Radiofrequency treatment for electrical storm: evolution and monitoring. / Tratamiento con radiofrecuencia de la tormenta eléctrica: evolución y seguimiento.

Introducción y objetivos: La tormenta eléctrica (TE) se caracteriza por episodios repetidos de taquicardia ventricular o fibrilación ventricular relacionados con mal pronóstico a corto y largo plazos. El objetivo fue evaluar la prevalencia, resultados y supervivencia de los pacientes sometidos a tratamiento intervencionista por TE en un centro de referencia. Métodos: Estudio unicéntrico, observacional y retrospectivo. Se revisaron los procedimientos de ablación por TE y se evaluaron las características basales de los pacientes, tipo de procedimiento, mortalidad total, recurrencia de arritmia, mortalidad cardiovascular y necesidad de trasplante. Resultados: Desde enero de 2009 hasta diciembre de 2016 se realizaron 67 procedimientos (38% de complejos: 19% de ablación endoepicárdica, 7.5% de crioablación epicárdica quirúrgica, 3% de simpatectomía, 3% de inyección coronaria con alcohol; 6% de apoyo con oxigenación con membrana extracorpórea) en 41 pacientes (61% de causa isquémica) por TE. La mortalidad intraprocedimiento fue del 1.5%. La mediana de seguimiento fue de 23.5 meses (RIQ, 14.2-52.7). Tras el primer ingreso por TE (uno o varios procedimientos), la mortalidad a un año fue de 9.8%. La incidencia acumulada de trasplante cardiaco por TE fue de 2.4%. En el análisis multivariado, el riesgo de recurrencias arrítmicas o muerte por cualquier causa fue significativamente mayor en pacientes con arritmias clínicas inducibles (HR, 9.03; p = 0.017). Conclusiones: El tratamiento de pacientes con TE, instituido en un centro de referencia y con experiencia, se relacionó con una tasa baja de recurrencia y supervivencia elevada, con una tasa de trasplante cardiaco por TE muy baja. Ante una recurrencia temprana es recomendable practicar un nuevo procedimiento durante el ingreso. Introduction and objective: Electrical storm (ES) is characterized by repeated episodes of ventricular tachycardia or ventricular fibrillation, with poor short and long term prognosis. Our objective was to evaluate the prevalence, results of interventional treatment and survival of patients undergoing interventional treatment for ES in our center. Methods: Retrospective, unicentric and observational study. ES ablation procedures were revised and data regarding baseline characteristics of the patients, type of procedure, total mortality, recurrence of arrhythmia, cardiovascular mortality and the need for transplantation were evaluated. Results: From January 2009 to December 2016, 67 procedures (38% complex procedures: 19% epicardial ablation, 7.5% surgical epicardial crioablation, 3% simpatectomy, 3% coronary alcohol injection, 6% extracorporeal membrane oxygenation support) were performed in 41 patients (61% Ischemic etiology) due to ES. Intraprocedural mortality was 1.5%. The median follow-up was 23.5 months (IQR [14.2-52.7]). After the first admission for ES (one or several procedures), 1-year mortality was 9.8%. The cumulative incidence of cardiac transplantation was 2.4%. The risk of arrhythmic recurrences or death was significantly higher in patients with inducible clinical arrhythmias after ablation (HR: 9.03, p = 0.017). Conclusions: The treatment of patients with ES, performed in a reference center, allows obtaining good rates of recurrence and survival, with very low rates of cardiac transplantation for ES. In the presence of an early recurrence, it is advisable to perform a new procedure during admission.

Tratamiento con radiofrecuencia de la tormenta eléctrica: evolución y seguimiento / Radiofrequency treatment for electrical storm: evolution and monitoring

Resumen Introducción y objetivos: La tormenta eléctrica (TE) se caracteriza por episodios repetidos de taquicardia ventricular o fibrilación ventricular relacionados con mal pronóstico a corto y largo plazos. El objetivo fue evaluar la prevalencia, resultados y supervivencia de los pacientes sometidos a tratamiento intervencionista por TE en un centro de referencia. Métodos: Estudio unicéntrico, observacional y retrospectivo. Se revisaron los procedimientos de ablación por TE y se evaluaron las características basales de los pacientes, tipo de procedimiento, mortalidad total, recurrencia de arritmia, mortalidad cardiovascular y necesidad de trasplante. Resultados: Desde enero de 2009 hasta diciembre de 2016 se realizaron 67 procedimientos (38% de complejos: 19% de ablación endoepicárdica, 7.5% de crioablación epicárdica quirúrgica, 3% de simpatectomía, 3% de inyección coronaria con alcohol; 6% de apoyo con oxigenación con membrana extracorpórea) en 41 pacientes (61% de causa isquémica) por TE. La mortalidad intraprocedimiento fue del 1.5%. La mediana de seguimiento fue de 23.5 meses (RIQ, 14.2-52.7). Tras el primer ingreso por TE (uno o varios procedimientos), la mortalidad a un año fue de 9.8%. La incidencia acumulada de trasplante cardiaco por TE fue de 2.4%. En el análisis multivariado, el riesgo de recurrencias arrítmicas o muerte por cualquier causa fue significativamente mayor en pacientes con arritmias clínicas inducibles (HR, 9.03; p = 0.017). Conclusiones: El tratamiento de pacientes con TE, instituido en un centro de referencia y con experiencia, se relacionó con una tasa baja de recurrencia y supervivencia elevada, con una tasa de trasplante cardiaco por TE muy baja. Ante una recurrencia temprana es recomendable practicar un nuevo procedimiento durante el ingreso.

Abstract Introduction and objective: Electrical storm (ES) is characterized by repeated episodes of ventricular tachycardia or ventricular fibrillation, with poor short and long term prognosis. Our objective was to evaluate the prevalence, results of interventional treatment and survival of patients undergoing interventional treatment for ES in our center. Methods: Retrospective, unicentric and observational study. ES ablation procedures were revised and data regarding baseline characteristics of the patients, type of procedure, total mortality, recurrence of arrhythmia, cardiovascular mortality and the need for transplantation were evaluated. Results: From January 2009 to December 2016, 67 procedures (38% complex procedures: 19% epicardial ablation, 7.5% surgical epicardial crioablation, 3% simpatectomy, 3% coronary alcohol injection, 6% extracorporeal membrane oxygenation support) were performed in 41 patients (61% Ischemic etiology) due to ES. Intraprocedural mortality was 1.5%. The median follow-up was 23.5 months (IQR [14.2-52.7]). After the first admission for ES (one or several procedures), 1-year mortality was 9.8%. The cumulative incidence of cardiac transplantation was 2.4%. The risk of arrhythmic recurrences or death was significantly higher in patients with inducible clinical arrhythmias after ablation (HR: 9.03, p = 0.017). Conclusions: The treatment of patients with ES, performed in a reference center, allows obtaining good rates of recurrence and survival, with very low rates of cardiac transplantation for ES. In the presence of an early recurrence, it is advisable to perform a new procedure during admission.

Safety and efficacy of cryoablation vs. radiofrequency ablation of septal accessory pathways: systematic review of the literature and meta-analyses.

Aims: Radiofrequency ablation (RFA) of septal accessory pathways (APs) is associated with a significant rate of first procedure failures and complications. Cryoablation is an alternative energy source but there are no studies comparing both ablation techniques. We aimed to systematically review the literature and compare the efficacy and safety of cryoablation vs. RFA of septal APs. Methods and results: We conducted two separate meta-analysis of cryoablation and RFA of septal APs and calculated the global estimates of the efficacy and safety. Sixty-four articles were included: 38 articles reporting RFA and 27 articles reporting cryoablation procedures. Additionally, we included the previously non-published cryoablation registry of septal APs performed at our institution. Overall, 4244 septal APs constitute our study population, 3495 in the RFA cohort and 749 in the cryoablation cohort. Acute procedural success rate of cryoablation was 86.0% (95% CI 81.6-89.4%) and RFA 89.0% (95% CI 86.8-91.0%). Recurrence rate of cryoablation was 18.1% (95% CI 14.8-21.8%) and RFA 9.9% (95% CI 8.2-12.0%). Long-term success rate after multiple ablation procedures of cryoablation was 75.9% (95% CI 68.2-82.3%) and RFA 88.4% (95% CI 84.7-91.3%). There were no reported cases of persistent atrioventricular block (AVB) with cryoablation and 2.7% (95% CI 2.2-3.4%) with RFA. Conclusion: Studies of RFA for treatment of septal APs report higher efficacy rates than do studies using cryoablation, but a significantly higher rate of AVB.

Relationship of quality of life with procedural success of atrial fibrillation (AF) ablation and postablation AF burden: substudy of the STAR AF randomized trial.

BACKGROUND: The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation (STAR AF) trial compared 3 strategies for ablation of high-burden paroxysmal/persistent atrial fibrillation (AF): complex fractionated electrogram ablation (CFE), pulmonary vein isolation (PVI), or a combined approach (PVI with CFE). This subanalysis aimed to identify the effect on quality of life (QOL) conferred by ablation strategy, AF recurrence, and type of AF. METHODS: The STAR AF study (n = 100) found 88%, 68%, and 38% freedom from AF > 30 seconds at 12 months for PVI with CFE, PVI, and CFE approaches, respectively (P = 0.001). QOL was measured before ablation and at 12 months after ablation using the Short-Form Health Survey (SF-36) scale. Transformed scores were calculated for each of the 8 subscales of the SF-36, and also converted to physical health and mental health component scores. RESULTS: There was a significant improvement in physical health (24%) and mental health (19%) component scores from baseline to 12 months after ablation (P < 0.05 for both). Significant QOL improvements were seen for all 3 ablation strategies despite differences in outcome. QOL measurements also improved regardless of AF recurrence, except in patients with an AF burden in the highest quartile (median 27.2 hours per month). AF recurrence independently predicted aggregate QOL score. CONCLUSIONS: QOL after AF ablation improves regardless of procedural outcome. QOL scores were only negatively affected in patients with a high symptomatic burden of arrhythmia recurrence suggesting that significant reduction in AF burden can improve QOL without total elimination of AF.

Incidence and significance of early recurrences associated with different ablation strategies for AF: a STAR-AF substudy.

BACKGROUND: Early recurrences of atrial tachyarrhythmias (ERAT) are common after atrial fibrillation (AF) ablation, and predict late recurrences (LR). We sought to determine the impact of different ablation strategies on ERAT and LR. METHODS AND RESULTS: The STAR-AF trial randomized 100 patients with paroxysmal or persistent AF to ablation of complex fractionated electrograms (CFAE) alone, pulmonary vein isolation (PVI) alone, or combined PVI + CFAE. Patients were followed for 12 months. ERAT was defined as any recurrence of AF, atrial tachycardia, or flutter (AT/AFL) >30 seconds during the first 3 months of follow-up. LR was defined as any recurrence of AF/AT/AFL >30 seconds 3-12 months post. Forty-nine patients experienced ERAT. The index ablation strategy was the only independent predictor of ERAT on multivariate analysis (HR 2.24 PVI vs PVI + CFAE; and HR 2.65 CFAE vs PVI + CFAE). Fifty-two patients experienced LR. The presence of ERAT (HR 3.23), the use of antiarrhythmic drug (AAD) in the first 3 months postablation (HR 2.85), and the index ablation strategy were independently associated with LR (HR 3.42 PVI vs PVI + CFAE; HR 4.72 CFAE vs PVI + CFAE). Thirty-five of 49 (71%) patients with ERAT and 17 (33%) of 51 patients without ERAT had LR (P < 0.0001). Among patients with ERAT, increased left atrium size (HR 1.08), the use of AAD in the first 3 months postablation (HR 2.86) and the index ablation strategy were independently associated with LR (HR 4.77 PVI vs PVI + CFAE; HR 4.45 CFAE vs PVI + CFAE). CONCLUSION: ERAT is common following AF ablation and is strongly associated with LR. Although CFAE ablation alone results in higher rates of early and LR, the addition of CFAE to PVI results in increased long-term success without an increase in ERAT.

Substrate and Trigger Ablation for Reduction of Atrial Fibrillation (STAR AF): a randomized, multicentre, international trial.

AIMS: This multicentre, randomized trial compared three strategies of AF ablation: ablation of complex fractionated electrograms (CFE) alone, pulmonary vein isolation (PVI) alone, and combined PVI + CFE ablation, using standardized automated mapping software. METHODS AND RESULTS: Patients with drug-refractory, high-burden paroxysmal (episodes >6 h, >4 in 6 months) or persistent atrial fibrillation (AF) were enrolled at eight centres. Patients (n = 100) were randomized to one of three arms. For CFE alone (n = 34), spontaneous/induced AF was mapped using validated, automated CFE software and all sites <120 ms were ablated until AF termination/non-inducibility. For PVI (n = 32), all four PV antra were isolated and confirmed using a circular catheter. For PVI + CFE (n = 34), all four PV antra were isolated, followed by AF induction and ablation of all CFE sites until AF termination/non-inducibility. Patients were followed at 3, 6, and 12 months with a visit, ECG, 48 h Holter. Atrial fibrillation symptoms were confirmed by loop recording. Repeat procedures were allowed within the first 6 months. The primary endpoint was freedom from AF >30 s at 1 year. Patients (age 57 +/- 10 years, LA size 42 +/- 6 mm) were 35% persistent AF. In CFE, ablation terminated AF in 68%. Only 0.4 PVs per patient were isolated as a result of CFE. In PVI, 94% had all four PVs successfully isolated. In PVI + CFE, 94% had all four PVs isolated, 76% had inducible AF with additional CFE ablation, with 73% termination of AF. There were significantly more repeat procedures in the CFE arm (47%) vs. PVI (31%) or PVI + CFE (15%) (P = 0.01). After one procedure, PVI + CFE had a significantly higher freedom from AF (74%) compared with PVI (48%) and CFE (29%) (P = 0.004). After two procedures, PVI + CFE still had the highest success (88%) compared with PVI (68%) and CFE (38%) (P = 0.001). Ninety-six percent of these patients were off anti-arrhythmics. Complications were two tamponades, no PV stenosis, and no mortality. CONCLUSION: In high-burden paroxysmal/persistent AF, PVI + CFE has the highest freedom from AF vs. PVI or CFE alone after one or two procedures. Complex fractionated electrogram alone has the lowest one and two procedure success rates with a higher incidence of repeat procedures. ClinicalTrials.gov identifier number NCT00367757.

Spanish implantable cardioverter-defibrillator registry. 5th official report of the spanish society of cardiology working group on implantable cardioverter-defibrillators (2008).

INTRODUCTION AND OBJECTIVES: To summarize the findings of the Spanish Implantable Cardioverter-Defibrillator (ICD) Registry for 2008 compiled by the Spanish Society of Cardiology Working Group on Implantable Cardioverter-Defibrillators. METHODS: Prospective data recorded voluntarily on single-page questionnaires were sent to the Spanish Society of Cardiology by each implantation team. RESULTS: Overall, 3486 device implantations were reported, which is 84.7% of the estimated total number of implantations. The reported implantation rate was 76 per million population and the estimated total implantation rate was 90 per million. The proportion of first implantations was 78.1%. There continued to be substantial regional variations within Spain. The majority of ICD implantations took place in men (mean age 62+/-12 years) who had severe or moderate-to-severe ventricular dysfunction and were in New York Heart Association functional class II. Ischemic heart disease was the most frequent underlying cardiac condition, followed by dilated cardiomyopathy. The number of indications for primary prevention increased relative to the previous year, especially in patients with ischemic cardiomyopathy, and now account for 57% of first implantations. The types of ICD implanted were unchanged from 2007. Overall, 73.6% of ICDs were implanted by cardiac electrophysiologists. CONCLUSIONS: The 2008 Spanish ICD Registry includes data on almost 85% of all ICD implantations performed in Spain. Although the number has continued to increase, it still remains far from the European average. There was a significant increase in indications for primary prevention. Substantial regional variations continue to exist within Spain.

Real-time dominant frequency mapping and ablation of dominant frequency sites in atrial fibrillation with left-to-right frequency gradients predicts long-term maintenance of sinus rhythm.

BACKGROUND: Spectral analysis identifies localized sites of high-frequency activity during atrial fibrillation (AF). OBJECTIVE: This study sought to determine the effectiveness of using real-time dominant frequency (DF) mapping for radiofrequency ablation of maximal DF (DFmax) sites and elimination of left-to-right frequency gradients in the long-term maintenance of sinus rhythm (SR) in AF patients. METHODS: DF mapping was performed in 50 patients during ongoing AF (32 paroxysmal, 18 persistent), acquiring a mean of 117 +/- 38 points. Ablation was performed targeting DFmax sites, followed by circumferential pulmonary vein isolation. RESULTS: Ablation significantly reduced DFs (Hz) in the LA (7.9 +/- 1.4 vs. 5.7 +/- 1.3, P <.001), coronary sinus (CS) (5.7 +/- 1.1 vs. 5.3 +/- 1.2, P = .006), and RA (6.3 +/- 1.4 vs. 5.4 +/- 1.3, P <.001) abolishing baseline left-to-right atrial DF gradient (1.7 +/- 1.7 vs. 0.2 +/- 0.9; P <.001). Only a significant reduction in DFs in all chambers with a loss of the left-to-right atrial gradient after ablation was associated with a higher probability of long-term SR maintenance in both paroxysmal and persistent AF patients. After a mean follow-up of 9.3 +/- 5.4 months, 88% of paroxysmal and 56% of persistent AF patients were free of AF (P = .02). Ablation of DFmax sites was associated with a higher probability of remaining both free of arrhythmias (78% vs. 20%; P = .001) and free of AF (88% vs. 30%; P <.001). CONCLUSION: Radiofrequency ablation leading to elimination of LA-to-RA frequency gradients predicts long-term SR maintenance in AF patients.

[Spanish Implantable Cardioverter-Defibrillator Registry. Fourth Official Report of the Spanish Society of Cardiology Working Group on Implantable Cardioverter-Defibrillators (2007)]. / Registro Español de Desfibrilador Automático Implantable. IV Informe Oficial del Grupo de Trabajo de Desfibrilador Automático Implantable de la Sociedad Española de Cardiología (2007).

INTRODUCTION AND OBJECTIVES: This article presents the 2007 findings of the Spanish Implantable Cardioverter-Defibrillator (ICD) Registry, established by the Working Group on Implantable Cardioverter-Defibrillators, Electrophysiology and Arrhythmia Section, Spanish Society of Cardiology. METHODS: The Spanish Society of Cardiology received prospective data recorded on a single-page questionnaire on 96.6% of device implantations. RESULTS: Overall, 3,291 implantations were reported (90.1% of the estimated total). The reported implantation rate was 72.8 per million inhabitants, and 77.1% were first implantations. The majority of ICDs were implanted in males (mean age, 61 [12] years) in functional class II with severe or moderate-to-severe left ventricular dysfunction. The most frequent form of heart disease was ischemic heart disease, followed by dilated cardiomyopathy. Indications for primary prevention remained unchanged relative to the previous year and now account for half of all first implantations, with an increasing number of patients with dilated cardiomyopathy. The number of ICDs incorporating cardiac resynchronization therapy has increased slightly and now comprises 30.1% of the total. Around 70% of ICD implantations were performed in an electrophysiology laboratory by a cardiac electrophysiologist. The incidence of complications was very low. CONCLUSIONS: The 2007 Spanish Implantable Cardioverter-Defibrillator Registry contains data on more than 90% of all ICD implantations performed in Spain, thereby confirming that it has become increasingly representative in recent years. The number of implantations has continued to grow, though the proportion carried out for primary prevention has stabilized at around 50%.

[Spanish Implantable Cardioverter-Defibrillator Registry. Third Official Report of the Spanish Society of Cardiology Working Group on Implantable Cardioverter-Defibrillators (2006)]. / Registro Español de Desfibrilador Automático Implantable. III Informe Oficial del Grupo de Trabajo de Desfibrilador Automático Implantable de la Sociedad Española de Cardiología (2006).

INTRODUCTION AND OBJECTIVES: To report the 2006 findings of the Spanish Implantable Cardioverter-Defibrillator (ICD) Registry, established by the Working Group on Implantable Cardioverter-Defibrillators, Electrophysiology and Arrhythmia Section, Spanish Society of Cardiology. METHODS: Each ICD team voluntarily reported data to the Spanish Society of Cardiology by completing a single-page questionnaire. Prospective data were collected on 91.8% of implantations. RESULTS: In total, 2679 implantations were reported to the registry (86.6% of the estimated total). The reported implantation rate was 60 per million inhabitants, and the estimated rate was 69 per million. The proportion of first implantations was 80%. The majority of ICDs were implanted in males (mean age 61.5 [14] years) with severe or moderate-to-severe left ventricular dysfunction who were in functional class II or I. Ischemic heart disease was the most frequent etiology, followed by dilated cardiomyopathy. This is the first year that half of first device implantations were carried out for primary prevention, with substantial increases among patients with ischemic heart disease and dilated cardiomyopathy. The number of ICDs incorporating cardiac resynchronization therapy has continued to grow, and now comprises 28.6% of all devices implanted. As in the previous year, around 70% of ICD implantations were performed in an electrophysiology laboratory by a cardiac electrophysiologist. The incidence of complications during device implantation was very low. CONCLUSIONS: The 2006 Spanish Implantable Cardioverter-Defibrillator Registry contains data on more than 86% of all ICD implantations performed in Spain. Half of first device implantations were carried out for the purposes of primary prevention.

[Spanish registry of implantable cardioverter defibrillator. Second official report of the Spanish Society of Cardiology Working Group on Implantable Cardioverter Defibrillators (2005)]. / Registro Español de desfibrilador automático implantable. II informe oficial del Grupo de Trabajo de Desfibrilador Implantable de la Sociedad Española de Cardiología (2005).

INTRODUCTION AND OBJECTIVE: We report the results for the Spanish Registry on Implantable Cardioverter Defibrillators (ICD) (year 2005), developed by the Working Group on ICD of the Spanish Society of Cardiology. METHODS: Data were collected (prospectively in 77% of implants) by single page form questionnaires transmitted after the procedure to the Spanish Society of Cardiology. Participation was voluntary. RESULTS: The number of implants sent to the Registry was 2050 and this represents 74.4% of the total ICDs implanted. The implantation rate per million was 46.5 and the estimated total implantation rate per million was 62.5. The proportion of first implants was 70.3%. The majority of patients were males, with a median age of 65 years, severe or moderate to severe left ventricular dysfunction and in functional class II or I. Ischemic heart disease was the more frequent underlying heart disease followed by dilated cardiomyopathy. The main reason for ICD indication was secondary prevention related to sustained monomorphic ventricular tachycardia or aborted sudden cardiac death. A significant number of prophylactic indications were done, specially in non ischemic heart disease. The proportion of ICD implanted at the electrophysiology laboratory by cardiac electrophysiologist continues increasing. There was an increase in the number of ICD plus cardiac resynchronization therapy, that represent a 23.6% of the implants. The incidence of complications during the implant was very low. CONCLUSIONS: The National Registry on ICD, with a participation rate greater than in previous years, provides a representative sample of the ICD implants performed at our country.

Activation of inward rectifier potassium channels accelerates atrial fibrillation in humans: evidence for a reentrant mechanism.

BACKGROUND: It is unclear whether atrial fibrillation (AF) drivers in humans are focal or reentrant. To test the hypothesis that functional reentry is involved in human AF maintenance, we determined the effects of adenosine infusion on local dominant frequency (DF) at different atrial sites. By increasing inward rectifier potassium channel conductance, adenosine would increase DF of reentrant drivers but decrease it in the case of a focal mechanism. METHODS AND RESULTS: Thirty-three patients were studied during AF (21 paroxysmal, 12 persistent) using recordings from each pulmonary vein-left atrial junction (PV-LAJ), high right atrium, and coronary sinus. DFs were determined during baseline and peak adenosine effect. In paroxysmal AF, adenosine increased maximal DF at each region compared with baseline (PV-LAJ, 8.03+/-2.2 versus 5.7+/-0.8; high right atrium, 7+/-2.2 versus 5.4+/-0.7; coronary sinus, 6.6+/-1.1 versus 5.3+/-0.7 Hz; P=0.001) and increased the left-to-right DF gradient (P=0.007). In contrast, in persistent AF, adenosine increased DF only in the high right atrium (8.33+/-1.1 versus 6.8+/-1.2 Hz; P=0.004). In 4 paroxysmal AF patients, real-time DF mapping of the left atrium identified the highest DF sites near the PV-LAJ, where adenosine induced an increase in DF (6.7+/-0.29 versus 4.96+/-0.26 Hz; P=0.008). Finally, simulations demonstrate that the frequency of reentrant drivers accelerates proportionally to the adenosine-modulated inward rectifier potassium current. CONCLUSIONS: Adenosine accelerates drivers and increases frequency differently in paroxysmal compared with persistent human AF. The results strongly suggest that AF is maintained by reentrant sources, most likely located at the PV-LAJ in paroxysmal AF, whereas non-PV locations are more likely in persistent AF.

[Prognosis of heart transplant candidates stabilized on medical therapy]. / Pronóstico de una población inicialmente candidata a trasplante cardíaco controlada con tratamiento médico.

INTRODUCTION AND OBJECTIVES: A significant percentage of patients selected as candidates for heart transplantation can be stabilized by medical treatment, thereby enabling indefinite postponement of inclusion on the operation list. The aim of this study was to investigate the prognosis of these patients. PATIENTS AND METHOD: We studied retrospectively 118 patients with severe left ventricular systolic dysfunction (ejection fraction < or = 35%) who were consecutively evaluated for cardiac transplantation but who did not undergo transplantation because they became clinically stable on medical treatment. The mean follow-up period was 2.14 (2.19) years. Kaplan-Meier survival analysis, and univariate and multivariate Cox proportional risk analyses of factors predicting survival were performed. RESULTS: There were 18 deaths (15.2%): 12 were sudden (66.7%), 5 were due to heart failure (27.8%), and 1, to a non-cardiac cause (5.5%). The survival rate was 88% in the first year and 82% in the following 2 years. Univariate analysis showed that the parameters associated with mortality (P< or =.05) were pulmonary artery and capillary wedge pressures, diuretic treatment, and the absence of beta-blocker therapy. In the multivariate analysis, only the absence of beta-blocker therapy remained statistically significant (P=.003; RR = 0.13; 95%CI, 0.03-0.50). CONCLUSIONS: In a population of patients with severe left ventricular systolic dysfunction who were candidates for heart transplantation but who were stabilized by medical therapy, mortality during the first year of follow-up was 12%. Beta-blocker therapy was the only variable associated with better survival.

Predictors of in-hospital ventricular fibrillation or torsades de pointes in patients with acute symptomatic bradycardia.

Severe bradyarrythmias remain as an important cause for hospital urgent admission and these patients can suffer potentially lethal complications (such as ventricular fibrillation [VF] and torsades de pointes [TdP]) between hospital admission and final therapy. Incidence and predictors of these tachyarrhythmias have not been well established. We retrospectively studied all consecutive patients (N = 243, age 75 +/- 10 years; 47% men) admitted to the emergency department of a general hospital between January 1998 and July 2000 for symptomatic bradyarrhythmia. Concomitant therapy included diuretics (25%), digitalis (10%), beta-blockers (10%), amiodarone (2%), and verapamil or diltiazem (8%). Syncope was the most frequent symptom at admission (54%). The most prevalent inclusion bradyarrhythmia was > or =second-degree AV block (82%). Eleven patients (4.5%) presented VF or TdP. Univariate predictors for these complications were previous amiodarone or diuretic intake, presentation as syncope, low serum potassium level, and longer QTc at admission. Multivariate analysis with logistic regression showed only therapy with diuretics and/or amiodarone and QTc at admission as significant predictors for TdP or VF development. Incidence of VF or TdP in patients admitted for symptomatic bradyarrhythmia is relatively important. A prolonged QTc interval and/or therapy with amiodarone or diuretics can predict their presentation.

Acute and long-term outcome of transvenous cryoablation of midseptal and parahissian accessory pathways in patients at high risk of atrioventricular block during radiofrequency ablation.

The ability of transvenous cryothermal catheter ablation to create reversible lesions (cryomapping) and to avoid catheter dislodgment (cryoadherence) has been shown to be safe and highly effective in elimination of atrioventricular nodal reentrant tachycardia. In addition, cryoablation may be useful in the management of perinodal accessory pathways, but its efficacy and safety in patients at high risk of atrioventricular block during radiofrequency catheter ablation is unknown. This study prospectively evaluated the efficacy and safety of cryoablation in patients with midseptal and parahissian accessory pathways.