José M. Rubín

Atrioventricular Conduction Disturbance Characterization in Transcatheter Aortic Valve Implantation With the CoreValve Prosthesis

Background— Atrioventricular (AV) block is one of the most frequent complications of CoreValve transcatheter aortic valve implantation (TAVI). The aim of this study was to analyze the effects of CoreValve implantation on AV conduction. Methods and Results— Electrophysiological study was performed immediately before and after CoreValve implantation in 18 consecutive, permanent pacemaker-free patients. An electrode was placed on the His bundle during valve implantation, and data were continuously recorded during the procedure. With surface ECG, a median (first, third quartile) QRS width of 96 (84, 116) to 150 (121, 164) ms (P=0.001) and PR interval of 180 (159, 216) to 210 (190, 240) ms (P=0.008) were significantly prolonged, and QRS axis was left deviated 30° (−32°, 46°) to −20° (−60°, 2°) (P=0.005). With intracardiac electrograms, the AH (97 [70, 123] to 115 [96, 135] ms, P=0.021) and HV (52 [42, 55] to 60 [50, 70] ms, P=0.002) intervals were increased. At the end of the procedure, we observed significant ECG- or electrophysiological study-persistent conduction disturbances in 14 (78%) patients. Five patients experienced transient changes (2 AV blocks and 3 left bundle branch blocks). Conclusions— CoreValve implantation worsens AV conduction in most patients, either transiently or permanently. This worsening is the result of direct damage either on the His bundle or on the AV node.

Shock Reduction With Long-Term Quinidine in Patients With Brugada Syndrome and Malignant Ventricular Arrhythmia Episodes

High-risk Brugada syndrome (BrS) is treated with an implantable cardioverter-defibrillator (ICD). However, ventricular arrhythmias (VA) and high-energy shocks may be frequent events after ICD implantation [(1)][1], resulting in an impact on quality of life. Quinidine, a class Ia antiarrhythmic agent

Bloqueo intrahisiano durante el implante de la prótesis aórtica percutánea CoreValve

1. Avanzas P, Muñoz-Garcı́a AJ, Segura J, Pan M, Alonso-Briales JH, Lozano I, et al. Implante percutáneo de la prótesis valvular aórtica autoexpandible CoreValve en pacientes con estenosis aórtica severa: experiencia inicial en España. Rev Esp Cardiol. 2010;63:141–8. 2. Al Ali AM, Altwegg L, Horlick EM, Feindel C, Thompson CR, Cheung A, et al. Prevention and management of transcatheter balloon expandable aortic valve malposition. Catheter Cardiovasc Interv. 2008;72:575–80. 3. Ussia GP, Mulè M, Tamburino C. The valve-in-valve technique: transcatheter treatment of aortic bioprothesis malposition. Catheter Cardiovasc Interv. 2009; 73:713–6. 4. Gerckens U, Latsios G, Mueller R, Buellesfeld L, John D, Yuecel S, et al. Procedural and mid-term results in patients with aortic stenosis treated with implantation of 2 (in-series) CoreValve prostheses in 1 procedure. JACC Cardiovasc Interv. 2010;3:244–50.

Espectro mutacional del gen SCN5A en pacientes españoles con síndrome de Brugada

El sindrome de Brugada se caracteriza por un bloqueo de la rama derecha y elevacion del segmento ST en las derivaciones precordiales derechas del electrocardiograma. Con frecuencia se observa una transmision familiar, y en aproximadamente el 25% de los casos se han hallado mutaciones en el gen SCN5A. Hemos analizado la secuencia de este gen en 25 pacientes espanoles con sindrome de Brugada. En 4 de ellos (16%) hallamos mutaciones que no habian sido descritas previamente: 3 eran cambios de aminoacidos (Ala2>Tre, Ala735>Tre y Val1340>Ile) y 1 era intronica y afectaria al procesamiento del ARNm (intron 18 IVS18-1G>A). En los 4 habia familiares portadores, y varios de ellos tenian electrocardiogramas normales, incluso tras induccion con flecainida. Nuestro estudio indica que el analisis genetico seria util para el diagnostico presintomatico, pero de utilidad limitada para estratificar el riesgo de eventos adversos.

Time-dependent responses to provocative testing with flecainide in the diagnosis of Brugada syndrome

BACKGROUND Time-dependent variability of electrocardiogram (ECG) in patients with Brugada syndrome could affect the interpretation of provocative testing. OBJECTIVE The aim of this study was to characterize ECG changes during and after flecainide infusion. METHODS We studied 59 consecutive patients. The ECG was continuously analyzed during the first 30 minutes of provocative testing, and a single ECG was recorded 60 minutes later. We analyzed CYP2D6 and CYP3A5 variants affecting flecainide metabolism and performed blinded measurements at lead II. RESULTS At baseline, ECG patterns were classified as follows: type II in 31 patients (53%), type III in 15 (25%), and normal ECG in 13 (22%). Because of induction of type I ECG, the percentage of responders progressively increased with longer recording time periods (6.8% in 10 minutes vs 11.9% in 20-30 minutes vs 18.6% in 90 minutes; P < .01). Four patients displayed a late response, which was evidenced 90 minutes after the initiation of provocative testing. QRS width differentially increased between responders and nonresponders (P < .01), with a maximum QRS width of 110 ms during the first 30 minutes being effective for identifying possible late responders (sensitivity 100%; specificity 85.6%; positive predictive value 88%; negative predictive value 100%). The incidence of CYP2D6 variants was lower in late responders than in early or delayed responders (0% vs 75% vs 100%; P = .04), while a homogeneous distribution of CYP3A5*3/*3 was observed in our population. CONCLUSION Response to flecainide exhibits time-dependent variability of ECG patterns and intervals. Longer periods of ECG recording increase the recognition probability of type I ECG.

Ablation of Rotor Domains Effectively Modulates Dynamics of Human: Long-Standing Persistent Atrial Fibrillation

Background In human long-standing persistent atrial fibrillation, rotors potentially explain atrial fibrillation maintenance, but their ablation remains controversial. We aimed to explore original phase/frequency mapping methods to locate rotors and track changes induced by their ablation. Methods and Results Thirteen patients with long-standing persistent atrial fibrillation (duration, 12–72 months) underwent phase/frequency mapping (Hilbert/Fourier transforms; CARTO-Finder) of the left and right atria (PentaRay catheter). A rotor domain was defined as an area displaying at least 3 consecutive rotations. Ablation was performed by circumferential pulmonary vein isolation plus linear ablation of extrapulmonary rotor domains. We identified 19 rotor domains in 10 patients (1.8±1.1 per patient; 7 in the right atrium versus 12 in the left atrium; 15 extrapulmonary). Overall, rotor domains (9.2±2.2 rotations) displayed higher frequency of activation (6.41 Hz; 95% confidence interval, 6.24–6.57) than nonrotor domains (6.17 Hz; 95% confidence interval, 6.1–6.23; P=0.021), with interatrial frequency gradients established by the spatial location of the rotor domain (P=0.016). Fibrillatory conduction was suggested as a decrease in the frequency of the slower atria after ablation close to main interatrial conduction fascicles (P=0.035). Ablation of rotor domains (ablation line, 3.5±0.9 cm) effectively decreased the frequency of activation in both ipsilateral and contralateral atria (P<0.05 for both), whereas ablation of nonrotor domains did not. Acute conversion to sinus rhythm was observed in 2 patients after ablation of rotor domains. At 1-year follow-up, 70% remained in sinus rhythm (85% out-of-antiarrhythmic drugs). Conclusions Rotor domains appropriately explain long-standing persistent atrial fibrillation physiology at its frequency content. Their ablation effectively modifies dynamics on restricted ablation.

The Spectrum of SCN5A Gene Mutations in Spanish Brugada Syndrome Patients

Brugada syndrome is characterized by right bundle branch block and ST-segment elevation in the right precordial ECG leads. Familial transmission is frequent and approximately 25% of cases exhibit mutations in the SCN5A gene. We analyzed the sequence of this gene in 25 Spanish patients with Brugada syndrome. In 4 (16%), we found mutations that had not previously been described: three were amino acid changes (i.e. Ala2>Thr, Ala735>Thr and Val1340>Ile) and one was an intron mutation that affected messenger RNA processing (i.e. IVS18-1G>A). These four patients had relatives who were also mutation carriers, several of whom had normal ECGs, even on flecainide challenge. Our study suggests that genetic analysis could be helpful in the presymptomatic diagnosis of Brugada syndrome, but may be less useful for stratifying the risk of adverse events.

Conduction Disorders and Transcatheter Aortic Valve. Clinically Relevant or Just a Mild Complication

Cuando se cumple el decimo aniversario del inicio del implante valvular aortico transcateter (TAVI, por sus siglas en ingles), se estima que se han realizado mas de 90.000 procedimientos en el mundo. Este crecimiento explosivo de un nuevo tratamiento puede explicarse por varias razones: a) un elevado numero de pacientes susceptibles de ser tratados, ya que la estenosis aortica es la afeccion valvular mas frecuente en el adulto y con una incidencia creciente; b) la ventaja de resolver la estenosis de la valvula aortica sin necesidad de cirugia, y por ultimo, c) un balance riesgo/beneficio favorable. Las expectativas son, ademas, que en el futuro se trate a pacientes mas jovenes y con menos comorbilidades. Para ello es necesario disminuir las actuales complicaciones asociadas al procedimiento, entre las que se encuentran los trastornos de la conduccion auriculoventricular (TCAV). En este editorial se presenta la evidencia disponible sobre la frecuencia de nuevos TCAV asociados al TAVI, su etiopatogenia, los factores predictivos tanto de los TCAV como del implante de marcapasos (MP) permanente y sus consecuencias clinicas y, finalmente, posibles areas de mejora.

Registro del Infarto de Miocardio en Asturias: proyecto RIMAS

BACKGROUND AND OBJECTIVE: Spanish hospital registers of myocardial infarction (MI) are not uniform. The RIMAS project is trying to know the real situation of myocardial infarction in Asturias and to observe possible differences among hospitals and with other registers. PATIENTS AND METHOD: It was a cohorts study using a hospital registry of patients with MI. All cases arriving alive to all public and private-public Asturian hospitals during 1998 were included. Demographic data, cardiovascular risk factors, delays, evolution, treatments and techniques used, were all registered. RESULTS: 875 cases were registered with a coverage rate of 77%. The average age was 66.5 years (45.6% older than 70 years) and women represented 29.1%. Sixty three per cent of the patients had tobacco consumption, 43% had arterial hypertension, and 22.3% were diabetics. The extrahospital delay was 135 min and thrombolysis delay was 180 min. Thrombolytic therapy was administered to 34.1% of patients and 4% were treated with primary angioplasty. Intrahospital mortality was 14.4%. At discharge, antiagregant therapy was administrated to 94%, betablockers to 43.2%, ACE inhibitors to 33.3% and hypolipemiants to 25% of treated patients. CONCLUSIONS: People attended in Asturias with a MI are older and there is a higher percentage of women. There are delays which include the start of thrombolytic therapy. However, there are significant differences with regard to the adhesion to clinical practice guidelines between different hospitals.

Estudio prospectivo, comparativo entre implantes de marcapasos realizados en el laboratorio de electrofisiología y en el quirófano

Introduccion y objetivos El implante de marcapasos permanentes es realizado por diversos especialistas con entrenamiento quirurgico o clinico. El objetivo del estudio fue analizar si existian diferencias en los parametros de implante y complicaciones entre los implantes realizados por cardiologos en el laboratorio de electrofisiologia y cirujanos cardiacos en el quirofano. Material y metodos Se recogieron prospectivamente datos de los primoimplantes de marcapasos realizados durante 1998 por cirugia cardiovascular y electrofisiologia. Se recolectaron datos demograficos, diagnostico que motivo el implante, tiempo de procedimiento, complicaciones del mismo, umbrales de estimulacion y deteccion y tipo de estimulacion. Resultados Se implantaron 216 marcapasos, 101 por cirugia cardiovascular y 115 por electrofisiologia. El 56% de los pacientes eran varones. La edad promedio del grupo de cirugia cardiovascular fue 74 ± 9 anos y 72 ± 12,3 anos para el de electrofisiologia (p = NS). Los principales diagnosticos fueron bloqueos AV completos en el 32,9% de los pacientes, bloqueos AV de segundo grado en el 16,4%, disfuncion sinusal en el 12,2%, ablacion del nodo AV en el 12,2%. La tasa de complicaciones del procedimiento fue del 4% para cirugia cardiovascular y 1,7% para electrofisiologia (p = NS). Hubo mas implantes de marcapasos bicamerales en electrofisiologia, y minimas diferencias sin significacion clinica en los parametros de implante. Conclusiones El implante de marcapasos por cardiologos en el laboratorio de electrofisiologia se puede realizar de manera segura y sin mas complicaciones que en los implantes realizados por cirujanos. Esto permite optimizar los recursos hospitalarios y disminuir los dias de estancia.