P322Understanding the multiple P-wave morphologies in paroxysmal atrial fibrillation, during sinus rhythm, using computer simulation

Abstract Background Atrial Fibrillation (AF) is the most common atrial arrhythmia. The initiation and perpetuation of AF are related to atrial remodeling affecting the electrical and structural atrial characteristics. The beat-to-beat analysis of the P-wave morphology (PWM), during sinus rhythm (SR), revealed the existence of a secondary PWM, while the proportion of the P-waves which follow the secondary morphology is higher in patients with a history of paroxysmal AF (pAF). This observation has led to the hypothesis that the multiple PWM may be the result of a transient shift in the stimulus origin, possibly within the broader anatomical region of the sinoatrial (SA) node, and it is the atrial electrical remodeling that contributes to more frequent P-waves following a secondary morphology in patients with pAF. Purpose To better understand the pathophysiology of AF there is a need to link different levels of analysis, in order to interpret macroscopic observations, through a surface electrocardiogram, with changes occurring at cell and tissue level. Towards this direction, computational modeling can be used as it is a non-invasive and reproducible method of analyzing the electrical activity of the heart. Methods The CRN atrial model was used, and a two-dimensional geometry of the atrial architecture was considered, including the major anatomical structures, like Crista Terminalis, Pectinate Muscles and Pulmonary Veins. Using existing knowledge, the CRN model was adapted to describe the ionic properties of the atrial structures as well as the electrical remodeling occurring under pAF conditions. Several scenarios were considered related to the extent of the electrical remodeled tissue and Heart Rate (HR) values. The stimulation protocol was designed as 5 stimuli originated at a specific point within the SA node area whereas the sixth stimulus originated either at the same location or 1 mm far from the previous one. The temporal variations of the atrial activation as a result of the transient shift of the sixth stimulus origin were computed. Results In electrically remodeled tissue, the displacement of the excitation site within the SA node resulted in a significant increase of the differences in atrial activation compared to healthy tissue, and the greater the spatial extent of the remodeling the greater the differences in the completion of the electrophysiological processes. In addition, increased HR or HR variability led to the increase of the differences especially when electrical remodeling coexists. Conclusions The observed differences in atrial substrate activation can explain the increased number of P-waves that match a secondary PWM in pAF patients during SR, while a future perspective is to use PWM as a marker to estimate the electrical remodeling extent in the atrial tissue. These results underline the need to link the macroscopic findings to the suspected microscopic electrical activity in order to better understand the pathophysiology of AF.

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Beat-to-Beat P-Wave Analysis Outperforms Conventional P-Wave Indices in Identifying Patients with a History of Paroxysmal Atrial Fibrillation during Sinus Rhythm

Diagnostics ◽

10.3390/diagnostics11091694 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1694

Author(s):

Dimitrios Tachmatzidis ◽

Dimitrios Filos ◽

Ioanna Chouvarda ◽

Anastasios Tsarouchas ◽

Dimitrios Mouselimis ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Paroxysmal Atrial Fibrillation ◽

Univariate Analysis ◽

Multivariate Logistic Regression Analysis ◽

P Wave ◽

P Value ◽

Wave Analysis ◽

P Waves ◽

History Of

Early identification of patients at risk for paroxysmal atrial fibrillation (PAF) is essential to attain optimal treatment and a favorable prognosis. We compared the performance of a beat-to-beat (B2B) P-wave analysis with that of standard P-wave indices (SPWIs) in identifying patients prone to PAF. To this end, 12-lead ECG and 10 min vectorcardiogram (VCG) recordings were obtained from 33 consecutive, antiarrhythmic therapy naïve patients, with a short history of low burden PAF, and from 56 age- and sex-matched individuals with no AF history. For both groups, SPWIs were calculated, while the VCG recordings were analyzed on a B2B basis, and the P-waves were classified to a primary or secondary morphology. Wavelet transform was used to further analyze P-wave signals of main morphology. Univariate analysis revealed that none of the SPWIs performed acceptably in PAF detection, while five B2B features reached an AUC above 0.7. Moreover, multivariate logistic regression analysis was used to develop two classifiers—one based on B2B analysis derived features and one using only SPWIs. The B2B classifier was found to be superior to SPWIs classifier; B2B AUC: 0.849 (0.754–0.917) vs. SPWIs AUC: 0.721 (0.613–0.813), p value: 0.041. Therefore, in the studied population, the proposed B2B P-wave analysis outperforms SPWIs in detecting patients with PAF while in sinus rhythm. This can be used in further clinical trials regarding the prognosis of such patients.

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219A machine learning classification algorithm to detect patients with paroxysmal atrial fibrillation during sinus rhythm

EP Europace ◽

10.1093/europace/euaa162.164 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

D Tachmatzidis ◽

D Filos ◽

I Chouvarda ◽

D Mouselimis ◽

A Tsarouchas ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

P Wave ◽

Support Vector ◽

Svm Classifier ◽

P Waves ◽

Machine Learning Classification ◽

Increased Risk ◽

Wave Morphology ◽

The Mean

Abstract Background Atrial fibrillation (AF) - the most common sustained cardiac arrhythmia - while not a life-threatening condition itself, leads to an increased risk of stroke and high rates of mortality. Early detection and diagnosis of AF is a critical issue for all health stakeholders. Purpose The aim of this study is to identify P-wave morphology patterns encountered in patients with Paroxysmal AF (PAF) and to develop a classifier discriminating PAF patients from healthy volunteers. Methods Three-dimensional 1000Hz ECG signals of 5 minutes duration were obtained through the use of a Galix GBI-3S Holter monitor from a total of 68 PAF patients and 52 healthy individuals. Signal pre-processing, consisting of denoising, QRS auto-detection, and ectopic beats removal was performed and a signal window of 250ms prior to the Q-wave (Pseg) was considered for every single beat. P‑wave morphology analysis based on the dynamic application of the k‑means clustering process was performed. For those Pseg that were assigned in the largest cluster, the mean P-wave was computed. The correlation of every P-wave with the mean P-wave of the main cluster was calculated. In case that it exceeded a prespecified threshold, the P-wave was allocated to the main morphology. For the remaining P‑waves, the same approach was followed once again, and the secondary morphology was extracted (picture). The P-waves of the dominant morphology were further analyzed using wavelet transform, whereas time-domain characteristics were also extracted. A Support Vector Machine (SVM) model was created using the Gaussian Radial Basis Function kernel and the forward feature selection wrapper approach was followed. ECGs were allocated to the training, internal validation, and testing datasets in a 3:1:1 ratio. Results The percentage of P-waves following the main morphology in all three leads was lower in PAF patients (91.2 ±7.3%) than in healthy subjects (96.1 ±3.5%, p = 0.02). Classification between the two groups highlighted 7 features, while the SVM classifier resulted in a balanced accuracy of 91.4 ± 0.2% (sensitivity 94.2 ± 0.3%, specificity 88.6 ± 0.1%) Conclusion An Artificial Intelligence based ECG Classifier can efficiently identify PAF patients during normal sinus rhythm. Abstract Figure.

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Multifocal atrial tachycardia

10.1093/med/9780199568741.003.0113 ◽

2018 ◽

Author(s):

Michael Jones ◽

Norman Qureshi ◽

Kim Rajappan

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Atrial Tachycardia ◽

The Other ◽

P Wave ◽

Qrs Complex ◽

P Waves ◽

Ectopic Beats ◽

Atrial Rhythm ◽

Pathophysiologic Mechanisms

Multifocal atrial tachycardia (MAT) is an atrial arrhythmia arising in the left or right atrium, or both, with multiple different P wave morphologies (at least three), with an atrial rate usually faster than 100 min−1. The atrial rhythm may be irregular; however, the defining difference between MAT and atrial fibrillation is the presence of a P wave prior to each QRS complex in MAT (but the absence of P waves in atrial fibrillation). MAT may be compared to sinus rhythm with very frequent polymorphic atrial ectopic beats, and in fact similar pathophysiologic mechanisms underlie both conditions; thus, differentiating one from the other may be difficult—the principle difference is the lack of a single dominant sinus pacemaker in MAT.

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Beat-to-beat P-wave analysis outperforms conventional P-wave indices in identifying patients with a history of paroxysmal atrial fibrillation, during sinus rhythm

European Heart Journal ◽

10.1093/eurheartj/ehab724.0306 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

D Tachmatzidis ◽

D Filos ◽

A Tsarouchas ◽

D Mouselimis ◽

C Bakogiannis ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Roc Curves ◽

P Wave ◽

Wave Analysis ◽

P Waves ◽

Receiver Operating Characteristic Curves ◽

Funding Sources ◽

History Of ◽

The One

Abstract Introduction Atrial fibrillation (AF) is the most common arrhythmia and is associated with high risk of morbidity and mortality. In many patients, AF is of episodic character (paroxysmal AF – PAF), which makes the identification of these patients during sinus rhythm (SR) challenging. Purpose The aim of the present study is to compare the performance of beat-to-beat P-wave analysis with P-wave indices used as predictors of PAF, such as P-wave duration, area, voltage, axis, terminal force in V1, inter-atrial block or orthogonal type, in identifying patients with history of PAF during sinus rhythm. Methods Standard 12-lead ECG and 10-minute orthogonal ECG recordings were obtained from 40 consecutive patients with short history of PAF under no antiarrhythmic medication and 60 age- and sex- matched healthy controls. The P-waves on the 10-minute recordings were analyzed on a beat-to-beat basis and classified as belonging to a primary or secondary morphology according to previous study. Wavelet transform used to further analyze P-wave orthogonal signals of main morphology on a beat-to-beat basis. Results 38 out of 327 studied features were found to differ significantly among the two groups. These features were tested for their diagnostic ability and receiver operating characteristic curves were ploted. Only 3 of them performed adequetly, with an area under curve (AUC) above 0.65; Two of them came from morphology analysis (percentage of beats following main morphology in axis X and Y) and one from wavelet analysis (max energy in high frequency zone -Y axis). Among standard P-wave indices, P-wave area in lead II was the one with the highest AUC (0.64). Conclusion Novel indices derived from beat-to-beat analysis outperform stadard P-wave markers in identifying patients with PAF history during sinus rhythm. FUNDunding Acknowledgement Type of funding sources: None. ROC curves of most significant features AUC characteristics of P-wave indices

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Biomarkers of Atrial Fibrillation in Hypertension

Current Medicinal Chemistry ◽

10.2174/0929867324666171006155516 ◽

2019 ◽

Vol 26 (5) ◽

pp. 888-897 ◽

Cited By ~ 2

Author(s):

Costas Tsioufis ◽

Dimitris Konstantinidis ◽

Ilias Nikolakopoulos ◽

Evi Vemmou ◽

Theodoros Kalos ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Ventricular ◽

P Wave ◽

Diagnostic Tools ◽

Atrial Remodeling ◽

Hypertensive Patients ◽

Risk Patients ◽

Underlying Mechanisms ◽

Prompt Diagnosis ◽

The Ideal

Background: Atrial fibrillation (AF) is the most frequently encountered cardiac arrhythmia globally and substantially increases the risk for thromboembolic disease. Albeit, 20% of all cases of AF remain undiagnosed. On the other hand, hypertension amplifies the risk for both AF occurrences through hemodynamic and non-hemodynamic mechanisms and cerebrovascular ischemia. Under this prism, prompt diagnosis of undetected AF in hypertensive patients is of pivotal importance. Method: We conducted a review of the literature for studies with biomarkers that could be used in AF diagnosis as well as in predicting the transition of paroxysmal AF to sustained AF, especially in hypertensive patients. Results: Potential biomarkers for AF can be broadly categorized into electrophysiological, morphological and molecular markers that reflect the underlying mechanisms of adverse atrial remodeling. We focused on P-wave duration and dispersion as electrophysiological markers, and left atrial (LA) and LA appendage size, atrial fibrosis, left ventricular hypertrophy and aortic stiffness as structural biomarkers, respectively. The heterogeneous group of molecular biomarkers of AF encompasses products of the neurohormonal cascade, including NT-pro BNP, BNP, MR-pro ANP, polymorphisms of the ACE and convertases such as corin and furin. In addition, soluble biomarkers of inflammation (i.e. CRP, IL-6) and fibrosis (i.e. TGF-1 and matrix metalloproteinases) were assessed for predicting AF. Conclusion: The reviewed individual biomarkers might be a valuable addition to current diagnostic tools but the ideal candidate is expected to combine multiple indices of atrial remodeling in order to effectively detect both AF and adverse characteristics of high risk patients with hypertension.

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Advanced interatrial block precedes atrial fibrillation and stroke. The prospective interatrial Block And Yearly EventS (BAYES) registry

European Heart Journal ◽

10.1093/ehjci/ehaa946.0485 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

M Martinez-Selles ◽

R Elosua ◽

M Ibarrola ◽

M De Andres ◽

P Diez-Villanueva ◽

...

Keyword(s):

Atrial Fibrillation ◽

Heart Disease ◽

Sinus Rhythm ◽

Structural Heart Disease ◽

P Wave ◽

Wave Duration ◽

P Wave Duration ◽

Previous Diagnosis ◽

Surface Ecg ◽

Interatrial Block

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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Simultaneous Catheter and Epicardial Ablations Enable a Comprehensive Atrial Fibrillation Procedure

Innovations Technology and Techniques in Cardiothoracic and Vascular Surgery ◽

10.1097/imi.0b013e31822ca15c ◽

2011 ◽

Vol 6 (4) ◽

pp. 243-247 ◽

Cited By ~ 11

Author(s):

Andy C. Kiser ◽

Mark D. Landers ◽

Ker Boyce ◽

Matjaž šinkovec ◽

Andrej Pernat ◽

...

Keyword(s):

Atrial Fibrillation ◽

Radiofrequency Ablation ◽

Sinus Rhythm ◽

Pulmonary Veins ◽

Persistent Atrial Fibrillation ◽

Chronic Atrial Fibrillation ◽

Lesion Pattern ◽

Atrial Size ◽

Cardiac Surgeon ◽

Successful Collaboration

Objective Transmural and contiguous ablations and a comprehensive lesion pattern are difficult to create from the surface of a beating heart but are critical to the successful treatment of persistent, isolated atrial fibrillation. A codisciplinary simultaneous epicardial (surgical) and endocardial (catheter) procedure (Convergent procedure) addresses these issues. Methods Patients with symptomatic atrial fibrillation who failed medical treatment were evaluated. Using only pericardioscopy, the surgeon performed near-complete epicardial isolation of the pulmonary veins and a “box” lesion on the posterior left atrium using unipolar radiofrequency ablation. Simultaneous endocardial catheter radiofrequency ablation completed pulmonary vein isolation, performed a mitral annular and cavotricuspid isthmus line of block, and debulked the coronary sinus. Twelve-month results for the Convergent procedure were compared with 12-month results for concomitant and pericardioscopic (stand-alone transdiaphragmatic/thoracoscopic) atrial fibrillation procedures using unipolar radiofrequency ablation. Results Sixty-five patients underwent the Convergent procedure (mean age, 62 y; mean body surface area, 2.17 m2; mean atrial fibrillation duration, 4.8 y; mean left atrial size, 5.2 cm). Ninety-two percent were in persistent or long-standing persistent atrial fibrillation. At 12 months, evaluation with 24-hour Holter monitors found 82% of patients in sinus rhythm, while only 47% of pericardioscopic and 77% of concomitant patients treated with unipolar radiofrequency ablation were in sinus rhythm. Conclusions Simultaneous epicardial and endocardial ablation improves outcomes for patients with persistent or longstanding persistent atrial fibrillation. This successful collaboration between cardiac surgeon and electrophysiologist is an important treatment option for patients with large left atriums and chronic atrial fibrillation.

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Abstract 2155: Plasma Adiponectin Levels in Patients with Atrial Fibrillation

Circulation ◽

10.1161/circ.118.suppl_18.s_677-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Masayuki Shimano ◽

Rei Shibata ◽

Yukiomi Tsuji ◽

Noriyuki Ouchi ◽

Yasuya Inden ◽

...

Keyword(s):

Atrial Fibrillation ◽

Collagen Type ◽

Collagen Type I ◽

High Plasma ◽

P Wave ◽

Atrial Remodeling ◽

Type I ◽

Plasma Adiponectin ◽

Type Iii ◽

And Control

The occurrence and development of atrial fibrillation (AF) are associated with changes in electrical properties and cardiac structure, known as electrical and structural atrial remodeling. AF characterized by atrial remodeling also occurs with obesity-related conditions. Adiponectin, an adipose tissue-derived hormone, exerts beneficial effects on the heart in various pathological conditions. These observations led us to speculate that adiponectin levels affect the development and prevalence of AF. Here, we investigated a potential association between circulating adiponectin levels and atrial remodeling in patients with AF. We measured plasma adiponectin levels, serum carboxy-terminal telopeptide of collagen type I (CITP) levels, as a collagen type I degradation marker, and serum type III procollagen-N-peptide (PIIINP) levels, as a collagen type III synthesis marker in consecutive 414 patients; 225 paroxysmal AF, 81 persistent AF and 108 paroxysmal supra-ventricular tachycardia without AF history (control) patients, who admitted for scheduled radiofrequency catheter ablation. Plasma adiponectin levels were significantly higher in patients with persistent AF compared to paroxysmal AF and control patients (p<0.05). Serum CITP levels, but not serum PIIINP levels, were also higher in patients with persistent AF compared to paroxysmal AF and control patients (p<0.05). In addition, a positive correlation was observed between adiponectin levels and CITP levels (r=0.39, p<0.005) or the P wave duration (r=−0.31, p<0.05) in patients with persistent AF. High plasma adiponectin levels are associated with the presence of persistent AF, which is accompanied by increased CITP levels. Hyperadiponectinemia might also attenuate atrial conduction disturbance. Thus, measurement of plasma adiponectin could be useful for assessment of AF.

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Galectin-3 in Patients with Atrial Fibrillation and Restored Sinus Rhythm

Folia Medica ◽

10.3897/folmed.63.e55313 ◽

2021 ◽

Vol 63 (3) ◽

pp. 329-336

Author(s):

Antoniya Kisheva ◽

Yoto Yotov ◽

Trifon Chervenkov ◽

Atanas Angelov ◽

Yana Bocheva

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Renal Dysfunction ◽

Cardiac Fibrosis ◽

Antihypertensive Drugs ◽

Female Gender ◽

Control Treatment ◽

Atrial Remodeling ◽

Galectin 3 ◽

One Year

Introduction: Cardiac fibrosis is the hallmark of atrial remodeling in atrial fibrillation. Galectin-3 (Gal-3) is a biomarker of fibrosis. It is well studied in heart failure, but the data about its role in atrial fibrillation are sparse.Aim: The aim of the study was to evaluate the levels of Gal-3 in patients with atrial fibrillation after sinus rhythm restoration, to examine the association between this biomarker and other factors for developing atrial fibrillation and to assess its prognostic role.Materials and methods: We included 67 patients (35 male) at the mean age of 67.36±7.25 years, with Gal-3 test after sinus rhythm restoration, a subgroup of participants in placebo-controlled randomized clinical trial of treatment with spironolactone. They were followed up for atrial fibrillation recurrence and hospitalizations. The effect of demographic parameters and other factors on Gal-3 levels were evaluated before and one year after treatment.Results: Mean Gal-3 at baseline was 16.9±6.8 ng/ml. Higher levels of Gal-3 were associated with female gender (р=0.008), increasing age (р=0.005), renal dysfunction (p<0.0001) and gout (р=0.002). Higher thromboembolic risk as assessed by CHA2DS2-VASc score was significantly related to Gal-3. The levels of biomarker did not affect the number of atrial fibrillation recurrences (p=0.9) and hospitalizations. No correlation was found with treatment with spironolactone, antiarrhythmic and antihypertensive drugs.Conclusions: Higher Gal-3 in atrial fibrillation was associated with female sex, renal dysfunction, and history of gout. The levels of Gal-3 were not related to rhythm control. Treatment with spironolactone did not affect the biomarker of fibrosis Gal-3 in AF patients. Higher Gal-3 was related to high embolic risk.

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An Atrial Fibrillation with Normal Limits using Signal Processing- A Review

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.24.12133 ◽

2018 ◽

Vol 7 (2.24) ◽

pp. 453

Author(s):

S. Sathish ◽

K Mohanasundaram

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Normal Sinus Rhythm ◽

P Wave ◽

Wave Duration ◽

Normal Limits ◽

Normal Sinus ◽

P Wave Duration ◽

Standard Lead ◽

Wave Morphology

Atrial fibrillation is an irregular heartbeat (arrhythmia) that can lead to the stroke, blood clots, heart failure and other heart related complications. This causes the symptoms like rapid and irregular heartbeat, fluttering, shortness of breath etc. In India for every around 4000 people eight of them are suffering from Atrial Fibrillation. P-wave Morphology. Abnormality of P-wave (Atrial ECG components) seen during sinus rhythm are associated with Atrial fibrillation. P-wave duration is the best predictor of preoperative atrial fibrillation. but the small amplitudes of atrial ECG and its gradual increase from isometric line create difficulties in defining the onset of P wave in the Standard Lead Limb system (SLL).Studies shows that prolonged P-wave have duration in patients (PAF) In this Study, a Modified Lead Limb (MLL) which solves the practical difficulties in analyzing the P-ta interval for both in healthy subjects and Atrial Fibrillation patients. P-Ta wave interval and P-wave duration can be estimated with following proposed steps which is applicable for both filtered and unfiltered atrial ECG components which follows as the clinical database trials. For the same the p-wave fibrillated signals that escalates the diagnosis follows by providing minimal energy to recurrent into a normal sinus rhythm.

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