Evaluation of P wave duration and P wave dispersion in adult patients with secundum atrial septal defect during normal sinus rhythm

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).

Mid-Term Electrical Remodeling after Percutaneous Atrial Septal Defect Closure with GCO Device in a Pediatric Population

BACKGROUND AND AIM

The GORE® CARDIOFORM (GCO) septal occluder is an atrial septal defect/patent foramen ovale closure device with theoretical advantages over other commercialized devices thanks to its softness and anatomical compliance. Our aim was to evaluate the short- and medium-term electrocardiographic changes after percutaneous ASD closure with GCO in a pediatric population.

METHODS

We enrolled 39 patients with isolated ASD submitted to trans-catheter closure from January 2020 to June 2021. ECG was performed before, at 24 h and 6 months after the procedure. P wave dispersion, QTc and QTc dispersion were calculated. ECG Holter was recorded at 6 months after implantation.

RESULTS

Patients' age and body surface area (BSA) were 8.2 ± 4.2 years and 1.0 ± 0.3 m2 respectively. At the baseline, mean P wave dispersion was 40 ± 15 msec and decreased at 24 h (p < 0.002), without any further change at 6 months. At 24 h, PR conduction and QTc dispersion significantly improved (p = 0.018 and p < 0.02 respectively), while the absolute QTc value considerably improved after 6 months. During mid-term follow-up, QTc dispersion remained stable without a significant change in PR conduction. The baseline cardiac frequency was 88.6 ± 12.6 bpm, followed by a slight reduction at 24 h, with a further amelioration at 6 months after the procedure (87.3 ± 14.2, p = 0.9 and 81.0 ± 12.7, p = 0.009, respectively). After device deployment, two patients developed transient, self-limited junctional rhythm. One of them needed a short course of Flecainide for atrial ectopic tachycardia. No tachy/brady-arrhythmias were recorded at the 6-month follow-up. ASD closure resulted in a marked decrease in right heart volumes and diameters at 6 months after percutaneous closure.

CONCLUSIONS

Percutaneous ASD closure with the GCO device results in significant, sudden improvement of intra-atrial, atrio-ventricular and intraventricular electrical homogeneity. This benefit persists unaltered over a medium-term follow-up. These electrical changes are associated with a documented positive right heart volumetric remodeling at mid-term follow-up.

Cryoballoon pulmonary vein isolation and left atrial appendage occlusion prior to atrial septal defect closure: A case report

BACKGROUND

In patients who suffer from both atrial fibrillation (AF) and atrial septal defect (ASD), cryoballoon pulmonary vein isolation (PVI), sequential left atrial appendage (LAA) occlusion and ASD closure could be a strategy for effective prevention of stroke and right heart failure.

CASE SUMMARY

A 65-year-old man was admitted to our institution due to recurrent episodes of palpitations and shortness of breath for 2 years, which had been worsening over the last 48 h. He had a history of AF, ASD, coronary heart disease with stent implantation and diabetes. Physical and laboratory examinations showed no abnormalities. The score of CHA2DS2VASc was 3, and HAS-BLED was 1. Echocardiography revealed a 25-mm secundum ASD. Pulmonary vein (PV) and LAA anatomy were assessed by cardiac computed tomography. PV mapping with 10-pole Lasso catheter was performed following ablation of all four PVs with complete PVI. Following the cryoballoon PVI, the patient underwent LAA occlusion under transesophageal echocardiographic monitoring. Lastly, a 34-mm JIYI ASD occlude device was implanted. A follow-up transesophageal echocardiography at 3 mo showed proper position of both devices and neither thrombi nor leakage was found.

CONCLUSION

Sequential cryoballoon PVI and LAA occlusion prior to ASD closure can be performed safely in AF patients with ASD.

Clinical review of sick sinus syndrome and atrial fibrillation

Sick sinus syndrome (SSS) is a set of diseases with abnormal cardiac pacing, which manifests as diverse cardiac arrhythmias, especially bradycardia. The clinical presentation is inconspicuous in the early stage, but with the progression of this disease, patients may present with symptoms and signs of end-organ hypoperfusion. As a common result in the natural history of the disease, SSS coexisting with atrial fibrillation (AF) forms the basis of bradycardia-tachycardia syndrome. Age-related interstitial fibrosis is considered to be the common pathophysiological mechanism between SSS and AF. The combination of these diseases will adversely affect the condition of patients and the efficiency of subsequent treatment. Although the exact mechanism is not clear to date, the extensive structural and electrical remodeling of the atrium are considered to be the important mechanism for the occurrence of AF in patients with SSS. Pacemaker implantation is the first-line treatment for symptomatic patients with SSS and documented bradycardia history. In view of the adverse effects of AF on the treatment of SSS, researchers have focused on evaluating different pacing modes and algorithms to reduce the risk of AF during pacing. Catheter ablation may also be used as an alternative second-line therapy for some patients with SSS and AF.

P wave dispersion in assessment of dysrhythmia risk in patients with secundum type atrial septal defect and the effect of transcatheter or surgical closure

Atrial dysrhythmia is an important cause of mortality and morbidity in patients with atrial septal defect. Increased P wave duration can predict the risk of atrial dysrhythmia. The aim of this study is to evaluate the risk of atrial dysrhythmia by measuring P wave dispersion, and to observe the effect of surgical and transcatheter closure. Sixty-one patients and 30 controls were investigated. In patient group, before and after closure and in control group at the time of presentation, 12-lead electrocardiography records were evaluated. P wave duration and amplitude, P wave axis, PR interval, P wave dispersion, QRS axis, corrected QT interval, and QT dispersion were calculated. The measurements in patient and control groups, measurements before and after closure, and measurements of surgical and transcatheter group were compared. There were 27 patients in surgical group and 34 patients in transcatheter group. In patient group, signs of right heart volume overload were apparent but there was no significant difference in terms of P wave dispersion between two groups. We compared patient group in itself and found that while the use of medication, cardiothoracic index, ratio of right ventricular dilation, and paradoxical movement in interventricular septum were increased, mean age of closure was younger in surgical group. While P wave dispersion decreased in transcatheter group after closure, it increased in surgical group (p = 0.021). In conclusion, atrial septal defects may cause atrial repolarisation abnormalities and this effect persists even after surgical closure. Transcatheter closure in childhood may decrease dysrhythmia risk in long-term follow-up.

Immediate and short term effects of percutaneous atrial septal defect device closure on cardiac electrical remodeling in children

Background

The beneficial effects of atrial septal defect (ASD) device closure on electrical cardiac remodeling are well established. The timing at which these effects starts to take place has yet to be determined.

Objectives

To determine the immediate and short term effects of ASD device closure on cardiac electric remodeling in children.

Methods

30 pediatric patients were subjected to 12 lead Electrocardiogram immediately before ASD device closure, 24 h post procedure, 1 and 6 months after. The maximum and minimum P wave and QT durations in any of the 12 leads were recorded and P wave and QT dispersions were calculated and compared using paired T test.

Results

The immediate 24 h follow up electrocardiogram showed significant decrease in P maximum (140.2 ± 6 versus 130.67 ± 5.4 ms), P dispersion (49.73 ± 9.01 versus 41.43 ± 7.65 ms), PR interval (188.7 ± 6.06 ms versus 182.73 ± 5.8 ms), QRS duration (134.4 ± 4.97 ms versus 127.87 ± 4.44), QT maximum (619.07 ± 15.73 ms versus 613.43 ± 11.87), and QT dispersion (67.6 ± 5.31 versus 62.6 ± 4.68 ms) (P = 0.001). After 1 month all the parameters measured showed further significant decrease with P dispersion reaching 32.13 ± 6 (P = 0.001) and QT dispersion reaching 55.0 ± 4.76 (P = 0.001). These effects were maintained 6 months post device closure.

Conclusion

Percutaneous ASD device closure can reverse electrical changes in atrial and ventricular myocardium as early as the first 24 h post device closure.

Noninvasive evaluation of reverse atrial remodeling after catheter ablation of atrial fibrillation by P wave dispersion

Atrial fibrillation (AF) itself creates structural and electrophysiological changes such as atrial enlargement, shortening of refractory period and decrease in conduction velocity, called "atrial remodeling", promoting its persistence. Although the remodeling process is considered to be reversible, it has not been elucidated in detail. The aim of this study was to assess the feasibility of P wave dispersion in the assessment of reverse atrial remodeling following catheter ablation of AF. Consecutive 126 patients (88 males, age 63.0 ± 10.4 years) who underwent catheter ablation for paroxysmal AF were investigated. P wave dispersion was calculated from the 12 lead ECG before, 1 day, 1 month, 3 months and 6 months after the procedure. Left atrial diameter (LAD), left atrial volume index (LAVI), left ventricular ejection fraction (LVEF), transmitral flow velocity waveform (E/A), and tissue Doppler (E/e') on echocardiography, plasma B-type natriuretic peptide (BNP) concentrations, serum creatinine, and estimated glomerular filtration rate (eGFR) were also measured. Of all patients, 103 subjects remained free of AF for 1 year follow-up. In these patients, P wave dispersion was not changed 1 day and 1 month after the procedure. However, it was significantly decreased at 3 and 6 months (50.1 ± 14.8 to 45.4 ± 14.4 ms, p < 0.05, 45.2 ± 9.9 ms, p < 0.05, respectively). Plasma BNP concentrations, LAD and LAVI were decreased (81.1 ± 103.8 to 44.8 ± 38.3 pg/mL, p < 0.05, 38.2 ± 5.7 to 35.9 ± 5.6 mm, p < 0.05, 33.3 ± 14.2 to 29.3 ± 12.3 mL/m², p < 0.05) at 6 months after the procedure. There were no significant changes in LVEF, E/A, E/e', serum creatinine, and eGFR during the follow up period. P wave dispersion was decreased at 3 and 6 months after catheter ablation in patients without recurrence of AF. P wave dispersion is useful for assessment of reverse remodeling after catheter ablation of AF.

Impact of Continuous Positive Airway Pressure Therapy on Atrial Electromechanical Delay in Obesity-Hypoventilation Syndrome Patients

BACKGROUND

Obesity-hypoventilation syndrome (OHS) is defined as daytime hypercapnia and hypoxemia in obese patients with sleep-disordered breathing. We evaluated the electrocardiographic P-wave duration and dispersion (PD) and echocardiographic noninvasive indicators of atrial conduction heterogeneity in OHS patients and the impact of CPAP on atrial conduction and atrial fibrillation incidence.

METHODS AND RESULTS

We enrolled 50 OHS patients and 50 sex- and age-matched obese subjects as control. Study population underwent cardiologic evaluation and polysomnography before enrollment, at 1- and 6-month follow-ups after CPAP therapy. The OHS group showed a significant increase in inter-atrial (35.2 ± 8 milliseconds vs. 20.1 ± 2.7 milliseconds, P < 0.0001), intra-left (30.5 ± 7.2 milliseconds vs. 16.5 ± 2 milliseconds, P < 0.0001), and intra-right atrial electromechanical delays (AEMD)(24.8 ± 10 milliseconds vs. 15 ± 2.6 milliseconds, P < 0.0001) as well as in Pmax (130 ± 7.4 milliseconds vs. 97 ± 7.2 milliseconds, P = 0.002) and PD (56.5 ± 8.5 milliseconds vs. 31 ± 7.2 milliseconds, P = 0.002) compared to the control group. Significant improvement was noted after 6 months of CPAP therapy in inter-atrial (35.2 ± 8 milliseconds vs. 24.5 ± 6.3 milliseconds, P < 0.0001), intra-left (30.5 ± 7.2 milliseconds vs. 20.6 ± 5 milliseconds, P = 0.003), and intra-right AEMD (24.8 ± 10 milliseconds vs. 17 ± 7.5 milliseconds, P < 0.0001), as well as in Pmax (130 ± 7.4 milliseconds vs. 95 ± 10 milliseconds, P < 0.0001) and in PD (56.5 ± 8.5 milliseconds vs. 32.5 ± 6 milliseconds, P < 0.0001) in the OHS group. External loop recorder monitoring detected paroxysmal AF in 19 OHS patients (38%) with significant reduction in paroxysmal AF episodes (12 ± 6 vs. 47 ± 12, P < 0.0001) after 6-month CPAP therapy.

CONCLUSION

Our findings showed a significant increase of electrocardiographic and echocardiographic indexes of atrial conduction heterogeneity in OHS patients. The CPAP therapy, having a positive impact on atrial conduction time, seems to reduce AF incidence in OHS patients.

Atrial Septal Aneurysms and Supraventricular Arrhythmias: The Role of Atrial Electromechanical Delay

BACKGROUND

Paroxysmal supraventricular arrhythmias (SVAs) frequently occur in patients with atrial septal aneurysm (ASA). The aim of the current study was to evaluate the electrocardiographic (P-wave duration and dispersion) and echocardiographic (atrial electromechanical delay, AEMD) noninvasive indicators of atrial conduction heterogeneity in healthy ASA subjects without interatrial shunt and to assess the AEMD role in predicting the SVAs onset in this population.

MATERIALS AND METHODS

One hundered ASA patients (41 males, mean age of 32.5 ± 8 years) and 100 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of SVAs during a 4-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 3 months. ASAs were diagnosed by transthoracic echocardiography based on the criteria of a minimal aneurismal base of ≥15 mm and an excursion of ≥10 mm. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram (ECG).

RESULTS

Compared to the healthy control group, the ASA group showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the ASA group into 2 subgroups (patients with or without SVAs), the inter-AEMD, intra-left AEMD, P max, and PD were significantly higher in the subgroup with SVAs compared to the subgroup without SVAs. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cutoff value of 40.1 msec for intra-left AEMD had a sensitivity of 82% and a specificity of 83% in identifying ASA patients at risk for SVA.

CONCLUSION

Our results showed that the echocardiographic AEMD indices (intra-left and inter-AEMD) and the PD were significantly increased in healthy ASA subjects without interatrial shunt. PD and AEMD represent noninvasive, inexpensive, useful, and simple parameters to assess the SVAs' risk in ASA patients.

Atrial Fibrillation and Beta Thalassemia Major: The Predictive Role of the 12-lead Electrocardiogram Analysis

BACKGROUND

Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (β-TM) patients.The aim of our study was to investigate the role of maximum P-wave duration (P max) and dispersion (PD), calculated trough a new manually performed measurement with the use of computer software from all 12-ECG-leads,as predictors of atrial-fibrillation (AF) in β-TM patients with conserved systolic or diastolic cardiac function during a twelve-months follow-up.

MATERIALS AND METHODS

50 β-TM-patients (age38.4±10.1; 38M) and 50-healthy subjects used as controls, matched for age and gender, were studied for the occurrence of atrial arrhythmias during a 1-year follow-up, through ECG-Holter-monitoring performed every three months. The β-TM-patients were divided into two groups according to number and complexity of premature-supraventricular-complexes at the Holter-Monitoring (Group1: <30/h and no repetitive forms, n:35; Group2: >30/h or couplets, or run of supraventricular tachycardia and AF, n:15).

RESULTS

Compared to the healthy control-group, β-TM patients presented increased P-max (107.5± 21.2 vs 92.1±11ms, P=0.03) and PD-values (41.2±13 vs 25.1±5 ms,P=0.03). In the β-TM population, the Group2 showed a statistically significant increase in PD (42.8±8.6 vs 33.2±6.5ms, P<0.001) and P-max (118.1±8.7 vs 103.1±7.5ms, P<0.001) compared to the Group1. Seven β-TM patients who showed paroxysmal AF during this study had significantly increased P-max and PD than the other patients of the Group2. Moreover, P-max (OR:2.01; CI:1.12-3.59; P=0.01) and PD (OR=2.06;CI:1.17-3.64;P=0.01) demonstrated a statistically significant association with the occurrence of paroxysmal AF,P min was not associated with AF-risk (OR=0.99; CI:0.25-3.40; P=0.9) in β-TM-patients. A cut-off value of 111ms for P-max had a sensitivity of 80% and a specificity of 87%, a cut-off value of 35.5ms for PD had a sensitivity of 90% and a specificity of 85% in identifying β-TM patients at risk for AF.

CONCLUSION

Our results indicate that P-max and PD are useful electrocardiographic markers for identifying the β-TM-high-risk patients for AF onset, even when the cardiac function is conserved.

How valuable is P-wave dispersion in the determination of carboxyhemoglobin levels?

Objective:

To determine whether or not wave/interval dispersions in electrocardiography (ECG) are increased, and to define whether wave and interval dispersions are correlated with carboxyhemoglobin (COHb) levels.

Methods:

ECG, complete blood count, and biochemical parameters were taken from 87 patients with carbon monoxide (CO) poisoning as well as 90 control patients with similar age, gender, and body mass index distribution. COHb levels were recorded in CO-poisoning patients. The COHb levels and the relationships with ECG parameters were studied.

Results:

Pmax, Pmin, Pd, PRmax, PRmin, PRd, QTmax, QTmin, QTd, cQTmax, cQTmin, cQTd, Tmax, Tmin, and Td in ECG were higher in intoxicated patients than the control group ( p < 0.05 for all). Pearson’s correlation analyses showed moderately significant positive correlations between COHb level and Pmax ( r = 0.224; p = 0.037) and Pd ( r = 0.222; p = 0.039). The receiver–operator characteristic (ROC) curve showed that a Pd value of 38 ms determined by ECG separates patients with a COHb ≥ 20% with area under the ROC curve of 0.78 (95%CI = 0.71–0.83), a sensitivity of 67.9% (95%CI = 59.4–75.6), a specificity of 95% (95%CI = 83.0–99.2], a positive predictive value of 97.9% (95%CI = 92.5–99.7), and a negative predictive value of 46.3% (95%CI = 35.3–57.7.)

Conclusion:

A significant increase in wave/interval dispersions in the ECG of CO-poisoning patients compared with controls may show that not only a part is affected but both atrium and the ventricles as a whole are affected by hypoxic ischemia. When COHb levels of the patients are unavailable, P dispersion on ECG may show CO poisoning level of the patient.

Surgical extraction of an embolized atrial septal defect occluder device into pulmonary artery after percutaneous closure

An atrial septal defect is the most common type of congenital heart disease among adults. Surgical repair or percutaneous closure of the defect is the treatment options. Even though percutaneous closure seems to be less risky than surgical repair, it may result in fatal complications like device embolism, cardiac perforation and tamponade. Herein we report a case of the embolism of a device into the pulmonary artery after one hour of percutaneous closure in which the embolized device was surgically removed and the defect was closed with a pericardial patch.

Meta-analysis of p-wave dispersion values in healthy individuals: the influence of clinical characteristics

BACKGROUND

P-wave dispersion (Pd) is an appealing marker for predicting the risk of developing atrial fibrillation. At present, no definitive cutoff value has been determined as to the diagnosis of high-risk patients. Our aims were to evaluate P-wave parameters of healthy subjects published in the literature, determine normal range and weighted means of Pd and P-wave parameters, and investigate the influences of gender, age, and BMI on the weighted results.

METHODS

A systematic search of studies published in PubMed was conducted. Only studies which included control groups of healthy individuals were included.

RESULTS

Of the 657 studies initially identified, 80 were eligible for inclusion. The total number of participants was 6,827. The highest reported Pd values were 58.56 ± 16.24 ms; the lowest were 7 ± 2.7 ms. The weighted mean was 33.46 ± 9.65 ms; weighted median was 32.2 ms. Gender and age were not found to be associated with significant influences on P-wave parameter values. High-normal BMI was not found to be associated with increased P-wave parameter values.

CONCLUSIONS

Pd, Pmax, and Pmin span a wide range of values in healthy individuals. Seemingly, abnormal values were often reported in healthy adults. The high variability of P-wave parameters in healthy individuals, and overlapping of the results with those reported for patients with increased risk for atrial fibrillation, might suggest that this technique has limited sensitivity and specificity. The variability between studies may stem from methodological issues and, therefore, there is a definite need for methodological standardization of Pd measurements.

Assessment of atrial electromechanical coupling characteristics and P-wave dispersion in patients with atrial septal aneurysm

OBJECTIVE

The aim of this study was to evaluate atrial conduction abnormalities obtained by Doppler tissue imaging (DTI) and electrocardiogram analysis in Atrial septal aneurysm (ASA) patients.

METHODS

A total of 30 patients with ASA (11 males/19 females, mean age 29.6 ± 11.3 years) and 25 controls (9 males/16 females, mean age 27.6 ± 9.98 years) were included. Interatrial and intraatrial electromechanical coupling (PA) intervals were measured with DTI. P-wave dispersion (Pd) was calculated from the 12-lead electrocardiogram. Systolic and diastolic left ventricular (LV) functions were measured by using conventional echocardiography and DTI.

RESULTS

Atrial electromechanical coupling at the left lateral mitral annulus (PA lateral) was significantly delayed in ASA patients (59.3 ± 4.2 vs. 48.5 ± 1.1 ms, P < 0.0001). Interatrial (PA lateral--PA tricuspid) and intraatrial (PA septum--PA tricuspid) electromechanical coupling interval were significantly longer in ASA patients (26.1 ± 6.2 vs. 14.4 ± 6.75 ms, P < 0.0001 and 9.04 ± 1.1 vs. 5.4 ± 2.5 ms, P < 0.0001). maximum P-wave (Pmax) duration and Pd were significantly longer in ASA patients (98.3 ± 8.1 vs. 86.4 ± 7.8 ms, P < 0.001 and 20.7 ± 0.9 vs. 12.3 ± 1.5, P < 0.0001). Systolic and diastolic left ventricular functions of both groups were comparable.

CONCLUSION

This study shows that atrial electromechanical coupling intervals and Pd are delayed in ASA patients.

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

Although previous studies have documented a variety of electrocardiogram abnormalities in beta-thalassemia major (β-TM), little is known about P-wave dispersion (PD), an independent risk factor for development of atrial fibrillation. The aim of our study was to evaluate PD in β-TM patients with conserved systolic and diastolic functions. The study involved 40 β-TM patients (age 37.5 ± 10.2; 33 M) and 40 healthy subjects used as controls, matched for age and gender. PD was carefully measured using a 12-lead electrocardiogram. Cardiac iron levels were measured by cardiac magnetic resonance T2 star (CMR T2*) imaging. Comparing to the healthy control group, β-TM group presented increased values of the PD (40.1 ± 12.9 vs. 24 ± 7 ms; P < 0.004) and decreased CMR T2* imaging (29 ± 15 vs. 55 ± 13 ms; P = 0.03). We found a significant correlation between PD and CMR T2* values. Our study showed a significant increase of PD in β-TM patients with conserved systolic and diastolic cardiac functions. Our results indicate that PD is correlated to myocardial iron deposit, as assessed by CMR T2* imaging.

P-wave dispersion between transcatheter and surgical closure of secundum-type atrial septal defect in childhood

Patients with atrial septal defect have an increased risk for atrial fibrillation. Increased P-wave dispersion predicts the development of atrial fibrillation. The aim of this study was to determine difference in P dispersion between transcatheter closure with Amplatzer septal occluder and surgical closure in childhood. A total of 68 children (the mean age was 7.2 plus or minus 3.3 years; the mean secundum atrial septal defects diameter was 17.3 plus or minus 5.4 millimetres) were evaluated in this study. Transcatheter closure was attempted in 41 children with secundum atrial septal defects, and the defect in 27 patients was closed by surgical techniques. P maximum, P minimum and P dispersion were measured by the 12-lead surface electrocardiography. P maximum, P minimum and P dispersion were found to be similar in patients with pre- and post-procedure (98.0 plus or minus 19.3 versus 95.1 plus or minus 23.0 milliseconds; 68.0 plus or minus 20.8 versus 67.6 plus or minus 24.3 milliseconds, 29.9 plus or minus 11.0 versus 27.1 plus or minus 12.1 milliseconds, respectively). There was no statistical significance in the comparison of P dispersion between the two groups. But in the surgical group, P-wave dispersion was decreased more significantly compared with baseline values (p-value equal to 0.03). In conclusion, there is no P dispersion between transcatheter closure with Amplatzer septal occluder and surgical closure of secundum atrial septal defect.

Evaluation of the relationship between atrial septal aneurysm and cardiac arrhythmias via P-wave dispersion and signal-averaged P-wave duration

OBJECTIVE

The aim of the study was to investigate the relationship between atrial septal aneurysms (ASAs) and cardiac arrhythmias via signal-averaged P-wave duration (SAPWD) and P-wave dispersion (Pd).

METHODS

Sixty-six patients with ASA served as the study group (group 1; 28 men and 38 women; mean age, 34 +/- 10 years) and 62 healthy volunteers served as the control group (group 2; 29 men and 33 women; mean age, 31 +/- 8 years) in the current study. ASAs were diagnosed by transthoracic echocardiography based on the criteria of a minimal aneurysmal base of > or =15 mm; and an excursion of > or =10 mm. All subjects were evaluated by 24-hour Holter monitoring, 12 lead body surface electrocardiogram for P-wave analysis, and signal-averaged electrocardiogram for P-wave duration (PWD).

RESULTS

There was no significant difference between the study and control groups in terms of age, gender, left atrium diameter, and left ventricular ejection fraction. Supraventricular arrhythmias (SVAs) were detected in 29 patients with ASA (43.9%) and 5 controls (8.1%; P < 0.001). The mean Pd in patients with ASA was significantly longer compared to the control group (14.1 +/- 8 ms vs 7.0 +/- 2.9 ms; P < 0.001). Similarly, the mean SAPWD in group 1 was significantly longer compared to group 2 (127.4 +/- 17.6 ms vs 99.8 +/- 12.3 ms; P < 0.001).

CONCLUSION

Prolonged SAPWD and Pd were determined to indicate electrical disturbances in the atrial myocardium, and predict the increase in the prevalence of SVA in patients with ASA.

P-wave indices, distribution and quality control assessment (from the Framingham Heart Study)

BACKGROUND

P-wave indices of maximum P-wave duration and P-wave dispersion have been examined in a broad array of cardiovascular and noncardiovascular disease states. The P-wave indices literature has been highly heterogeneous in measurement methodologies, described quality control metrics, and distribution of values. We therefore sought to determine the reproducibility of P-wave indices in a community-based cohort.

METHODS

P-wave indices were measured in sequential subjects enrolled in the Framingham Heart Study. Electrocardiograms were obtained at the 11th biennial visit of the Original Cohort (n = 250) and the initial visit of the Offspring Cohort (n = 252). We determined the mean P-wave durations, interlead correlations, and P-wave indices. We then chose 20 ECGs, 10 from each cohort, and assessed intrarater and interrater variability.

RESULTS

The maximum P-wave duration ranged from 71 to 162 ms with mean of 112 + or - 12 ms. The minimum P-wave duration ranged from 35 to 103 ms with mean of 65 + or - 10 ms. P-wave dispersion ranged from 12 to 82 ms. The mean P-wave dispersion was 48 + or - 12 ms (40-56). The intrarater intraclass correlation coefficient (ICC) was r = 0.80 for maximum P-wave duration and r = 0.82 for P-wave dispersion. The interrater ICC was 0.56 for maximum P-wave duration and 0.70 for P-wave dispersion.

CONCLUSIONS

We demonstrated excellent intrarater reproducibility and fair interrater reproducibility for calculating P-wave indices. Reproducibility is frequently lacking in studies of P-wave indices, but is an essential component for the field's growth and epidemiologic contribution.

Intermediate-term effects of transcatheter secundum atrial septal defect closure on cardiac remodeling in children and adults

The study aimed to investigate the intermediate-term effects of transcatheter atrial septal defect (ASD) closure on cardiac remodeling in children and adult patients. Between December 2003 and February 2009, 117 patients (48 males, 50 adults) underwent transcatheter ASD closure with the Amplatzer septal occluder (ASO). The mean age of the patients was 15 years, and the mean follow-up period was 25.9 +/- 12.4 months. New York Heart Association (NYHA) class, electrocardiographic parameters, and transthoracic echocardiographic (TTE) examination were evaluated before the ASD closure, then 1 day, 1 month, 6 months, 12 months, and yearly afterward. Transcatheter ASD closure was successfully performed for 112 (96%) of the 117 patients. The mean ASD diameter measured by transesophageal echocardiography (TEE) was 14.0 +/- 4.2 mm, and the mean diameter stretched with a sizing balloon was 16.6 +/- 4.8 mm. The mean size of the implanted device was 18.6 +/- 4.9 mm. The Qp/Qs ratio was 2.2 +/- 0.8. The mean systolic pulmonary artery pressure was 40 +/- 10 mmHg. At the end of the mean follow-up period of 2 years, the indexed right ventricular (RV) end-diastolic diameter had decreased from 36 +/- 5 to 30 +/- 5 mm/m(2) (p = 0.005), and the indexed left ventricular (LV) end-diastolic diameter had increased from 33 +/- 5 to 37 +/- 6 mm/m(2) (p = 0.001), resulting in an RV/LV ratio decreased from 1.1 +/- 0.2 to 0.8 +/- 0.2 (p = 0.001). The New York Heart Association (NYHA) functional capacity of the patients was improved significantly 24 months after ASD closure (1.9 +/- 0.5 to 1.3 +/- 0.5; p = 0.001). At the 2-year follow up electrocardiographic examination, the P maximum had decreased from 128 +/- 15 to 102 +/- 12 ms (p = 0.001), the P dispersion had decreased from 48 +/- 11 to 36 +/- 9 ms (p = 0.001), and the QT dispersion had decreased from 66 +/- 11 to 54 +/- 8 ms (p = 0.001). Five of six patients experienced resolution of their preclosure arrhythmias, whereas the remaining patient continued to have paroxysmal atrial fibrillation. A new arrhythmia (supraventricular tachycardia) developed in one patient and was well controlled medically. Transcatheter ASD closure leads to a significant improvement in clinical status and heart cavity dimensions in adults and children, as shown by intermediate-term follow-up evaluation. Transcatheter ASD closure can reverse electrical and mechanical changes in atrial myocardium, resulting in a subsequent reduction in P maximum and P dispersion times.

Assessment of atrial electromechanical coupling and influential factors in nonrheumatic paroxysmal atrial fibrillation

BACKGROUND

Sequential analysis of atrial electromechanical coupling (P-A) by Doppler tissue imaging (DTI) might provide important insight into the mechanisms of paroxysmal atrial fibrillation (PAF).

HYPOTHESIS

The purpose of this study was to evaluate P-A and the dispersion of P-A, and to analyze the influential factors of P-A.

METHODS

One hundred and ten patients with PAF and 87 normal controls were enrolled. Using DTI, the time intervals from the beginning of P-wave to the onset of atrioventricular ring motion related to atrial contraction were measured.

RESULTS

Atrial electromechanical coupling at the interventricular septum atrioventricular annulus (P-A1), left lateral mitral annulus (P-A2) and right lateral tricuspid annulus (P-A3) in PAF group were significantly longer than those in control (p < 0.001). The difference between P-A2 and P-A1 (T1), P-A2 and P-A3 (T3) in PAF group were greater than those in control before age correction (p < 0.05). The linear regression analysis showed that the duration of PAF episodes and age were the greatest influential factors of P-A1 (r = 0.564). Left atrial anterior-posterior dimension (LAD) and age were the greatest influential factors of P-A2 (r = 0.459). The LAD was the greatest influential factors of T1 and T3 (r = 0.408, 0.542).

CONCLUSIONS

The atrial electromechanical coupling was significantly longer and the dispersion of P-A at left lateral mitral annulus was greater in PAF patients. The prolongation of P-A may be related to left atrial enlargement, long episodes of PAF and aging and the dispersion of P-A at left lateral mitral annulus to LAD.

P wave detector with PP rhythm tracking: evaluation in different arrhythmia contexts

Automatic detection of atrial activity (P waves) in an electrocardiogram (ECG) is a crucial task to diagnose the presence of arrhythmias. The P wave is difficult to detect and most of the approaches in the literature have been evaluated on normal sinus rhythms and rarely considered arrhythmia contexts other than atrial flutter and fibrillation. A novel knowledge-based P wave detector algorithm is presented. It is self-adaptive to the patient and able to deal with certain arrhythmias by tracking the PP rhythm. The detector has been tested on 12 records of the MIT-BIH arrhythmia database containing several ventricular and supra-ventricular arrhythmias. On the overall records, the detector demonstrates Se = 96.60% and Pr = 95.46%; for the normal sinus rhythm, it reaches Se = 97.76% and Pr = 96.80% and, in the case of Mobitz type II, it demonstrates Se = 72.79% and Pr = 99.51%. It also shows good performance for trigeminy and bigeminy, and outperforms some more sophisticated techniques. Although the results emphasize the difficulty of P wave detection in difficult arrhythmias (supra and ventricular tachycardias), it shows that domain knowledge can efficiently support signal processing techniques.

Dispersion of P wave duration and P wave vector in patients with atrial septal aneurysm

AIMS

Atrial septal aneurysm (ASA) may be involved in the genesis of atrial arrhythmias as a consequence of disturbances in the propagation of depolarization, which may be easily assessed by P wave dispersion measurement. The aim of this study is to assess the dispersion of P wave duration and P wave vector in patients with ASA and to determine the effect of associated interatrial shunt on the magnitude of P wave dispersion.

METHODS AND RESULTS

The study population consisted of 23 healthy volunteers and 88 patients with ASA base more than 15 mm and protrusion more than 7.5 mm. The size of aneurysms and atria was determined by echocardiography and P wave dispersion was measured on the surface ECG. In ASA patients, dispersion of P wave duration was significantly increased when compared with healthy controls (7.8 +/- 12.1 vs. 3.7 +/- 3.5 ms; P < 0.01). Dispersion of P wave vector was also significantly increased (8.5 +/- 10.1 degrees vs. 4.6 +/- 3.6 degrees ; P < 0.005). In healthy volunteers, the mean values of both parameters were below the cutoff points.

CONCLUSION

In patients with ASA, there was a significant dispersion of P wave duration and P wave vector. Variation in P wave duration was significantly correlated with the dispersion of P wave vector and age of these patients. Dispersion of P wave vector was significantly decreased in ASA patients with interatrial shunt. P wave dispersion in ASA patients may predispose to the development of atrial arrhythmias.

Optimal timing of the Fontan conversion: change in the P-wave characteristics precedes the onset of atrial tachyarrhythmias in patients with atriopulmonary connection

OBJECTIVES

Atrial tachyarrhythmia is a common complication late after the atriopulmonary connection Fontan procedure. The P-wave duration and dispersion have been regarded as useful markers for its prediction. The purpose of this study was to analyze change in the P-wave characteristics over time after the atriopulmonary connection Fontan procedure, with a special emphasis on the timing of the Fontan conversion.

METHODS

We reviewed clinical and electrocardiographic data in 18 patients with classic tricuspid atresia who underwent the atriopulmonary connection Fontan procedure. Their median age at operation was 4.1 years (range, 1.1-22 years), and the median follow-up period was 18.1 years (range, 10-25 years). We measured the P-wave duration, dispersion, and axis from consecutive 12-lead electrocardiograms in each patient.

RESULTS

There was a significant increase in the maximum P-wave duration as well as the P-wave dispersion over time. Transient ectopic atrial rhythm was observed in 16 patients during follow-up. Atrial tachyarrhythmia developed subsequent to transient ectopic atrial rhythm in 8 patients. Ten patients underwent the conversion. Atrial tachyarrhythmia recurred in 2 patients who had sustained arrhythmia (6.0 and 8.0 years) before the conversion. In contrast, the other 8 patients with transient ectopic atrial rhythm alone or nonsustained atrial tachyarrhythmia have been free from arrhythmia after the conversion.

CONCLUSIONS

Patients commonly and increasingly had prolonged P-wave duration, larger P-wave dispersion, and ectopic atrial rhythm, along with an atrial tachyarrhythmia propensity, late after the atriopulmonary connection Fontan procedure. These P-wave characteristics were informative when considering the Fontan conversion before a sustained atrial tachyarrhythmia ensued.

P-wave dispersion is increased in pregnancy due to shortening of minimum duration of P: does this have clinical significance?

Most pregnant women complain of palpitation, and various kinds of arrhythmias can be observed during pregnancy. We investigated P-wave and QT dispersion during pregnancy. Healthy pregnant women (n=162) and healthy age-matched, non-pregnant women (n=150) were included. We performed electrocardiography and transthoracic echocardiography and determined serum oestradiol levels in both groups, and performed Holter monitoring in the pregnant group only. Resting heart rate, P-wave dispersion, left ventricular diastolic diameter, left atrial diameter and serum oestradiol levels in the pregnant group were significantly higher than in the control group. Minimum P-wave duration was shorter in the control group than in the pregnant group; however, there was no statistically significant difference in maximum P wavelength and corrected QT dispersion between the groups. No atrial fibrillation was detected in the pregnant group during Holter monitoring. Shortening of the minimum P-wave duration leads to increased P-wave dispersion during pregnancy. In contrast to other pathologies with increased P-wave dispersion, paroxysmal atrial fibrillation is absent in pregnant women; this may be a result of the stable maximum P wavelength that is present during pregnancy.

Atrial natriuretic peptide levels in adult patients before and after surgery for correction of atrial septal defects: relationship with atrial arrhythmias

In the present study, we have examined whether increased N-ANP (N-terminal pro-ANP) levels before and after surgery in patients with ASD (atrial septal defect) along with echocardiographic findings provide a better insight into the pathophysiology and increased morbidity and mortality following corrective surgery. Eighteen adult ASD patients (>20 years of age; six male and 12 female) with shunts (Qp/Qs≥2, where Qp/Qs is the pulmonary blood flow/systemic blood flow) had complete echocardiographic, clinical and laboratory parameters evaluated before and 6 months after surgery. Eight age- and sex-matched individuals (three male and five female) were enrolled as a control group. Blood samples for N-ANP analysis were obtained in both groups. N-ANP levels in the peripheral blood sample from ASD patients before surgery were significantly higher than those in the control group. In patients with ASD, mean N-ANP levels obtained from the pulmonary artery were significantly higher than that obtained from the peripheral vein. RA (right atrial) area, adjusted for body surface area, and RA long-axis and short-axis measurements were significantly higher in the patient group than the control group. N-ANP was correlated significantly with these parameters. Following corrective surgery, N-ANP values and RA area, RA long-axis and short-axis normalization decreased significantly and were accompanied by a decrease in systolic mean pulmonary artery pressure. N-ANP levels were normalized following septal closure in most patients, except in those with atrial fibrillation attacks following corrective surgery. In conclusion, we have shown correlations among variables indicating changes in the architecture of the right atrium along with temporal changes in ANP providing insights into the pathophysiology of post-operative atrial arrhythmias.