Spatial characteristics of atrial fibrillation using the surface ECG

Abstract Background Advanced interatrial block (IAB), prolonged and bimodal P waves in surface ECG inferior leads, is an unrecognized surrogate of atrial dysfunction and a trigger of atrial dysrhythmias, mainly atrial fibrillation (AF). Our aim was to prospectively assess whether advanced IAB in sinus rhythm precedes AF and stroke in elderly outpatients with structural heart disease, a group not previously studied. Methods Prospective observational registry that included outpatients aged ≥70 years with structural heart disease and no previous diagnosis of AF. Patients were divided into three groups according to P-wave characteristics. Results Among 556 individuals, 223 had normal P-wave (40.1%), 196 partial IAB (35.3%), and 137 advanced IAB (24.6%). After a median follow-up of 694 days; 93 patients (16.7%) developed AF, 30 stroke (5.4%), and 34 died (6.1%). Advanced IAB was independently associated with AF (hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.7–5.1, p<0.001), stroke (HR 3.8, 95% CI 1.4–10.7, p=0.010), and AF/stroke (HR 2.6, 95% CI 1.5–4.4, p=0.001). P-wave duration (ms) was independently associated with AF (HR 1.05, 95% CI 1.03–1.07, p<0.001), AF/stroke (HR 1.04, 95% CI 1.02–1.06, p<0.001), and mortality (HR 1.04, 95% CI 1.00–1.08, p=0.021). Conclusions The presence of advanced IAB in sinus rhythm is a risk factor for AF and stroke in an elderly population with structural heart disease and no previous diagnosis of AF. P-wave duration was also associated with all-cause mortality. Figure. Age- and sex-adjusted linear and non-linear association between P-wave duration (msec) and atrial fibrillation (A), stroke (B), and atrial fibrillation or stroke (C) risk. Results of a generalized additive model with spline smoothing functions and 4 degrees of freedom. Figure 1. Kaplan-Meyer curves of survival free of atrial fibrillation (A), stroke (B) and atrial fibrillation or stroke (C) in patients with normal P-wave, partial interatrial block (IAB) and advanced IAB. Funding Acknowledgement Type of funding source: None

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Inducibility, but not stability, of atrial fibrillation is increased by NOX2 overexpression in mice

Cardiovascular Research ◽

10.1093/cvr/cvab019 ◽

2021 ◽

Author(s):

Alexandra S Mighiu ◽

Alice Recalde ◽

Klemen Ziberna ◽

Ricardo Carnicer ◽

Jakub Tomek ◽

...

Keyword(s):

Atrial Fibrillation ◽

Superoxide Production ◽

Right Atrial ◽

Burst Stimulation ◽

Lv Mass ◽

Surface Ecg ◽

Tissue Homogenates ◽

Genotype Difference ◽

Left And Right

Abstract Aims Gp91-containing NADPH oxidases (NOX2) are a significant source of myocardial superoxide production. An increase in NOX2 activity accompanies atrial fibrillation (AF) induction and electrical remodelling in animal models and predicts incident AF in humans; however, a direct causal role for NOX2 in AF has not been demonstrated. Accordingly, we investigated whether myocardial NOX2 overexpression in mice (NOX2-Tg) is sufficient to generate a favourable substrate for AF and further assessed the effects of atorvastatin, an inhibitor of NOX2, on atrial superoxide production and AF susceptibility. Methods and results NOX2-Tg mice showed a 2- to 2.5-fold higher atrial protein content of NOX2 compared with wild-type (WT) controls, which was associated with a significant (twofold) increase in NADPH-stimulated superoxide production (2-hydroxyethidium by HPLC) in left and right atrial tissue homogenates (P = 0.004 and P = 0.019, respectively). AF susceptibility assessed in vivo by transoesophageal atrial burst stimulation was modestly increased in NOX2-Tg compared with WT (probability of AF induction: 88% vs. 69%, respectively; P = 0.037), in the absence of significant alterations in AF duration, surface ECG parameters, and LV mass or function. Mechanistic studies did not support a role for NOX2 in promoting electrical or structural remodelling, as high-resolution optical mapping of atrial tissues showed no differences in action potential duration and conduction velocity between genotypes. In addition, we did not observe any genotype difference in markers of fibrosis and inflammation, including atrial collagen content and Col1a1, Il-1β, Il-6, and Mcp-1 mRNA. Similarly, NOX2 overexpression did not have consistent effects on RyR2 Ca2+ leak nor did it affect PKA or CaMKII-mediated RyR2 phosphorylation. Finally, treatment with atorvastatin significantly inhibited atrial superoxide production in NOX2-Tg but had no effect on AF induction in either genotype. Conclusion Together, these data indicate that while atrial NOX2 overexpression may contribute to atrial arrhythmogenesis, NOX2-derived superoxide production does not affect the electrical and structural properties of the atrial myocardium.

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Early differentiation of long-standing persistent atrial fibrillation using the characteristics of fibrillatory waves in surface ECG multi-leads

Scientific Reports ◽

10.1038/s41598-019-38928-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Junbeom Park ◽

Chungkeun Lee ◽

Eran Leshem ◽

Ira Blau ◽

Sungsoo Kim ◽

...

Keyword(s):

Atrial Fibrillation ◽

Persistent Atrial Fibrillation ◽

Early Differentiation ◽

Surface Ecg

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A study of the clinical profile of atrial fibrillation in a tertiary care super-specialty referral centre in Central Nepal

Journal of College of Medical Sciences-Nepal ◽

10.3126/jcmsn.v8i3.8679 ◽

2013 ◽

Vol 8 (3) ◽

pp. 9-16

Author(s):

MP Gautam ◽

S Gautam ◽

S Guru Prasad ◽

G Subramanyam ◽

U Ghimire

Keyword(s):

Atrial Fibrillation ◽

Tertiary Care ◽

Clinical History ◽

Airway Disease ◽

Chronic Obstructive ◽

Medical Sciences ◽

Lone Atrial Fibrillation ◽

Common Cause ◽

Echocardiographic Study ◽

Surface Ecg

Background The conventional causes and risk factors for atrial fibrillation (AF) are somewhat arbitrary; overlap exists, multiple aetiologies are often present in one individual, and clinical presentation is non- specific. This study was an attempt to study the clinical and echocardiographic profile of patients with AF in a tertiary care super-specialty hospital of a developing country. Materials and Methods This study was conducted in College of Medical Sciences, Chitwan, Nepal throughout the year 2010. Subjects with AF, diagnosed based on clinical history, medical records and surface ECG, were included in the study. The presentation, types and causes of AF and structural as well as functional abnormalities were assessed. Results A total of 136 consecutive subjects were included in the study. The mean age was 42.40 (20.48) years ranging from 17 to 80 years. Majority of the AF subjects were female (54.41%). Among symptomatic cases, palpitation was the most common (23.53%) presentation followed by dyspnea (17.65%) and stroke or transient ischemic attack (15.44%). Asymptomatic presentation was also not uncommon (25%). Persistent AF was the most common form (31.62%). Rheumatic heart disease was the most common cause (33.09%) followed by lone atrial fibrillation (23.52%), coronary artery disease (16.18%), hypertension (8.82%) and thyrotoxicosis (7.35%). Other causes included chronic obstructive airway disease (5.88%), diabetes (2.94%), cardiomyopathy (1.47%), constrictive pericarditis (1.47%), myocarditis (0.74%) and infective endocarditis (0.74%). Nearly 65 % subjects had either structural or functional abnormalities in echocardiographic study; dilated left atrium was the most prevalent abnormality. Conclusion In contrast to the studies reported from developed nations, our subjects with AF were younger and female, the most common cause was RHD and the majority had either structural or functional abnormalities in echocardiographic study. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 9-16 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8679

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Chronic atrial fibrillation in patients with paroxysmal atrial fibrillation, atrioventricular node ablation and pacemakers

EP Europace ◽

10.1053/eupc.1998.0009 ◽

1999 ◽

Vol 1 (1) ◽

pp. 30-34 ◽

Cited By ~ 10

Author(s):

J. M. McComb ◽

G. M. Gribbin

Keyword(s):

Atrial Fibrillation ◽

Multivariate Analysis ◽

Pacemaker Implantation ◽

Atrioventricular Node ◽

Chronic Atrial Fibrillation ◽

Atrial Arrhythmias ◽

Av Node ◽

Surface Ecg ◽

History Of ◽

Atrial Rhythm

Abstract Aims This study examined the factors associated with the development of chronic (or permanent) atrial fibrillation (AF) in patients who had undergone atrioventricular (AV) node ablation with permanent pacing because of paroxysmal AF. Methods A retrospective review of case notes of all 65 consecutive patients identified as having had paroxysmal atrial arrhythmias, AV node ablation and permanent pacemaker implantation was performed. Atrial rhythm was established from all pacing records and from the surface ECG. Treatment with anti-arrhythmic drugs and with warfarin was recorded. A multivariate analysis was undertaken, using atrial rhythm on final ECG and chronic AF as outcome measures. Results During a mean follow-up of 30 months, 42% of patients with paroxysmal AF had developed chronic AF. Multivariate analysis showed that increasing age, history of electrical cardioversion and VVI pacing all contributed to the development of chronic AF. 25/62 patients were taking warfarin, and four had had strokes (2·5%/year). Conclusions The majority of patients with paroxysmal atrial arrhythmias treated with AV node ablation and pacing develop chronic AF eventually. Stroke remains a risk, particularly in those who develop chronic AF.

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