Long-Term Impact of Right Ventricular Pacing on Left Ventricular Systolic Function in Pacemaker Recipients With Preserved Ejection Fraction: Results From a Large Single-Center Registry.

Background: There is limited evidence of long-term impact of right ventricular pacing on left ventricular (LV) systolic function in pacemaker recipients with preserved LV ejection fraction (LVEF). The objective of the study was to evaluate the outcome and echocardiographic course of baseline preserved LVEF in a large cohort of pacemaker recipients with respect to pacing indication and degree of right ventricular pacing.

Methods And Results: We enrolled 991 patients (73±10 years, 54% male) with baseline normal (>55%) LVEF (n=791) or mildly reduced (41-55%) LVEF (n=200) who had paired echocardiographic data on LV systolic function recorded at implantation and last follow-up.

Cellular damage, platelet activation, and inflammatory response after pulmonary vein isolation: a randomized study comparing radiofrequency ablation with cryoablation.

Background: Experimental data suggest that use of cryoablation in pulmonary vein isolation (PVI) is associated with less cell damage and less thrombus formation compared to radiofrequency (RF) energy.

Objective: The purpose of this study was to test the hypothesis that cryoablation significantly reduces markers of cell damage, platelet activation, and inflammation in patients undergoing PVI for treatment of atrial fibrillation (AF).

Methods: Sixty patients with symptomatic drug-resistant AF (age 56 ± 9 years, 48 males, 38 with paroxysmal AF) were randomly assigned to undergo PVI using either an open irrigated-tip RF catheter or a cryoballoon.

The impact of body mass index on the efficacy and safety of catheter ablation of atrial fibrillation.

Background: Obesity is a well established risk factor for atrial fibrillation (AF) development. Our purpose was to determine the impact of body mass index (BMI) on the safety and efficacy of radiofrequency catheter ablation of AF.

Methods: Two hundred and twenty-six consecutive patients with symptomatic, drug-refractory paroxysmal (59.

Long-term prognosis of asymptomatic individuals with spontaneous or drug-induced type 1 electrocardiographic phenotype of Brugada syndrome.

Background: Risk stratification of asymptomatic individuals with type 1 electrocardiogram (ECG) phenotype of Brugada syndrome (BS) still remains controversial. This study investigated the long-term prognosis of asymptomatic subjects with spontaneous or drug-induced type 1 ECG pattern of BS.

Methods And Results: Data from 33 apparently healthy individuals (30 males; age, 43.

Epsilon-like waves and ventricular conduction abnormalities in subjects with type 1 ECG pattern of Brugada syndrome.

Background: Previous studies have demonstrated an overlap between the arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and Brugada syndrome (BS). Conduction delay in the right ventricle has been demonstrated in both entities.

Objective: This study investigated specific ARVC/D electrocardiographic (ECG) markers in subjects with spontaneous or drug-induced type 1 ECG pattern of BS.

Electrocardiographic differentiation of common type atrioventricular nodal reentrant tachycardia from atrioventricular reciprocating tachycardia via a concealed accessory pathway.

Objective: The present study aimed to evaluate the diagnostic value of specific ECG markers in the differentiation of common type atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) via a concealed accessory pathway.

Methods: One hundred and ten ECGs with paroxysmal narrow QRS complex, short RP tachycardia were evaluated. Subjects with overt ventricular pre-excitation during sinus rhythm were excluded from the study.

QRS complex abnormalities in subjects with idiopathic ventricular fibrillation.

Recent data point to a high incidence of early repolarization abnormalities among patients with idiopathic ventricular fibrillation (IVF). ECG data from 11 patients with idiopathic IVF were evaluated for the presence of initial (slurring or notching of the ascending limb of the R-wave that resembles a "pseudo" delta-wave) and terminal (slurring or notching of the descending limb of the R-wave resembling the early repolarization pattern) QRS complex abnormalities in at least two contiguous leads. The control group comprised 101 age- and gender-matched healthy individuals without structural heart disease in whom the presence of an accessory pathway was excluded during electrophysiological study.

Tpeak-Tend interval and Tpeak-Tend/QT ratio as markers of ventricular tachycardia inducibility in subjects with Brugada ECG phenotype.

Aims: The present study investigated whether several ECG markers of ventricular repolarization are associated with ventricular tachycardia/fibrillation (VT/VF) inducibility in subjects with type 1 ECG pattern of Brugada syndrome (BS).

Methods And Results: The clinical data of 23 individuals (19 males, age 42.69 +/- 14.

Pressure-guided cryoballoon isolation of the pulmonary veins for the treatment of paroxysmal atrial fibrillation.

Background: Pulmonary vein (PV) isolation using a balloon-mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Complete PV occlusion during balloon ablation has been shown to predict successful electrical isolation. The aim of this study was to correlate mechanical PV occlusion with changes in a pressure curve recorded at the distal tip of the cryoballoon catheter.

Cryoballoon pulmonary vein isolation guided by transesophageal echocardiography: novel aspects on an emerging ablation technique.

Background: Pulmonary vein (PV) isolation using a balloon-mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Transesophageal echocardiography (TEE) allows real-time visualization of cryoballoon positioning and successful vein occlusion via color Doppler. We hypothesized that PV mechanical occlusion monitored with TEE could predict effective electrical isolation.

Adenosine sensitive focal atrial tachycardia originating from the non-coronary aortic cusp.

We report on the characteristics and the ablation procedure of a focal atrial tachycardia originating from the non-coronary aortic cusp. The electrophysiological features of the tachycardia included: (i) incessant pattern; (ii) easy induction and termination by atrial stimulation; (iii) earliest right atrial activation at the para-hisian area; and (iv) termination by adenosine. Left-sided mapping revealed the earliest atrial activation during the tachycardia at the non-coronary aortic cusp.

Predictors of atrial tachyarrhythmias in subjects with type 1 ECG pattern of Brugada syndrome.

Background: Previous studies have demonstrated a high incidence of atrial tachyarrhythmias (ATs) in patients with Brugada syndrome (BS). The present study aimed to investigate whether various 12-lead electrocardiogram (ECG) and electrophysiological parameters may help to differentiate subjects with a high probability to develop ATs.

Methods And Results: The clinical records of 38 individuals (31 males, age 44.

Prevalence of early repolarization pattern in inferolateral leads in patients with Brugada syndrome.

Background: Recent data have shown a high incidence of the early repolarization pattern confined in inferolateral leads in patients with idiopathic ventricular fibrillation.

Objectives: The purpose of the present study was to investigate the prevalence and the prognostic significance of the early repolarization pattern in inferolateral leads in patients with Brugada syndrome.

Methods: Clinical, genetic, and electrophysiologic data from 290 individuals (223 males, mean age 48.

Pre-ablative predictors of atrial fibrillation recurrence following pulmonary vein isolation: the potential role of inflammation.

Aims: An increasing body of evidence has demonstrated the essential role of inflammation in the genesis and maintenance of atrial fibrillation (AF). The aim of the present study was to investigate whether success or failure of electrical pulmonary vein isolation (PVI) in patients with AF is related with the presence of a pre-ablative inflammatory state as determined by known clinical parameters and conventional markers of inflammation including high-sensitivity C-reactive protein, white blood cell (WBC) count, and fibrinogen.

Methods And Results: Seventy-two patients with paroxysmal (64%) or persistent AF (36%) underwent successful electrical PVI.

Catheter ablation of recipient-to-donor atrioatrial conduction with Wenckebach-like phenomenon after orthotopic heart transplantation.

This report describes a case of atrial tachycardia in the recipient atrium manifested electrocardiographically as typical atrial flutter in the donor atrium due to atrioatrial conduction delay with Wenckebach-like phenomenon at the anastomotic line. Radio-frequency energy application resulted in immediate recipient-to-donor conduction block.

Necessity for surgical revision of defibrillator leads implanted long-term: causes and management.

Background: Defibrillator lead malfunction is a potential long-term complication in patients with an implantable cardioverter-defibrillator (ICD). The aim of this study was to determine the incidence and causes of lead malfunction necessitating surgical revision and to evaluate 2 approaches to treat lead malfunction.

Methods And Results: We included 1317 consecutive patients with an ICD implanted at 3 European centers between 1993 and 2004.

Pulmonary edema after extensive radiofrequency ablation for atrial fibrillation.

Background: More extensive ablation strategies for the treatment of atrial fibrillation (AF) have increased success rates but are associated with new and sometimes serious complications. We describe a new complication after extensive radiofrequency (RF) ablation in the left atrium (LA) for persistent AF.

Methods And Results: Electroanatomic guided circumferential ablation around both ipsilateral pulmonary veins (PV) was performed with the endpoint of complete conduction block.

Small or large isolation areas around the pulmonary veins for the treatment of atrial fibrillation? Results from a prospective randomized study.

Background: Pulmonary vein (PV) isolation is a promising new treatment for atrial fibrillation (AF). We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV.

Methods And Results: A total of 110 patients, 67 with paroxysmal AF and 43 with persistent AF, were randomly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs.

Platelet activation and myocardial necrosis in patients undergoing radiofrequency and cryoablation of isthmus-dependent atrial flutter.

Aims: Lower platelet activation by cryoenergy compared with radiofrequency (RF) energy was recently demonstrated immediately following ablation procedures of cardiac arrhythmias. Due to the delayed occurrence of cryolesions it is currently unknown, if cryoenergy and RF energy are associated with similar platelet activation and myocardial necrosis in the days after the procedure.

Methods And Results: We enrolled 38 patients with common atrial flutter undergoing cavotricuspid isthmus ablation with either RF energy (n = 23) or cryoenergy (n = 13).

High-density mapping of spontaneous pulmonary vein activity initiating atrial fibrillation in humans.

Introduction: High-density three-dimensional (3D) mapping of the pulmonary vein (PV)-left atrial (LA) junction was performed to characterize spontaneous PV activity in humans.

Methods And Results: The activation patterns of ectopic beats and of the initial 2 seconds of atrial fibrillation (AF) from the PVs were analyzed using a 64-poles basket catheter. A focal mechanism was defined as a discrete site of early and centrifugal activation.

Permanent form of junctional reciprocating tachycardia in adults: peculiar features and results of radiofrequency catheter ablation.

Aim: PJRT occurs predominantly in infants and children and is limited to small series in adults. The aim of this study was to describe the clinical presentation, electrophysiological characteristics, feasibility and safety of radiofrequency ablation, and the long-term prognosis in a large group of adult patients with the permanent form of junctional reciprocating tachycardia (PJRT).

Methods And Results: Forty-nine adult patients (22 male and 27 female; mean age 43+/-16) with a diagnosis of PJRT confirmed at electrophysiological study were included.

An electrocardiogram-based algorithm to detect loss of left ventricular capture during cardiac resynchronization therapy.

Background: Loss of left ventricular capture in patients with cardiac resynchronization devices may account for worsening heart failure and can be difficult to diagnose without a programmer.

Objective: To determine whether distinct morphologic changes on the surface electrocardiogram indicate loss of left ventricular capture.

Design: After analysis of the R-S spike ratio in the 12-lead electrocardiogram during right ventricular and biventricular pacing in 10 patients, an algorithm to detect loss of left ventricular capture was developed.

Transesophageal echocardiography in comparison with magnetic resonance imaging in the diagnosis of pulmonary vein stenosis after radiofrequency ablation therapy.

Objective: Doppler-derived flow velocity measured by transesophageal echocardiography (TEE) may overestimate pulmonary vein stenosis. We hypothesized that combining peak velocity with a stenotic flow pattern improves diagnosis compared with magnetic resonance imaging (MRI).

Methods: TEE and MRI were performed in 44 patients 19 +/- 11 months after radiofrequency catheter ablation.