Terminal Force Research Articles

Diagnostic value of electrocardiographic P-wave characteristics in atrial fibrillation recurrence and tachycardia-induced cardiomyopathy after catheter ablation.

Abnormal P-wave characteristics were reportedly associated with left ventricular interstitial fibrosis as defined by cardiac magnetic resonance images. The objective of this study is to investigate the utility of P-wave characteristics to predict atrial fibrillation (AF) recurrence and the recovery of left ventricular systolic dysfunction (LVSD) after catheter ablation (CA) for AF. Two hundred and five AF patients (109 paroxysmal and 96 persistent) who underwent CA were enrolled. We measured maximum P-wave duration (max PWD) and P-wave terminal force in lead V1 (PTFV1) calculated as a product of P-wave terminal amplitude (PTaV1) and duration (PTdV1) in lead V1 during sinus rhythm. AF recurrence was noted in 50 patients at 12months after CA. Patients with AF recurrence had a higher prevalence of persistent AF, a larger left atrial volume, and a longer max PWD than those without. We divided the patients into 2 groups: 156 patients with left ventricular ejection fraction (LVEF) > 45% and 49 patients with LVEF ≤ 45% (Low-EF group). In Low-EF group, tachycardia-induced cardiomyopathy (TIC) was defined as improvement in LVEF ≥ 15% or LVEF ≥ 50% at 5months after CA. TIC and non-TIC groups consisted of 37 and 12 patients, respectively. Max PWD, PTFV1, PTdV1, and PTaV1 were significantly greater in non-TIC-group than in TIC-group. PTFV1 had the highest diagnostic accuracy to discriminate between TIC and no-TIC-groups; cut-off value for PTFV1 was determined as 56.7mVms (area under the ROC curve = 0.80; 75% sensitivity; and 76% specificity). Max PWD was a useful predictor of AF recurrence and the complete recovery of LVSD after CA. PTFV1 had the highest diagnostic accuracy to discriminate between TIC and no-TIC-groups.

Usefulness of Electrocardiographic Left Atrial Abnormality to Predict Response to Cardiac Resynchronization Therapy in Patients With Mild Heart Failure and Left Bundle Branch Block (a Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy Substudy)

Cardiac resynchronization therapy (CRT) has proven prognostic benefits in patients with heart failure (HF) with left bundle branch block (LBBB) QRS morphology. Electrocardiographic left atrial (LA) abnormality has been proposed as a noninvasive marker of atrial remodeling. We aimed to assess the impact of electrocardiographic LA abnormality for prognosis in patients with HF treated with CRT. Baseline resting 12-lead electrocardiograms recorded from 941 patients enrolled in the CRT arm of the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy was processed automatically using Glasgow algorithm, which included automated assessment of P-wave terminal force in lead V1 (PTF-V1) as a marker of LA abnormality. A PTF-V1 of ≥0.04 mm⋅s was considered abnormal. The primary end point was HF event and/or death. Total mortality and appropriate defibrillator therapies were the secondary end points. At baseline 550, patients treated with CRT with a defibrillator had LBBB QRS morphology and normal PTF-V1. Normal PTF-V1 was associated with significant risk reduction for all assessed end points and for the primary end point comprised a hazard ratio of 0.55 (95% confidence interval 0.36 to 0.84) compared with patients with LBBB with abnormal PTF-V1 (n = 120), and a hazard ratio of 0.42 (95% confidence interval 0.32 to 0.55) compared with patients with implanted defibrillator (n = 729). In CRT-treated patients with HF, electrocardiographic LA abnormality appears to be an electrocardiographic indicator of poor long-term outcome in patients with LBBB. In conclusion, our data suggest that PTF-V1 bears additive prognostic information in the context of CRT, thus further strengthening the role of electrocardiographic diagnostics in risk stratification of patients with HF.

Abnormal Atrial Activation at Surface Electrocardiogram Examination in Born Underweight Young Adults.

Recent published data demonstrated how subjects born preterm are at higher risk of developing early atrial fibrillation (AF). The surface ECG of twenty-four adults, former preterm infants born with an extremely low birth weight (ex-ELBW; mean age at study: 23.2±3.3 years; mean gestational age: 27.8±2.3 weeks; mean birth weight: 840±120.1 grams), were compared with those of 24 healthy counterparts born at term (C). A few parameters known to be capable of predicting a predisposition to develop AF were examined: P wave duration and dispersion, P terminal force, isoelectric interval length, PR interval length, and advanced interatrial blocks. A shorter PR interval length was found in ex-ELBW compared to C (p<0.0003) as well as longer P wave duration and dispersion, p terminal force, and isoelectric interval (p<0.0001, p<0.0001, p<0.01, and p<0.0004, respectively). Four cases of advanced interatrial block were detected in ex-ELBW, and none in C (p<0.0001). P wave duration, PR interval length, and P wave dispersion were significantly correlated with birth weight (r=0.51 p<0.01, r=0.46 p<0.02, and r=0.42 p<0.04, respectively). When excluding the possible influence of gestational age on birth weight, P wave duration and dispersion were found to be the only statistically significant determinants of abnormal atrial electrical activation (p<0.03 and p<0.04, respectively). On the contrary, when excluding the possible influence of birth weight on gestational age, only P wave duration remained statistically significant (p<0.05). Surface ECG findings of abnormal atrial activity in ex-ELBW may explain their previously reported predisposition to developing AF.

Atrial Cardiopathy and the Risk of Ischemic Stroke in the CHS (Cardiovascular Health Study).

Emerging evidence suggests that an underlying atrial cardiopathy may result in thromboembolism before atrial fibrillation (AF) develops. We examined the association between various markers of atrial cardiopathy and the risk of ischemic stroke. The CHS (Cardiovascular Health Study) prospectively enrolled community-dwelling adults ≥65 years of age. For this study, we excluded participants diagnosed with stroke or AF before baseline. Exposures were several markers of atrial cardiopathy: baseline P-wave terminal force in ECG lead V1, left atrial dimension on echocardiogram, and N terminal pro B type natriuretic peptide (NT-proBNP), as well as incident AF. Incident AF was ascertained from 12-lead electrocardiograms at annual study visits for the first decade after study enrollment and from inpatient and outpatient Medicare data throughout follow-up. The primary outcome was incident ischemic stroke. We used Cox proportional hazards models that included all 4 atrial cardiopathy markers along with adjustment for demographic characteristics and established vascular risk factors. Among 3723 participants who were free of stroke and AF at baseline and who had data on all atrial cardiopathy markers, 585 participants (15.7%) experienced an incident ischemic stroke during a median 12.9 years of follow-up. When all atrial cardiopathy markers were combined in 1 Cox model, we found significant associations with stroke for P-wave terminal force in ECG lead V1 (hazard ratio per 1000 μV*ms 1.04; 95% confidence interval, 1.001-1.08), log-transformed NT-proBNP (hazard ratio per doubling of NT-proBNP, 1.09; 95% confidence interval, 1.03-1.16), and incident AF (hazard ratio, 2.04; 95% confidence interval, 1.67-2.48) but not left atrial dimension (hazard ratio per cm, 0.96; 95% confidence interval, 0.84-1.10). In addition to clinically apparent AF, other evidence of abnormal atrial substrate is associated with subsequent ischemic stroke. This finding is consistent with the hypothesis that thromboembolism from the left atrium may occur in the setting of several different manifestations of atrial disease.

Abstract 173: Atrial Cardiopathy and the Risk of Ischemic Stroke in the Cardiovascular Health Study

Introduction: Several lines of evidence indicate that some cases of cryptogenic stroke may be due to an atrial cardiopathy that forms a nidus for thrombus formation and embolization even in the absence of atrial fibrillation (AF). Hypothesis: We hypothesized that evidence of atrial cardiopathy other than AF is independently associated with stroke. Methods: We examined the association between several markers of atrial cardiopathy and the risk of ischemic stroke among participants in the Cardiovascular Health Study, which prospectively enrolled community-dwelling adults ≥65 years of age. The exposures of interest were P-wave terminal force in electrocardiogram lead V 1 (PTFV 1 ), left atrial dimension on echocardiogram, amino terminal pro-B-type natriuretic peptide (NT-proBNP), and incident AF. The primary outcome was adjudicated ischemic stroke. We used Cox proportional hazards analysis to examine associations with stroke for all four markers together along with adjustment for traditional vascular risk factors. Results: Among 3,723 participants who were free of stroke and AF at baseline and who had data on all atrial cardiopathy markers, 585 patients (15.7%) experienced an incident ischemic stroke during a median 12.9 years of follow-up. When the four atrial cardiopathy markers were combined in one model along with traditional vascular risk factors, we found significant associations with stroke for PTFV 1 (hazard ratio [HR] per 1,000 μV*ms, 1.04; 95% confidence interval [CI], 1.0006-1.08), NT-proBNP (HR per doubling of NT-proBNP, 1.09; 95% CI, 1.03-1.16), and incident AF (HR, 2.04; 95% CI, 1.67-2.48), but not left atrial dimension (HR per cm, 0.96; 95% CI, 0.84-1.10). Conclusions: In a large, prospective, longitudinal study, we found that evidence of abnormal atrial substrate, defined more broadly than just AF, was associated with subsequent ischemic stroke. These findings support the hypothesis that left atrial thromboembolism can occur in the absence of AF.

The Utility of P-Wave Terminal Force V1 is Limited by its Reliability

The Utility of P-Wave Terminal Force V1 is Limited by its Reliability

Exact equilibrium solutions for nonlinear spatial deformations of nanorods with application to buckling under terminal force and couple

The paper is concerned with nonlinear spatial deformations of nanorods, described by exact solutions of the equilibrium equations of a rod theory based on the kinematics of Kirchhoff’s inextensible rods and the constitutive equation of Eringen’s nonlocal materials. The nonlinear equilibrium equations of nonlocal elastic rods that are prismatic in a natural state are established and their solutions are obtained for both configurations in which the axial curve has constant curvature and torsion, and general configurations in which the axial curve is described by means of elliptic functions. As an example of application of the theory, the buckling in space under terminal force and couple of nonlocal rods with one end clamped and the other one constrained to have the tangent parallel to the direction of the undeformed rod axis, is examined. For such rods, the eigencurves corresponding to bifurcation from configurations in which the axial curve is straight are found, and the exact solutions for the post-buckling configurations are presented. The results show that, along bifurcating branches on which the axial force is constant the rods, through a sequence of spatial equilibrium configurations, arrive at configurations in which the axial curve is a (planar) non-inflexional elastica. The comparison of the behavior of rods made of usual and nonlocal elastic materials shows that the presence of a nonlocal material has effects analogous to those due to a reduction in the rigidity of the rods.

Electrocardiographic alterations in patients consuming synthetic cannabinoids.

The aim of this study was to investigate the electrocardiographic parameters in patients consuming synthetic cannabinoids. Thirty-five patients who were consuming synthetic cannabinoids were enrolled to the study, prospectively. The control group included 35 healthy age and sex-matched volunteers. The standard 12-lead surface electrocardiograms of the study population were recorded. P maximum (Pmax), P minimum (Pmin), P wave dispersion, interatrial duration, P wave area in D2 derivation, abnormal P terminal force in V1 derivation, heart rate, QT interval, corrected QT, QT dispersion, PR interval duration and macrovolt T-wave alternans were evaluated by two experienced cardiologists. The intra-observer and inter-observer variations for all measurements were non-significant. Pmax and Pmin duration was not different between the groups ( p=0.96, p=0.15, respectively). However, P wave dispersion was higher in the patient group compared to control group (34±9.4, 29.5±6.6, p=0.02, respectively). QT interval was significantly higher in the patient group than the control group (380.3±25, 365.6±22.8, p=0.01, respectively). Besides, corrected QT was higher in the patient group compared to control group (415±36.8, 392±15.5, p=0.001, respectively). QT dispersion was also higher in the patient group than the control group (39.8±10.0, 29.2±5.4, p<0.001, respectively). Altered electrocardiography parameters linked with atrial and ventricular arrhythmia development may be observed in patients consuming synthetic cannabinoids. These patients should be evaluated regularly for cardiovascular disease and arrhythmia development. The electrocardiogram, which is a cheap and easy test to apply, can be used to determine the pro-arrythmic risk in patients consuming synthetic cannabinoids.

The association between acute mental stress and abnormal left atrial electrophysiology.

Acute stress may trigger atrial fibrillation (AF), but the underlying mechanisms are unclear. We examined if acute mental stress results in abnormal left atrial electrophysiology as detected by more negative deflection of P-wave terminal force in lead V1 (PTFV1 ), a well-known marker of AF risk. We examined this hypothesis in 422 patients (mean age =56 ± 10 years; 61% men; 44% white) with stable coronary heart disease who underwent mental (speech task) stress testing. PTFV1 was defined as the duration (milliseconds) times the value of the depth (μV) of the downward deflection (terminal portion) of the P-wave in lead V1 measured on digital electrocardiograms (ECG). Electrocardiographic left atrial abnormality was defined as PTFV1 ≤ -4000 μV*ms. Mean PTFV1 values during stress and recovery were compared with rest. The percentage of participants who developed left atrial abnormality during stress and recovery was compared with the percentage at rest. Compared with rest, PTFV1 became more negative during mental stress (mean change = -348, 95% CI = [-515, -182]; P<0.001) and no change was observed at recovery (mean change =12, 95%CI = [-148, 172]; P=0.89). A larger percentage of participants showed left atrial abnormality on ECGs obtained at stress (n=163, 39%) and recovery (n=142, 34%) compared with rest (n=127, 30%). Acute mental stress alters left atrial electrophysiology, suggesting that stressful situations promote adverse transient electrical changes to provide the necessary substrate for AF.

Fifteen Genetic Loci Associated With the Electrocardiographic P Wave.

The P wave on an ECG is a measure of atrial electric function, and its characteristics may serve as predictors for atrial arrhythmias. Increased mean P-wave duration and P-wave terminal force traditionally have been used as markers for left atrial enlargement, and both have been associated with increased risk of atrial fibrillation. Here, we explore the genetic basis of P-wave morphology through meta-analysis of genome-wide association study results for P-wave duration and P-wave terminal force from 12 cohort studies. We included 44 456 individuals, of which 6778 (16%) were of African ancestry. Genotyping, imputation, and genome-wide association study were performed at each study site. Summary-level results were meta-analyzed centrally using inverse-variance weighting. In meta-analyses of P-wave duration, we identified 6 significant (P<5×10-8) novel loci and replicated a prior association with SCN10A. We identified 3 loci at SCN5A, TBX5, and CAV1/CAV2 that were jointly associated with the PR interval, PR segment, and P-wave duration. We identified 6 novel loci in meta-analysis of P-wave terminal force. Four of the identified genetic loci were significantly associated with gene expression in 329 left atrial samples. Finally, we observed that some of the loci associated with the P wave were linked to overall atrial conduction, whereas others identified distinct phases of atrial conduction. We have identified 6 novel genetic loci associated with P-wave duration and 6 novel loci associated with P-wave terminal force. Future studies of these loci may aid in identifying new targets for drugs that may modify atrial conduction or treat atrial arrhythmias.

P-Wave Terminal Force in Lead V1 Predicts Paroxysmal Atrial Fibrillation in Acute Ischemic Stroke

Detection of paroxysmal atrial fibrillation (PAF) in cryptogenic stroke is critical to selecting an antithrombotic therapy for preventing recurrent stroke. However, the predictor of PAF in patients with acute ischemic stroke is not well elucidated. P-wave terminal force in lead V1 (PTFV1) is a standard electrocardiogram marker of left atrial abnormality. In this study, we aimed to investigate the utility of PTFV1 for the prediction of PAF in patients with acute ischemic stroke. The study included 295 consecutive patients who had acute ischemic stroke and were admitted to the hospital between September 2014 and August 2016. Patients with a known history of PAF, persistent atrial fibrillation, or cardiac pacemaker were excluded from the study. The clinical characteristics of patients with or without PAF were compared, and multiple logistic regression analysis was performed to assess the independent contribution of each variable. Among 226 patients eligible for our analysis, 16 (7.1%) were diagnosed with PAF after admission. PTFV1 was significantly higher in patients with PAF than those without PAF (.051 versus .027 mm⋅s; P < .001). Multivariate analysis showed that PTFV1 per .01 mm⋅s increase was strongly associated with PAF (odds ratio, 1.61; 95% confidence interval, 1.24-2.09; P < .001). The optimal cutoff value of PTFV1 for the prediction of PAF was .04 mm⋅s. PTFV1 is a strong predictor of PAF detection in acute ischemic stroke.

Incidence rates, correlates, and prognosis of electrocardiographic P-wave abnormalities – a nationwide population-based study

BackgroundScant data exist on incidence rates, correlates, and prognosis of electrocardiographic P-wave abnormalities in the general population. MethodsWe recorded ECG and measured conventional cardiovascular risk factors in 5667 Finns who were followed up for incident atrial fibrillation (AF). We obtained repeat ECGs from 3089 individuals 11years later. ResultsThe incidence rates of prolonged P-wave duration, abnormal P terminal force (PTF), left P-wave axis deviation, and right P-wave axis deviation were 16.0%, 7.4%, 3.4%, and 2.2%, respectively. Older age and higher BMI were associated with incident prolonged P-wave duration and abnormal PTF (P≤0.01). Higher blood pressure was associated with incident prolonged P-wave duration and right P-wave axis deviation (P≤0.01). During follow-up, only prolonged P-wave duration predicted AF (multivariable-adjusted hazard ratio, 1.38; P=0.001). ConclusionsModifiable risk factors associate with P-wave abnormalities that are common and may represent intermediate steps of atrial cardiomyopathy on a pathway leading to AF.

P-Wave Indices and Risk of Ischemic Stroke: A Systematic Review and Meta-Analysis.

Atrial cardiomyopathy is associated with an increased risk of ischemic stroke. P-wave terminal force in lead V1, P-wave duration, and maximum P-wave area are electrocardiographic parameters that have been used to assess left atrial abnormalities related to developing atrial fibrillation. The aim of this systematic review and meta-analysis was to examine their values for predicting ischemic stroke risk. PubMed and EMBASE databases were searched until December 2016 for studies that evaluated the association between P-wave indices and stroke risk. Both fixed- and random-effects models were used to calculate the overall effect estimates. Ten studies examining P-wave terminal force in lead V1, P-wave duration, and maximum P-wave area were included. P-wave terminal force in lead V1 was found to be an independent predictor of stroke as both a continuous variable (odds ratio [OR] per 1 SD change, 1.18; 95% confidence interval [CI], 1.12-1.25; P<0.0001) and categorical variable (OR, 1.59; 95% CI, 1.10-2.28; P=0.01). P-wave duration was a significant predictor of incident ischemic stroke when analyzed as a categorical variable (OR, 1.86; 95% CI, 1.37-2.52; P<0.0001) but not when analyzed as a continuous variable (OR, 1.05; 95% CI, 0.98-1.13; P=0.15). Maximum P-wave area also predicted the risk of incident ischemic stroke (OR per 1 SD change, 1.10; 95% CI, 1.04-1.17). P-wave terminal force in lead V1, P-wave duration, and maximum P-wave area are useful electrocardiographic markers that can be used to stratify the risk of incident ischemic stroke.

Pre- and post-orthotopic heart transplantation electrocardiogram characteristics of 998 patients

Objective: To analyze pre- and post-operation electrocardiograms (ECGs) features of patients underwent orthotopic heart transplantation (OHT), and provide evidences for identifying and analyzing post OHT ECGs. Methods: Nine hundreds and ninty-eight pre- and post- OHT standard 12-leads ECGs from 110 consecutive patients, who underwent OHT in our hospital from May 2008 to May 2014, were analyzed. Results: The mean heart rate(HR)was (86.9±16.4) beats per minute before OHT, and (100.0±0.4) beats per minute after OHT. P wave's amplitude, duration, amplitude multiplied by duration of donor heart in lead Ⅱ were (0.124±0.069)mV, (111.1±17.2)ms, (14.34±9.51)mV·ms before OHT; (0.054±0.037)mV, (86.9±27.0)ms, (5.02±4.03)mV·ms at 1 month after OHT; (0.073±0.049)mV, (93.9±17.5) ms, (7.00±4.81)mV·ms at 6 years after OHT. ECGs rotation occurred in 83.64%(92/110) patients after OHT, and prevalence of clockwise rotation was 76.36%(84/110). Sinus tachycardia was evidenced in 99.09%(109/110) patients after OHT, and incomplete right bundle branch block was present in 60.91%(67/110) patients after OHT. Pseudo complete atrioventricular block mostly occurred at 2 days after OHT. Prevalence of double sinus rhythm was 27.95%(263/941) post OHT, 40% of them occurred between the 1st and the 2nd month post OHT; the atrial rate of recipient hearts was (104.0±10.2) beats per minucte between the 3rd and the 6th month post OHT, and was (95.3±4.2) beats per minucte between the 4th year and the 5th year. P wave's amplitude, duration, amplitude multiplied by duration of recipient heart in lead Ⅱ were (0.066±0.055) mV, (52.8±34.7) ms, (4.67±4.95) mV·ms at 1 month after OHT, (0.043±0.040)mV, (44.4±40.5) ms , (3.11±3.61) mV·ms between the 1st year and 2nd year after OHT. The absolute value of P-wave(originating from the donor heart) terminal force in chest leads increased in 48.99%(461/941) patients post OHT, the P-wave terminal force of V(1) , V(2) and V(3) were -0.044(-0.066, -0.028), -0.060(-0.087, -0.038), -0.035(-0.056, 0) mm·s. Notched P wave in chest leads was presented in 10.31%(97/941) patients post OHT. PR segment depression in chest leads occurred in 60.24%(100/166) patients between the 3rd month and the 6th month, the incidence of PR segment depression in V(1) , V(2) and V(3) was 21.04%(198/941), 37.41%(352/941) and 28.69%(270/941), respectively. Conclusions: OHT is related to significantly changed ECGs. The mean HR increased significantly after OHT, then decreased gradually after half a year to one year, but it was still higher than preoperative mean HR after five or six years; the P waves of donor heart were usually inconspicuous or small in first month after OHT, and they became bigger after 2 months, and their duration and amplitude then became relatively steady afterwards. ECGs rotation, especially the clockwise rotation, was common post OHT. A variety of arrhythmias originating from the donor heart including sinus tachycardia and incomplete right bundle branch block could be found. Pseudo complete atrioventricular block could also be found in the early phase after OHT. With the extension of time, the incidence of double sinus rhythm reduced gradually. The atrial rate and P wave of recipient heart presented with a tendency to become lower. The absolute value of P-waves(originating from the donor heart) terminal force in chest leads (mainly V(1), V(2) and V(3)) increased, notched P waves in chest leads (mainly V(1), V(2)) and PR segments depression in chest leads (mainly V(2), V(3) and V(4)) also belong to typical post OHT ECGs features.

Association between electrocardiographic and echocardiographic markers of stage B heart failure and cardiovascular outcome.

AimsThe detection of non‐ischaemic (mainly hypertension, diabetes, and obesity) stage B heart failure (SBHF) may facilitate the recognition of those at risk of progression to overt HF and HF prevention. We sought the relationship of specific electrocardiographic (ECG) markers of SBHF to echocardiographic features of SBHF and their prognostic value for development of HF. The ECG markers were Cornell product (Cornell‐P), P‐wave terminal force in lead V1 (PTFV1), ST depression in lead V5 V6 (minSTmV5V6), and increased heart rate. Echocardiographic assessment of SBHF included left ventricular hypertrophy (LVH), impaired global longitudinal strain (GLS), and diastolic dysfunction (DD).Method and resultsAsymptomatic subjects ≥65 years without prior cardiac history, but with HF risks, were recruited from the local community. At baseline, they underwent clinical assessment, 12‐lead ECG, and comprehensive echocardiography. New HF was assessed clinically at mean follow‐up of 14 ± 4 months, and echocardiography was repeated in subjects with HF. Of the 447 study subjects (age 71 ± 5, 47% men) with SBHF, 13% had LVH, 32% impaired GLS, and 65% ≥grade I DD (10% ≥grade II DD). Forty were lost to follow‐up. Clinical HF developed in 47 of 407, of whom 20% had echocardiographic LVH, 51% abnormal GLS, and 76% DD at baseline. Baseline LVH and abnormal GLS (not grade I DD) were independently associated with outcomes (clinical HF and cardiovascular death). Cornell‐P and heart rate (not minSTmV5V6 nor PTFV1) were independently associated with LVH, impaired GLS, and DD. Cornell‐P and minSTV5V6 (not heart rate nor PTFV1) were independently associated with outcomes. More ECG abnormalities improved sensitivity, but ECG‐markers were not independent of or incremental to echocardiographic markers to predict HF in SBHF.ConclusionsIn this elderly study population, ECG markers showed low diagnostic sensitivity for non‐ischaemic SBHF and low prognostic value for outcomes. Cornell‐P and minSTmV5V6 had predictive value for outcomes in non‐ischaemic SBHF independent of age, gender, and common comorbidities but were not incremental to echocardiography.

Abstract 46: The Association between Acute Mental Stress and Changes in Left Atrial Electrophysiology

Background: Acute stress may trigger atrial fibrillation, but the mechanisms are not clear. We hypothesized that acute mental stress results in abnormal atrial remodeling via electrophysiologic effects. Methods: We examined our hypothesis in 168 patients (mean age=63±8.7 years; 74% men; 65% Caucasian) with stable coronary heart disease who underwent mental (speech task) stress testing. PTFV 1 duration (ms) times the value of the depth (μV) of the downward deflection (terminal portion) of the median P-wave in lead V 1 , and was automatically measured on digital electrocardiograms (ECG) at rest, stress, recovery. Electrocardiographic left atrial abnormality was defined as P-wave terminal force in lead V1 (PTFV1) ≤ -4000 μV*ms. The mean values of PTFV 1 during stress and recovery were compared with rest. Additionally, the percentage of participants who had left atrial abnormality during stress and recovery was compared with those at rest. Results: The mean PTFV 1 at rest was -2857±2459 μV*ms. There were 51 (30%) participants who had baseline left atrial abnormality. Compared with rest, PTFV 1 became more negative with stress [mean change=-474, 95%CI=(-103, -845); p=0.013] and during recovery [mean change=-420, 95%CI=(-79, -761); p=0.016]. A larger percentage of participants showed left atrial abnormality during stress (n=63, 38%) and recovery (n=67, 40%) compared with rest. Similar changes in PTFV 1 with stress [mean change=-833, 95%CI=(-372, -1295); p&lt;0.001] and recovery [mean change=-796, 95%CI=(-389, -1204); p&lt;0.001] were observed when we excluded those with baseline left atrial abnormality. No differences were noted in the PTFV 1 response based on age, gender, race, or hemodynamic response to stress. Conclusion: Acute mental stress alters left atrial electrophysiology, as measured by PTFV 1 , suggesting that stressful situations promote adverse atrial remodeling. This possibly explains the poor cardiovascular outcomes associated with acute mental stress that are triggered by left atrial abnormalities such as atrial arrhythmias and stroke.

Factors influencing P terminal force in lead V1 of the ECG in hemodialysis patients.

IntroductionAtrial fibrillation (AF) is a highly prevalent arrhythmia in hemodialysis (HD) patients, and an HD session may be a trigger for AF episodes. An abnormal P-terminal force in lead V1 (PTFV1) may predict new-onset AF in HD patients. The aim of the study was to assess the influence of the HD process on PTFV1 and to evaluate possible factors influencing PTFV1 in a group of selected HD patients.Material and methodsOne hundred and fifty-three selected HD patients entered the study. Blood chemistry, electrocardiography, and impedance cardiography were evaluated before and after HD. Echocardiography was performed on the morning after dialysis. Abnormal PTFV1 was defined as PTFV1 > 40 mm × ms.ResultsAbnormal PTFV1 was found in 35.3% of patients before dialysis and in 48.4% of patients after dialysis. The results of multiple regression analysis revealed that the independent predictors of pre-dialysis abnormal PTFV1 were: left atrial volume index (p = 0.002), left ventricular mass index (p = 0.014), and pre-dialysis thoracic fluid content (p = 0.021) values. The independent predictors of HD-induced abnormal PTFV1 values were larger differences between pre-dialysis and post-dialysis values of serum potassium (p < 0.001) and mean arterial pressure (p = 0.008).ConclusionsAbnormal PTFV1 is prevalent in HD patients. The HD process adversely affects PTFV1 values. Pre-dialysis abnormal PTFV1 is mainly associated with structural heart abnormalities and hydration status. HD-induced abnormal PTFV1 is associated predominantly with serum potassium changes as well as HD-induced hypotension. Our results suggest possible risk factors for AF; however, their clinical significance needs to be confirmed in follow-up studies.

Biomarkers of Atrial Cardiopathy and Atrial Fibrillation Detection on Mobile Outpatient Continuous Telemetry After Embolic Stroke of Undetermined Source

Biomarkers of atrial dysfunction or "cardiopathy" are associated with embolic stroke risk. However, it is unclear if this risk is mediated by undiagnosed paroxysmal atrial fibrillation or flutter (AF). We aim to determine whether atrial cardiopathy biomarkers predict AF on continuous heart-rhythm monitoring after embolic stroke of undetermined source (ESUS). This was a single-center retrospective study including all patients with ESUS undergoing 30 days of ambulatory heart-rhythm monitoring to look for AF between January 1, 2013 and December 31, 2015. We reviewed medical records for clinical, radiographic, and cardiac variables. The primary outcome was a new diagnosis of AF detected during heart-rhythm monitoring. The primary predictors were atrial biomarkers: left atrial diameter on echocardiography, P-wave terminal force in electrocardiogram (ECG) lead V1, and P wave - R wave (PR) interval on ECG. A multiple logistic regression model was used to assess the relationship between atrial biomarkers and AF detection. Among 196 eligible patients, 23 (11.7%) were diagnosed with AF. In unadjusted analyses, patients with AF were older (72.4 years versus 61.4 years, P < .001) and had larger left atrial diameter (39.2 mm versus 35.7 mm, P = .03). In a multivariable model, the only predictor of AF was age ≥ 60 years (odds ratio, 3.0; 95% CI, 1.06-8.5; P = .04). Atrial biomarkers were weakly associated with AF after ESUS. This suggests that previously reported associations between these markers and stroke may reflect independent cardiac pathways leading to stroke. Prospective studies are needed to investigate these mechanisms.

Abstract WMP64: Utility of Left Atrial Abnormality on Admission Electrocardiography in Acute Ischemic Stroke

Introduction and Hypothesis: Clinical categorization of ischemic stroke is very important to select the antithrombotic therapy for preventing the recurrent stokes. However, about 25% of ischemic stroke is the stroke for undetermined cause, termed as cryptogenic stroke. Recently, proactive detecting of paroxysmal atrial fibrillation (PAF) in cryptogenic stroke has gained attention. P-wave terminal force in lead V1 (PTFV1) of electrocardiography (ECG) is a specific indicator of left atrial abnormality. In this study, we tested PTFV1 for the utility of PAF detection and further clinical categorization in acute ischemic stroke. Methods: One hundred forty eight consecutive acute ischemic stroke patients were admitted to our hospital from September 2014 to March 2016. We included 105 patients (mean age 72.8±13.4 years), who had sinus rhythm on admission 12-lead ECG without atrial fibrillation, or cardiac pacing. PTFV1 (mmхsec) of participants was assessed, and had analyzed the association with PAF detection in a 24-hour ECG monitoring and clinical categories of ischemic stroke. Results: PTFV1 was significantly higher in the patients with PAF (n=11) than in those without PAF (0.049±0.024 vs 0.031±0.027; p&lt;0.05). Multiple logistic regression analysis revealed that PTFV1 was an independent predictor for PAF detection (odds ratio, 1.46; 95% confidence interval, 1.02-2.08; p&lt;0.05). According to the clinical categorization, PTFV1 of cardioembolic stroke (0.061±0.022) was significantly higher, compared to lacunar stroke (0.018±0.019; p&lt;0.01), atherothrombotic stroke (0.035±0.026; p&lt;0.05), and cryptogenic stroke (0.031±0.029; p&lt;0.05). The proportion of patients with left atrial abnormality defined by PTFV1 (≧0.04), was 10 out of 11 (91%) for cardioembolic stroke, and 10 out of 27 (37%) for cryptogenic stroke. Conclusions: PTFV1 on admission ECG in acute ischemic stroke was a strong predictor for PAF detection and cardioembolic stroke diagnosis. Extended ECG monitoring may be useful in cryptogenic stroke with left atrial abnormality defined by PTFV1.

Abstract WP232: Biomarkers of Atrial Cardiopathy and Atrial Fibrillation Detection on Mobile Continuous Outpatient Telemetry After Cryptogenic Stroke

Background: In population-based studies, biomarkers of atrial dysfunction or “cardiopathy” have been shown to be associated with embolic stroke risk. However, it is unclear if this risk is mediated by undiagnosed paroxysmal atrial fibrillation or flutter (AF). We aim to determine whether atrial cardiopathy biomarkers predict atrial fibrillation on continuous heart-rhythm monitoring after embolic stroke of undetermined source (ESUS). Methods: This was a single-center retrospective study including all patients who met consensus criteria for ESUS and who underwent 30 days of ambulatory heart-rhythm monitoring looking for AF between Jan 1 st , 2013 and Dec 31 st , 2015. We reviewed medical records for clinical, radiographic, and cardiac variables. The primary outcome was new diagnosis of AF detected during heart-rhythm monitoring. The primary predictors were atrial biomarkers: left atrial diameter on echocardiography, P-wave terminal force in ECG lead V1 , and PR interval on ECG. Multiple logistic regression was used to assess the relationship between atrial biomarkers and AF detection. Results: Among 196 eligible patients, 23 (11.7%) were diagnosed with AF. In unadjusted analyses, patients with AF were older (72.4 vs. 61.4 years, p &lt; 0.001) and had larger left atrial diameter (39.2 vs. 35.7 mm, p = 0.03). In a multivariable model including variables significant on univariate analyses, the only predictor of AF was age ≥ 60 years (odds ratio, 3.0; 95% CI, 1.06-8.5; p = 0.04). Atrial biomarkers were not associated with AF detection. Conclusion: Atrial biomarkers were not associated with AF after ESUS. This suggests that previously reported associations between these markers and stroke may reflect independent cardiac pathways leading to stroke. Prospective studies are needed to investigate these mechanisms and study anticoagulation versus antiplatelet treatment for secondary stroke prevention in patients with ESUS and atrial cardiopathy.