P-wave duration and dispersion in obese subjects

Association between body mass index and electrocardiogram indices: A Mendelian randomization study

INTRODUCTION

Cardiovascular diseases (CVDs) remain a global health concern, and body mass index (BMI) is known to be associated with an increased risk of CVD, but the exact mechanisms underlying this relationship remain unclear. This study employs Mendelian randomization (MR) to investigate the causal association between BMI and electrocardiogram (ECG) indices, providing insights into potential pathways linking obesity to CVD.

METHODS

We conducted a comprehensive MR study utilizing large-scale genetic and ECG data from diverse populations. Instrumental variables were selected from genome-wide association studies, ensuring their relevance to BMI. Causal relationships between BMI and ECG indices, including P wave duration, PR interval, QRS duration, and QT interval, were assessed using various MR methods, with inverse variance weighted (IVW) considered as the primary analysis.

RESULTS

Our MR analysis revealed a significant positive causal association between higher BMI and P wave duration (β = 8.078, 95% CI: 5.322 to 10.833, p < 0.001), suggesting a potential mechanism through which higher BMI may contribute to arrhythmogenic risks. However, no significant causal associations were observed between BMI and PR interval, QRS duration, or QT interval (all p > 0.005). In addition, our study also found that there is no horizontal pleiotropy between BMI and P wave duration, PR interval, QRS duration, and QT interval, suggesting that the conclusions of this study are robust.

CONCLUSION

This study supports a causal relationship between elevated BMI and prolonged P wave duration, a marker of increased atrial arrhythmogenic risk. Further investigations are still needed to elucidate the underlying mechanisms.

Modifications of long-term heart rate variability produced in an experimental model of diet-induced metabolic syndrome

Metabolic syndrome (MetS) has been linked to a higher prevalence of cardiac arrhythmias, the most frequent being atrial fibrillation, but the mechanisms are not well understood. One possible underlying mechanism may be an abnormal modulation of autonomic nervous system activity, which can be quantified by analysing heart rate variability (HRV). Our aim was to investigate the modifications of long-term HRV in an experimental model of diet-induced MetS to identify the early changes in HRV and the link between autonomic dysregulation and MetS components. NZW rabbits were randomly assigned to control (n = 10) or MetS (n = 10) groups, fed 28 weeks with high-fat, high-sucrose diet. 24-hour recordings were used to analyse HRV at week 28 using time-domain, frequency-domain and nonlinear analyses. Time-domain analysis showed a decrease in RR interval and triangular index (Ti). In the frequency domain, we found a decrease in the low frequency band. Nonlinear analyses showed a decrease in DFA-α1 and DFA-α2 (detrended fluctuations analysis) and maximum multiscale entropy. The strongest association between HRV parameters and markers of MetS was found between Ti and mean arterial pressure, and Ti and left atrial diameter, which could point towards the initial changes induced by the autonomic imbalance in MetS.

P-wave indices and left atrial mechanics as predictors of atrial cardiopathy in embolic stroke of undetermined source

Recent research has shed light on the culpability of LA (left atrial) abnormality, in the form of atrial cardiopathy, as an independent risk factor for the development of atrial fibrillation, LA thrombus and subsequent stroke. The aim of this study was to measure LA electromechanical dissociation (EMD), LA volumes, P-wave dispersion (PWD) and P-wave terminal force in V1 (PTFV1) as markers of atrial cardiopathy in patients with ESUS (embolic stroke of undetermined source), to determine whether atrial cardiopathy is an integral part in the causal pathway of ESUS. 28 patients presenting with ischemic stroke and fulfilling the criteria for ESUS were enrolled into this cross-sectional, observational study along with a control group of 28 age- and gender-matched apparently healthy individuals. On ECG, PWD and PTFV1 were measured. On echocardiography, LA EMD and LA volumes were recorded. Increased PWD (34.14 ± 9.89 ms vs. 27.32 ± 8.95 ms; p = 0.01), atrial EMD (73.32 ± 16.31 ms vs. 63.63 ± 13.59 ms; p = 0.02) and LA volumes were observed in patients with ESUS as compared to controls. A significant correlation was also found between these parameters (p < 0.01). According to the results of our study, PWD, atrial EMD and LA volumes may be novel predictors for ESUS. Our results support the notion that atrial cardiopathy is a distinct mechanism of thrombosis in ESUS patients. Further research is required to clarify its function in the causation of stroke, ESUS in particular.

Increased P-wave dispersion in patients with obstructive sleep apnea syndrome: a meta-analysis

PURPOSE

Prolonged atrial conduction and inhomogeneous sinus impulse propagation may play a role in the initiation and maintenance of atrial tachyarrhythmias. Such a process could be reflected in inter-lead P-wave duration differences known as "P-wave dispersion" (PWD). Abnormal PWD may be related to obstructive sleep apnea syndrome (OSAS). A meta-analysis of the available publications was conducted.

METHODS

A MEDLINE, Web of Science, and Google Scholar search from 2000 to 2021 was performed. The keywords used for search were apnea AND "P wave dispersion." Case-control studies and surveys were selected as long as they included healthy subjects and subjects with diagnosed OSAS who did not have any other major health problems. PWD values and correlations between apnea-hypopnea indices (AHI) and PWD were used as outcome measures.

RESULTS

Ten studies met the inclusion creteria, encompassing 773 patients with OSAS and 347 healthy controls. The mean ages of the patients with OSAS ranged from 6.9 to 58.8 years. The estimated average Hedges's g standardized mean difference in PWD values was equal to 1.883 (95% CI: 1.140 to 2.626, p < 0.001). The estimated average Fisher r-to-z transformed correlation coefficient between AHI and PWD was equal to 0.530 (95% CI: 0.075 to 0.985, p = 0.0225). Meta-regression analysis failed to find statistically significant correlations between the effect sizes and the mean age, male proportion, and the body mass index in the OSAS groups.

CONCLUSION

OSAS is associated with increased PWD, which may predispose to atrial tachyarrythmias.

P wave dispersion, Tpeak-Tend interval, and Tp-e/QT ratio in children with psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory, multi-system disease that often begins in childhood and characterised by inflammatory skin, nails, scalp, and joint manifestations. The inflammation in psoriasis may promote some effect on the cardiac conduction system.

OBJECTIVE

The aim of this study is to investigate myocardial repolarisation anomaly on the conducting system in the paediatric psoriasis using P wave dispersion, Tpeak-Tend interval, and Tp-e/QT ratio.

METHODS

Forty-two patients diagnosed with psoriasis and 37 age- and sex-matched healthy children were enrolled in the study. Electrocardiographic parameters in psoriasis and control group were recorded from an electrocardiogram for each patient.

RESULTS

The results indicated that the parameters including Pdis, QTc dis, Tp-e dis interval, and Tp-e max/QTmax ratios, which are known to be key indicators for the prediction of severe atrial or ventricular arrhythmia and sudden cardiac death and also important parameters used as the indicators for the non-invasive evaluation of the transmural heterogeneity were significantly longer in the study group compared to the control group (p < 0.05).

CONCLUSIONS

This study includes the evidence linking psoriasis with increased myocardial repolarisation heterogeneity. These findings suggest that this patient population may be at an increased risk for arrhythmias. Our findings may be a basis for further studies.

Effects of epicardial fat reduction on P-wave duration of morbidly obese patients submitted to bariatric surgery: an observational study

Introduction: Epicardial fat (EF) is biologically active and, through its paracrine effect, interacts with the atrial myocardium and may be involved in the atrial remodeling observed in obese individuals. P-wave duration (PWD) is a non-invasive marker of atrial conduction time and reflects changes related to atrial remodeling. The effects of the reduction of EF induced by bariatric surgery on PWD have not yet been defined. Methods: We prospectively recruited 22 morbidly obese patients with no other comorbidities at the Unidade de Cirurgia Bariátrica (Bariatric Surgery Unit) of Unviversidade de São Paulo’s Hospital das Clínicas. The patients were submitted to clinical and laboratorial evaluations, 12-lead eletrocardiography (ECG), two-dimensional echocardiogram and 24 h Holter. The same evaluation was performed 12 months after bariatric surgery. In order to make a comparison of the continuous variables, we used the paired and Wilcoxon T tests. To evaluate the association between independent variables, a regression model was used for repeated measures. Results: A total of 20 patients completed the protocol (age: 36.35 ± 10.26 years, 18 women). There was a significant reduction of PWD, body mass index (BMI) and EF after bariatric surgery (p<0.05). There was also an average reduction of 11.55 ± 8.49 ms in PWD. In the multiple regression analysis, an association was observed between the reduction of PWD and the reduction of EF and BMI. Conclusions: In morbidly obese patients with no other comorbidities, the reduction of EF after bariatric surgery was associated with an improvement in atrial remodeling indicated by a significant reduction in PWD.

Efeitos da Redução da Gordura Epicárdica na Duração da Onda P de Obesos Mórbidos Submetidos à Cirurgia Bariátrica: um Estudo Observacional

Introduction: Epicardial fat (EF) is biologically active and, through its paracrine effect, interacts with the atrial myocardium and may be involved in the atrial remodeling observed in obese individuals. P-wave duration (PWD) is a non-invasive marker of atrial conduction time and reflects changes related to atrial remodeling. The effects of the reduction of EF induced by bariatric surgery on PWD have not yet been defined. Methods: We prospectively recruited 22 morbidly obese patients with no other comorbidities at the Unidade de Cirurgia Bariátrica (Bariatric Surgery Unit) of Unviversidade de São Paulo’s Hospital das Clínicas. The patients were submitted to clinical and laboratorial evaluations, 12-lead eletrocardiography (ECG), two-dimensional echocardiogram and 24 h Holter. The same evaluation was performed 12 months after bariatric surgery. In order to make a comparison of the continuous variables, we used the paired and Wilcoxon T tests. To evaluate the association between independent variables, a regression model was used for repeated measures. Results: A total of 20 patients completed the protocol (age: 36.35 ± 10.26 years, 18 women). There was a significant reduction of PWD, body mass index (BMI) and EF after bariatric surgery (p<0.05). There was also an average reduction of 11.55 ± 8.49 ms in PWD. In the multiple regression analysis, an association was observed between the reduction of PWD and the reduction of EF and BMI. Conclusions: In morbidly obese patients with no other comorbidities, the reduction of EF after bariatric surgery was associated with an improvement in atrial remodeling indicated by a significant reduction in PWD.

Lipidomics, Atrial Conduction, and Body Mass Index

BACKGROUND

Lipids are increasingly involved in cardiovascular risk prediction as potential proarrhythmic influencers. However, knowledge is limited about the specific mechanisms connecting lipid alterations with atrial conduction.

METHODS

To shed light on this issue, we conducted a broad assessment of 151 sphingo- and phospholipids, measured using mass spectrometry, for association with atrial conduction, measured by P wave duration (PWD) from standard electrocardiograms, in the MICROS study (Microisolates in South Tyrol) (n=839). Causal pathways involving lipidomics, body mass index (BMI), and PWD were assessed using 2-sample Mendelian randomization analyses based on published genome-wide association studies of lipidomics (n=4034) and BMI (n=734 481), and genetic association analysis of PWD in 5 population-based studies (n=24 236).

RESULTS

We identified an association with relative phosphatidylcholine 38:3 (%PC 38:3) concentration, which was replicated in the ORCADES (Orkney Complex Disease Study; n=951), with a pooled association across studies of 2.59 (95% CI, 1.3-3.9; P=1.1×10^-4) ms PWD per mol% increase. While being independent of cholesterol, triglycerides, and glucose levels, the %PC 38:3-PWD association was mediated by BMI. Results supported a causal effect of BMI on both PWD ( P=8.3×10^-5) and %PC 38:3 ( P=0.014).

CONCLUSIONS

Increased %PC 38:3 levels are consistently associated with longer PWD, partly because of the confounding effect of BMI. The causal effect of BMI on PWD reinforces evidence of BMI's involvement into atrial electrical activity.

Evaluation of Atrial Electromechanical Delay in Children with Obesity

Background and Objective: Childhood obesity is one of the worldwide health problems with an increasing prevalence and accompanied by severe morbidity and mortality. It is a serious predisposing risk factor especially for the development of cardiovascular diseases and arrhythmias. Electromechanical delay (EMD) is known to be a predictor for the development of atrial fibrillation (AF). Our study aims to investigate whether EMD, which is a predictor of AF, prolongs in obese children or not.

MATERIAL AND METHODS

The study included 59 obese patients aged between 8-18 years and 38 healthy patients as the control group with a similar age and gender. All the individuals underwent transthoracic echo and tissue Doppler echocardiography. Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by tissue Doppler imaging (TDI) and conventional echocardiography.

RESULTS

Obese patients had significantly lengthened P-wave on surface ECG to the beginning of the late diastolic wave (PA) lateral, PA septum, intra- and inter-atrial electromechanical delays when compared with the control group (p < 0.001, p = 0.001, p < 0.001 and p < 0.001, respectively) Inter-atrial EMD and intra-atrial EMD correlated positively with body mass index (BMI) values (r = 0.484, p < 0.001 and r = 0.376, p = 0.001; respectively) BMI was significantly related with inter-atrial EMD (β = 0.473, p < 0.001) However, there was no relationship between inter-atrial EMD and serum glucose and platelet count.

CONCLUSION

In our study, we declared that electromechanical delay was increased in obese children when compared to the control group and intra- and inter-atrial electromechanical delay was in correlation with body mass index. Furthermore, we discovered that BMI is an independent predictor of the inter-atrial EMD in obese children.

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

INTRODUCTION

The 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.

METHODS

A 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.

RESULTS

Median (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%.

CONCLUSION

PWD was significantly increased in children with OSAS, particularly in severe cases. PWD could be a useful tool for screening childhood OSAS.

Correlation of P-wave dispersion with insulin sensitivity in obese adolescents

BACKGROUND

P-wave dispersion is a new and simple electrocardiographic marker that has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. In the present study, we evaluated P-wave dispersion in obese adolescents and investigated the relationship between P-wave dispersion, cardiovascular risk factors, and echocardiographic parameters.

METHODS

We carried out a case-control study comparing 150 obese adolescents and 50 healthy controls. Maximum and minimum P-wave durations were measured using a 12-lead surface electrocardiogram, and P-wave dispersion was calculated as the difference between these two measures. Echocardiographic examination was also performed for each subject. Multivariate linear regression analysis with stepwise variable selection was used to evaluate parameters associated with increased P-wave dispersion in obese subjects.

RESULTS

Maximum P-wave duration and P-wave dispersion were significantly higher in obese adolescents than control subjects (143±19 ms versus 117±20 ms and 49±15 ms versus 29±9 ms, p<0.0001 for both). P-wave dispersion was positively correlated with body mass index, waist and hip circumferences, systolic and diastolic blood pressures, total cholesterol, serum levels of low-density lipoprotein cholesterol, triglycerides, glucose, and insulin, homoeostasis model assessment for insulin resistance score, left ventricular mass, and left atrial dimension. P-wave dispersion was negatively correlated with high-density lipoprotein cholesterol levels. By multiple stepwise regression analysis, left atrial dimension (β: 0.252, p=0.008) and homoeostasis model assessment for insulin resistance (β: 0.205; p=0.009) were independently associated with increased P-wave dispersion in obese adolescents.

CONCLUSIONS

Insulin resistance is a significant, independent predictor of P-wave dispersion in obese adolescents.

P-wave dispersion: What we know till now?

P-wave dispersion is defined as the difference between the maximum and the minimum P-wave duration recorded from multiple different-surface ECG leads. It has been known that increased P-wave duration and P-wave dispersion reflect prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses, which are well-known electrophysiologic characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation. Extensive clinical evaluation of P-wave dispersion has been performed in the assessment of the risk for atrial fibrillation in patients without apparent heart disease, in hypertensives, in patients with coronary artery disease, in patients undergoing coronary artery bypass surgery, in patients with congenital heart diseases, as well as in other groups of patients suffering from various cardiac or non-cardiac diseases. In this paper, we aimed to summarize the measurement methods, current use in different clinical situations, strengths and limitations of the of P-wave dispersion.

Electrocardiographic P-Wave Duration, QT Interval, T Peak to End Interval and Tp-e/QT Ratio in Pregnancy with Respect to Trimesters

BACKGROUND

P-wave duration helps to determine the risk of atrial arrhythmia, especially atrial fibrillation. QT interval, T peak to end interval (Tp-e), and Tp-e/QT ratio are electrocardiographic indices related to ventricular repolarization which are used to determine the risk of ventricular arrhythmias. We search for any alterations in electrocardiographic indices of arrhythmia in the pregnancy period with respect to trimesters.

METHODS

We enrolled 154 pregnant and 62 nonpregnant, healthy women into this cross-sectional study. Maximum and minimum P-wave durations (Pmax, Pmin), and QT intervals (QTmax, QTmin) were measured from 12 leads. QT measurements were corrected using Fridericia (QTc-Fr) and Bazett's (QTc-Bz) correction. Tp-e interval was obtained from the difference between QT interval, and QT peak interval (QTp) measured from the beginning of the QRS until the peak of the T wave. Tp-e/QT ratio was calculated using these measurements.

RESULTS

Pmax were 93.0 ± 9.1, 93.9 ± 8.9, 97.9 ± 5.6, 99.0 ± 6.1 in nonpregnant women, first, second, third trimesters of pregnancy, respectively (P = 0.001); whereas Pmin values were not significantly different. QTc-Fr max were 407.4 ± 14.2, 408.5 ± 16.1, 410.1 ± 13.1, 415.1 ± 10.1 (P = 0.007); Tp-e were 72.7 ± 6.2, 73.2 ± 6.5, 77.2 ± 8.9, 87.2 ± 9.6 (P < 0.001); and Tp-e/QT were 0.17 (0.14-0.20), 0.17 (0.14-0.20), 0.18 (0.15-0.23), 0.20 (0.16-0.25) in nonpregnant women, first, second, and third trimesters of pregnancy respectively (P < 0.001). None of the participants experienced any arrhythmic event.

CONCLUSIONS

P-wave duration is prolonged in the second trimester, and resumes a plateau thereafter. Maximum QTc interval, Tp-e interval and Tp-e/QT ratio are increased in the late pregnancy. Although these indices are altered during the course of pregnancy, they all remain in the normal ranges.

Relationship between anthropometric measures and early electrocardiographic changes in obese rats

BACKGROUND

The degree of cardiovascular function impairment parallels the degree of obesity and obese subjects have abnormal changes on the electrocardiogram (ECG). Early ECG changes in obesity have not been previously studied. The objective of the present study was to determine the early ECG changes in obese rats and their relationship with anthropometric measurements.

RESULTS

At seven weeks all rats in the experiment were obese and in sinus rhythm. In the experiment resting heart rate was increased (364±13 vs. 313±12 bpm, P<0.01). In contrast, the following parameters were shortened: QRS duration (77±3.6 vs. 65±2.6 ms, P<0.01); QT interval (102±5.2 vs. 88±3.7 ms, P<0.05); Q wave amplitude (-12.8±1.0 vs. -5.1±0.9 μv, P<0.01); and T wave amplitude (18.8±1.4 vs. 5.8±0.6, P<0.01). All other ECG parameters remained unchanged. With increased weight the resting heart rate (r=0.46, P<0.01) and R wave amplitude (r=0.60, P<0.01) increased.

CONCLUSION

Early in obesity there are no rhythm disturbances, but resting heart rate is increased. The QRS duration is shortened and Q and T-wave amplitudes reduced signifying ventricular changes related to impaired myocardial depolarization and repolarization. Furthermore, weight gain is correlated with an increase in heart rate and accentuation of the R wave amplitude.

Prolonged PR interval predicts clinical recurrence of atrial fibrillation after catheter ablation

BACKGROUND

A prolonged PR interval is known to be a poor prognostic factor in cardiovascular disease. The aim of this study was to investigate the association between PR interval and clinical outcome in patients undergoing radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF).

METHODS AND RESULTS

We prospectively included 576 patients with AF (75.5% male, 57.8±11.6 years old, 68.8% paroxysmal AF) who underwent RFCA. We analyzed preprocedural sinus rhythm ECGs obtained in the absence of antiarrhythmic drug, and all enrolled patients were categorized into 4 groups based on the quartile values of the PR interval (166, 182, and 202 ms), and were analyzed according to the left atrium (LA) volume (CT; Computed tomography), LA voltage (NavX), and clinical outcome of AF ablation. Based on quartile value of PR interval, the highest quartile of PR interval (Q4; PR ≥202 ms) was oldest (P<0.001), and most likely to have persistent AF (P<0.001) and hypertension (P=0.013) compared with the other groups. However, there was no significant difference in LA conduction velocity and atrial effective refractory period. Q4 had the greatest LA dimension (P<0.001) and volume index (P<0.001), and lowest LA appendage-emptying velocity (P<0.032) and LA voltage (P<0.001) compared with the others. For 13.1±7.5 months, the classification based on the PR interval was a significant predictor of AF recurrence after RFCA of AF (HR=1.969, 95% CI 1.343 to 2.886, P=0.001).

CONCLUSIONS

The PR interval was closely associated with advanced LA remodeling due to AF, and had a noninvasive significant predictive value of clinical recurrence of AF after RFCA.

[P wave dispersion increased in childhood depending on blood pressure, weight, height, and cardiac structure and function]

INTRODUCTION

Increased P wave dispersion are identified as a predictor of atrial fibrillation. There are associations between hypertension, P wave dispersion, constitutional and echocardiographic variables. These relationships have been scarcely studied in pediatrics.

OBJECTIVE

The aim of this study was to determine the relationship between P wave dispersion, blood pressure, echocardiographic and constitutional variables, and determine the most influential variables on P wave dispersion increases in pediatrics.

METHOD

In the frame of the PROCDEC II project, children from 8 to 11 years old, without known heart conditions were studied. Arterial blood pressure was measured in all the children; a 12-lead surface electrocardiogram and an echocardiogram were done as well.

RESULTS

Left ventricular mass index mean values for normotensive (25.91±5.96g/m(2.7)) and hypertensive (30.34±8.48g/m(2.7)) showed significant differences P=.000. When we add prehypertensive and hypertensive there are 50.38% with normal left ventricular mass index and P wave dispersion was increased versus 13.36% of normotensive. Multiple regression demonstrated that the mean blood pressure, duration of A wave of mitral inflow, weight and height have a value of r=0.88 as related to P wave dispersion.

CONCLUSIONS

P wave dispersion is increased in pre- and hypertensive children compared to normotensive. There are pre- and hypertensive patients with normal left ventricular mass index and increased P wave dispersion. Mean arterial pressure, duration of the A wave of mitral inflow, weight and height are the variables with the highest influence on increased P wave dispersion.

Ventricular remodelling in rabbits with sustained high-fat diet

AIM

Excess weight gain and obesity are one of the most serious health problems in the western societies. These conditions enhance risk of cardiac disease and have been linked with increased prevalence for cardiac arrhythmias and sudden death. Our goal was to study the ventricular remodelling occurring in rabbits fed with high-fat diet (HFD) and its potential arrhythmogenic mechanisms.

METHODS

We used 15 NZW rabbits that were randomly assigned to a control (n = 7) or HFD group (n = 8) for 18 weeks. In vivo studies included blood glucose, electrocardiographic, and echocardiographic measurements. Optical mapping was performed in Langendorff-perfused isolated hearts.

RESULTS

Body weight (3.69 ± 0.31 vs. 2.94 ± 0.18 kg, P < 0.001) and blood glucose levels (230 ± 61 vs. 141 ± 14 mg dL(-1) , P < 0.05) were higher in the HFD group vs. controls. The rate-corrected QT interval and its dispersion were increased in HFD rabbits vs. controls (169 ± 10 vs. 146 ± 13 ms and 37 ± 11 vs. 9 ± 2 ms, respectively; P < 0.05). Echocardiographic analysis showed morphological and functional alterations in HFD rabbits indicative of left ventricle (LV) hypertrophy. Isolated heart studies revealed no changes in repolarization and propagation properties under conditions of normal extracellular K(+) , suggesting that extrinsic factors could underlie those electrocardiographic modifications. There were no differences in the dynamics of ventricular fibrillation (frequency, wave breaks) in the presence of isoproterenol. However, HFD rabbits showed a small reduction in action potential duration and an increased incidence of arrhythmias during hyperkalaemia.

CONCLUSION

High-fat feeding during 18 weeks in rabbits induced a type II diabetes phenotype, LV hypertrophy, abnormalities in repolarization and susceptibility to arrhythmias during hyperkalaemia.

Increased P-wave dispersion in patients with newly diagnosed lichen planus

OBJECTIVE

Lichen planus is a chronic inflammatory autoimmune mucocutaneous disease. Recent research has emphasized the strong association between inflammation and both P-wave dispersion and dyslipidemia. The difference between the maximum and minimum P-wave durations on an electrocardiogram is defined as P-wave dispersion. The prolongation of P-wave dispersion has been demonstrated to be an independent risk factor for developing atrial fibrillation. The aim of this study was to investigate P-wave dispersion in patients with lichen planus.

METHODS

Fifty-eight patients with lichen planus and 37 age- and gender-matched healthy controls were included in this study. We obtained electrocardiographic recordings from all participants and used them to calculate the P-wave variables. We also assessed the levels of highly sensitive C-reactive protein, which is an inflammatory marker, and the lipid levels for each group. The results were reported as the means ± standard deviations and percentages.

RESULTS

The P-wave dispersion was significantly higher in lichen planus patients than in the control group. Additionally, highly sensitive C-reactive protein, LDL cholesterol, and triglyceride levels were significantly higher in lichen planus patients compared to the controls. There was a significant positive correlation between highly sensitive C-reactive protein and P-wave dispersion (r=0.549, p<0.001) in lichen planus patients.

CONCLUSIONS

P-wave dispersion increased on the surface electrocardiographic measurements of lichen planus patients. This result may be important in the early detection of subclinical cardiac involvement. Increased P-wave dispersion, in terms of the tendency for atrial fibrillation, should be considered in these patients.

Association of increased arterial stiffness and p wave dispersion with left ventricular diastolic dysfunction

BACKGROUND

The association between increased arterial stiffness and left ventricular diastolic dysfunction (LVDD) may be influenced by left ventricular performance. P wave dispersion is not only a significant determinant of left ventricular performance, but is also correlated with LVDD. This study is designed to compare left ventricular diastolic function among patients divided by brachial-ankle pulse wave velocity (baPWV) and corrected P wave dispersion (PWDC) and assess whether the combination of baPWV and PWDC can predict LVDD more accurately.

METHODS

This cross-sectional study enrolled 270 patients and classified them into four groups according to the median values of baPWV and PWDC. LVDD was defined as impaired relaxation and pseudonormal/restrictive mitral inflow patterns.

RESULTS

The ratio of transmitral E wave velocity to early diastolic mitral annulus velocity (E/Ea) was higher in group with higher baPWV and PWDC than in the other groups (all p <0.001). The prevalence of LVDD was higher in group with higher baPWV and PWDC than in the two groups with lower baPWV (p ≤ 0.001). The baPWV and PWDC were correlated with E/Ea and LVDD in multivariate analysis (p ≤ 0.030). The addition of baPWV and PWDC to a clinical mode could significantly improve the R square in prediction of E/Ea and C statistic and integrated discrimination index in prediction of LVDD (p ≤ 0.010).

CONCLUSIONS

This study showed increased baPWV and PWDC were correlated with high E/Ea and LVDD. The addition of baPWV and PWDC to a clinical model improved the prediction of high E/Ea and LVDD. Screening patients by means of baPWV and PWDC might help identify the high risk group of elevated left ventricular filling pressure and LVDD.

P-wave dispersion by 12-lead electrocardiography in carotid artery stenting

OBJECTIVE

Although carotid artery stenting (CAS) is an effective treatment for severe carotid stenosis, it has been associated with alterations in autonomic functions during or shortly after the procedure. And, autonomic functions influence P-wave durations. In this study, our aim was to investigate P-wave durations on 12-lead surface electrocardiography after CAS.

METHODS

Patients (19 male, 8 female) who are suitable for CAS, without a history of hypertension, diabetes mellitus, severe coronary artery or valvular heart disease, were enrolled in our study. 12-lead surface electrocardiography recordings were obtained at the beginning, immediately after and at the 24 h of the procedure. P-wave maximum, minimum and dispersion durations were analyzed by double-blinded observers. Results were statistically analysed using Friedman and Wilcoxon tests.

RESULTS

The P maximum and P dispersion values were significantly increased immediately after the procedure and continued with high levels at 24-h recordings, respectively (128 ± 10/19 ± 7, 143 ± 14/37 ± 11, and 137 ± 11/30 ± 7 ms, p value <0.05). The P minimum value was significantly decreased immediately after the procedure (109 ± 11/105 ± 10 ms, p value <0.05). At 24-h recordings, a nonsignificant increase occured in P minimum values (106 ± 8 ms).

CONCLUSIONS

P maximum and dispersion durations were significantly increased after the CAS and continued with high levels at 24-h recordings, which may be associated with the alterations in autonomic functions via augmented parasympathetic activity by vagally mediated stimulus. Overall, these findings suggest that decline in cardiovascular activity is prolonged at least 24 h after CAS.

The role of obesity and sleep apnea in atrial fibrillation

PURPOSE OF REVIEW

To discuss the relationship between obesity and obstructive sleep apnea as they relate to the growing atrial fibrillation epidemic, and to discuss possible mechanistic links and implications for treatment of atrial fibrillation.

RECENT FINDINGS

Increasing BMI plays an important role in development of atrial fibrillation in both men and women. Sleep-disordered breathing contributes to cardiac chamber enlargement, which may be responsible for increasing atrial fibrillation in this population. Patients with obstructive sleep apnea and/or obesity have less freedom from atrial fibrillation recurrence after catheter ablation for atrial fibrillation.

SUMMARY

BMI is a strong predictor of future development of atrial fibrillation and should be considered as a risk factor for atrial fibrillation. Patients with obstructive sleep apnea and/or obesity have high atrial fibrillation recurrence rates following atrial fibrillation ablation.

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.

Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods

Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.

Assessment of atrial electromechanical delay by tissue Doppler echocardiography in obese subjects

Our aim was to evaluate whether atrial electromechanical delay measured by tissue Doppler imaging (TDI), which is an early predictor of atrial fibrillation (AF) development, is prolonged in obese subjects. A total of 40 obese and 40 normal-weight subjects with normal coronary angiograms were included in this study. P-wave dispersion (PWD) was calculated on the 12-lead electrocardiogram (ECG). Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by TDI and conventional echocardiography. Inter- and intra-atrial electromechanical delay were significantly longer in the obese subjects compared with the controls (44.08 ± 10.06 vs. 19.35 ± 5.94 ms and 23.63 ± 6.41 vs. 5.13 ± 2.67 ms, P < 0.0001 for both, respectively). PWD was higher in obese subjects (53.40 ± 5.49 vs. 35.95 ± 5.93 ms, P < 0.0001). Left atrial (LA) diameter, LA volume index and LV diastolic parameters were significantly different between the groups. Interatrial electromechanical delay was correlated with PWD (r = 0.409, P = 0.009), high-sensitivity C-reactive protein (hsCRP) levels (r = 0.588, P < 0.0001). Interatrial electromechanical delay was positively correlated with LA diameter, LA volume index, and LV diastolic function parameters consisting of mitral early wave (E) deceleration time (DT) and isovolumetric relaxation time (IVRT; r = 0.323, P = 0.042; r = 0.387, P = 0.014; r = 0.339, P = 0.033; r = 0.325, P = 0.041; respectively) and, negatively correlated with mitral early (E) to late (A) wave ratio (E/A) (r = -0.380, P = 0.016) and myocardial early-to-late diastolic wave ratio (E(m)/A(m)) (r = -0.326, P = 0.040). This study showed that atrial electromechanical delay is prolonged in obese subjects. Prolonged atrial electromechanical delay is due to provoked low-grade inflammation as well as LA enlargement and early LV diastolic dysfunction in obese subjects.

Anesthesia induction with sevoflurane and propofol: evaluation of P-wave dispersion, QT and corrected QT intervals

The present study compared the effects of anesthesia induction with sevoflurane and propofol on hemodynamics, P-wave dispersion (Pwd), QT interval and corrected QT (QTc) interval. A total of 72 adult patients were included in this prospective study. All patients had control electrocardiograms (ECGs) before anesthesia induction. Anesthesia was induced with sevoflurane inhalation or intravenous propofol. Electrocardiography for all patients was performed during the 1(st) and 3(rd) minutes of induction, 3 minutes after administration of muscle relaxant, and at 5 minutes and 10 minutes after intubation. Pwd and QT intervals were measured on all ECGs. QTc intervals were determined using the Bazett formula. There was no significant difference in Pwd and QT and QTc intervals on control ECGs. In the sevoflurane group, except for control ECGs, Pwd and QTc interval on all ECGs were significantly longer than those in the propofol group (p < 0.05). We conclude that propofol should be used for anesthesia induction in patients with a predisposition to preoperative arrhythmias, and in those whose Pwd and QTc durations are prolonged on preoperative ECGs.

Evaluation of QT and P wave dispersion and mean platelet volume among inflammatory bowel disease patients

BACKGROUND

In inflammatory bowel disease (IBD) number of thromboembolic events are increased due to hypercoagulupathy and platelet activation. Increases in mean platelet volume (MPV) can lead to platelet activation, this leads to thromboembolic events and can cause acute coronary syndromes. In IBD patients, QT-dispersion and P-wave dispersion are predictors of ventricular arrhythmias and atrial fibrilation; MPV is accepted as a risk factor for acute coronary syndromes, we aimed at evaluating the correlations of these with the duration of disease, its localization and activity.

METHODS

The study group consisted of 69 IBD (Ulcerative colitis n: 54, Crohn's Disease n: 15) patients and the control group included 38 healthy individuals. Disease activity was evaluated both endoscopically and clinically. Patients with existing cardiac conditions, those using QT prolonging medications and having systemic diseases, anemia and electrolyte imbalances were excluded from the study. QT-dispersion, P-wave dispersion and MPV values of both groups were compared with disease activity, its localization, duration of disease and the antibiotics used.

RESULTS

The P-wave dispersion values of the study group were significantly higher than those of the control group. Duration of the disease was not associated with QT-dispersion, and MPV levels. QT-dispersion, P-wave dispersion, MPV and platelet count levels were similar between the active and in mild ulcerative colitis patients. QT-dispersion levels were similar between IBD patients and the control group. No difference was observed between P-wave dispersion, QT-dispersion and MPV values; with regards to disease duration, disease activity, and localization in the study group (p>0.05).

CONCLUSIONS

P-wave dispersion which is accepted as a risk factor for the development of atrial fibirilation was found to be high in our IBD patients. This demonstrates us that the risk of developing atrial fibrillation may be high in patients with IBD. No significant difference was found in the QT-dispersion, and in the MPV values when compared to the control group.

P wave duration is associated with cardiovascular and all-cause mortality outcomes: the National Health and Nutrition Examination Survey

BACKGROUND

P wave indices are an intermediate phenotype modulated by atrial conduction and electrophysiology. Their clinical correlates and association with all-cause mortality have received limited scrutiny.

OBJECTIVE

To determine the relationship between P wave indices and cardiovascular and all-cause mortality in the National Health and Nutrition Examination Survey (NHANES), a highly representative United States sample.

METHODS

NHANES III (1988-1994) quantified PR interval and P wave duration and amplitude. Mortality data through 2006 were obtained from National Death Index (NDI) records.

RESULTS

Of 8,561 subjects with electrocardiograms (ECGs), 7,486 (mean age 60.0 ± 13.3 years., 51.9% women, 50.1% ethnic minorities) had ECGs in sinus rhythm, linked mortality data, and complete assessments. Over a median 8.6-year follow-up (range 0.1-12.2 years), there were 679 cardiovascular deaths and 1,559 all-cause mortality deaths. Older age, male sex, and higher body mass index were significantly associated with greater PR interval and P wave duration and with lower P wave amplitude. African Americans had higher mean values of all three P wave indices. In a multivariable model adjusting for cardiovascular risk factors, P wave duration was the only P wave index significantly associated with cardiovascular mortality (hazard ratio [HR] 1.13, per 1 standard deviation [SD], 95% confidence interval [CI] 1.04-1.23; P = .004) and all-cause mortality (HR 1.06 per 1 SD; 95% CI 1.00-1.13; P = .050).

CONCLUSIONS

In a highly representative U.S. sample, P wave duration was significantly associated with increased cardiovascular and all-cause mortality. P wave duration may reflect subclinical disease and merits elucidation as a marker of risk for adverse outcomes.

Effect of obesity on p-wave parameters in a Chinese population

OBJECTIVE

To study the association between obesity and P-wave duration and dispersion (P(d)) in order to evaluate the potential risk for atrial fibrillation development in Chinese subjects using the definitions applied for Asian populations.

METHODS

The study population consisted of 40 obese (body mass index (BMI) > or = 25 Kg/m(2), according to the World Health Organization classification for the Asian population) subjects and 20 age- and sex-matched normal weight controls. Maximum P-wave duration (P(max)), minimum P-wave duration (P(min)), and P(d) were carefully measured using a 12-lead electrocardiogram, while the presence of interatrial block (IAB; P > or = 110 ms) was assessed.

RESULTS

There were no significant differences between the two groups regarding age, sex, history of hypertension or diabetes, and hyperlipidemia. Compared to controls, BMI, left atrial diameter (LAD), and interventricular septal thickness were increased, while P(max) (111.9 +/- 9.3 vs 101.1 +/- 6.0 ms, P < 0.01) and P(d) (47.9 +/- 9.3 vs 31.8 +/- 6.9 ms, P < 0.01) were significantly prolonged in the obese group. P(min) was similar between the two groups. The prevalence of IAB was significantly greater in the obese subjects. Pearson's correlation analysis showed that there were positive correlations between P(d) and BMI (r = 0.6, P < 0.001), as well as between P(d) and LAD (r = 0.366, P < 0.05).

CONCLUSION

Our data suggest that obesity is associated with increased P(max) and P(d), and increased prevalence of IAB, parameters that have been associated with atrial fibrillation. The correlation of these electrocardiogram parameters with LAD indicates an association between increased BMI and atrial remodeling in Asian subjects.

Preoperative abnormal P and QTc dispersion intervals in patients with metabolic syndrome

We evaluated P wave dispersion (Pwd), QT, corrected QT (QTc), QT dispersion, and corrected QT dispersion (QTcd) intervals in patients with metabolic syndrome (MetS). Patients scheduled to undergo elective noncardiac surgery were included in the study. The main diagnoses, anthropometric measurements, waist circumferences, body mass index, electrocardiograms, serum levels of electrolytes, glucose, and lipids were recorded for all patients. QTc, QTcd intervals were determined with the Bazett formula. MetS (group M, n = 36) was diagnosed using the Adult Treatment Panel III. Controls (group C, n = 40) were chosen on the basis of patients with no MetS and matched for age and gender. There were no differences between groups in terms of age, sex, or serum electrolyte levels (P > 0.05). Waist circumferences, body mass index, serum glucose, and triglyceride values in group M were significantly higher than those in group C (P < 0.001). In group M, Pwd, QTc, QT dispersion and QTcd intervals were significantly longer than those in group C (P < 0.001). This finding and our retrospective analysis suggest that these patients may be at greater risk of perioperative arrhythmias.

Pericardial fat is associated with prevalent atrial fibrillation: the Framingham Heart Study

BACKGROUND

Obesity represents an important risk factor for atrial fibrillation (AF). We tested the hypothesis that pericardial fat, a unique fat deposit in close anatomic proximity to cardiac structures and autonomic fibers, is associated with prevalent AF.

METHODS AND RESULTS

Participants from the Framingham Heart Study underwent multidetector computed tomography from 2002 to 2005. We estimated the association between quantitative pericardial, intrathoracic and visceral adipose tissue volumes (per standard deviation of volume) with prevalent AF adjusting for established AF risk factors (age, sex, systolic blood pressure, blood pressure treatment, PR interval, and clinically significant valvular disease). Of the 3217 eligible participants (mean age, 50.6+/-10.1 years; 48% women), 54 had a confirmed diagnosis of AF. Pericardial fat but not intrathoracic or visceral abdominal fat was associated with prevalent AF in multivariable-adjusted models (odds ratio per standard deviation of pericardial fat volume, 1.28; 95% confidence intervals, 1.03 to 1.58). Further adjustments for body mass index, heart failure, myocardial infarction, and intrathoracic fat volume did not materially change the association between pericardial fat and AF.

CONCLUSIONS

Pericardial fat was associated with prevalent AF even after adjustment for AF risk factors, including body mass index. If this association is replicated, further investigations into the mechanisms linking pericardial fat to AF are merited.

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.

P-wave duration and dispersion in patients with metabolic syndrome

BACKGROUND

Metabolic syndrome (MS) has been reported to be associated with an increased risk of atrial fibrillation (AF). The aim of this study was to investigate P-wave dispersion (PWD) in patients with MS.

METHODS

The study population included 66 patients with MS (21 men, 45 women; mean age, 49.7 +/- 9.1 years) and 63 control subjects without MS (26 men, 37 women; mean age, 47.0 +/- 10.6 years). The diagnosis of MS was based on the National Cholesterol Education Program Adult Treatment Panel III criteria. A 12-lead electrocardiogram was recorded for each subject. The difference between maximum and minimum P-wave duration was calculated and defined as PWD. An echocardiographic examination was also performed for each subject.

RESULTS

Maximum P-wave duration and PWD were found to be significantly higher in patients with MS compared with the control subjects (Maximum P-wave duration: 113.5 +/- 9.7 ms vs 101.0 +/- 8.1 ms, PWD: 37.8 +/- 7.6 vs 23.3 +/- 5.9, respectively, P < 0.001 for both). However, there was no statistically significant difference between two groups regarding minimum P-wave duration (75.6 +/- 6.9 ms vs 77.6 +/- 7.8 ms, respectively, P = 0.18). In addition, PWD was positively correlated with age, body mass index, waist circumference, systolic and diastolic blood pressure, triglyceride level, deceleration time, isovolumetric relaxation time and negatively correlated with high-density lipoprotein cholesterol level and early-to-late diastolic velocity ratio.

CONCLUSION

We have shown that patients with MS have higher PWD, indicating increased risk for AF, compared to the control subjects without MS.

Perindopril decreases P wave dispersion in patients with stage 1 hypertension

INTRODUCTION

Angiotensin-converting enzyme inhibitors prevent atrial fibrillation episodes by effective control of blood pressure and improving electrical and structural remodelling in the atria. Increased P wave dispersion (PWD) is a non-invasive electrocardiographic marker for paroxysmal atrial fibrillation. The aim of the study was to evaluate the effect of perindopril treatment on PWD in hypertensive patients.

METHODS

Forty-eight hypertensive patients (mean age 57.4+/-11.8 years, 18 men) were included. Blood pressure values were determined and 12-lead electrocardiograms were recorded at the beginning and at the first week, first month, third month and sixth month of the perindopril treatment.The difference between maximum and minimum P wave durations was calculated as PWD.

RESULTS

PWDs were significantly shortened at the first, third and sixth months (41.7+/-8.8 ms, 39.1+/-6.9 ms and 38.3+/-7.1 ms, respectively) compared with baseline and first-week measurements (54.3+/-9.2 ms and 49.0+/-9.1 ms, respectively, p<0.001). Baseline PWD was correlated with body mass index (r=0.32, p=0.026), while PWD at the sixth month of treatment was significantly correlated with left atrial volume index (r=0.30, p=0.042). Multiple linear regression analysis revealed that PWD at the sixth month was related to baseline PWD (p=0.001).

CONCLUSION

Perindopril treatment significantly reduced PWD in hypertensive patients.

Effect of anaesthetic agents on p-wave dispersion on the electrocardiogram: comparison of propofol and desflurane

Anaesthetics influence cardiac electrical activity by various mechanisms; thus, they may have pro-arrhythmic or anti-arrhythmic actions. Increased P-wave dispersion is associated with a risk of paroxysmal atrial fibrillation. The aim of the present study was to analyse the impact of propofol and desflurane on changes in P wave dispersion, which may reflect the anti-arrhythmic effects of these drugs. Fifty patients undergoing scheduled surgery were included in the study. Patients were divided into two equal groups: a propofol group and a desflurane group. Patients in the propofol group were initially administered 2.5 mg/kg propofol, followed by infusion of 6 mg/kg per h propofol. Anaesthesia in the desflurane group was achieved using inhalation induction, with concentrations up to 8-12.5 vol%. When signs of adequate anaesthesia were observed, the concentration of desflurane was reduced to 6 vol%. An electrocardiogram (ECG) was obtained before induction and then again 1, 3 and 5 min after the initiation of propofol infusion or the induction of anaesthesia in the desflurane group; additional measurements were performed after tracheal intubation. P-wave dispersion was assessed by differences in maximal and minimal P-wave duration on a 12-lead ECG. P-wave dispersion did not change over time in the desflurane group. In the propofol group, there was a significant decrease in P-wave dispersion after 3 and 5 min of anaesthesia. Significant differences were observed between study groups after 1, 3 and 5 min of anaesthesia, and disappeared after tracheal intubation. Mean and maximal P-wave duration did not change in either group. In conclusion, propofol decreases P-wave dispersion and this seems to be connected with the anti-arrhythmic properties of the drug.