Jesús Martínez-Alday

Comparison of radiofrequency catheter ablation of drivers and circumferential pulmonary vein isolation in atrial fibrillation: a noninferiority randomized multicenter RADAR-AF trial.

BACKGROUND Empiric circumferential pulmonary vein isolation (CPVI) has become the therapy of choice for drug-refractory atrial fibrillation (AF). Although results are suboptimal, it is unknown whether mechanistically-based strategies targeting AF drivers are superior. OBJECTIVES This study sought to determine the efficacy and safety of localized high-frequency source ablation (HFSA) compared with CPVI in patients with drug-refractory AF. METHODS This prospective, multicenter, single-blinded study of 232 patients (age 53 ± 10 years, 186 males) randomized those with paroxysmal AF (n = 115) to CPVI or HFSA-only (noninferiority design) and those with persistent AF (n = 117) to CPVI or a combined ablation approach (CPVI + HFSA, superiority design). The primary endpoint was freedom from AF at 6 months post-first ablation procedure. Secondary endpoints included freedom from atrial tachyarrhythmias (AT) at 6 and 12 months, periprocedural complications, overall adverse events, and quality of life. RESULTS In paroxysmal AF, HFSA failed to achieve noninferiority at 6 months after a single procedure but, after redo procedures, was noninferior to CPVI at 12 months for freedom from AF and AF/AT. Serious adverse events were significantly reduced in the HFSA group versus CPVI patients (p = 0.02). In persistent AF, there were no significant differences between treatment groups for primary and secondary endpoints, but CPVI + HFSA trended toward more serious adverse events. CONCLUSIONS In paroxysmal AF, HFSA failed to achieve noninferiority at 6 months but was noninferior to CPVI at 1 year in achieving freedom of AF/AT and a lower incidence of severe adverse events. In persistent AF, CPVI + HFSA offered no incremental value. (Radiofrequency Ablation of Drivers of Atrial Fibrillation [RADAR-AF]; NCT00674401).

Epidemiological characteristics and diagnostic approach in patients admitted to the emergency room for transient loss of consciousness: Group for Syncope Study in the Emergency Room (GESINUR) study

AIMS To assess the clinical presentation and acute management of patients with transient loss of consciousness (T-LOC) in the emergency department (ED). METHODS AND RESULTS A multi-centre prospective observational study was carried out in 19 Spanish hospitals over 1 month. The patients included were > or =14 years old and were admitted to the ED because of an episode of T-LOC. Questionnaires and corresponding electrocardiograms (ECGs) were reviewed by a Steering Committee (SC) to unify diagnostic criteria, evaluate adherence to guidelines, and diagnose correctly the ECGs. We included 1419 patients (prevalence, 1.14%). ECG was performed in 1335 patients (94%) in the ED: 498 (37.3%) ECGs were classified as abnormal. The positive diagnostic yield ranged from 0% for the chest X-ray to 12% for the orthostatic test. In the ED, 1217 (86%) patients received a final diagnosis of syncope, whereas the remaining 202 (14%) were diagnosed of non-syncopal transient loss of consciousness (NST-LOC). After final review by the SC, 1080 patients (76%) were diagnosed of syncope, whereas 339 (24%) were diagnosed of NST-LOC (P < 0.001). Syncope was diagnosed correctly in 84% of patients. Only 25% of patients with T-LOC were admitted to hospitals. CONCLUSION Adherence to clinical guidelines for syncope management was low; many diagnostic tests were performed with low diagnostic yield. Important differences were observed between syncope diagnoses at the ED and by SC decision.

Ventricular fusion during resetting and entrainment of orthodromic supraventricular tachycardia involving septal accessory pathways. Implications for the differential diagnosis with atrioventricular nodal reentry.

BackgroundVentricular fusion during transient entrainment of orthodromic atrioventricular reciprocating tachycardias (OAVRT) was originally found to be absent and recently observed only with left ventricular stimulation. However, previous studies were restricted to cases with a left free wall accessory pathway. The hypothesis of the present study was that fusion is likely during resetting and entrainment of OAVRT with right ventricular stimulation if the accessory pathway is septally located, since its insertion is relatively close to the stimulation site. This phenomenon can help in the differential diagnosis with atrioventricular nodal reentry (AVNR). Methods and ResultsWe performed programmed right ventricular stimulation during regular inducible supraventricular tachycardia with concentric atrial activation in 44 patients- 20 with OAVRT and 24 with AVNR Fusion in the ECG morphology of extrastimuli producing resetting was observed in 19 of 19 OAVRT but in 0 of 11 AVNR reset (P<.001). Transient entrainment was demonstrated in all 31 cases undergoing rapid ventricular pacing (14 OAVRT and 17 AVNR). Entrainment with fusion occurred in 13 of 14 OAVRT and in 0 of 17 AVNR (P<.001). Fusion was critically dependent on the coupling intervals or pacing rates, sometimes having a narrow window for its observation. ConclusionsThe relative proximity (conduction time) among pacing site, site of entrance to a reentrant circuit, and site of exit from the circuit to the paced chamber are critical for the occurrence of fusion during resetting and/or entrainment. The presence or absence of fusion during these phenomena can help in the differential diagnosis of certain supraventricular tachycardias.

Prognostic value of the electrocardiogram in patients with syncope: Data from the Group for Syncope Study in the Emergency Room (GESINUR)

BACKGROUND The Group for Syncope Study in the Emergency Room (GESINUR) was a Spanish multicenter, prospective, observational study that evaluated the clinical presentation and acute management of loss of consciousness in Spain. Several studies have shown that an abnormal ECG is a poor prognostic factor in patients with syncope. However, the prognostic significance of each ECG abnormality is not well known. OBJECTIVE The purpose of this study was to study the association between specific ECG abnormalities and mortality in patients with syncope from the GESINUR study. METHODS All patients in the GESINUR study who had syncope and had available, readable ECG and 12-month follow-up data were included in this retrospective observational study (n = 524, age 57 ± 22 years, 50.6% male). ECG abnormalities were analyzed and assessed to evaluate whether an association with all-cause mortality existed at 12 months. RESULTS ECGs were classified as abnormal in 344 patients (65.6%). Thirty-three patients died during follow-up (6.3%), but only 1 due to sudden cardiovascular death. Atrial fibrillation (odds ratio [OR] 6.8, 95% confidence interval [CI] 2.8-16.3, P <.001), intraventricular conduction disturbances (OR 3.8, 95% CI 1.7-8.3, P = .001), left ventricular hypertrophy ECG criteria (OR 6.3, 95% CI 1.5-26.3, P = .011), and ventricular pacing (OR 21.8, 95% CI 4.1-115.3, P <.001) were the only independent ECG predictors of all-cause mortality. CONCLUSION Although an abnormal ECG in patients with syncope is a common finding, only the presence of atrial fibrillation, intraventricular conduction disturbances, left ventricular hypertrophy ECG criteria, and ventricular pacing is associated with 1-year all-cause mortality.

Transseptal Catheterization Using Electrophysiological Landmarks in Ablation Procedures

Since the development of radiofrequency catheter ablation for the treatment of atrial fibrillation, electrophysiology laboratories have experienced a significant rise in the number of transseptal catheterization procedures. Traditionally, the procedure requires the presence of a interventional cardiologist who carries out transseptal catheterization following arterial puncture and placement of a reference pigtail catheter in the aortic root. Use of His bundle and coronary sinus catheters to provide anatomical and electrophysiological landmarks enables transseptal catheterization to be carried out without the need for arterial puncture or intracavity pressure measurement. We report our experience with transseptal catheterization in an electrophysiology laboratory using only electrophysiological landmarks. The procedure was carried out on 68 occasions and was successful in all patients except one, in whom catheterization could not be performed for anatomical reasons and because the patient had previously received anticoagulation therapy. One other patient developed transient ST elevation, which was probably due to an air embolism.

Punción transeptal mediante referencias electrofisiológicas para procedimientos de ablación

Desde el desarrollo de la ablacion con radiofrecuencia para el tratamiento curativo de la fibrilacion auricular, los laboratorios de electrofisiologia han experimentado un incremento considerable en el numero de cateterismos transeptales. Tradicionalmente, el procedimiento requeria la intervencion de un hemodinamista que procedia a realizar el cateterismo transeptal previa puncion arterial y colocacion de un cateter pigtail de referencia en la raiz aortica. Utilizando el cateter del His y el del seno coronario como referencias anatomo-electrofisiologicas se puede llevar a cabo el cateterismo transeptal sin necesidad de realizar puncion arterial ni medicion de presiones intracavitarias. Presentamos nuestra experiencia en cateterizacion transeptal en el laboratorio de electrofisiologia utilizando referencias puramente electrofisiologicas. Hemos realizado el procedimiento en 68 ocasiones, con resultado exitoso en todos los casos salvo en uno, en el que la puncion no pudo llevarse a cabo por dificultades en el acceso anatomico y porque el paciente se encontraba previamente anticoagulado. Un paciente presento elevacion transitoria del segmento ST, probablemente debida a un embolismo aereo.

Differences in the yield of the implantable loop recorder between secondary and tertiary centers

BACKGROUND The implantable loop recorder (ILR) is a useful tool for diagnosis of syncope or palpitations. Its easy use and safety have extended its use to secondary hospitals (those without an Electrophysiology Lab). The aim of the study was to compare results between secondary and tertiary hospitals. METHODS National prospective and multicenter registry of patients with an ILR inserted for clinical reasons. Data were collected in an online database. The follow-up ended when the first diagnostic clinical event occurred, or 1 year after implantation. Data were analyzed according to the center of reference; hospitals with Electrophysiology Lab were considered Tertiary Hospitals, while those hospitals without a lab were considered Secondary Hospitals. RESULTS Seven hundred and forty-three patients (413 [55.6%] men; 65 ± 16 year-old): 655 (88.2%) from Tertiary Centers (TC) and 88 (11.8%) from Secondary Centers (SC). No differences in clinical characteristics between both groups were found. The electrophysiologic study and the tilt table test were conducted more frequently in Tertiary Centers. Follow-up was conducted for 680 (91.5%) patients: 91% in TC and 94% in SC. There was a higher rate of final diagnosis among SC patients (55.4% vs. 30.8%; p < 0.001). Tertiary Hospital patients showed a trend towards a higher rate of neurally mediated events (20% vs. 4%), while bradyarrhythmias were more frequent in SC (74% vs. 60%; p = 0.055). The rate of deaths and adverse events was similar in both populations. CONCLUSIONS Patients with an ILR in SC and TC have differences in terms of the use of complementary tests, but not in clinical characteristics. There was a higher rate of diagnosis in Secondary Hospital patients.

Comparison of Radiofrequency Catheter Ablation of Drivers and Circumferential Pulmonary Vein Isolation in Atrial Fibrillation

BACKGROUND Empiric circumferential pulmonary vein isolation (CPVI) has become the therapy of choice for drug-refractory atrial fibrillation (AF). Although results are suboptimal, it is unknown whether mechanistically-based strategies targeting AF drivers are superior. OBJECTIVES This study sought to determine the efficacy and safety of localized high-frequency source ablation (HFSA) compared with CPVI in patients with drug-refractory AF. METHODS This prospective, multicenter, single-blinded study of 232 patients (age 53 ± 10 years, 186 males) randomized those with paroxysmal AF (n = 115) to CPVI or HFSA-only (noninferiority design) and those with persistent AF (n = 117) to CPVI or a combined ablation approach (CPVI + HFSA, superiority design). The primary endpoint was freedom from AF at 6 months post-first ablation procedure. Secondary endpoints included freedom from atrial tachyarrhythmias (AT) at 6 and 12 months, periprocedural complications, overall adverse events, and quality of life. RESULTS In paroxysmal AF, HFSA failed to achieve noninferiority at 6 months after a single procedure but, after redo procedures, was noninferior to CPVI at 12 months for freedom from AF and AF/AT. Serious adverse events were significantly reduced in the HFSA group versus CPVI patients (p = 0.02). In persistent AF, there were no significant differences between treatment groups for primary and secondary endpoints, but CPVI + HFSA trended toward more serious adverse events. CONCLUSIONS In paroxysmal AF, HFSA failed to achieve noninferiority at 6 months but was noninferior to CPVI at 1 year in achieving freedom of AF/AT and a lower incidence of severe adverse events. In persistent AF, CPVI + HFSA offered no incremental value. (Radiofrequency Ablation of Drivers of Atrial Fibrillation [RADAR-AF]; NCT00674401).

Acute Intraprocedural Gastroparesis During Pulmonary Vein Cryoablation

Gastroparesis is a syndrome characterized by delayed gastric emptying in the absence of obstruction leading to epigastric discomfort, abdominal distention, nausea, and vomiting, although it can also be asymptomatic. One of the causes of acute gastroparesis, which is not widely reported and is unfamiliar to many cardiologists, is gastroparesis secondary to pulmonary vein (PV) cryoablation, a technique that is available at over 50% of Spanish electrophysiology laboratories. Based on a case of gastroparesis, we have reviewed this syndrome. We report the case of a 59-year-old man, with a history of symptomatic paroxysmal atrial fibrillation despite the use of antiarrhythmic drugs, in whom we decided to perform PV cryoablation. During the procedure, performed under sedation with remifentanil and propofol, we observed a small left atrium on angiography (37 mm in the previous echocardiogram) with 4 independent PVs. We decided to use a 28-mm second-generation Medtronic Arctic Front cryoballoon. Due to poor occlusion and poor temperatures, 4 applications were required to isolate the left upper PV, 2 applications for the left lower PV, and another 2 for the right upper PV. In the right lower PV, which was the smallest in terms of the balloon, 3 applications were initially performed with a minimum temperature of –36 8C; there was a transient loss of phrenic nerve capture during 1 application. The vein was finally isolated with a 23-mm balloon with a single application for 64 s at –60 8C. The total cryoablation time was 26 minutes. The mean minimum temperature reached in all applications was –40 16 8C. No bonus applications were given after isolating the veins. On removal of the catheters, fluoroscopy revealed gastric dilation with air accumulation in the fundus (Figure 1). Although the patient only had abdominal distension with tympanism and flatulence, we decided to place him under observation in the coronary care unit for 6 hours. Treatment was started with prokinetics (metoclopramide and erythromycin), antisecretory drugs, and a nil per os diet for the first 24 hours. A nasogastric tube was not required. In the following 24 hours, the symptoms and radiological changes were resolved (Figure 2). The patient remains asymptomatic. Several studies have related acute gastroparesis following ablation to injury to the nerve fibers that innervate the pyloric sphincter and the stomach. These nerves mainly travel with the left vagal trunk through the anterior part of the esophagus, close to the posterior wall of the left atrium and the ostium of the PVs. Application of heat or cold in the posterior wall of the left atrium may damage these perioesophageal nerves, whether transiently or permanently, and may lead to gastroparesis. Of the few published cases of gastroparesis following PV ablation, the majority occurred in patients undergoing radiofrequency ablation. Symptoms appeared within a few hours of the procedure, and spontaneously resolved with medical treatment and observation. In the case of PV cryoablation, a study by Guiot et al. in 66 patients showed, using endoscopic assessment of gastric Figure 1. Image of fluoroscopy showing gastric bubble distension.

Update on Arrhythmias and Cardiac Pacing 2013

This report discusses a selection of the most relevant articles on cardiac arrhythmias and pacing published in 2013. The first section discusses arrhythmias, classified as regular paroxysmal supraventricular tachyarrhythmias, atrial fibrillation, and ventricular arrhythmias, together with their treatment by means of an implantable cardioverter defibrillator. The next section reviews cardiac pacing, subdivided into resynchronization therapy, remote monitoring of implantable devices, and pacemakers. The final section discusses syncope.