Ryszard B. Krol

Bio: Ryszard B. Krol is an academic researcher from Atlantic Health System. The author has contributed to research in topics: Atrial fibrillation & Coronary sinus. The author has an hindex of 5, co-authored 5 publications receiving 348 citations.

Regional endocardial mapping of spontaneous and induced atrial fibrillation in patients with heart disease and refractory atrial fibrillation.

Abstract: We performed simultaneous catheter mapping of right and left atrial regions at onset and during sustenance of spontaneous atrial fibrillation (AF) in patients with ischemic and/or hypertensive heart disease. Seventeen patients with structural heart disease had spontaneous and electrically induced AF episodes mapped from their onset simultaneously in multiple right and left atrial regions. Atrial premature complexes (APCs) that initiated spontaneous AF had coupling intervals ranging from 260 to 400 ms (mean 332 ± 61), most commonly arising from the lateral right atrium (31%), right atrioventricular junction (13%), atrial septum (6%), superior left atrium (25%), or inferior left atrium (25%). APC morphology on surface electrocardiograms did not correlate with origin in specific atrial regions. The earliest regions of atrial activation for the first AF cycle were the lateral right atrium (n = 5), superior left atrium (n = 4), distal or mid coronary sinus (n = 4), atrial septum (n = 2), and right atrioventricular junction at the His bundle location (n = 2). Spontaneous AF at onset usually showed discrete but irregular electrograms at virtually all right and left atrial sites mapped, with a reproducible region of AF initiation in all 8 patients with multiple events. The region of earliest atrial activation at spontaneous AF onset was in close proximity to the APC origin in 15 of 16 patients (94%), and 39 of 40 episodes (97%) mapped. Stable patterns of right and left atrial activation were observed at AF onset in 14 patients. Induced AF elicited with right atrial stimulation demonstrated different sites of earliest regional atrial activation at onset compared with spontaneous AF events in 4 of 8 patients. However, discrete intracardiac electrograms were also present in induced AF in all of the mapped atrial regions. Furthermore, the site of extrastimulus delivery in induced AF was also found to be in close proximity to the earliest region of atrial activation for the first AF beat. We conclude that spontaneous AF is initiated by APCs arising in different right or left atrial regions in patients with structural heart disease and the initial region of atrial activation in AF is in proximity to the region of APC origin. Organized and repetitive electrical activation is frequently observed in both right and left atria at AF onset. Although electrically induced AF may have different activation patterns than spontaneous AF at onset in many patients, both types of AF demonstrate organization and earliest atrial activation in proximity to the initiating APC.

Catheter ablation of inducible atrial flutter, in combination with atrial pacing and antiarrhythmic drugs ("hybrid therapy") improves rhythm control in patients with refractory atrial fibrillation.

Abstract: Atrial flutter or tachycardia may coexist with atrial fibrillation [AF] and can be treated with ablation techniques in attempt to reduce the total AF burden. The role of ablation of latent atrial tachyarrhythmias elicited at electrophysiologic study in conjunction with atrial pacing and antiarrhythmic drugs in patients with refractory AF has not been evaluated. We evaluated the efficacy of catheter ablation of electrically induced atrial flutter or atrial tachycardia in improving rhythm control in patients with refractory AF. Methods: Consecutive patients with refractory AF, and spontaneous atrial flutter (Group 1) or without spontaneous atrial flutter (Group 2) underwent programmed stimulation in a baseline drug-free state. All patients had electrically induced atrial flutter or tachycardia. Radiofrequency ablation of the arrhythmia substrate was performed in all patients. Primary endpoints evaluated for patient outcome in both groups included maintenance of rhythm control and freedom from recurrent atrial tachyarrhythmias. Results: Forty-three patients, with a mean age of 66±13 years were studied. Group 1 consisted of 22 patients while Group 2 had 21 patients. Ablation of the tricuspid valve-inferior venacaval isthmus was performed in 41 patients who had common atrial flutter induced at electrophysiologic study. Ablation of other atrial sites was performed in 8 patients with induced atypical flutter and 4 patients with induced atrial tachycardia. Ten of these patients had ablation of more than one arrhythmia. 17 patients (40%) had atrial pacing instituted and 28 patients remained on a class 1/3 antiarrhythmic drug. During a mean follow-up of 26±14 months, 33 patients (82.5%) remained in rhythm control. Actuarial analysis showed 96% of patients in rhythm control at 6 months, 94% at 12 months, and 90% at 24 months. Freedom from symptomatic AF recurrence was 64% at 6 months, 58% at 12 months, and 42% at 24 months. The outcome for both of these endpoints was similar for Group 1 and Group 2 (p = NS). The AF free interval increased significantly from 7±9 days to 172±121 days (p < 0.01) after ablation. This increase was again similar in both the groups. In the 14 patients were who did not receive atrial pacing and who remained on the same class 1/3 antiarrhythmic drug, the AF free interval increased from 18±17 days to 212±102 days (p < 0.01).

Right and left atrial activation during external direct-current cardioversion shocks delivered for termination of atrial fibrillation in humans.

Abstract: We examined the regional electrophysiologic effects of successful and unsuccessful direct-current cardioversion shocks on different right and left atrial regions in patients with sustained atrial fibrillation (AF). Patients with sustained AF undergoing external cardioversion underwent simultaneous mapping of the right and left atria. Electrogram changes after shock delivery, regional atrial activation, and effects of shock intensity were analyzed. Twenty-two patients with sustained AF received 52 shocks (mean 2.4/patient, 22 successful and 30 unsuccessful). The efficacy of 50, 100, 200, and 300 J was 18%, 39%, 100%, and 100%, respectively. In all 22 successful shocks, there was virtually simultaneous termination of electrical activity in all right and left atrial regions mapped. Unsuccessful shocks resulted in a significant increase in mean atrial cycle length at lateral right atrium, superior left atrium, and proximal, mid, and distal coronary sinus (p = 0.01), but not at the interatrial septum (p >0.2), which often disappeared before the next shock. This cycle length prolongation was accompanied by reduction in fragmented and chaotic electrograms (p <0.03) and emergence of discrete electrograms at all right and left atrial regions that persisted until the next shock. The changes in electrogram morphology failed to alter the surface electrocardiographic appearance of AF. There was no correlation between the shock intensity and the magnitude of these effects. We conclude that termination of AF with external cardioversion shocks is associated with the widespread extinction of regional atrial wave fronts. Unsuccessful shocks are associated with a temporary slowing of atrial activation at all regions except at the interatrial septum and emergence of organized and/or rapidly propagating wave fronts.

Catheter mapping of spontaneous and induced atrial fibrillation in man.

Abstract: The clinical electrophysiologic study of atrial fibrillation [AF] has recently progressed from static characterization of the substrate to the dynamic investigation of both induced and spontaneous AF in man. Prior studies have demonstrated inhomogeneity and greater dispersion of atrial refractoriness in patients with AF, but recently atrial electrical remodeling with consequent abbreviation of atrial refractory periods has also been reported. Yet further experimental observations have suggested the existence of additional arrhythmogenic mechanisms for certain AF subsets. These include studies that have demonstrated a stable atrial “flutter” circuit in one atrium with fibrillatory conduction or a “focal” atrial tachyarrhythmia arising commonly in the left atrium.

2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS

Abstract: The Task Force for the management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC Endorsed by the European Stroke Organisation (ESO)

ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation): Developed in Collaboration With the European Heart Rhythm Association and the Heart Rhythm Society

Abstract: Sidney C. Smith, Jr, MD, FACC, FAHA, FESC, Chair; Alice K. Jacobs, MD, FACC, FAHA, Vice-Chair; Cynthia D. Adams, MSN, APRN-BC, FAHA; Jeffery L. Anderson, MD, FACC, FAHA; Elliott M. Antman, MD, FACC, FAHA[‡][1]; Jonathan L. Halperin, MD, FACC, FAHA; Sharon Ann Hunt, MD, FACC, FAHA; Rick Nishimura,

ACC/AHA/ESC Guidelines for the Management of Patients With Atrial Fibrillation: Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients With Atrial Fibrillation) Developed in Collaboration With the North American Society of Pacing and Electrophysiology

Abstract: Atrial fibrillation (AF), the most common sustained cardiac rhythm disturbance, is increasing in prevalence as the population ages. Although it is often associated with heart disease, AF occurs in many patients with no detectable disease. Hemodynamic impairment and thromboembolic events result in significant morbidity, mortality, and cost. Accordingly, the American College of Cardiology (ACC), the American Heart Association (AHA), and the European Society of Cardiology (ESC) created a committee of experts to establish guidelines for management of this arrhythmia. The committee was composed of 8 members representing the ACC and AHA, 4 representing the ESC, 1 from the North American Society of Pacing and Electrophysiology (NASPE), and a representative of the Johns Hopkins University Evidence-Based Practice Center representing the Agency for Healthcare Research and Quality’s report on Atrial Fibrillation in the Elderly. This document was reviewed by 3 official reviewers nominated by the ACC, 3 nominated by the AHA, and 3 nominated by the ESC, as well as by the ACC Clinical Electrophysiology Committee, the AHA ECG and Arrhythmia Committee, NASPE, and 25 reviewers nominated by the writing committee. The document was approved for publication by the governing bodies of the ACC, AHA, and ESC and officially endorsed by NASPE. These guidelines will be reviewed annually by the task force and will be considered current unless the task force revises or withdraws them from distribution. The committee conducted a comprehensive review of the literature from 1980 to June 2000 relevant to AF using the following databases: PubMed/Medline, EMBASE, the Cochrane Library (including the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Registry), and Best Evidence. Searches were limited to English language sources and to human subjects. ### A. Atrial Fibrillation AF is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function. On the electrocardiogram (ECG), AF …