Avances en el diagnóstico y tratamiento de las arritmias cardíacas

The era of catheter ablation for the treatment of arrhythmias began in 1981 when Dr Scheinman performed the first atrioventricular junction ablation using direct current shocks in a patient with drug refractory atrial fibrillation and an uncontrolled ventricular rate. With the progress of radiofrequency catheter ablation, the range of arrhythmias amenable to catheter ablation and the number of patients that could be treated safely by this procedure expanded enormously. Lastly, although still in an evolutionary phase, catheter ablation to eliminate atrial fibrillation has been demostrated in the past years to be feasible and clinically useful. On the other hand, innovations in technology and pharmacology, and better preventive and diagnostic tools, have provided our patients with an important improvement in their prognosis. The new developments in molecular genetics and biology are likely to change the way we approach a cardiac patient in the future. The diseases are now being deciphered at the most basic level, and the information obtained opens new possibilities not only for better therapeutic and diagnostic measures but also for prevention of the disease

Cardiac resynchronization therapy and valvular cardiomyopathy after corrective surgery

Cardiac resynchronization therapy (CRT) has been shown to have clinical benefits in certain groups of patients with advanced heart failure (HF). However, patients with valvular cardiomyopathy are underrepresented in randomized clinical studies. The aim of this study was to assess the medium-term (i.e., at 6 months) effects of CRT in patients with HF exclusively due to valvular disease. The study included 40 consecutive patients who underwent CRT device implantation. At 6 months, there were improvements in functional class, left ventricular remodeling, and intraventricular dyssynchrony parameters in treated patients. In this particular subgroup of patients, the benefits of CRT were similar to those observed in patients with HF due to other etiologies

Efecto de la localización del electrodo ventricular izquierdo sobre los parámetros ecocardiográficos de asincronía en pacientes sometidos a terapia de resincronización cardíaca

Introduction and objectives. Cardiac resynchronization therapy has been shown to be an option in the treatment of patients with congestive heart failure. The current indication for this treatment is based on clinical and electrocardiographic criteria, although echocardiography has also been shown to be a useful tool for the diagnosis of ventricular dyssynchrony. The aim of this study was to assess left ventricular dyssynchrony by echocardiography and to evaluate the effect of the stimulation site on the magnitude of resynchronization. Patients and method. We studied 25 patients with biventricular stimulation (left ventricular lead located in a lateral position in 13 patients, and in an anterior position in 12). A complete echo-Doppler evaluation, including left ventricular ejection fraction, ventricular diameters and parameters of inter- and intraventricular dyssynchrony, was performed before implantation and 3 months after the procedure, with the device connected and disconnected. Results. Left ventricular ejection fraction increased significantly from 23.7 (6.5) to 27.8 (5.5) (P=.007) at 3 months. In the group as a whole, biventricular pacing was associated with a significant decrease in all intraventricular dyssynchrony parameters (septal-to-lateral wall motion delay and septal-to-posterior wall motion delay). This decrease in septal-to-posterior wall motion delay and septalto- lateral wall motion delay was significantly greater in patients with the electrode implanted in the lateral position (58.1 ms vs 118 ms; P=.02) than with the lead in the anterior position (39.5 ms vs 86.5 ms; P=.04). Three patients, all with the electrode in an anterior location, were considered non-responders. Conclusions. Left lateral free wall stimulation provided significantly better intraventricular resynchronization compared to stimulation at an anterior site. Echocardiography is a useful tool to evaluate changes in intra- and interventricular synchrony related to the pacing site

High-density mapping to guide ablation of a right bundle branch morphology premature ventricular contraction from the right outflow tract

The Rhythmia ultrahigh-density mapping system with a specific algorithm seems to be helpful in identifying the target area to successfully treat multiple morphologies by catheter ablation in the right ventricular outflow tract RVOT. Interestingly, the acquisition process seemed to be extremely faster than a standard manual point-by-point premature ventricular contraction (PVC) mapping

Tratamiento de la insuficiencia cardíaca avanzada mediante estimulación biventricular. Experiencia inicial en una serie de 22 casos consecutivos

Recent data suggest that biventricular pacing may play an important role in treating advanced heart failure in the presence of a significant interventricular and/or intraventricular conduction disorder by correcting cardiac dysynchrony. In this article, we review the initial technical and clinical experience with cardiac resynchronization therapy in an electrophysiology laboratory. METHODS: The first 22 consecutive patients with severe congestive heart failure, ejection fraction < 0.35, NYHA functional class III or IV, and QRS duration > 120 ms who were implanted biventricular pacemakers were studied. Clinical, electrocardiographic, and echocardiographic evaluations were made before and three months after pacemaker implantation. Acute functional capacity testing with peak oxygen uptake was measured during biventricular pacing and during intrinsic rhythm or right ventricular pacing three months after the implantation procedure. RESULTS: The success rate of pacemaker implantation was 95%. Pre-discharge left ventricular pacing was achieved in 91%, with an average pacing threshold of 1.53 (1.04) volts. NYHA functional class improved (p = 0.039) from 3.4 (0.7) to 2.3 (0.78). The rate of hospitalization for heart failure decreased from an average of 3.12 (0.58) three months before the procedure to 1.38 (0.34) three months after the procedure. Peak oxygen uptake was significantly greater (p = 0.028) during biventricular pacing: 14.89 (2.1) ml/min/kg, than during intrinsic rhythm or right ventricular pacing: 12.65 (2.3) ml/min/kg. CONCLUSIONS: Cardiac resynchronization therapy can be performed safely and with a high success rate in the electrophysiology laboratory. Biventricular pacing seems to improve the symptoms of congestive heart failure in patients with evidence of atrioventricular and/or interventricular/intraventricular dysynchrony. An acute benefit in peak oxygen uptake was associated with biventricular pacing after the implantation procedure

Rol de sCD40L en la predicción de súper-respuesta a la terapia de resincronización cardiaca

Background. The aim of this paper is to analyze the role of the biomarkers Interleukin 6, Tumoral Necrosis Factor α, sCD40L, high sensitive Troponin T, high sensitive C-Reactive Protein and Galectin-3 in predicting super response (SR) to Cardiac Resynchronization Therapy (CRT), as they have not been studied in this field before. Methods. Clinical, electrocardiographic and echocardiographic data was obtained preimplant and after one year. SR was defined as reduction in LVESV ≥ 30% at one year follow-up. Blood samples were extracted preimplant. Multivariate logistic regression and ROC curves were performed. Results. 50 patients were included, 23 (46%) were SR. Characteristics related to SR were: female (35 vs. 11%, p=0.04), suffering from less ischemic cardiomyopathy (13 vs. 63%, p<0.0001) and lateral (0 vs. 18%, p=0.03), inferior (4 vs. 33%, p=0.01) and posterior infarction (0 vs. 22%, p=0.01); absence of mitral regurgitation (47% vs. 22%, p=0.04), wider QRS width (157.7±22.9 vs. 140.8±19.2ms, p=0.01), higher concentrations of sCD40L (6.9±5.1 vs. 4.4±3.3 ng/mL, p=0.02), and left ventricular lead more frequent in lateral medial position (69 vs. 26%, p=0.002). QRS width, lateral medial position of the lead and absence of mitral regurgitation were independent predictors of SR. sCD40L showed a moderate direct correlation with SR (r=0.39, p=0.02) and with the reduction of LVESV (r=0.44, p=0.02). Conclusion. sCD40L correlates significantly with SR to CRT. QRS width, absence of mitral regurgitation and lateral medial position of the lead are independent predictors of SR in this cohort.Fundamento. Analizar los biomarcadores Interleuquina 6, factor de necrosis tumoral α, sCD40L, troponina T hipersensible, proteína C-reactiva hipersensible y galectina-3 en la predicción de súper-respuesta (SR) a la terapia de resincronización cardiaca (TRC), ya que no han sido valorados con anterioridad. Material y métodos. Se recopilaron datos clínicos, electrocardiográficos y ecocardiográficos preimplante y al año. Se definió SR como disminución del VTSVI ≥ 30% al año de seguimiento. Las muestras sanguíneas fueron extraídas preimplante. Se realizó regresión logística multivariante y curvas ROC. Resultados. Se incluyeron 50 pacientes, 23 (46%) fueron SR.Las características relacionadas con la SR fueron: ser mujer (35 vs. 11%, p=0,04), sufrir menos cardiopatía isquémica (13 vs. 63%, p<0,0001) e infarto lateral (0 vs. 18%, p=0,03), inferior (4 vs. 33%, p=0,01) y posterior (0 vs. 22%, p=0,01); ausencia de insuficiencia mitral (47% vs. 22%, p=0,04), mayor anchura del QRS (157,7±22,9 vs. 140,8±19,2 ms, p=0,01), mayor concentración de sCD40L (6,9±5,1 vs. 4,4±3,3 ng/mL, p=0,02), y electrodo ventricular izquierdo más frecuentemente en posición lateral media (69 vs. 26%, p=0,002). El QRS, la posición lateral media del electrodo y la ausencia de insuficiencia mitral fueron predictores independientes de SR. sCD40L mostró una correlación moderada directa con SR (r=0,39, p=0,02) y con la disminución del VTSVI (r=0,44, p=0,02). Conclusiones. sCD40L se correlaciona significativamente con SR a la TRC. El QRS, la ausencia de insuficiencia mitral y la posición lateral media del electrodo son predictores independientes de SR en esta cohorte

Avances en el diagnóstico y tratamiento de las arritmias cardíacas

The era of catheter ablation for the treatment of arrhythmias began in 1981 when Dr Scheinman performed the first atrioventricular junction ablation using direct current shocks in a patient with drug refractory atrial fibrillation and an uncontrolled ventricular rate. With the progress of radiofrequency catheter ablation, the range of arrhythmias amenable to catheter ablation and the number of patients that could be treated safely by this procedure expanded enormously. Lastly, although still in an evolutionary phase, catheter ablation to eliminate atrial fibrillation has been demostrated in the past years to be feasible and clinically useful. On the other hand, innovations in technology and pharmacology, and better preventive and diagnostic tools, have provided our patients with an important improvement in their prognosis. The new developments in molecular genetics and biology are likely to change the way we approach a cardiac patient in the future. The diseases are now being deciphered at the most basic level, and the information obtained opens new possibilities not only for better therapeutic and diagnostic measures but also for prevention of the disease

Estudio de la utilidad de los mapas auriculares de alta densidad y de biomarcadores circulantes de fibrosis miocárdica en pacientes con fibrilación auricular

INTRODUCCIÓN Los sistemas de navegación no fluoroscópica capaces de realizar mapas de alta densidad (HDM) permiten obtener información precisa de las propiedades eléctricas de la aurícula izquierda durante procedimientos de ablación.Por otro lado, la detección de biomarcadores sanguíneos es una técnica mínimamente invasiva que podría permitir caracterizar la fibrosis intersticial miocárdica (FIM), elemento clave en la fisiopatología de la fibrilación auricular (FA).En este sentido, niveles circulantes elevados de propéptido C-terminal del procolágeno tipo I (PICP) y un bajo cociente entre el telopéptido C-terminal del colágeno tipo I y la metaloproteinasa de matriz tipo 1 (CITP:MMP-1) han sido correlacionados con la extensión y el entrecruzamiento del colágeno tipo I miocárdico, respectivamente. Además,la combinación de niveles elevados de PICP y baja relación CITP:MMP-1 (patrón CD+CCL+) se ha asociado a eventos adversos en pacientes con insuficiencia cardíaca (IC). OBJETIVOS Crear un protocolo específico para la realización de HDM en pacientes candidatos a ablación de FA para evaluar seguridad, detección del sitio de reconexión de las venas pulmonares, caracterización de las propiedades eléctricas de la aurícula y predicción de la evolución de la FA. Analizar la relación entre los niveles circulantes de PICP y CITP:MMP-1 con la prevalencia, incidencia y recurrencia post ablación de FA y su relación con las características eléctricas de la aurícula izquierda MÉTODOS Realizamos HDM previo a la ablación de FA. Los resultados se compararon con una cohorte de pacientes sometidos a ablación guiada por mapas electroanatómicos convencionales.Para cada paciente se estimó: El voltaje medio auricular (Vm) y el valor absoluto de la pendiente del histograma de los voltajes (VSlope).Estudiamos además la relación entre los niveles en sangre periférica de PICP y CITP:MMP-1 con la FA en 2 cohortes, 1 de pacientes con IC de origen hipertensivo y otra con FA sometidos a ablación. RESULTADOS En comparación con los mapas electroanatómicos convencionales, la utilización de HDM no prolongó el tiempo de procedimiento (P=0,4) ni se asoció a un aumento de complicaciones (P=1), permitiendo una detección más precisa de los gap de reconexión (39,6% vs 60,9%, respectivamente; P=0,001). Los pacientes con recurrencia de FA presentaron un Vm menor (0,71±0,4 vs 1,22±0,6 mV; P<0,0001) y un VSlope mayor (mediana [rango intercuartílico]: 0,90 [0,65-1,25] vs 0,57 [0,45-0,79]; P=0,0003) que los pacientes que permanecieron libres de arritmias. Los pacientes que progresaron de FA paroxística a persistente presentaron basalmente valores de Vm más bajos (0,37±0,25 vs 0,95±0,30 mV; P=0,01) y de VSlope más elevados (1,65 [1,29-3,10] vs 0,66 [0,51-0,84]; P=0,03) que los pacientes que presentaron recurrencia como FA paroxística. Además, los que presentaron taquicardia auricular macroreentrante (TAMR) post ablación tenían basalmente un VSlope mayor (1,30 [0,95-2,84]) que los pacientes con recurrencia de FA sin TAMR (0,73 [0,58-0,97]; P=0,003). En pacientes con IC, un patrón CD+CCL+ se asoció con una prevalencia 3 veces superior de FA en comparación con los CCL-CD- (OR=3,32 [95%CI: 1,25-8,83], P=0,01) y con un aumento en la incidencia de FA de nuevo diagnóstico (chi-cuadrado=8,1 en la prueba de log-rank, P=0,01). Además, se asoció a mayor riesgo de recurrencia de FA post ablación (chi cuadrado de la prueba log-rank 14,5, P=0,001). Por último, comparando con el resto de los pacientes, los CCL+CD+ exhibieron menor Vm (0,75±0,39 mV vs. 1,15±0,67 mV; P=0,005) y mayor VSlope (mediana: 0,62 [0,45-0,93] vs 0,92 [0,56-1,21]; P=0,04) CONCLUSIONES Los HDM permiten la identificación de alteraciones auriculares asociadas a recurrencia y progresión de la FA tras un procedimiento de ablación. Un perfil de biomarcadores de FIM compleja se asocia con signos de remodelado auricular, así como con una mayor incidencia, prevalencia y resistencia al tratamiento de la FA