RESUMEN

BACKGROUND: Right ventricular apical (RVA) pacing can induce left ventricular (LV) dyssynchrony and dysfunction. In this article, we describe the prevalence, clinical characteristics, and outcome in a subset of patients with unrecognized LV apical akinetic aneurysmatic area associated with permanent RVA pacing as potential causes of heart failure (HF) and/or ventricular tachyarrhythmias (VT). METHODS AND RESULTS: We retrospectively studied 220 patients with permanent RVA pacing and no pre-existing structural heart disease in our follow-up clinic for high-degree atrioventricular block. Patients who presented with new-onset HF, chest pain, or VT following RVA pacing were evaluated by echocardiogram and cardiac catheterization. RVA pacing-induced LV apical akinetic aneurysmatic area was diagnosed in the absence of significant coronary artery disease by left ventriculogram. After a mean 8.8 ± 6.3 years, eight patients (3.6%) had LV apical akinetic aneurysmatic area. Of those with LV apical akinetic aneurysmatic area, four patients presented with or died of VT. There was no evidence of LV apical akinetic aneurysmatic area on echocardiogram or left ventriculogram in the remaining 212 patients. The four patients with LV apical akinetic aneurysmatic area and HF underwent cardiac resynchronization therapy: in all cases LV ejection fraction improved (from 33 ± 6 to 47 ± 10%, P = 0.03), and LV apical akinetic aneurysmatic area resolved in two. CONCLUSION: Permanent RVA pacing for high-degree atrioventricular block is associated with LV apical akinetic aneurysmatic area. This condition was associated with a high incidence of VT and cardiovascular complication, but was possibly reversible with cardiac resynchronization therapy.

Asunto(s)

Bloqueo Atrioventricular/terapia , Estimulación Cardíaca Artificial/efectos adversos , Estimulación Cardíaca Artificial/métodos , Disfunción Ventricular Izquierda/epidemiología , Disfunción Ventricular Izquierda/etiología , Función Ventricular Derecha/fisiología , Anciano , Terapia de Resincronización Cardíaca , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/terapia , Humanos , Incidencia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Taquicardia Ventricular/epidemiología , Taquicardia Ventricular/etiología , Taquicardia Ventricular/terapia , Resultado del Tratamiento , Disfunción Ventricular Izquierda/terapia

Asunto(s)

Síndrome Coronario Agudo/terapia , Adenosina Monofosfato/análogos & derivados , Angioplastia Coronaria con Balón , Inhibidores de Agregación Plaquetaria/uso terapéutico , Síndrome Coronario Agudo/tratamiento farmacológico , Síndrome Coronario Agudo/mortalidad , Adenosina Monofosfato/efectos adversos , Adenosina Monofosfato/uso terapéutico , Anciano , Terapia Combinada , Trombosis Coronaria/epidemiología , Trombosis Coronaria/prevención & control , Método Doble Ciego , Femenino , Hemorragia/inducido químicamente , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Infarto del Miocardio/prevención & control , Inhibidores de Agregación Plaquetaria/efectos adversos , Retratamiento , Stents , Resultado del Tratamiento

RESUMEN

Cardiac pacemakers have been the standard therapy for patients with bradyarrhythmias for several decades. The pacing lead is an integral part of the system that serves as a conduit for the delivery of energy pulses to stimulate the myocardium. However, it is also an Achilles tendon that directly causes most device complications both acutely during implant and chronically years afterwards. Both durability and optimization of the stimulation site are important areas of improvement for manufacturers and implanters. Elimination of the pacing lead and the utilization of other means for energy transfer is the only way to avoid lead complications and allow a better choice of stimulation site. Leadless pacing with ultrasound-mediated energy has been demonstrated in animals and humans in acute studies. This has aroused intense interest in the field of cardiac pacing. With concerted effort from the profession and the industry, leadless pacing may indeed become a realizable concept.

Asunto(s)

Marcapaso Artificial , Animales , Tecnología Biomédica/instrumentación , Bradicardia/terapia , Diseño de Equipo/tendencias , Insuficiencia Cardíaca/terapia , Humanos , Marcapaso Artificial/efectos adversos , Marcapaso Artificial/tendencias , Transductores

RESUMEN

INTRODUCTION: Atrial electromechanical dysfunction might contribute to the development of atrial fibrillation (AF) in patients with sinus node disease (SND). The aim of this study was to investigate the prevalence and impact of atrial mechanical dyssynchrony on atrial function in SND patients with or without paroxysmal AF. METHODS: We performed echocardiographic examination with tissue Doppler imaging in 30 SND patients with (n = 11) or without (n = 19) paroxysmal AF who received dual-chamber pacemakers. Tissue Doppler indexes included atrial contraction velocities (Va) and timing events (Ta) were measured at midleft atrial (LA) and right atrial (RA) wall. Intraatrial synchronicity was defined by the standard deviation and maximum time delay of Ta among 6 segments of LA (septal/lateral/inferior/anterior/posterior/anterospetal). Interatrial synchronicity was defined by time delay between Ta from RA and LA free wall. RESULTS: There were no differences in age, P-wave duration, left ventricular ejection fraction, LA volume, and ejection fraction between with or without AF. Patients with paroxysmal AF had lower mitral inflow A velocity (70 +/- 19 vs 91 +/- 17 cm/s, P = 0.005), LA active empting fraction (24 +/- 14 vs 36 +/- 13%, P = 0.027), mean Va of LA (2.6 +/- 0.9 vs 3.4 +/- 0.9 cm/s, P = 0.028), and greater interatrial synchronicity (33 +/- 25 vs 12 +/- 19 ms, P = 0.022) than those without AF. Furthermore, a lower mitral inflow A velocity (Odd ratio [OR]= 1.12, 95% Confidence interval [CI] 1.01-1.24, P = 0.025) and prolonged interatrial dyssynchrony (OR = 1.08, 95% CI 1.01-1.16, P = 0.020) were independent predictors for the presence of AF in SND patients. CONCLUSION: SND patients with paroxysmal AF had reduced regional and global active LA mechanical contraction and increased interatrial dyssychrony as compared with those without AF. These findings suggest that abnormal atrial electromechanical properties are associated with AF in SND patients.

Asunto(s)

Arritmia Sinusal/diagnóstico , Arritmia Sinusal/epidemiología , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/epidemiología , Anciano , Causalidad , Femenino , Hong Kong/epidemiología , Humanos , Incidencia , Masculino , Medición de Riesgo , Factores de Riesgo

RESUMEN

BACKGROUND: Left ventricular stimulation for cardiac resynchronization therapy is largely limited by access and anatomy of coronary veins. OBJECTIVE: This study sought to apply ultrasound-mediated leadless pacing technology in heart failure patients and to evaluate the effects of respiration and body posture on the acoustic window. METHODS: Patients with advanced heart failure and ejection fraction

Asunto(s)

Estimulación Cardíaca Artificial/métodos , Insuficiencia Cardíaca/terapia , Marcapaso Artificial , Ultrasonografía Intervencional/instrumentación , Adulto , Anciano , Electrodos Implantados , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Volumen Sistólico , Factores de Tiempo , Resultado del Tratamiento

RESUMEN

INTRODUCTION: Emerging data have suggested that right ventricular (RV) apical pacing results in progressive left ventricular (LV) dysfunction and contributes to the development of heart failure (HF). This study aimed to investigate the prevalence and clinical predictors for the development of new-onset HF after long-term RV apical pacing in patients with acquired atrioventricular (AV) block who require permanent pacing. METHODS: We studied the clinical outcomes after long-term RV apical pacing for acquired AV block in 304 patients without a prior history of HF. All patients had >90% ventricular pacing as determined by device diagnostic data. RESULTS: After a median follow-up of 7.8 years, 79 patients (26.0%) developed new-onset HF after RV apical pacing. Univariate Cox-regression analysis revealed that older age at the time of pacemaker implantation (P < 0.001), the presence of coronary artery disease (CAD) (P < 0.001) or atrial fibrillation (P = 0.03), VVI pacemaker (P < 0.001), wider paced QRS duration (P < 0.001), and new-onset myocardial infarction (P < 0.001) were predictors for HF. Multivariate analysis revealed that older age at implantation (Hazard ratio [HR] 1.06, 95% confidential interval [CI] 1.04-1.09, P < 0.001), CAD (HR 1.98, 95% CI 1.12-3.50, P < 0.05), and a wider paced QRS duration (HR 1.27 for each 10 ms increment, 95% CI 1.11-1.45, P = 0.001) were independent predictors of HF. Furthermore, cardiovascular mortality was significantly increased in those with HF (36.7% vs. 2.7%, P < 0.001). CONCLUSIONS: After a median follow-up of 7.8 years, permanent RV apical pacing was associated with HF in 26% of patients. Elderly age at the time of implant, a wider paced QRS duration and the presence of CAD independently predicted new-onset HF. More importantly, HF after RV apical pacing was associated with a higher cardiovascular mortality.

Asunto(s)

Bloqueo Atrioventricular/fisiopatología , Estimulación Cardíaca Artificial/efectos adversos , Insuficiencia Cardíaca/fisiopatología , Función Ventricular Izquierda/fisiología , Función Ventricular Derecha/fisiología , Anciano , Anciano de 80 o más Años , Bloqueo Atrioventricular/terapia , Estimulación Cardíaca Artificial/métodos , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/terapia , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo

RESUMEN

OBJECTIVES: The purpose of this study was to evaluate the feasibility and safety of a novel technology that uses energy transfer from an ultrasound transmitter to achieve cardiac stimulation without the use of a pacing lead in humans. BACKGROUND: To overcome the limitations of pacemaker leads, a new technology enabling stimulation without the use of a lead is desirable. METHODS: A steerable bipolar electrophysiology catheter incorporating a receiver electrode into the tip and circuitry to convert ultrasound energy to electrical energy was inserted transvenously into the heart. An ultrasound transmitting transducer was placed on the chest wall with ultrasound gel. Ultrasound energy was amplitude-adjusted and transmitted at 313 to 385 kHz. The output waveform of the receiver electrode was monitored while the transmitter was moved on the chest wall to target the receiver. The ultrasound transmission amplitude was limited to a mechanical index of 1.9, the maximum allowed for ultrasound imaging systems. Ultrasound-mediated pacing with minimum voltage but consistent capture was obtained for 12 s. RESULTS: Twenty-four patients (48 +/- 12 years) were tested during or after completion of clinical electrophysiology procedures. A total of 80 pacing sites were tested (mean 3.3 sites/patient): 12 right atrial, 35 right ventricular, and 33 left ventricular (31 endocardial) sites. The transmit-to-receive distance was 11.3 +/- 3.2 cm (range 5.3 to 22.5 cm). Ultrasound-mediated pacing was achieved at all 80 test sites, with consistent capture at 77 sites. The mechanical index during pacing was 0.5 +/- 0.3 (range 0.1 to 1.5). The mean ultrasound-mediated capture threshold was 1.01 +/- 0.64 V. There was no adverse event related to ultrasound pacing. No patient experienced discomfort during pacing. CONCLUSIONS: The feasibility and safety of pacing usng ultrasound energy has been shown acutely.

Asunto(s)

Arritmias Cardíacas/terapia , Estimulación Cardíaca Artificial/métodos , Marcapaso Artificial , Ultrasonografía Intervencional/instrumentación , Adulto , Ablación por Catéter , Electrodos Implantados , Técnicas Electrofisiológicas Cardíacas , Diseño de Equipo , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugía , Transductores , Ultrasonido

RESUMEN

BACKGROUND: Cardiac resynchronization therapy (CRT) applied by pacing the left and right ventricles (BiV) has been shown to provide synchronous left ventricular (LV) contraction in heart failure patients. CRT may also be accomplished through synchronization of a properly timed LV pacing impulse with intrinsically conducted activation wave fronts. Elimination of right ventricular (RV) pacing may provide a more physiological RV contraction pattern and reduce device current drain. We evaluated the effects of LV and BiV pacing over a range of atrioventricular intervals on the performance of both ventricles. METHODS: Acute LV and RV hemodynamic data from 17 patients with heart failure (EF = 30 +/- 1%) and a wide QRS (138 +/- 25 msec) or mechanical dyssynchrony were acquired during intrinsic rhythm, BiV, and LV pacing. RESULTS: The highest LV dP/dt(max) was achieved during LV pre- (LV paced prior to an RV sense) and BiV pacing, followed by that obtained during LV post-pacing (LV paced after an RV sense) and the lowest LV dP/dt(max) was recorded during intrinsic rhythm. Compared with BiV pacing, LV pre-pacing significantly improved RV dP/dt(max) (378 +/- 136 mmHg/second vs 397 +/- 136 mmHg/second, P < 0.05) and preserved RV cycle efficiency (61.6 +/- 14.6% vs 68.6 +/- 11.4%, P < 0.05) and stroke volume (6.6 +/- 4.4 mL vs 9.0 +/- 6.3 mL, P < 0.05). Based on LV dP/dt(max), the optimal atrioventricular interval could be estimated by subtracting 30 msec from the intrinsic atrial to sensed RV interval. CONCLUSIONS: Synchronized LV pacing produces acute LV and systemic hemodynamic benefits similar to BiV pacing. LV pacing at an appropriate atrioventricular interval prior to the RV sensed impulse provides superior RV hemodynamics compared with BiV pacing.

Asunto(s)

Estimulación Cardíaca Artificial/métodos , Insuficiencia Cardíaca/prevención & control , Disfunción Ventricular Izquierda/prevención & control , Disfunción Ventricular Derecha/prevención & control , Femenino , Insuficiencia Cardíaca/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Derecha/etiología

Asunto(s)

Aleteo Atrial/cirugía , Ablación por Catéter/métodos , Microondas/uso terapéutico , Adulto , Electrocardiografía , Humanos , Masculino

RESUMEN

OBJECTIVES: The purpose of this research was to investigate the effect of using rate-adaptive pacing and atrioventricular interval (AVI) adaptation on exercise performance during cardiac resynchronization therapy (CRT). BACKGROUND: The potential incremental benefits of using rate-adaptive pacing and AVI adaptation with CRT during exercise have not been studied. METHODS: We studied 20 patients with heart failure, chronotropic incompetence (<85% age-predicted heart rate [AP-HR] and <80% HR reserve), and implanted with CRT. All patients underwent a cardiopulmonary exercise treadmill test using DDD mode with fixed AVI (DDD-OFF), DDD mode with adaptive AVI on (DDD-ON), and DDDR mode with adaptive AVI on (DDDR-ON) to measure metabolic equivalents (METs) and peak oxygen consumption (VO2max). RESULTS: During DDD-OFF mode, not all patients reached 85% AP-HR during exercise, and 55% of patients had <70% AP-HR. Compared to patients with >70% AP-HR, patients with <70% AP-HR had significantly lower baseline HR (66 +/- 3 beats/min vs. 80 +/- 5 beats/min, p = 0.015) and percentage HR reserve (27 +/- 5% vs. 48 +/- 6%, p = 0.006). In patients with <70% AP-HR, DDDR-ON mode increased peak exercise HR, exercise time, METs, and VO2max compared with DDD-OFF and DDD-ON modes (p < 0.05), without a significant difference between DDD-OFF and DDD-ON modes. In contrast, there were no significant differences in peak exercise HR, exercise time, METs, and VO2max among the three pacing modes in patients with >70% AP-HR. The percentage HR changes during exercise positively correlated with exercise time (r = 0.67, p < 0.001), METs (r = 0.56, p < 0.001), and VO2max (r = 0.55, p < 0.001). CONCLUSIONS: In heart failure patients with severe chronotropic incompetence as defined by failure to achieve >70% AP-HR, appropriate use of rate-adaptive pacing with CRT provides incremental benefit on exercise capacity during exercise.

Asunto(s)

Adaptación Fisiológica , Gasto Cardíaco Bajo/fisiopatología , Gasto Cardíaco Bajo/terapia , Estimulación Cardíaca Artificial/métodos , Ejercicio Físico , Frecuencia Cardíaca , Anciano , Algoritmos , Nodo Atrioventricular/fisiopatología , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad

Asunto(s)

Electrocardiografía/métodos , Infarto del Miocardio/diagnóstico , Humanos , Medición de Riesgo/métodos

RESUMEN

UNLABELLED: Lesion dimension of cryoablation. BACKGROUND: Transvenous catheter cryoablation is a novel technique for treating cardiac arrhythmias. However, the relative importance of temporal application parameters on lesion dimension and clinical efficacy has not been studied. METHODS AND RESULTS: We investigated the effects of (1) application duration: single 2.5 (2.5x1) versus single 5 versus double 2.5 (2.5x2) versus double 5 (5x2) minutes, (2) number of freeze-thaw cycles: single versus double, and (3) electrode contact area: horizontal versus vertical orientation, on the lesion diameter and depth during catheter cryoablation (10F, 6.5-mm tip-electrode, CryoCor, San Diego) in a thigh muscle preparation. A total of 175 lesions (horizontal=90, vertical=85) were created in thigh muscle preparations on 10 swine. The lesion diameter and depth were significantly greater using 2.5x2 and 5x2 application modes as compared with 2.5x1 applications (P<0.05). Horizontal tip-electrode orientation produced larger lesion diameter (P<0.05), but not lesion depth as compared with vertical orientation. Multivariate analysis demonstrated that both tip-electrode orientation and duration of freeze >2.5 minutes were independent predictors for lesion diameter (P<0.001). However, only duration of freeze >2.5 minutes was an independent predictor for lesion depth (P<0.001). CONCLUSIONS: The dimensions of lesions created by catheter cryoablation are affected by mode of cryoablation application and electrode orientation. Increasing the duration of application, employing multiple freeze-thaw cycles at shorter cycle durations, and orienting the catheter to enhance/increase tissue contact can create a larger lesion.

Asunto(s)

Ablación por Catéter/métodos , Criocirugía/métodos , Animales , Electrodos , Análisis Multivariante , Músculos/patología , Porcinos , Factores de Tiempo

RESUMEN

BACKGROUND: Data on the phenotypical pattern and natural history of hypertrophic cardiomyopathy in Chinese patients are very limited. The purpose of this study was to describe the clinical characteristics of and long-term outcome in Chinese patients with hypertrophic cardiomyopathy. METHODS: We evaluated 118 Chinese patients (62 male) who were diagnosed with hypertrophic cardiomyopathy at Queen Mary Hospital from 1973 to 2002. Diagnosis was based on the demonstration of left ventricular hypertrophy (wall thickness > or =15 mm during diastole), either in a specific region or with diffuse distribution, using echocardiography or magnetic resonance imaging. Clinical predictors of major cardiovascular events related to hypertrophic cardiomyopathy (cardiovascular death, potentially fatal cardiac arrhythmia, and refractory heart failure requiring cardiac transplantation or percutaneous alcohol septal ablation) were evaluated with univariate and multivariate Cox proportional hazards regression models. RESULTS: The mean (+/- SD) age at presentation was 54 +/- 18 years. During a mean follow-up of 5.8 +/- 4.3 years (range, 1 to 29 years) from presentation, major cardiovascular events related to hypertrophic cardiomyopathy occurred in 19 patients (16%), including 9 deaths. Annual cardiovascular mortality was 1.6%. Fifty-five patients (47%) had one or more cardiovascular complications related to hypertrophic cardiomyopathy, of which atrial fibrillation was the most common (35%, n = 41). The most common type of hypertrophic cardiomyopathy was the apical variant (41%, n = 49). In multivariate analysis, female sex was the only independent predictor of major cardiovascular events related to hypertrophic cardiomyopathy (hazard ratio = 5.86; 95% confidence interval: 1.77 to 7.21; P = 0.007). CONCLUSION: Hypertrophic cardiomyopathy in Chinese patients is characterized by late onset of presentation, a high incidence of the apical form of the condition, and adverse clinical outcome in female patients, which suggest a different phenotypical pattern than in white patients.

Asunto(s)

Cardiomiopatía Hipertrófica/diagnóstico , Hipertrofia Ventricular Izquierda/diagnóstico , Adulto , Anciano , Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/mortalidad , Cardiomiopatía Hipertrófica/cirugía , Causas de Muerte , Ecocardiografía , Electrocardiografía , Femenino , Estudios de Seguimiento , Tabiques Cardíacos/cirugía , Trasplante de Corazón , Hong Kong/epidemiología , Humanos , Hipertrofia Ventricular Izquierda/complicaciones , Hipertrofia Ventricular Izquierda/mortalidad , Hipertrofia Ventricular Izquierda/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Análisis de Supervivencia , Tasa de Supervivencia

RESUMEN

We describe a case of atrial tachycardia originating from an epicardial site with a venous connection between the left superior pulmonary vein (LSPV) and superior vena cava (SVC). Initial endocardial mapping with multiple electrodes catheters demonstrated early endocardial activation at both the SVC and LSPV. However, radiofrequency applications at the SVC failed to terminate the atrial tachycardia. With three-dimensional electroanatomic mapping, the earliest endocardial activation was found to be in the left atrial appendage (LAA). However, radiofrequency energy applications at multiple sites in the LAA resulted in only transient termination of the tachycardia. A left atrial angiogram demonstrated a venous connection between the LSPV and SVC, overlying the LAA. An application of radiofrequency energy with a saline-irrigated ablation catheter delivered at the earliest activation site in the LAA terminated the tachycardia. The tachycardia did not recur during 18-month follow-up.

Asunto(s)

Anomalías Múltiples/patología , Pericardio/patología , Venas Pulmonares/anomalías , Taquicardia Atrial Ectópica/patología , Vena Cava Superior/anomalías , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/cirugía , Adolescente , Mapeo del Potencial de Superficie Corporal , Ablación por Catéter , Humanos , Imagenología Tridimensional , Masculino , Pericardio/cirugía , Venas Pulmonares/cirugía , Taquicardia Atrial Ectópica/diagnóstico , Taquicardia Atrial Ectópica/cirugía , Vena Cava Superior/cirugía

RESUMEN

BACKGROUND: Mechanoelectrical feedback caused by atrial dilatation plays an important role in atrial fibrillation (AF). To test the hypothesis that remodeling is reversible by reducing atrial stretch, we investigated electrophysiological changes after a reduction of left atrial (LA) pressure in patients undergoing percutaneous balloon mitral commissurotomy (PBMC). METHODS AND RESULTS: In 22 patients with chronic AF who were undergoing PBMC for mitral stenosis, internal cardioversion was successful in 19 patients (86%). Twelve patients with sinus rhythm acted as controls. Mean LA pressure was significantly reduced after PBMC (18.5+/-5.9 mm Hg versus 10.2+/-4.1 mm Hg; P<0.001). The effective refractory period (ERP), conduction delay (CD), and the index of heterogeneity (CoV) of the ERP and CD were compared. Changes in LA pressure were only significantly correlated with AF vulnerability (r=0.7; P=0.02) and CoV of CD (r=0.3; P=0.03). There were no significant changes in ERP and CD immediately after PBMC in the AF group. However, the overall CoV of ERP was reduced in the AF group after PBMC. There were homogenous, although not significant, increases in regional ERP in the control group immediately after PBMC. Atrial CD and CoV of CD were significantly reduced after PBMC in the control group; this was most prominent within the regions of the LA. CONCLUSIONS: AF vulnerability and CoV of CD correlated significantly with LA pressure. A homogenous increase in regional ERPs could be demonstrated in the control group after an immediate reduction of atrial stretch, whereas the recovery course of electrical remodeling was prolonged and heterogenous in the AF group. Regional conductions were irreversible in patients with preexisting AF.

Asunto(s)

Angioplastia Coronaria con Balón , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/cirugía , Estenosis de la Válvula Mitral/cirugía , Fibrilación Atrial/etiología , Fibrilación Atrial/patología , Función Atrial , Fenómenos Biomecánicos , Enfermedad Crónica , Dilatación Patológica , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Retroalimentación , Femenino , Sistema de Conducción Cardíaco/fisiopatología , Humanos , Cinética , Masculino , Persona de Mediana Edad , Resultado del Tratamiento

Asunto(s)

Adenosina Trifosfato , Fibrilación Atrial/cirugía , Ablación por Catéter , Venas Pulmonares/diagnóstico por imagen , Humanos , Persona de Mediana Edad , Flebografía , Venas Pulmonares/cirugía , Intensificación de Imagen Radiográfica/métodos

RESUMEN

RF ablation of ectopic foci in the pulmonary veins (PVs) is a promising treatment for patients with paroxysmal AF. The aim of this study was to evaluate the feasibility of using nonfluoroscopic magnetic electroanatomic mapping of PV during spontaneous or induced ectopy to facilitate focal ablation procedure. The study included 35 patients with drug refractory paroxysmal AF who underwent focal RF ablation of the PV. In 10 (29%) patients, mapping and RF ablation procedures were performed using the nonfluoroscopic magnetic electroanatomic mapping system to enable automatic capture of the location and the timing of the ectopy. As a control, 25 patients underwent conventional endocardial activation mapping technique. There were no significant differences in the clinical characteristics between the two groups. Overall procedural duration was similar between them (199 +/- 52 vs 221 +/- 82 minutes, P > 0.05). However, the mean fluoroscopy time (25 +/- 6 vs 52 +/- 12 minutes, P = 0.01) and the mean number of RF applications (5 +/- 3 vs 12 +/- 9, P = 0.02) were significantly less in patients who underwent electroanatomic mapping. There were no significant differences between the two groups in the acute (90 vs 84%) and long-term success rate (60 vs 56%) after a mean follow-up of 12 +/- 9 months. In conclusion, RF ablation of ectopic foci using nonfluoroscopic magnetic electroanatomic mapping of PVs during spontaneous or induced ectopy is useful even in patients with a limited number of ectopy, and is associated with a similar success rate, but less fluoroscopy time and RF application compared to the conventional approach.

Asunto(s)

Fibrilación Atrial/cirugía , Ablación por Catéter/métodos , Técnicas Electrofisiológicas Cardíacas , Venas Pulmonares/cirugía , Adulto , Fenómenos Electromagnéticos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Venas Pulmonares/fisiopatología , Resultado del Tratamiento