct injection of acetylcholine into the SVC-Ao-GP initiated rapid firing from the SVC in every case. CONCLUSIONS: the SVC-Ao-GP preferentially modulates the electrophysiological function of the SVC sleeves and may contribute to rapid firing from the SVC.