P-wave Dispersion Values Research Articles

The effect of recanalization of a chronic total coronary occlusion on P-wave dispersion.

Introduction: P-wave dispersion (PWD) obtained from the standard 12-lead electrocardiography (ECG) is considered to reflect the homogeneity of the atrial electrical activity. The aim of this investigation was to evaluate the effect of percutaneous chronic total occlusion (CTO) revascularization on the parameters of P wave duration and PWD on ECG in cases before and after procedure at 12th months. Methods: We analyzed 90 consecutive CTO cases who were on sinus rhythm and underwent percutaneous coronary intervention (PCI). P-wave maximum (P-max) and P-wave minimum (P-min), P-wave time, and PWD were determined before and twelve months after the CTO intervention. The study population was categorized into two groups as successful and unsuccessful CTO PCI groups. Results: The CTO PCI was successful in 71% of cases (n=64) and it was unsuccessful in 29% of cases (n=26). Both groups, except for age and hypertension, were similar in terms of demographic and clinical aspects. CRP levels were significantly elevated in the unsuccessful CTO PCI group. Pre-PCI ECG parameters showed no significant difference. Irrespective of the target vessel revascularization, we observed that PWD and P-max values were significantly lower in the 12th months follow-up. In all Rentrop classes, PWD values were significantly decreased at 12th months follow-up in comparison to the pre-CTO PCI values. Conclusion: This study has determined that PWD and P-max, which are both risk factors for atrial arrhythmias, are significantly reduced within 12th months after successful CTO PCI regardless of the target vessel.

The Effect of Recanalization of a Chronic Total Coronary Occlusion on Atrial Conduction Velocities.

P-wave duration and P-wave dispersion (PWD) give information about inhomogeneous and discontinuous atrial conduction, which are believed to be the leading electrophysiological causes of atrial fibrillation. The aim of this study was to investigate the effect of percutaneous chronic total occlusion (CTO) revascularization on P-wave duration and PWD in electrocardiography (ECG). We enrolled 98 consecutive patients with sinus rhythm who underwent percutaneous coronary interventions (PCIs) for CTO. The maximum (Pmax) and minimum P-wave duration and PWD were measured before CTO interventions and at the first and sixth months after the procedure. There was no significant differences between the successful and failed CTO PCI groups in pre-procedural demographic, clinical, laboratory, angiographic data, and ECG parameters. Pmax values and PWD at 1 month and 6 months after successful CTO PCI were statistically lower than those at baseline (p < 0.001), while there was no significant change in the failed CTO PCI group. PWD values were significantly lower at 6 months of follow-up, regardless of the target vessel (p = 0.010, p < 0.001, p < 0.001; for left anterior descending, circumflex and right coronary artery, respectively). Compared to pre-CTO values in all Rentrop classes, PWD values were significantly lower at the sixth month. This study demonstrated that Pmax and PWD, which are risk factors for atrial arrhythmias, significantly reduced within 1 and 6 months after successful CTO PCI irrespective of the target vessel.

Supraventricular arrhythmia in mitral valve prolapse : Predictive value of P-wave dispersion and atrial conduction time.

The incidence of supraventricular arrhythmia (SVA) is high in patients with mitral valve prolapse (MVP). The purpose of our study was to determine the role of parameters showing atrial conduction heterogeneity such as P‑wave dispersion (PWD) and atrial electromechanical delay (AEMD) in predicting the development of SVA in MVP patients. Atotal of 76patients with MVP (56female, 20male) were included in the study. The patients were divided into two groups according to the presence or absence of SVA: 36patients were allocated to the non-SVA group and 40patients to the SVA group. Heart rate variability (HRV), PWD, and AEMD values were determined and compared. The PWD was found to be higher in the SVA group. Interatrial EMD was 32.00 ms (25.00-35.00) in patients with SVA while it was 18.00 ms in patients without SVA (11.00-23.75); the intra-atrial EMD was 17.0 ms (10.00-20.00) in patients with SVA whereas it was 10.00 ms (4.00-14.00) in patients without SVA. Lower HRV was found in the SVA group. In the SVA group, PWD and AEMD were increased while HRV values were decreased. Noninvasive parameters may help predict the presence and incidence of SVA during the follow-up of this group of patients.

The prognostic value of P-wave dispersion and left atrial functions assessed with three-dimensional echocardiography in patients with cirrhosis.

Cirrhotic cardiomyopathy (CCM) is a well-known entity. The aim of this study was to compare left atrial three-dimensional (3D) volume and P-wave dispersion (PWd) in patients with cirrhosis and a healthy population. The secondary purpose was to assess the left phasic volumes and reservoir functions with 3D echocardiography for the prediction of an increased risk of poor outcomes in patients with cirrhosis. The study included 50 patients with cirrhosis and 43 healthy control subjects without atrial fibrillation. All patients were assessed with two-dimensional (2D), 3D, and tissue Doppler transthoracic echocardiography. The PWd was calculated using a 12-lead surface electrocardiogram (ECG). Cirrhotic patients were followed up for 2.5 years for the evaluation of poor outcomes and the development of atrial fibrillation. Patients with cirrhosis were observed to have significantly higher left atrial phasic volumes such as minimal left atrial volume (3D-LAVmin, P = 0.004) and indexed LAVmin (3D-LAVImin, P = 0.0001), and significantly decreased left atrial reservoir functions such as left atrial emptying volume (3D-LAEV, P = 0,001), left atrial ejection fraction (3D-LAEF, P = 0,001) on 3D echocardiography. PWd was determined to be significantly longer in the cirrhotic group compared with the control group (P = 0.003). In the 2.5-year follow-up period, poor outcomes occurred in 34 patients (22 patients died, six patients had liver transplantation, six patients developed atrial fibrillation/AHRE episodes). In Cox regression analysis, the MELD score (HR, 1.16 (1.06-1.26), P = 0.001) and 3D-LAVImin (HR, 0.95 (0.86-1.00), P = 0.040) were significantly associated with all-cause mortality. Cirrhotic patients with LAVImin of >15 ml/m2 were seen to have poor survival (long rank P = 0.033). The results of this study showed that patients with cirrhosis had higher left atrial volume, longer PWd and worse diastolic functions compared with the control group. Higher disease severity scores were associated with left atrial function and volume. In addition, left atrial volume measured with 3DE was a strong predictor of future adverse events, and minimal left atrial volumes had a higher prognostic value than any other left atrial function indices.

Relation of p - wave dispersion with presystolic a - wave and aortic valve sclerosis in asymptomatic subjects.

P-wave duration and P-wave dispersion (PWD) are thought to be the surrogate marker of devoloping atrial fibrillation (AF). The main purpose of present study was to investigate the association between presystolic wave (PSW), aortic valve sclerosis, and PWD. Patients with sinus rhythm admitted to the cardiology outpatient clinic were consecutively enrolled. Maximum (Pmax) and minimum (Pmin) P-wave duration and PWD were measured. Echocardiography was used to assess the aortic valve morphology and presence of PSW. The patients were divided into two groups according to presence or absence of AVSc and PSW. A total of 100 patients were enrolled consecutively. Patients with both PSW and AVSc had higher PWD values compared with those without PSW (42±15 vs 65±20) and AVSc (52±21 vs 69±19). The patients were categorized on the basis of median PWD values. According to univariate analysis, there was significant association between PWD and presence of PSW (P: .004), presence of AVS (P: .011), hypertension (P: .01) interventricular septal thickness (IVST) (P: .026), and posterior wall thickness (PWT) (P: .022). Multivariate logistic regression analyses demonstrated presence of PSW (95% confidence interval (1.058-6.505, P: .037) as an independent determinant of PWD. Assessment of presystolic A-wave on echocardiography examination may provide important information regarding the atrial conduction velocities that is a electrophysiological cause of AF. While there was a significant association between AVSc and PWD in univariate analysis, this significance disappeared in multivariate analysis.

P-wave dispersion and renal biomarkers in canine visceral leishmaniasis stage III and IV infected dogs

Canine visceral leishmaniasis is a protozoan disease affecting most vital organs and also causing myocardial and/or renal damage. P-wave dispersion, a newly used non-invasive ECG indicator, is used to follow atrial arrhythmias, atrial fibrillation, valvular disease in both human and veterinary medicine. The purpose of this study involving Canine Visceral Leishmaniasis (CVL)-infected dogs in stage III and IV was to verify whether the P-wave dispersion was related to the renal failure. For this purpose, a total of 17 dogs of different ages, both sexes, comprising eleven animals with CVL (at stage III and IV) diagnosed using a rapid ELISA (enzyme-linked immunosorbent assay) test and serological IFAT (immunofluorescence.antibody titres) and six healthy dogs used as controls were enrolled. Significant differences between the P-wave dispersion (regarding the mean values) of the control, stage III and IV-infected groups (P = 0.003) were detected as follows: 21.8 ± 0.5, 20.6 ± 1.2 and 25.0 ± 0.4 ms, respectively. The P-wave dispersion value was moderately longer in the stage IV-infected group compared with the control one (P = 0.022), however, the aforementioned relationship was determined as significant between the stage IV and III-infected groups (P = 0.003). Regarding all of the biomarkers of the renal function monitored within this study, there were differences between the control and stage IV-infected group for the creatinine (P = 0.002), the control and stage IV-infected group for the urine protein/creatinine ratio (P &amp;lt; 0.001), and the stage III and stage IV-infected groups for the urine protein/creatinine ratio (P &amp;lt; 0.001). In conclusion, an increased P-wave dispersion was not associated with renal failure. It might be related to the limitation of our study including small sample sizes in the groups. Therefore, the cardiac indicators were not analysed. For more accurate results, it is desirable to perform further studies including a larger sample size along with an investigation of the cardiac and renal indicators.

Analysis of QT Dispersion, Corrected QT Dispersion, and P-Wave Dispersion Values in Alcohol Use Disorder Patients With Excessive Alcohol Use.

To identify the changes in QT dispersion (QTd), corrected QTd (QTcd), and P-wave dispersion (Pd) values with long-term alcohol abuse that could lead to severe ventricular arrhythmia, atrial fibrillation, and sudden death in alcohol use disorder (AUD) patients with excessive alcohol use. This cross-sectional study included 48 individuals diagnosed with AUD based on DSM-5 criteria. Patients with a history of psychiatric diseases were not included. The control group comprised 48 individuals with no psychiatric diagnosis who did not abuse alcohol or other substances. Participants with body mass index > 24.9 kg/m² were excluded. Twelve-derivation electrocardiograms (ECG) were obtained from all participants. The mean ± SD age was 44.35 ± 10.24 years in the AUD group and 40.90 ± 13.45 years in the control group. There was no significant difference between the groups based on age (P = .108). There was a significant difference between the groups based on smoking status (P = .000). The mean ± SD period of alcohol use was 20.71 ± 12.04 years, and the alcohol intake was 5.88 ± 1.65 units/d. The AUD group demonstrated elevations in all ECG measures (QTd: 46.56 vs 26.67 ms, QTcd: 54.25 vs 30.88 ms, Pd: 44.69 vs 28.54 ms, all P = .000). AUD patients with excessive alcohol use had a higher risk of arrhythmia and sudden death compared to the control group. Consideration of ECG and referral to cardiologic examinations would contribute to the follow-up and health of patients with AUD.

Evaluation of P Dispersion and P Dispersion Recovery in Patients with Pseudoexfoliative Syndrome

Background: Pseudoexfoliative syndrome (PEX) is an old-age disease characterized by the accumulation of fibril materials in both the eye and extraocular organs. PEX is associated with many morbid and mortal cardiovascular diseases. The aim of our study was to investigate the effects of the stress test on P Wave dispersion (PWD) in patients with PEX. Patients and Methods: Forty patients who presented to the ophthalmology outpatient clinic between February 2018 and September 2018 and diagnosed as PEX in the ophthalmologic examination were included in the study. As a control group, forty-four patients, age and gender-matched, who applied to the cardiology outpatient clinic, diagnosed in the outpatient clinic of ophthalmology non-PEX, were included in the study. The study and control group were subjected to treadmill exercise test (TET) according to Bruce protocol. Results: The recovery PWD value of the study group in the third minutes was 34.4 ±4.35 ms and rest PWD value of study group 32.925±5.17 ms. There was no statistically significant difference between the two values (t=1.37992, p=0.08). The basal PWD value of the control group was 31.79±3.9ms, the recovery PWD value of the control group in the second minute 32.65±3.48 ms. There was no statistically significant difference between the two values (t=1.09495, p=0.13). Conclusion: The most interesting result of the study was that the difference between the recovery PWD value and the resting PWD value in the study group was statistically insignificant in the third recovery minute, whereas in the control group it occurred in the second minute.

Predictive value of P-wave and QT interval dispersion in children with congenital heart disease and pulmonary arterial hypertension for the occurrence of arrhythmias

ObjectivesTo evaluate P-wave dispersion (PWD) and QT dispersion (QTd) in children with congenital heart disease and pulmonary arterial hypertension (PAH-CHD) and to investigate the predictive value of both PWD and QTd for prediction of arrhythmias in such children. Materials and methodsWe included 40 children with PAH-CHD as Group I. Forty other children with CHD and no PAH were included as Group II. Forty healthy children of matched age and sex served as a Control group. Electrocardiography was performed to determine PWD and QTd. Furthermore, 24-hour Holter monitoring was performed to detect the presence of arrhythmias. Echocardiographic evaluation was also performed. ResultsQTd and PWD were significantly higher in Group I than in Group II and Control group. A significant positive correlation was present between both QTd and PWD and mean pulmonary artery pressure, right ventricular diameter, pulmonary vascular resistance (PVR), and PVR to systemic vascular resistance ratio. QTd showed 93% sensitivity, 80% specificity, and 85% accuracy for prediction of occurrence of arrhythmias in patients with PAH-CHD at a cutoff point of 61 ms, whereas PWD showed 87% sensitivity, 80% specificity, and 85% accuracy for prediction of arrhythmias at a cutoff point of 32.5 ms in such patients. Logistic regression analysis showed that both QTd and PWD were good predictors for the occurrence of arrhythmias in children with PAH-CHD (p = 0.003 and p = 0.01, respectively). ConclusionsPWD and QTd were good predictors for the occurrence of various arrhythmias in children with PAH-CHD.

P-wave dispersion as a simple tool for screening childhood obstructive sleep apnea syndrome

IntroductionThe gold standard for the diagnosis of childhood obstructive sleep apnea syndrome (OSAS) diagnosis is polysomnography; however, electrocardiography (ECG) may provide a simpler alternative. P-wave dispersion (PWD), the difference between the maximum and minimum P-wave duration measured by 12-lead ECG, is increased in adult OSAS but has not been researched in childhood OSAS. The aims of this study were to determine the PWD and cut-off value for the diagnosis of childhood OSAS and its association with severity. MethodsA total of 77 children with confirmed OSAS and 44 control participants underwent surface 12-lead ECG. P-wave duration was measured using a digital caliper by a researcher blinded to the groups. ResultsMedian (interquartile range) PWD in children with OSAS (median age = 82.8 months, range = 24–194 months) was significantly higher than that in the control group (median age = 73.4 months, range = 12–156 months): 38.3 (29.7–50.5) vs 25.5 (20.5–30.5) milliseconds, respectively (p < 0.0001). Subgroup analysis according to OSAS severity categorized by the apnea–hypopnea index from polysomnography demonstrated that PWD in the severe OSAS group (n = 24) was significantly higher than that in the mild-to-moderate OSAS group (n = 53): 48.5 (34.7–67.4) vs 35.5 (28.2–47.8) milliseconds, respectively (p = 0.006). A cut-off value of PWD at 26.5 ms from the receiver operating characteristic curve for the diagnosis showed the area under the curve to be 0.839, with a sensitivity of 89.6% and a specificity of 61.4%. ConclusionPWD was significantly increased in children with OSAS, particularly in severe cases. PWD could be a useful tool for screening childhood OSAS.

Evaluation of atrial electromechanical functions in dipper and nondipper hypertension patients using left atrial strain P-wave dispersion and P terminal force.

Nondippers are known to carry a high risk of cardiovascular morbidity and mortality. The aim of this study was to investigate the effects of dipper and nondipper status of hypertension on left atrial (LA) systolic and diastolic functions using two-dimensional speckle tracking echocardiography (2D-STE), P-wave dispersion (PWD), and P terminal force (PTF) in hypertensive patients. A total of 72 patients and 39 healthy individuals were included in the study. The patients were classified as nondippers if their daytime ambulatory systolic and diastolic blood pressure did not decrease by at least 10% during the night. Atrial electromechanical delay times, LA strain values were obtained by 2D-STE with automated software and compared between the groups. PWD and PTF data were calculated on the electrocardiography. Inter-atrial (dippers: 25.5±3.9, nondippers: 32.2±7.4, P<.001), left-atrial (dippers: 14.9±3.7, nondippers: 18.2±6.0, P=.016), and right atrial (dippers: 10.5±2.1, nondippers: 14.2±5.2, P<.001) electromechanical delay times were significantly longer in nondippers. LA strain S (dippers: 34.2 [29.7-38.7], nondippers: 27.7 [22.7-32.2], P<.001), LA strain E (dippers: 18.2 [16.6-20.1], nondippers: 14.4 [11.6-16.8], P<.001), and LA strain A (dippers: 15.8 [13.5-17.9], nondippers: 12.7 [9.9-14.5], P<.001) were significantly lower in nondippers. Nondippers also had an increased values of maximum P-wave duration (dippers: 0.117 [0.10-0.12], nondippers: 0.126 [0.12-0.14], P<.001), PWD (dippers: 0.062 [0.06-0.07], nondippers: 0.069 [0.06-0.08], P=.004), and PTF (dippers: 0.055±0.02, nondippers: 0.066±0.02, P=.02). Nondipping pattern in hypertensive patients had a worse cardiac remodeling, and impaired mechanical LA function compared with dipping pattern. The PWD and PTF findings support these changes.

Prediction of Reperfusion and Infarct-Related Artery Patency after Thrombolysis in Acute Anterior Myocardial Infarction by Degree of P Wave Dispersion on ECG

Background: The prognosis of patients with persistent occlusion of the infarct related artery (IRA), despite lytic therapy is poor. Early detection of successful reperfusion and IRA patency is of great importance in terms of prognosis and identification of candidates for rescue percutaneous coronary intervention (PCI). P wave dispersion (PWD), a new parameter measured before and after fibrinolytic therapy (FT) is supposed to predict successful reperfusion in patients with anterior acute myocardial infarction (AMI).Objectives:To examine the prediction of successful reperfusion and infarct related artery (IRA) patency by measuring P wave dispersion in 12-lead surface ECG.Method:132 patients were selected and divided into two groups on the basis of ST segment resolution (STR) after 120 minutes of thrombolysis. Group I: patients with STR &gt;70%; Group II: patients with STR &lt; 70%. All patients underwent coronary angiography (CAG). IRA patency was considered if TIMI flow grade was &gt;2.Results: Mean age of the successfully thrombolysed group was 49.12±9.54 and mean age of failedthrombolysis group was 52.08±8.23 years. Though higher age was associated with failed thrombolysis and it was statistically insignificant (p=0.06). Patients with higher BMI showed no significant difference in thrombolysis. It was observed that diabetes mellitus and dyslipidemia were significantly higher in group II patients (p=0.04 and p=0.03, respectively). The mean level of PWD after 120 minutes of thrombolysis (PWD120) was statistically significant (p=0.001) between two groups. After multivariate regression analysis PWD120 was found to be the significant predictor of ST segment resolution as well as IRA patency (OR = 1.101; 95% CI = 1.012 – 1.240; p = 0.01).Conclusion: P wave dispersion (PWD) in patients receiving thrombolytic therapy can be a predictor of successful reperfusion and patent infarct related artery (IRA). PWD values, in combination with other reperfusion parameters, can contribute to the identification of rescue PCI candidates.Bangladesh Heart Journal 2017; 32(2) : 100-105

Prediction of Reperfusion and Infarct Related Artery Patency after Thrombolysis in Acute Anterior Myocardial Infarction by Degree of P Wave Dispersion on ECG

Background: Early detection IRA patency following thrombolytic therapy is of great importance in terms of prognosis and identification of candidates for rescue percutaneous coronary intervention (PCI). P wave dispersion (PWD), a new parameter measured before and after thrombolytic therapy is supposed to predict successful reperfusion in patients with anterior acute myocardial infarction (AMI).Methods: 132 patients were selected and divided into two groups on the basis of ST Segment resolution (STR) after 120 minutes of thrombolysis. Group I: patients with STR &gt;70%; Group II: patients with STR &lt; 70%. P wave dispersion was measured in both groups before and after thrombolysis. All patients underwent coronary angiography (CAG). IRA was considered patent if TIMI flow grade was e”2.Results: It was observed that diabetes mellitus and dyslipidemia were significantly higher in group II patients (p=0.04 and p=0.03, respectively). PWD before thrombolysis (PWD0) and 90 minutes after thrombolysis (PWD90) in both groups were statistically insignificant (p=0.45 and p=0.19, respectively). The mean level of PWD120 was statistically significant (p=0.001). After multivariate regression analysis PWD120 was found to be the significant predictor of IRA patency (OR = 1.101; 95% CI = 1.012 – 1.240; p = 0.01).Conclusion: P wave dispersion in patients receiving thrombolytic therapy can be a predictor of successful reperfusion and patent IRA. PWD values, in combination with other reperfusion parameters, can contribute to the identification of rescue PCI candidates.Cardiovasc. j. 2018; 10(2): 158-163

Diagnostic Values of P-Wave Dispersion to Detect Diastolic Function in Patient with Hypertension

Background: Hypertension is one of the main causes of cardiovascular disease. Patients with hypertension have increase risk of heart failure compared to populations with normal blood pressure. Clinical evidence shows diastolic dysfunction (DD) can lead to heart failure. Diagnostic of DD with echocardiography is important but access to echocardiography machines is limited compared to electrocardiography (ECG). ECG research correlates P-wave dispersion (PWD) with DD. The aim of this study is to determine the value of PWD to diagnose DD in patients with hypertension.Methods: A cross sectional study was conducted in patients with hypertension at Dr. Sardjito Hospital. Patients received echocardiography, ECG, blood pressure measurement and data recording. The diastolic dysfunction was determined based on 2016 ASE/EACVI criteria. We conducted ROC analysis to determine the cut-off point of P-wave dispersion and the area under the curve (AUC) value, and bivariate analysis on demographic and clinical factors related to PWD. Multivariate analysis was performed to determine the independent factors affecting PWD.Results: 113 patients met the criteria of the study subjects, with 47 men (37.2%), mean age 58.32±11.17 years. Thirteen (11.5%) subjects had DD and 37 subjects (32.7%) with increased PWD. Results showed increased PWD above 71.4 m.s with AUC 76.2%, sensitivity 75%, specifcity 72.2%, positive predictive value 33.3%, negative predictive value 96%, and accuracy of 72.5% in diagnosing DD.Conclusion: This is the frst study to examine the diagnostic value of PWD to detect diastolic function based on 2016 ASE/EACVI criteria. We found PWD above cut-off point 71.4 m.s has a moderate diagnostic value for detecting DD in patients with hypertension.

Previous use of Statins and Atrial Electrical Remodeling in Patients with Cryptogenic Stroke.

In the general population the leading cause of cardioembolic stroke is atrial fibrillation (AF). A silent AF is also the possible cause of many cryptogenic strokes. P wave dispersion (PWD), a predictor of AF, has been proposed as a marker of silent AF occurrence in these strokes. PWD correlates with high-sensitive C-reactive protein levels reflecting the role of inflammation in promoting a slowed and inhomogeneous atrial conduction. Statins have a multitude of additional effects beyond lipid lowering, in particular anti-inflammatory effects that may influence atrial conduction. The aim of this study was to evaluate the effects of previous statin use on PWD in patients with cryptogenic stroke, in order to highlight a possible role for statins in preventing atrial conduction alterations that predispose to AF. We enrolled 131 patients (67 males, 64 females; mean age 69±13 years) with cryptogenic stroke. All patients underwent neuroimaging examination, arterial ultrasound examination, echocardiography and ECG. PWD was measured in all subjects. Patients previously treated with statins (n: 34) had lower PWD and P index values in comparison with no-statin group (41.7±12.2 vs 48.7±15.2 ms, p=0.01, and 14.2±3.7 vs 16.5±5.3 ms, p=0.02, respectively). Our results show lower PWD values in cryptogenic stroke patients previously treated with statins. These findings provide support to the hypothesis that statins may play a role in modulating atrial electrophysiological and structural properties, preventing the occurrence of a slowed and heterogeneous atrial conduction and finally, reducing the occurrence of AF.

Assessment of Atrial Fibrillation and Ventricular Arrhythmia Risk after Bariatric Surgery by P Wave/QT Interval Dispersion

The association of obesity with atrial fibrillation (AF) and with ventricular arrhythmias is well documented. The aim of this study was to investigate whether weight reduction by a laparoscopic sleeve gastrectomy has any effect on P wave dispersion (PWD), a predictor of AF, and corrected QT interval dispersion (CQTD), a marker of ventricular arrhythmias, in obese individuals. In a prospective study, a total of 114 patients (79 females, 35 males) who underwent laparoscopic sleeve gastrectomy were examined. The patients were followed 1year. PWD and CQTD values before and 3rd, 6th, and 12th months after the surgery were calculated and compared. There was a statistically significant decline in body mass index (BMI), PWD, and CQTD values among baseline, 3rd, 6th, and 12th months (p<0.001 for all comparisons). Correlation analysis showed a statistically significant correlation between ΔPWD and ΔBMI (r = 0.719, p < 0.001), ΔPWD and Δleft ventricular end-diastolic diameter (LVEDD) (r = 0.291, p = 0.002), ΔPWD and Δleft atrial diameter (LAD) (r = 0.65, p < 0.001), ΔCQTD and ΔBMI (r = 0.266, p = 0.004), ΔCQTD and ΔLVEDD (r = 0.35, p < 0.001), ΔCQTD and ΔLAD (r = 0.289, p = 0.002). In multiple linear regression analysis, there was a statistically significant relationship between ΔPWD and ΔBMI (β = 0.713, p < 0.001), ΔPWD and ΔLVEDD (β = 0.174, p = 0.016), ΔPWD and ΔLAD (β = 0.619, p < 0.001), ΔCQTD and ΔBMI (β = 0.247, p = 0.011), ΔCQTD and ΔLVEDD (β = 0.304, p < 0.001), ΔCQTD and ΔLAD (β = 0.235, p = 0.009). PWD and CQTD values of patients were shown to be attenuated after bariatric surgery. These results indirectly offer that there may be a reduction in risk of AF, ventricular arrhythmia, and sudden cardiac death after obesity surgery.

The Effect of Synthetic Cannabinoids on P-Wave Dispersion: An Observational Study

Objective: The aim of this study was to investigate the effect of synthetic cannabinoids (SC) on P-wave dispersion (PD) in patients who consume SC. Materials and Methods: The study population included 72 patients who consumed SC and 36 age- and sex-matched healthy controls. The severity of addiction was detected using the addiction profile index (BAPI). The PD was measured by 12-lead ECG obtained upon admission to hospital. Statistical analyses were performed using the SPSS v20.0 statistical software package. Results: The mean age of the patients and controls was 26.9 ± 7.0 and 26.3 ± 6.5 years, respectively. Mean duration of SC consumption was 1.7 ± 0.7 years. Mean BAPI score of patients who consumed SC was 12.8 ± 3.4. Patients who consumed SC had a significantly higher PD value than controls (37.7 ± 11.5 vs. 30.6 ± 6.4 ms, p < 0.001). The BAPI score was significantly correlated with PD value (r = 0.675, p < 0.001). In the linear regression model that included PD value, age and heart rate, PD value was significantly and independently correlated with BAPI score (r² of the model = 0.339; p < 0.001). Conclusions: In this study, patients who consumed SC had significantly higher PD values than controls, and the BAPI score correlated with the PD value. Hence SC consumption could lead to an increased risk of cardiovascular disease through prolonged PD. We recommend the use of the simple and inexpensive ECG to assess cardiovascular risk in patients who consume SC.

P wave dispersion on 12-lead electrocardiography in adolescents with neurocardiogenic syncope.

PurposeNeurocardiogenic syncope (NCS) is the most frequent cause of fainting during adolescence. Inappropriate cardiovascular autonomic control may be responsible for this clinical event. The head-up tilt test has been considered a diagnostic standard, but it is cumbersome and has a high false-positive rate. We performed a study to evaluate whether P-wave dispersion (PWD) could be a useful electrocardiographic parameter of cardiac autonomic dysfunction in children with NCS.MethodsFifty-four patients with NCS (28 boys and 26 girls; mean age, 12.3±1.4 years) and 55 age- and sex-matched healthy controls were enrolled. PWD was obtained as the difference between maximum and minimum durations of the P wave on standard 12-lead electrocardiography in all patients and controlsResultsThe value of PWD was significantly higher in the syncope group than in the control group (69.7±19.6 msec vs. 45.5±17.1 msec, respectively; P<0.001). The minimum duration of P wave was shorter in the syncope group than in the control group (43.8±16.8 msec vs. 53.5±10.7 msec, respectively; P<0.001). Left atrial volume was not different between the groups on transthoracic echocardiographyConclusionPWD on echocardiography could be used as a clinical parameter in patients with NCS.

Predictors of Future Atrial Fibrillation Development in Patients with Hypertrophic Cardiomyopathy: A Prospective Follow‐Up Study

We evaluated whether left atrial (LA) phasic functions, P-wave dispersion (PWD), and plasma NT-proBNP levels could predict future development of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). Seventy patients with HCM were evaluated. The LA phasic functions including the LA total emptying volume (LATEV), LA total emptying fraction (LATEF), LA active emptying volume (LAAEV), LA active emptying fraction (LAAEF), LA passive emptying volume (LAPEV), and LA passive emptying fraction (LAPEF) were evaluated. P-wave dispersion was calculated. Plasma NT-proBNP levels were measured on the same day with echocardiographic study. Patients were followed up 53.09 ± 1.87 months. Patients who developed AF (n = 18) had significantly higher PWD values, NT-proBNP levels, LAVI, E/E' av, and resting LVOT gradients and significantly lower LATEF and LAAEF. In multivariate analysis, LATEF (P = 0.002), LAAEF (P = 0.007), logNT-proBNP level (P = 0.022), and PWD (P = 0.018) were associated with AF development. The results of receiver operating characteristic analysis revealed that a LATEF cutoff value 49% with 72% sensitivity and 81% specificity, a LAAEF cutoff value of 36% with 72% sensitivity and 71% specificity, and an NT-proBNP cutoff value of 720 pg/mL predicted future AF development with 72% sensitivity and 60% specificity. A PWD cutoff value of 47.5 msecond predicted future AF development with 78% sensitivity and 72% specificity. In patients with HCM, LA phasic functions, PWD, and NT-proBNP levels predict future development of AF. Assessment of LA phasic functions during routine echocardiographic evaluation and measuring NT-proBNP levels and PWD values of patients with HCM during daily practice may provide important data in predicting those at high risk of AF occurrence.

Changes in P-wave velocity with different full waveform sonic transmitter centre frequency

Full waveform sonic logging, with the transmitter set at different centre frequencies, often provides different compressional wave velocities over the same interval. There may be several reasons why these velocity differences are recovered where the source has different frequency content. Examples include: intrinsic dispersion, scattering dispersion, geometric dispersion, processing artefacts and acquisition artefacts. We acquired and analysed multifrequency monopole full waveform sonic logging data from the cored drill hole intersecting a high-permeability sandy aquifer in the Northern Gnangara Mound, Perth Basin, Western Australia. A key interval of the shallow, sand-dominated Yarragadee Formation was selected and logged four times with transmitter centre frequencies set to 1, 3, 5 and 15 kHz. We compute apparent velocity dispersion as the percentage velocity differences in the P-wave velocity recovered from full waveform sonic logs completed at different dominant transmitter centre frequencies. We find that high-permeability sediments could be placed into broad groups: cross-bedded and non-cross-bedded sandstones.We find a distinctly different relationship between apparent P-wave velocity dispersion and permeability for cross-bedded and non-cross-bedded sandstones. Cross plots for the two sediment types show a general trend of increasing apparent dispersion with increasing permeability. Grouping the sandstone layers based on sediment type, as observed from core samples, illustrates different but positive correlation between the apparent P-wave velocity dispersion and permeability in these shallow, weakly-consolidated sandstones. The cross-bedded sandstone, for its part, has a wider range of permeability than the non-cross-bedded sandstone but a smaller range of apparent P-wave velocity dispersion. Given these results, our hypothesis is that while permeability plays a role, other factors such as geometric dispersion or scattering dispersion likely contribute the net value of P-wave dispersion recovered between any two receivers. Finally the results from these experiments have shown that there exists at least a weak empirical relationship between P-wave velocity dispersion and hydraulic permeability at the field site.