P-wave Duration Research Articles

Ratio of P-Wave Duration to P-Wave Amplitude and Left Atrial Remodeling: Insights from Electrophysiological Findings and Myocardial Injury After Cryoballoon Ablation

The impact of the P-wave morphology on clinical outcomes post-catheter ablation (CA) and recurrent arrhythmia characteristics or electrophysiological findings in paroxysmal atrial fibrillation (PAF) patients remains unclear. PAF patients who underwent cryoballoon ablation were enrolled. In twelve-lead electrocardiography recorded within one-month before CA, the P-wave duration (Pd) and P-wave vector magnitude (Pvm) (square root of the sum of the squared P-wave amplitude in leads II, V6 and one-half of the P-wave amplitude in V2) were measured and divided into two groups; patients with high and low Pd/Pvm based on a statistically calculated cut-off value. We evaluated the incidence of late recurrence of AF (LRAF), myocardial injury (high-sensitive troponin I [hs-TnI]) and the electrophysiological findings in repeat ablation sessions. This study included 269 PAF patients. The median follow-up duration was 697 days. The cut-off value of the Pd/Pvm for predicting LRAF was 740.7ms/mV (AUC=0.81, sensitivity=58.2% and specificity=89.6%). Multivariable Cox proportional hazards analysis showed high Pd/Pvm (>740.7ms/mV) was significantly associated with LRAF (p<0.001). The hs-TnI level was significantly lower and ratio of DR-FLASH score>3 significantly higher in those with high than low Pd/Pvm (p=0.044, p=0.002, respectively). In the repeat ablation sessions, the Pd/Pvm in patients with atrial tachycardia (AT) induced or spontaneously occurring during the repeat CA sessions was significantly higher than in those without (p=0.009). There was a significant difference between the Pd/Pvm and low-voltage area (LVA) (p<0.001). In conclusion, the Pd/Pvm is significantly associated with LRAF after cryoballoon ablation in PAF patients and predicts left atrial LVAs and AT inducibility.

Speckle tracking echocardiography for diagnosis of right ventricular failure in children with totally corrected tetralogy of Fallot in Sulaimani, Iraq

ObjectivesThe study was aimed at using speckle tracking echocardiography as a novel technique to diagnose right ventricular failure (RVF) in children with total correction of tetralogy of Fallot (TOF) through surgery. MethodsA quasi-experimental study was performed at the Children's Heart Hospital of Sulaimani for 9 months. A total of 150 children with completely repaired TOF were enrolled to investigate RVF. Conventional echocardiographic data were recorded, including right ventricular (RV) ejection fraction (EF), tricuspid annular plane systolic excursion (TAPSE), myocardial performance index (MPI), and RV end-systolic and diastolic volume (RVESV and RVEDV). Additionally, speckle tracking was performed for the regional and longitudinal strain and strain rate in four-chamber apical view. RVF diagnosis was determined on the basis of electrocardiography measurement of P-wave dispersion, T-wave dispersion, and QRS duration. ResultsChildren with repaired TOF who were diagnosed with RVF through conventional echocardiography exhibited abnormalities with respect to children with normal RV function, including a TAPSE of 1.3 ± 0.11 cm, RVEF of 35.5 ± 6.72, RVESV of 69.8 ± 15.13 ml, RVEDV of 110.1 ± 14.13 ml, MPI of 0.60 ± 0.12, and Pmax of 52.4 ± 14.08. The use of speckle tracking in RVF diagnosis revealed a relatively lower longitudinal strain and strain rate (−12.1 ± 2.3 and −0.9 ± 0.3, respectively) in the children with RVF. Moreover, longitudinal right ventricular strain was positively correlated with TAPSE (r = 0.656) and EF (r = 0.675), and negatively correlated with RVEDV (r = −0.684), RVESV (r = −0.718), MPI (r = −0.735), and Pmax (r = −0.767). ConclusionsThe application of speckle tracking with the longitudinal RV strain and strain rate to estimate RV function in children with repaired TOF is a new advanced method that, compared with conventional echo, significantly improves the diagnosis of regional myocardial deformations and cardiac muscle motion velocity.

Prevalence and Prognostic Value of Atrial Cardiopathy in Embolic Stroke of Undetermined Source

Introduction: We utilized data from the Third China National Stroke Registry to investigate the prevalence of atrial cardiopathy markers in patients with embolic stroke of undetermined source (ESUS) and to assess their association with death and stroke recurrence. Methods: In China, patients experiencing transient ischemic attack or ischemic stroke were recruited consecutively by the Third China National Stroke Registry. We compared atrial cardiopathy markers, such as left atrial (LA) enlargement, increased P-wave terminal force in lead V1 (PTFV1), premature atrial contractions, paroxysmal supraventricular tachycardia, advanced interatrial block, prolonged PR interval, prolonged P-wave dispersion, and prolonged P-wave duration between ESUS patients and those with small vessel disease and large artery atherosclerosis strokes. The association between these markers and the recurrence of stroke as well as mortality risk in ESUS patients was evaluated using Cox regression analysis. Results: Of 8,528 ischemic stroke patients who underwent a standard diagnostic workup, 2,415 were identified as having ESUS. Multivariable analysis revealed a significant association between elevated PTFV1 and an increased risk of stroke recurrence (HR: 2.50; 95% CI: 1.53–4.09; p < 0.01) as well as mortality (HR: 3.76; 95% CI: 1.58–8.91; p < 0.01) at 1 year in patients with ESUS. Furthermore, we observed that moderate-severe LA enlargement slightly increased the risk of stroke recurrence in patients with ESUS (HR: 1.95; 95% CI: 0.90–4.26; p = 0.09). Both LA diameter (HR: 1.03; 95% CI: 1.00–1.06; p = 0.03) and the top quartile of the LA diameter index (HR: 1.56; 95% CI: 1.03–2.40; p = 0.04) were associated with stroke recurrence in patients with ESUS. Conclusions: PTFV1 was independently associated with an elevated risk of stroke recurrence and mortality in ESUS patients. Additionally, a trend toward a correlation between LA enlargement and high stroke recurrence risk after ESUS was observed.

Impact of P-wave morphology on recurrent arrhythmia characteristics and low-voltage risk score in paroxysmal atrial fibrillation patients underwent catheter ablation

Abstract Background The P-wave morphology’s impact on clinical outcomes post-catheter ablation (CA) and recurrent arrhythmia characteristics or electrophysiological findings in paroxysmal atrial fibrillation (PAF) patients remains unclear. Purpose The aim of this study was to elucidate the impact of combination of Pd and Pvm (Pd/Pvm) on the clinical outcomes after CA and recurrent characteristic or electrophysiological findings in repeated ablation. Methods PAF patients who underwent CA in the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry were enrolled. P-wave duration and P-wave vector magnitude (the square root of the sum of the squared P-wave amplitude in leads II, V6 and one-half of the P-wave amplitude in V2) were measured. We divided the patients into two groups; patients with high and low Pd/Pvm based on the cut-off value calculated by statistical methods. We evaluated (1) late recurrence of atrial fibrillation (AF) / atrial tachycardia (AT) (LRAF) (2) clinical risk score for low-voltage area (DR-FLASH score) and (3) recurrent characteristics and electrophysiological findings in repeated ablation between the two groups. Results This study included 1005 PAF patients. The median follow-up duration was 722 [288, 1119] days. LRAF occurred in 251 patients (25.0%). A cut-off value of Pd/Pvm=699.1ms/mV gave AUC=0.87, sensitivity=72.9%, specificity=85.3%. High Pd/Pvm had a greater risk of LRAF than low Pd/Pvm (p&amp;lt;0.001). The ratio of the patients with DR-FLASH score&amp;gt;3 was significantly higher in those with high Pd/Pvm than low. The ratio of AT recurrence was significantly higher in the patients with high Pd/Pvm than in those with low Pd/Pvm (32.4% vs 18.8%, p=0.034). The ratio of AT occurring during repeated ablation and reproducible frequently occurring atrial premature contractions or AF triggers in left atrium (LA) were significantly higher in the patients with high Pd/Pvm than low Pd/Pvm. Conclusion Combination of P-wave morphology, Pd/Pvm, was significantly associated with LRAF. Pd/Pvm was significantly correlated with clinical risk score for predicting LA low-voltage area and incidence of AT and LA-origin AF triggers.

Inter-atrial block and atrial fibrillation predict cardiac adverse events in heart failure with preserved ejection fraction

Abstract Background Atrial fibrillation (AF) is a prognostic risk-factor in heart failure with preserved ejection fraction (HFpEF). Earlier stages of atrial dysfunction identified by the ECG, particularly inter-atrial block (IAB), may provide additional risk predictions in HFpEF patients in sinus rhythm. Purpose To assess the prevalence of IAB in patients diagnosed with HFpEF compared to non-HFpEF, and to evaluate the prognostic association of IAB and AF in patients diagnosed with HFpEF. Methods Consecutive symptomatic patients referred for a systematic diagnostic work-up to rule-in or rule-out HFpEF were included. The diagnosis of HFpEF was based on current guidelines (including HFA-PEFF and H2FPEF algorithms) and confirmed by consensus of multiple experienced HF specialists. Patients in whom HFpEF was ruled-out were included as non-HFpEF. We excluded patients with cardiac valve interventions before or up to 1 year after baseline, or with paced rhythm during IAB assessment. ECGs at baseline were assessed in detail for P-wave duration, morphology, and presence of IAB using digital calipers by investigators blinded to clinical data. IAB was defined based on a P-wave duration of &amp;gt;120ms. Patients with HFpEF and non-HFpEF were grouped into either i) AF based on ECG or medical history, ii) IAB based on ECG, or iii) no IAB or AF based on ECG. Adverse events were evaluated only in HFpEF patients and included HF hospitalization, cardiac or sudden death, and a composite of both. Results 372 patients with HFpEF and 68 non-HFpEF were included (females: 67.7% vs. 64.7%, p = 0.726; mean age: 75±7 vs. 67±10 years, p&amp;lt;0.001). AF was more common in HFpEF than non-HFpEF (64.8% vs. 23.5%, p&amp;lt;0.001). In sinus rhythm, presence of IAB was comparable between HFpEF and non-HFpEF (87.0% vs. 80.8%). During a mean follow-up of 3.2±1.6 years in HFpEF patients, more adverse cardiac events were observed when AF was present (23.7%, HR 10.6 [95%CI 1.5-1334.4]) compared to IAB (10.5%, HR 4.2 [95%CI 0.56-542.6]) and no IAB (0%), p = 0.0004 (Figure 1). Pairwise comparisons confirmed these observations: AF vs. IAB p = 0.006, AF vs. no IAB p = 0.031. In HFpEF patients with sinus rhythm, a trend was found for more adverse events when IAB was present versus no IAB (p = 0.06). Conclusion Patients with HFpEF have a higher prevalence of AF and similar prevalence of IAB compared to symptomatic patients ruled-out for HFpEF. Presence of IAB or AF in HFpEF may predispose to adverse cardiac events in patients without severe valve disease. IAB may enrich cardiac risk stratification in addition to AF in HFpEF.Survival curves for no IAB, IAB, and AF

Sex differences in individuals with high normal blood pressure who developed hypertension in three-year follow-up

Abstract Background Recent data demonstrated that females are at risk for cardiovascular disease at a lower blood pressure (BP) level than males. Purpose Identify normotensive individuals with high normal BP who are going to develop hypertension in three-year follow-up and demonstrate differences according to their gender. Methods 100 individuals with high normal BP were followed-up for 3 consecutive years. During enrolment they underwent ambulatory BP monitor (ABPM), electrocardiogram (ECG), echocardiogram, carotid-femoral pulse wave velocity (PWV), sympathetic drive assessed by muscle sympathetic nerve activity (MSNA), a negative for ischemia treadmill exercise stress test (TST) (Bruce protocol) and blood sampling. Follow-up was scheduled every 6 months for 3 consecutive years, where BP measurements were assessed in office and with ABPM. All participants offered lifestyle advise to lower their BP. Endpoint was development of hypertension (HTN). Results 19 males and 21 females developed HTN. Office and ABPM measurements did not differ significantly but women who developed HTN demonstrate higher pulse pressure 50vs45 mmHg (p=0.03). In ABPM systolic blood pressure (SBP) differ (123 vs 119 mmHg, p=0.01) in future hypertensive females. Additionally night-time SBP differ in both genders who were going to develop HTN (women: 116vs111 mmHg, p=0.007 and men: 116vs111 mmHg, p=0.043). Both genders demonstrate significantly different PWV values among future hypertensives and those who remained normotensives (women: 8.2vs7.2 m/s, p&amp;lt;0.001, men: 8.3vs7.2 m/s, p&amp;lt;0.001). Males and females who developed hypertension had higher sympathetic activity as reflected from MSNA levels (men: 33vs27 bursts/minute, p&amp;lt;0.001, women: 36vs28 bursts/minute, p&amp;lt;0.001). Both genders who developed HTN had higher SBP at peak exercise (men: 208vs184 mmHg, p&amp;lt;0.0001, women: 197vs173 mmHg, p&amp;lt;0.0001) as also steeper SBP/MET slope (men: 6.7vs5.0, p=0.038, women: 7.1vs3.8, p&amp;lt;0.0001), while their maximal heart rate achieved differ (men: 158bpm vs 167bpm, p=0.014, women: 153bpm vs 162bpm, p&amp;lt;0.0001). Only in women's baseline ECG who developed HTN had wider p-wave duration (103vs94ms, p=0.032) and QRS length (88vs80ms, p=0.018). While echocardiographicly they displayed increased left ventricular mass index (LVMI) (81vs72 g/m²,p=0.006), atrial diameter (37vs34 mm,p&amp;lt;0.0001) and decrease E/A ratio of transmitral flow velocity (0.8vs1.0, p=0.005). Kidney function assessed by 2021 CKD-EPI eGFR reveals a deterioration in those women who are going to develop HTN (87 vs 97 mL/min/1.73 m², p=0.009). Conclusions Both men and women benefit from treadmill exercise stress test as a prognostic tool that can reveal the likelihood of development of hypertension in both sexes and arouse the need to research for target organ damage in women who are in prehypertensive state and may benefit from an early intervention until clarify sex-specific thresholds for diagnosis of hypertension.

Validation of novel electrocardiographic classification for stroke prediction in patients with atrial fibrillation undergoing cardioversion

Abstract Introduction Atrial cardiomyopathy (aCM) is an electromechanical entity reflecting abnormal conduction, structure and function of the myocardium predisposing to stroke and atrial fibrillation (AF), however, its electrocardiographic (ECG) definition is poorly characterized. We systematically assessed potential ECG markers of aCM in an attempt to identify those at risk for stroke and systemic embolism (SSE) or a combination of SSE, heart failure and death (major adverse events, MAE). Methods and Results We manually reviewed 1591 ECGs from patients with AF undergoing an acute cardioversion from the Finnish Cardioversion study (FIN-CV). Using post-CV 30d follow-up data as the derivation cohort, we determined the predictive performance of various P-wave indices including P-wave duration, morphology, and P-terminal force (PTF) for SSE prediction. The best predictive performance was found using a combination of prolonged P-wave (≥180ms), deflected P-wave morphology in lead II, biphasic P-waves in all inferior leads or increased PTF (≥80mm*ms) as markers for extensive aCM. We validated the findings using the long-term follow-up in patients with no anticoagulation of whom 219/874 (25.1%) had extensive aCM. During the median follow-up of 4.9 years, there was 51 (5.8%) new SSE and 152 (17.4%) MAE in total. At 3 years, 9 (4.1%), 4 (1.2%) and 1 (0.3%) patients with extensive, moderate or no aCM had suffered from SSE, respectively (p=0.002). At 5 years, the rates were 16 (7.3%), 8 (2.5%) and 5 (1.5%) (p&amp;lt;0.001). Extensive aCM remained an independent predictor for SSE (HR 4.5, 95%CI 2.1-9.5, p&amp;lt;0.001) and MAE (HR 1.7, 95%CI 1.1-2.6, p=0.01) after adjusting for CHA2DS2-VASc score (Figure 1). Conclusion Novel electrocardiographic markers of extensive aCM provided additional prognostic insight on risk for stroke in atrial fibrillation patients.Figure 1Graphical Abstract

Abstract 16636: Correlation Between Interatrial Block Detected by High-Resolution Electrocardiography and Echocardiographic Markers of Left Atrial Cardiomyopathy

Introduction: Left atrial cardiomyopathy (LACM) involves electromechanical changes in the left atrium (LA) and is linked to atrial fibrillation (AF) and embolic stroke. Several diagnostic ECG and transthoracic echocardiogram (TTE) parameters have been suggested, but information about their interrelationship is limited. Hypothesis: To evaluate if partial or advanced interatrial block (IAB) using high-resolution 12-lead ECG (HR-ECG) is related to TTE indicators of LACM. Methods: A retrospective analysis of consecutive patients aged over 18 was performed. The evaluation included HR-ECG (signal-averaging technique, ≥ 200 cycles, QRS-triggered, 0.25-262 Hz bandwidth, 1000 samples/sec) and TTE. Exclusion criteria: AF, pacemaker/ICD carriers, heart surgery history, poor ultrasound window, or significant ECG noise. Inferior leads (DII, DIII, aVF) classified patients into three groups: no IAB, partial IAB (P wave ≥ 120 ms), and advanced IAB (typical/atypical patterns with negative aVF terminal component). TTE parameters of LACM considered were LA volume indexed to body surface area (LAVI), PA-TDI (surface ECG onset P wave to A' peak of LA lateral wall on Tissue-Doppler Imaging), and PALS (peak atrial longitudinal strain) during reservoir phase. Results: Of 851 patients, 533 met the inclusion criteria. Both IAB groups had a higher prevalence of TTE indicators of LACM (Table 1), and a statistically significant correlation was found between P wave duration (PWD) and TTE markers of LACM (Figure 1). Conclusions: Patients with partial or advanced IAB (assessed by HR-ECG) show a higher prevalence of TTE markers of LACM and a significant correlation between PWD, LAVI, PA-TDI, and PALS.

Abstract 14478: Electrocardiographic Predictors of Response to Sacubitril/Valsartan Therapy in Heart Failure With Reduced Ejection Fraction: A Retrospective Cohort Study

Introduction: Sacubitril/valsartan (SV) therapy is currently recommended as first-line therapy in patients with heart failure and reduced ejection fraction (HFrEF) due to its significant clinical and prognostic benefit; however, not all patients respond to therapy and predictors of clinical response to SV remain under-studied. Hypothesis: Certain electrocardiographic (ECG) parameters may predict response to SV therapy in HFrEF patients. Methods: Retrospective analysis of a hospital heart failure registry was undertaken. Consecutive HFrEF patients (NHYA class II - III) on maximal-dose SV were studied. Response to SV was defined as ≥10% relative improvement in left ventricular ejection fraction (LVEF) at 3-months post-therapy. Pre-therapy ECGs were retrospectively analyzed for axes and standard wave and interval durations. Logistic regression was used to estimate odds ratios and 95% confidence intervals for associations between predictors and therapeutic response. For P-wave duration (PWD), the reference level was set to &lt;100ms; for the remaining variables, reference levels were set as: (a) the normal range for ECG variables; (b) absence for bundle branch blocks; and (c) the other category for binary variables. Calibration and discriminative performance of the models were also assessed. Results: In the 102 patients studied, PWD 100 - 120ms, PWD &gt;120ms, and QTc &gt;460ms were independently associated with response to SV therapy: OR 18.00 (4.45 - 122.90), 5.00 (1.47 - 20.42), and 3.10 (1.18 - 9.22) respectively. A multivariate logistic regression model including these predictors, and adjusting for pre-therapy LVEF, was both highly selective (area under the ROC curve = .840) and well-calibrated (Hosmer-Lemeshow p = .973). Conclusions: Prolongation of both PWD and QTc interval on baseline ECG in HFrEF patients is predictive of therapeutic response to maximal-dose SV therapy and may indicate early cardiac remodeling that is highly amenable to reversal.

Atrial and ventricular arrhythmia predictors with electrocardiographic parameters in myocardial infarction with non-obstructive coronary artery disease (MINOCA).

The clinical importance and recognition of myocardial infarction with non-obstructive coronary artery disease (MINOCA) is increasing. Nevertheless, no studies are investigating the risk of atrial fibrillation and ventricular arrhythmia in MINOCA patients. This study aimed to determine the risk of arrhythmia with electrocardiographic predictors in MINOCA patients. In this study, patients diagnosed with MINOCA and stable out-patients without significant lesions in their coronary arteries were compared. Morphology-voltage-Pwave duration electrocardiography (MPV ECG) score was used to determine atrial arrhythmia risk. QT interval and QT dispersion Tpeak-Tend time and Tpeak-Tend/QT interval were used to determine ventricular arrhythmia risk. A total of 155 patients were included in our study. Seventy-seven of these patients were in the MINOCA group. There was no statistically significant difference between the two groups in MPV ECG score (1.95 ± 1.03 vs 1.68 ± 1.14, p = 0.128). P-wave voltage, P-wave morphology and P-wave duration, which are components of the MPV ECG score, were not statistically significantly different. The QRS complex duration (90.21 ± 14.87 vs 82.99 ± 21.59 ms, p = 0.017), ST interval (271.95 ± 45.91 vs 302.31 ± 38.40 ms, p < 0.001), corrected QT interval (438.17 ± 43.80 vs 421.41 ± 28.39, p = 0.005) and QT dispersion (60.75 ± 22.77 vs 34.19 ± 12.95, p < 0.001) were statistically significantly higher in the MINOCA group. The Tpeak-Tend (89.53 ± 32.16 vs 65.22 ± 18.11, p < 0.001), Tpeak-Tend/QT interval (0.2306 ± 0.0813 vs 0.1676 ± 0.0470, p < 0.001) and Tpeak-Tend/corrected QT interval (0.2043 ± 0.6997 vs 0.1551 ± 0.4310, p < 0.001) ratios were also significantly higher in patients with MINOCA. In the MINOCA patients, there was no increase in the risk of atrial fibrillation based on ECG predictors. However, it was shown that there could be a significant increase in the risk of ventricular arrhythmia. We believe this study could be helpful for specific recommendations concerning duration of hospitalisation and follow up in MINOCA patients.

Pinocembrin attenuates susceptibility to atrial fibrillation in rats with pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension (PAH) is a disease characterized by pulmonary vascular remodeling that triggers fibrosis and excessive myocardium apoptosis, ultimately facilitating atrial fibrillation (AF). In various rat models, Pinocembrin has anti-fibrotic and anti-apoptotic effects, reducing arrhythmia vulnerability. However, whether pinocembrin alleviates to AF in a PAH model remains unclear. The experiment aims to investigate how pinocembrin affects AF susceptibility in PAH rats and the possible mechanisms involved. MethodsThe PAH model was induced by monocrotaline (MCT; i. p. 60 mg/kg). Concurrently, rats received pinocembrin (i.p.50 mg/kg) or saline. Hemodynamics parameters, electrocardiogram parameters, lung H.E. staining, atrial electrophysiological parameters, histology, Western blot, and TUNEL assay were detected. ResultsCompared to the control rats, MCT-induced PAH rats possessed prominently enhancive mPAP (mean pulmonary artery pressure), pulmonary vascular remodeling, AF inducibility, HRV, right atrial myocardial fibrosis, apoptosis, atrial ERP, APD, and P-wave duration. Additionally, there were lowered protein levels of Cav1.2, Kv4.2, Kv4.3, and connexin 40 (CX40) in the MCT group in right atrial tissue. However, pinocembrin reversed the above pathologies and alleviated the activity of the Rho A/ROCKs signaling pathway, including the expression of Rho A, ROCK1, ROCK2, and its downstream MYPT-1, LIMK2, BCL-2, BAX, cleaved-caspase3 in right atrial and HL-1 cells. ConclusionPresent data exhibited pinocembrin attenuated atrial electrical, ion-channel, and autonomic remodeling, diminished myocardial fibrosis and apoptosis levels, thereby reducing susceptibility to AF in the MCT-induced PAH rats. Furthermore, we found that pinocembrin exerted inhibitory action on the Rho A/ROCK signaling pathway, which may be potentially associated with its anti-AF effects.

Identification of Brugada syndrome based on P-wave features: an artificial intelligence-based approach.

Brugada syndrome (BrS) is an inherited disease associated with an increased risk of ventricular arrhythmias. Recent studies have reported the presence of an altered atrial phenotype characterized by abnormal P-wave parameters. The aim of this study was to identify BrS based exclusively on P-wave features through an artificial intelligence (AI)-based model. Continuous 5 min 12-lead ECG recordings were obtained in sinus rhythm from (i) patients with spontaneous or ajmaline-induced BrS and no history of AF and (ii) subjects with suspected BrS and negative ajmaline challenge. The recorded ECG signals were processed and divided into epochs of 15 s each. Within these epochs, P-waves were first identified and then averaged. From the averaged P-waves, a total of 67 different features considered relevant to the classification task were extracted. These features were then used to train nine different AI-based supervised classifiers. A total of 2228 averaged P-wave observations, resulting from the analysis of 33 420 P-waves, were obtained from 123 patients (79 BrS+ and 44 BrS-). Averaged P-waves were divided using a patient-wise split, allocating 80% for training and 20% for testing, ensuring data integrity and reducing biases in AI-based model training. The BrS+ patients presented with longer P-wave duration (136 ms vs. 124 ms, P < 0.001) and higher terminal force in lead V1 (2.5 au vs. 1.7 au, P < 0.01) compared with BrS- subjects. Among classifiers, AdaBoost model had the highest values of performance for all the considered metrics, reaching an accuracy of over 81% (sensitivity 86%, specificity 73%). An AI machine-learning model is able to identify patients with BrS based only on P-wave characteristics. These findings confirm the presence of an atrial hallmark and open new horizons for AI-guided BrS diagnosis.

Markers of Atrial Myopathy in the GeneralPopulation: Prevalence, Predictors, and Inter-Relations.

Atrial myopathy refers to structural and functional cardiac abnormalities associated with atrial fibrillation and stroke, but appropriate diagnostic criteria are lacking. This study aimed to assess prevalence, clinical correlates, and overlap between potential atrial myopathy markers. The population-based SCAPIS (Swedish CArdioPulmonary bioImage Study) prospectively included 6,013 subjects without atrial fibrillation with 24-hour electrocardiograms. Resting electrocardiograms measuring P-wave indices were collected at 1 screening site (n=1,201), and a random sample (n=385) had echocardiographic left atrial volume index (LAVi). Atrial myopathy markers were defined as≥500 premature atrial complexes/24 h, LAVi≥34mL/m2, P-wave duration >120 milliseconds, or P-wave terminal force in V1 >4,000 ms·s. Clinical correlates included age, sex, body mass index, height, smoking, physical activity, coronary artery disease, diabetes, systolic blood pressure, antihypertensive medication, and low education. Atrial myopathy was common; 42% of the sample with all diagnostic modalities available had≥1 atrial myopathy marker, but only 9% had 2 and 0.3% had≥3. Only P-wave duration and LAVi were correlated (ρ=0.10; P = 0.04). Clinical correlates of premature atrial complexes, P-wave indices, and LAVi differed; current smoking (34% increase; P< 0.001), systolic blood pressure (4%/mmHg increase; P = 0.01), diabetes (35% increase; P = 0.001), and coronary artery disease (71% increase; P = 0.003) were associated with premature atrial complexes, physical activity≥2h/wk was associated with increased LAVi (β-coefficient=3.1; P< 0.0001) and body mass index was associated with P-wave duration (β-coefficient=0.4/kg/m2; P< 0.0001). In the general population, indirect markers of atrial myopathy are common but only weakly correlated, and their risk factor patterns are different. More studies are needed to accurately identify individuals with atrial myopathy with diagnostic methods.

Electrocardiographic Characteristics in 438 Neonates with Atrial Septal Defects

Arrhythmias and electrocardiographic (ECG) abnormalities are common among patients with atrial septal defects (ASDs). We studied a large cohort of neonates with ASDs to investigate whether ECG abnormalities are present at this early stage or develop later, secondary to hemodynamic changes. We analyzed the echocardiograms and ECGs from the Copenhagen Baby Heart Study, a population-based cohort study. We compared ECG characteristics of 438 neonates with secundum ASDs to 1314 matched controls. In subgroup analyses, we investigated whether electrocardiographic characteristics were associated with age at examination. Neonates with ASDs (median age, 11 days; males, 51%) had longer P-wave durations (58 vs. 56 ms, p < 0.001), PR intervals (100 vs. 96 ms, p < 0.001), and a more rightward-shifted QRS axis (116 vs. 114 degrees, p = 0.032) compared to controls (median age, 10 days; males, 51%). There were no differences between cases and controls in the P-wave area, amplitude, or axis. Subgroup analyses showed that the differences in P-wave duration and PR interval were present in neonates examined in the first week after birth. The difference in the QRS axis was not found in neonates examined this early but was found in neonates examined at age two to four weeks. In conclusion, ASDs are associated with ECG changes from the neonatal phase. The P-wave duration and PR interval are longer in neonates with ASDs when compared to controls as early as the first week after birth, indicating that these changes are not purely secondary, but that neonates with an ASD have altered cardiac electrical activity.ClinicalTrials.gov Identifier NCT02753348 (April 27, 2016)

Cross-Sectional Relationship Between Atrial Conduction Delay and Arterial Stiffness in Patients with Obstructive Sleep Apnea.

Prolonged P-wave duration (PWD), which indicates atrial conduction delay, is a potent precursor of atrial fibrillation (AF) that may be induced by obstructive sleep apnea (OSA). The cardio-ankle vascular index (CAVI), which is an arterial stiffness parameter, is elevated in patients with OSA; moreover, an increased CAVI is associated with atrial conduction delay through left atrium enlargement in association with left ventricular diastolic dysfunction. We aimed to examine the relationship between the CAVI and PWD in patients with OSA. We included patients with a sinus rhythm who underwent overnight polysomnography. We measured the PWD and CAVI on standard 12-lead electrocardiograms; further, we analyzed the relationship between PWD and CAVI. We analyzed data from 300 participants (men, 89.0%; mean age, 52.3 ± 13.1 years; and body mass index, 26.2 ± 3.9 kg/m2). The mean PWD was 104.4 ± 10.4 ms while the mean CAVI was 7.5 ± 1.5. PWD was significantly correlated with CAVI (r = 0.478, p < 0.001); additionally, PWD and CAVI were directly associated with OSA severity (p = 0.002 and p = 0.002, respectively). Multivariate regression analysis revealed an independent significant correlation of PWD and CAVI with OSA severity. In patients with OSA, an increase in arterial stiffness is associated with atrial conduction delay.

Twelve-Lead ECG, Holter Monitoring Parameters, and Genetic Testing in Brugada Syndrome: Insights from Analysis of Multigenerational Family with a History of Sudden Cardiac Arrest during Physical Activity.

Brugada syndrome (BrS) is an arrhythmogenic disorder increasing the risk of syncopal episodes and sudden cardiac death. BrS usually runs through families with reduced penetrance and variable expression. We analyzed the multigenerational family of a patient who died after sudden cardiac arrest with post-mortem diagnosis of BrS. We analyzed clinical history, comprehensive arrhythmic risk, genetic findings, and additional tests, including electrocardiogram (ECG), detailed 24-hour Holter ECG results, and standard echocardiography findings, and followed up the patients in the ambulatory clinic. We analyzed a pedigree of 33 members of four generations of the family (19 male and 14 female patients). In this family, we identified 7 patients with BrS (median Modified Shanghai Score and Sieira model: 4.5 (4-6) and 1 (0-4) points, respectively), including both parents of the deceased patient, and 8 relatives with negative sodium channel blocker drug challenge test. Genetic testing revealed a novel mutation in sodium voltage-gated channel alpha subunit 5 (SCN5A) c.941A>G, (p.Tyr314Cys) inherited from the father of the proband. Patients with BrS were characterized by longer P-wave duration (120 (102-155) vs. 92.5 (88-110) ms, p = 0.013) and longer PR intervals (211.3 ±26.3 vs. 161.6 ± 18.9 ms, p = 0.001), along with more frequent positive aVR sign, but did not differ in terms of QRS duration or T-wave characteristics in resting ECGs. BrS patients were characterized by lower mean, minimal, and maximal (for all p ≤ 0.01) heart rates obtained from Holter ECG monitoring, while there was no difference in arrhythmias among investigated patients. Moreover, visual diurnal variability of ST segment changes and fragmented QRS complexes were observed in patients with BrS in Holter ECG monitoring. There were no major arrhythmic events during median follow-up of 68.7 months of alive BrS patients. These results suggest ECG features which may be associated with a diagnosis of BrS and indicate a novel SCN5A variant in BrS patients. Twelve-lead Holter ECG monitoring, with modified precordial leads placement, may be useful in BrS diagnostics and risk stratification in personalized medicine.

Atrial electrical remodeling and function after transcatheter aortic valve replacement in patients with aortic stenosis.

To examine reverse atrial electrical remodeling in patients with aortic stenosis (AS) after trans-catheter aortic valve replacement (TAVR). In 65 consecutive patients with severe AS (83 ± 4years, 47 (72.3%) females), we analyzed ECG records for the P wave duration (PWD) in lead II and P-terminal force (PTFV1) in V1, and measured cardiac dimensions and function by echocardiography (ECHO) following TAVR. Biomarkers were measured to assess myocardial injury by TAVR. TAVR was successfully performed without major complications: the aortic valve area increased from 0.62 ± 0.14 cm2 to 1.52 ± 0.24cm2, and the trans-aortic pressure gradient decreased from 58.4 ± 15.9mmHg to 15.0 ± 19.6mmHg. PWD and PTFV increased immediately after TAVR and returned to the pre-TAVR levels on the next day. Then, the PWD declined toward 6months after TAVR non-significantly in all patients, but significantly in 25 patients with baseline PWD ≥ 130ms (P = 0.039). PTFV1 showed no long-term change. Improvement was observed in the ejection fraction, all thickness of the left ventricle and in the left atrial dimensions on ECHO. After recovery from transient aggravation by TAVR procedure, PWD reversed slowly, and the change was significant in those with baseline PWD ≥ 130ms while change in PTFV1 was not significant at 6months of follow-up. ECHO showed a reversal of remodeling in the left ventricle and in the left atrial dimension after TAVR.

Comparison of Electrocardiographic Parameters by Gender in Heart Failure Patients with Preserved Ejection Fraction via Artificial Intelligence.

Heart failure (HF) causes high morbidity and mortality worldwide. The prevalence of HF with preserved ejection fraction (HFpEF) is increasing compared with HF with reduced ejection fraction (HFrEF). Patients with HFpEF are a patient group with a high rate of hospitalization despite medical treatment. Early diagnosis is very important in this group of patients, and early treatment can improve their prognosis. Although electrocardiographic (ECG) findings have been adequately studied in patients with HFrEF, there are not enough studies on these parameters in patients with HFpEF. There are very few studies in the literature, especially on gender-specific changes. The current research aims to compare gender-specific ECG parameters in patients with HFpEF based on the implications of artificial intelligence (AI). A total of 118 patients participated in the study, of which 66 (56%) were women with HFpEF and 52 (44%) were men with HFpEF. Demographic, echocardiographic, and electrocardiographic characteristics of the patients were analyzed to compare gender-specific ECG parameters in patients with HFpEF. The AI approach combined with machine learning approaches (gradient boosting machine, k-nearest neighbors, logistic regression, random forest, and support vector machines) was applied for distinguishing male patients with HFpEF from female patients with HFpEF. After determining the parameters (demographic, echocardiographic, and electrocardiographic) to distinguish male patients with HFpEF from female patients with HFpEF, machine learning methods were applied, and among these methods, the random forest model achieved an average accuracy of 84.7%. The random forest algorithm results showed that smoking, P-wave dispersion, P-wave amplitude, T-end P/(PQ*Age), Cornell product, and P-wave duration were the most influential parameters for distinguishing male patients with HFpEF from female patients with HFpEF. The proposed model serves as a valuable tool for physicians, facilitating the diagnosis, treatment, and follow-up for distinguishing male patients with HFpEF from female patients with HFpEF. Analyzing readily accessible electrocardiographic parameters empowers medical professionals to make informed decisions and provide enhanced care to a wide range of individuals.

P-wave duration-amplitude ratio quantifies atrial low-voltage area and predicts atrial arrhythmia recurrence following pulmonary vein isolation.

Atrial low-voltage area (LVA) in AF patients increase the risk of atrial arrhythmia (AA) recurrence following pulmonary vein isolation (PVI). Contemporary LVA prediction scores (DR-FLASH, APPLE) do not include P-wave metrics. We aimed to evaluate the utility of P-wave duration-amplitude ratio (PWR) in quantifying LVA and predicting AA recurrence post-PVI. In 65 patients undergoing first-time PVI, 12-lead ECGs were recorded during sinus rhythm. PWR was calculated as the ratio between the longest P-wave duration and P-wave amplitude in lead I. High-resolution bi-atrial voltage maps were collected and LVAs included bipolar electrogram amplitudes <0.5mV or <1.0mV. A LVA quantification model was created using clinical variables and PWR, then validated in a separate cohort of 24 patients. Seventy-eight patients were followed for 12-months to evaluate AA recurrence. PWR strongly correlated with left atrial (LA) (<0.5mV: r=0.60; <1.0mV: r=0.68; p<0.001) and bi-atrial LVA (<0.5mV: r=0.63; <1.0mV: r=0.70; p<0.001). Addition of PWR to clinical variables improved model quantification of LA LVA at the <0.5mV (adjusted R2: 0.59 to 0.68) and <1.0mV cutpoints (adjusted R2: 0.59 to 0.74). In the validation cohort, PWR model-predicted LVA correlated strongly with measured LVA (<0.5mV: r=0.78; <1.0mV: r=0.81; p<0.001). PWR model was superior to DR-FLASH (AUC 0.90 vs. 0.78; p=0.030) and APPLE (AUC 0.90 vs. 0.67; p=0.003) at detecting LA LVA and comparable at predicting AA recurrence post-PVI (AUC=0.67 vs. 0.65 and 0.60). Our novel PWR model accurately quantifies LVA and predicts AA recurrence post-PVI. PWR model-predicted LVA may help guide patient selection for PVI.

Effect of body mass index (BMI) on electrocardiographic P-wave dispersion among healthy adults

Background: According to the results of an electrocardiogram (ECG), a higher body mass index (BMI) indicates body fat and is linked toa higher risk of cardiovascular illnesses. A noninvasive ECG signal called P-wave dispersion (Pd) can predict the likelihood of an atrialarrhythmia and reflects atrial remodeling. Pd is calculated by computing the difference between the maximum and minimum P-wavelengths captured from the 12 ECG lead recordings. To assess the early-stage risk of acquiring cardiovascular illnesses, we investigatedthe effect of BMI on P-wave dispersion in healthy, overweight, and obese adults. Materials and Methods: Depending on their body massindex (BMI), we divided 200 participants into three groups (normal weight, overweight, and obese) during a comparative cross-sectionalstudy. We measured 12-lead surface ECG and P-wave dispersion in study participants. Results: Mean P-wave lengths were 33.23(±6.08), 33.15(± 5.16), and 46.15 (± 5.37), respectively, for people who were normal weight, overweight, and obese. Between the normalweightand obese groups and the overweight and obese groups, there was a statistically significant difference (p &lt; 0.001), according toTukey’s post-hoc analysis. However, the normal-weight and overweight groups showed no statistically significant difference (P = 0.997).Pearson’s correlation analysis shows that P-wave dispersion and BMI showed a significant positive connection (r = 0.632). Conclusion:A higher BMI is linked to a longer P-wave duration and dispersion, even in healthy adults. The likelihood of left atrial hypertrophy andatrial arrhythmia increases with a prolonged P-wave duration. This study emphasizes the importance of raising awareness about theneed to adopt healthy lifestyles to avoid the harmful effects of obesity on the heart