Ralph Lazzara

Development and Validation of an ECG Algorithm for Identifying Accessory Pathway Ablation Site in Wolff-Parkinson-White Syndrome

ECG Localization of Accessory AV Pathways. Introduction: Delta wave morphology correlates with the site of ventricular insertion of accessory AV pathways. Because lesions due to radiofrequency (RF) current are small and well defined, it may allow precise localization of accessory pathways. The purpose of this study was to use RF catheter ablation to develop an ECG algorithm to predict accessory pathway location.

Focal Atrial Fibrillation: Experimental Evidence for a Pathophysiologic Role of the Autonomic Nervous System

Focal AF and Autonomic Nerves. Introduction: Focal paroxysmal atrial fibrillation (AF) was shown recently to originate in the pulmonary veins (PVs) and superior vena cava (SVC). In the present study, we describe an animal model in which local high‐frequency electrical stimulation produces focal atrial activation and AF/AT (atrial tachycardia) with electrogram characteristics consistent with clinical reports.

Autonomic Mechanism to Explain Complex Fractionated Atrial Electrograms (CFAE)

Objective:u2002To simulate complex fractionated atrial electrograms (CFAE) during sustained atrial fibrillation (AF) in experimental animals.

Gradients of atrial refractoriness and inducibility of atrial fibrillation due to stimulation of ganglionated plexi.

Introduction. The mechanism(s) whereby atrial ectopy induces atrial fibrillation (AF) is still poorly understood.

Low‐Level Vagosympathetic Nerve Stimulation Inhibits Atrial Fibrillation Inducibility: Direct Evidence by Neural Recordings from Intrinsic Cardiac Ganglia

Intrinsic Cardiac Ganglia Activity Inhibited by Low‐Level Vagal Stimulation.u2002Introduction: We hypothesized that low‐level vagosympathetic stimulation (LL‐VNS) can suppress atrial fibrillation (AF) by inhibiting the activity of the intrinsic cardiac autonomic nervous system (ICANS).

Comparison of Cryothermia and Radiofrequency Current in Safety and Efficacy of Catheter Ablation within the Canine Coronary Sinus Close to the Left Circumflex Coronary Artery

Introduction: A canine model was used to compare cryoablation and radiofrequency ablation (RFA) within the coronary sinus (CS) in the ability to create a transmural CS myocardial (Trans‐CSM) lesion and risk of coronary artery stenosis.

The benefit of cardiac resynchronization therapy and QRS duration: a meta-analysis.

CRT and QRS Duration. Background: Cardiac resynchronization therapy (CRT) improves outcomes in patients with heart failure (HF) because of reduced left ventricular systolic function and a wide QRS complex. Whether this benefit is consistent across all degrees of QRS widening is unclear. We performed a meta‐analysis of randomized clinical trials to evaluate the impact of QRS duration on the efficacy of CRT.

Autonomic Mechanism for Complex Fractionated Atrial Electrograms: Evidence by Fast Fourier Transform Analysis

Introduction: The mechanism(s) underlying complex fractionated atrial electrograms (CFAE) is not well understood. We hypothesized that CFAE may be caused by enhanced activity of the intrinsic cardiac autonomic nervous system.

Analysis of troponin I levels after spontaneous implantable cardioverter defibrillator shocks.

Troponin I Levels After Spontaneous ICD Shocks. Introduction: Serum cardiac troponin I (cTnI) is a sensitive and specific marker for myocardial injury. Myocardial ischemia and/or injury can be a trigger for ventricular arrhythmias. The aim of this study was to assess the frequency and significance of elevated serum cTnI levels after spontaneous implantable cardioverter defibrillator (ICD) shocks.

Low-level right vagal stimulation: anticholinergic and antiadrenergic effects.

Right Vagal Stimulation Suppresses Atrial Fibrillation. Introduction: We sought to extend the use of low‐level vagal stimulation by applying it only to the right vagus nerve (LL‐RVS) to suppress atrial fibrillation (AF).