p wave duration
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Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 290
Author(s):  
Aikaterini Vraka ◽  
Vicente Bertomeu-González ◽  
Fernando Hornero ◽  
Aurelio Quesada ◽  
Raúl Alcaraz ◽  
...  

Atrial substrate modification after pulmonary vein isolation (PVI) of paroxysmal atrial fibrillation (pAF) can be assessed non-invasively by analyzing P-wave duration in the electrocardiogram (ECG). However, whether right (RA) and left atrium (LA) contribute equally to this phenomenon remains unknown. The present study splits fundamental P-wave features to investigate the different RA and LA contributions to P-wave duration. Recordings of 29 pAF patients undergoing first-ever PVI were acquired before and after PVI. P-wave features were calculated: P-wave duration (PWD), duration of the first (PWDon-peak) and second (PWDpeak-off) P-wave halves, estimating RA and LA conduction, respectively. P-wave onset (PWon-R) or offset (PWoff-R) to R-peak interval, measuring combined atrial/atrioventricular and single atrioventricular conduction, respectively. Heart-rate fluctuation was corrected by scaling. Pre- and post-PVI results were compared with Mann–Whitney U-test. PWD was correlated with the remaining features. Only PWD (non-scaling: Δ=−9.84%, p=0.0085, scaling: Δ=−17.96%, p=0.0442) and PWDpeak-off (non-scaling: Δ=−22.03%, p=0.0250, scaling: Δ=−27.77%, p=0.0268) were decreased. Correlation of all features with PWD was significant before/after PVI (p<0.0001), showing the highest value between PWD and PWon-R (ρmax=0.855). PWD correlated more with PWDon-peak (ρ= 0.540–0.805) than PWDpeak-off (ρ= 0.419–0.710). PWD shortening after PVI of pAF stems mainly from the second half of the P-wave. Therefore, noninvasive estimation of LA conduction time is critical for the study of atrial substrate modification after PVI and should be addressed by splitting the P-wave in order to achieve improved estimations.


Author(s):  
Arya Bhardwaj ◽  
J. Sivaraman ◽  
S. Venkatesan

Objective: This study aims to characterize P and Ta wave of Modified Limb Lead (MLL) Electrocardiogram (ECG) in Normal Sinus Rhythm (NSR) and Atrioventricular Block (AVB). Methods: ECGs were recorded using MLL configuration from 100 NSR volunteers (mean age 31 years, 35 women) and 20 male AVB patients (mean age 72 years). Amplitudes and durations of P, Ta wave, and PTa Interval (PTaI) were measured, plotted, and analyzed for both the groups. Results: P-wave amplitudes were larger in AVB, and also P, Ta waves correlated significantly in both groups with higher correlation in AVB (NSR: [Formula: see text]; AVB: [Formula: see text]). Ta-wave duration ([Formula: see text] ms) was longer than P-wave duration ([Formula: see text] ms) in AVB patients and was opposite to P-wave polarity in all the leads. PP Interval (PPI) correlated significantly with P wave (NSR: [Formula: see text]; AVB: [Formula: see text]), Ta wave ([Formula: see text]; [Formula: see text]), PTaI ([Formula: see text]; [Formula: see text]), and corrected PTaI ([Formula: see text]; [Formula: see text]). Conclusion: P-wave right axis shift leads to the higher P-wave amplitude in AVB which may be due to the advancing age and atrial chamber enlargement. In NSR, the duration of observable Ta wave was longer than P wave, whereas in AVB, the Ta wave duration was 3–3.5 times longer than P wave.


Author(s):  
Jose Manuel Rubio ◽  
Alberto Sánchez Arjona ◽  
Camila García-Talavera ◽  
Loreto Bravo Calero ◽  
Carla Lázaro Rivera ◽  
...  

Introduction: Atrial pacing can unmask or aggravate a preexisting interatrial block (IAB). Our study aimed to determine whether atrial pacing is associated with the development of atrial high-rate episodes (AHRE) during follow-up. Methods and Results: Patients with dual-chamber cardiac implantable electronic devices (CIED), no previous documented atrial fibrillation, and with a 6-month minimum follow-up were included. In all patients, sinus and paced P-wave duration was measured. AHRE was defined as an episode of atrial rate ≥ 225 bpm with a minimum duration of 5 min, excluding those documented during the first three months after implantation. Two hundred twenty patients were included (75 ± 10 years, 61% male). After a mean follow-up of 59±25 months, 46% of patients presented AHRE. Mean paced P-wave duration was significantly longer than the sinus P-wave duration (154±27 vs 115±18 ms; p < 0.001). Sinus and paced P-waves were significantly longer in those who developed AHRE (sinus: 119±20 vs 112±16; p = 0.006; paced: 161±29 vs 148±23; p < 0.001). A paced P-wave ≥160 ms was the best predictor of AHRE, especially those lasting >24 h (OR 4.2 (95% CI) [1.6-11.4]; p = 0.004). Conclusion: Atrial pacing significantly prolongs P-wave duration and is associated with further development of AHRE. A paced P-wave ≥160 ms is a strong predictor of AHRE and should be taken into consideration as a new definition of IAB in the presence of atrial pacing.


2021 ◽  
Vol 26 (12) ◽  
pp. 4661
Author(s):  
N. N. Ilov ◽  
O. N. Surikova ◽  
S. A. Boytsov ◽  
D. A. Zorin ◽  
A. A. Nechepurenko

According to current clinical guidelines, the risk of life-threatening ventricular tachyarrhythmias (VTAs) in patients with heart failure (HF) is determined by left ventricular ejection fraction (LVEF). The available clinical and experimental data indicate the imperfection of this one-factor approach, which specifies the need to search for new predictors of VTAs. In this prospective study, we performed a comparative analysis of surface electrocardiographic parameters in HF patients with LVEF ≤35% without syncope or sustained ventricular arrhythmias in history, who were implanted with cardioverter defibrillator as a primary prevention of sudden cardiac death. During the two-year follow-up, the primary endpoint (new-onset persistent VTA episode, or VTA/ventricular fibrillation that required electrotherapy) was recorded in 42 patients (25,5%). The secondary endpoint (an increase in LVEF by 5% or more of the initial level against the background of cardiac resynchronization therapy) was more often recorded in the group of patients without VTAs (41 (33%) vs 4 (9,5%), p=0,005). The studied cohort of patients was characterized by a left axis deviation (72%), LV hypertrophy signs (84%), impaired intra-atrial (P wave duration of 120 (101-120) ms) and intraventricular conduction (QRS duration of 140 (110-180) ms), ventricular electrical systole prolongation (QTcor — 465 (438-504) ms). Differences between the groups divided depending on reaching the primary endpoint in terms of the Cornell product, Cornell voltage index and ICEB, as well as the detection rate of complete left bundle branch block morphology had levels of significance close to critical (p=0,09; p=0,05; p=0,1; p=0,09, respectively). The multivariate predictive model included following factors: Cornell product, Tp-Te/ QRS, P wave duration (diagnostic efficiency of the model was 60%: sensitivity, 61,1%, specificity, 59,6%; p=0,007).


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Baturova ◽  
M M Demidova ◽  
J Carlson ◽  
D Erlinge ◽  
P G Platonov

Abstract Introduction New onset AF is a known complication in patients with acute ST-segment elevation myocardial infarction (STEMI). However, whether new-onset AF is linked to atrial structural abnormalities or has different underlying mechanisms is not fully clarified. Purpose We aimed to assess the association of P wave indices as ECG markers of atrial structural abnormalities with new-onset AF in STEMI patients undergoing primary percutaneous intervention (PCI). Methods Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission, including new-onset AF. The closest available ECGs prior to STEMI (median 448, interquartile rate 25–75% 112–1390 days before STEMI) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. Patients with sinus rhythm ECGs were included in the current analysis (n=1481, mean age 68±12 years, 33% females). P-wave duration, PR interval, P-wave frontal axis and P terminal force in lead V1 (PTF-V1) were assessed. PTF-V1 &gt;40 mm*ms was considered abnormal. Results Paroxysmal AF prior to STEMI was known in 77 patients (5.2%). Among patients without pre-existing AF (n=1404), new-onset AF during hospital admission was identified in 102 patients (6.9%). Patients with new-onset AF were older than those without AF history (74±9 vs 67±12 years, p&lt;0.001), but did not differ in regard to other clinical characteristics. In univariate logistic regression analysis P wave duration as continuous variable, P wave duration &gt;120 ms and PR interval were significantly associated with new onset AF (Table 1). However, after adjustment for age both, P wave duration &gt;120 ms (odds ratio (OR) 1.20, 95% CI 0.77–1.89, p=0.418) and PR interval (OR 1.01, 95% CI 1.00–1.01, p=0.068), failed to demonstrate the significant association with new onset AF while age (OR 1.06, 95% CI 1.04–1.08, p&lt;0.001) remained an independent risk factor for AF development. Conclusion In patients with acute STEMI new onset AF developed during hospital admission is common and strongly associated with age. P wave indices failed to demonstrate the significant association with new onset AF thus indicating that atrial structural abnormalities are unlikely the underlying cause of AF development in acute STEMI. FUNDunding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Scholarship grant from Swedish Institute. Table 1


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J Marti Almor ◽  
B Casteigt ◽  
J Jimenez-Lopez ◽  
J Conejos ◽  
E Valles ◽  
...  

Abstract Background Isolation of pulmonary veins is the cornerstone in the treatment of symptomatic atrial fibrillation rather with radiofrequency or cryo balloon. Recurrence rate is quite common in the long term follow up, clearly related to previosly described factors. Nevertheless some patients maintain sinus rhythm forever after the index ablation. The aim of this study is characterize this kind of patients (so called superresponders). Methods This is a Unicentric, retrospective, consecutive study including all patients summited for cryoablation in our hospital from January 2011 to September 2020. We looked for clinical, electrical, echocardiographic variables and those linked to the ablation procedure. A transversal FU to discard recurrences was done. A univariate and multivariate logistic regression was performed. Results We included 422 patients, 193 of them were finally excluded: 21 lost in the FU, 30 got radiofrequency ablation and 142 did not reach a minimum 5 years FU. About the 229 finally included, 85 (group 1) didn't have any recurrence during the FU, in front of 144 (group2) with recurrences. The univariate analysis showed that grup 1 patients were younger, the rate of hypertension, CHA2DS2VASc score, moderate sleep apnea, body mass index (BMI), p wave duration, and the size of left atrial was lower in grup 1 in front of patients of grup 2. Left ventricular ejection fraction was higher and the number of pulmonary veins in whom the temperature was lower than −40°C in grup 1 in front to grup 2. In the multivariate analysis the p wave duration: OR 0.92; 95% CI [0.89–0.94]; p&lt;0.001, BMI kg/m2: OR 0.74; 95% CI [0.65–0.85]; p&lt;0.001, a temperature &lt;−40°C in all the targeted veins: OR 3.52 95% CI [1.45–8.54]; p=0.005 and SR on the ablation index day OR: 7.29; 95% CI [1.53–34.71]; p=0.012, maintained statistical significance. Conclusions In our series patients with a p wave duration, BMI, SR the ablation index day and achieving a temperature &lt;−40°C in all the targeted veins, resulted as protective factors to maintain SR in the long term FU. An adequate selection of patients can improve results and optimize resources. FUNDunding Acknowledgement Type of funding sources: None.


2021 ◽  
Vol 7 (2) ◽  
pp. 307-310
Author(s):  
Claudia Nagel ◽  
Olaf Dössel ◽  
Axel Loewe

Abstract Features extracted from P waves of the 12-lead electrocardiogram (ECG) have proven valuable for noninvasively estimating the left atrial fibrotic volume fraction associated with the arrhythmogenesis of atrial fibrillation. However, feature extraction in the clinical context is prone to errors and oftentimes yields unreliable results in the presence of noise. This leads to inaccurate input values provided to machine learning algorithms tailored at estimating the amount of atrial fibrosis with clinical ECGs. Another important aspect for clinical translation is the network’s generalization ability regarding new ECGs. To quantify a network’s sensitivity to inaccurately extracted P wave features, we added Gaussian noise to the features extracted from 540,000 simulated ECGs consisting of P wave duration, dispersion, terminal force in lead V1, peak-to-peak amplitudes, and additionally thoracic and atrial volumes. For assessing generalization, we evaluated the network performance for train-validation-test splits divided such that ECGs simulated with the same atria or torso geometry only belonged to either the training and validation or the test set. The root mean squared error (RMSE) of the network increased the most in case of noisy torso volumes and P wave durations. Large generalization errors with a RMSE difference between training and test set of more than 2% fibrotic volume fraction only occurred if very high or low atria and torso volumes were left out during training. Our results suggest that P wave duration and thoracic volume are features that have to be measured accurately if employed for estimating atrial fibrosis with a neural network. Furthermore, our method is capable of generalizing well to ECGs simulated with anatomical models excluded during training and thus meets an important requirement for clinical translation.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
C Herrera ◽  
V Bruna ◽  
A Comella ◽  
A De La Rosa ◽  
L Diaz-Gonzalez ◽  
...  

Abstract Background Left atrial (LA) remodelling and enlargement in athletes is a well-kown component of the athlete's heart. However, information about the correlation between of LA enlargement and atrial electrophysiological features in athletes is scarce. Purpose Our aim was to characterize LA enlargement, P-wave duration, and the prevalence of interatrial block (IAB) in competitive athletes (with and without LA enlargement) and in controls. Methods ALMUDAINA (Analysis of Left atrial Measurements of Ultrasound Dilation Among International and National Athletes) was a nationwide, cross-sectional study involving 9 hospitals and sport clinics across Spain. Cases fulfilled the international consensus definition of a competitive athlete and were currently engaged in skill, power, mixed or endurance disciplines at a national or international level. The following P-wave parameters were analysed: 1) duration 2) voltage in lead I and 3) the presence of interatrial block (IAB). LA enlargement was defined as an indexed volume by body surface area ≥34 ml/m2, measured by transthoracic echocardiography. A contemporary cohort of otherwise healthy and active controls was used as a comparison group. Results Baseline clinical and echocardiographic characteristics of both cohorts are summarised in table 1 whereas electrocardiographic characteristics are displayed in table 2, respectively. 356 subjects were included, 308 athletes (mean age: 36.4±11.6 years) and 48 controls (mean age: 49.3±16.1 years). Athletes showed a higher mean LA indexed volume (29.8±8.6 vs. 25.6±8.0 mL/m2, P=0.006) and higher prevalence of LA enlargement (113 [36.7%] vs. 5 [10.4%], P&lt;0.001), but there were no relevant differences in P-wave duration (106.3±12.5 ms vs 108.2±7.7 ms; P=0.31), voltage in lead I (0.08±0.04 vs. 0.08±0,04 mV; P=0.79) and the prevalence of IAB (40 [13.0%] vs. 4 [8.3%], P=0.36). Only a case of advance IAB was detected, in an athlete without LA enlargement. Among athletes, those with LA enlargement (113, 36.7%) had higher P-wave duration (110.3±14.1 vs. 103.0±10.9 ms, P&lt;0.001) and a higher prevalence of interatrial blockade (23 [20.4%] vs. 17 [8.8%], P=0.004), but similar voltage of P-wave in lead I (0.08±0.003 vs. 0.08±0.05 mV, P=0.689). In a multivariate analysis, competitive training was independently associated with LA enlargement (odds ratio [OR] 14.7, 95% confidence interval [CI] 4.7–44.0; P&lt;0.001) but was not associated with P-wave duration (OR 1.02, 95% CI: 0.99–1.04; P=0.19) or IAB (OR 1.4, 95% CI 0.7–3.1; P=0.34). Conclusions LA enlargement is prevalent in adult competitive athletes. However, ECG indexes of atrial electrophysiology were not different from healthy controls. Our data suggest that LA enlargement and IAB are two different entities. FUNDunding Acknowledgement Type of funding sources: None.


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