Intra-atrial Conduction Time Research Articles

Increased inter-atrial and intra-atrial conduction times in pediatric patients with non-alcoholic fatty liver disease.

The global incidence of pediatric non-alcoholic fatty liver disease (NAFLD) is rising, and it is linked to various potentially dangerous complications such as cardiovascular complications, particularly atrial fibrillation (AF). Atrial electromechanical conduction delay (EMD) has been reported as an early predictor for AF development. This study aimed to explore the link between NAFLD and the increased risk of AF development. This cross-sectional study was performed on 100 newly diagnosed NAFLD children (aged 14-18 years) as the patient group and 100 healthy individuals as a control group. Transthoracic echocardiography and simultaneous electrocardiography (ECG) recording were employed to estimate atrial electromechanical properties. EMD values were calculated for the inter-atrial, left intra-atrial, and right intra-atrial. Our results showed that pediatric patients with NAFLD exhibited significantly prolonged EMD values in the left and right intra-atrial as well as in inter-atrial regions compared to the control group (P = 0.03, P < 0.001, P < 0.01, respectively). Conclusion: Children with NAFLD show atrial electromechanical alterations that may presage AF in adulthood.

Study of P wave dispersion in patients with paroxysmal atrial fibrillation and its role in prediction of atrial fibrillation recurrence

BackgroundIt has been known that increased P wave duration and P wave dispersion reflect prolongation of intra-atrial 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. The objective of this study was assessment of P wave dispersion value in cases with paroxysmal atrial fibrillation and its role in predicting recurrence.ResultsForty-eight patients with documented paroxysmal AF were subjected to clinical evaluation, electrocardiogram and routine Doppler echocardiogram. We found that a statistically significant association was detected between P wave dispersion and older age, diabetic and hypertensive cases with positive correlation also detected with left atrial dimension (LAD), left ventricle size and diastolic dysfunction grade. Mean corrected P wave dispersion and corrected QT interval were higher among cases using sotalol, ca channel blockers, among cases using nitrates and among cases with Morris index > 0.04. Higher mean value of corrected QT was associated with biphasic P v1 shape. Old age, female sex, P wave dispersion and QT wave dispersion are statistically significant predictors of PAF recurrence.ConclusionP wave dispersion in patients with paroxysmal atrial fibrillation was strongly correlated to older age, diabetic and hypertensive patients and also with left atrial dimension (LAD), left ventricle size and diastolic dysfunction grade. Also, mean corrected P wave dispersion can predict atrial fibrillation recurrence in patients with Morris index > 0.04, old age, female sex, and QT wave dispersion.

Long-term outcomes after catheter ablation for idiopathic atypical atrial flutter

BackgroundIdiopathic atypical (non–cavotricuspid isthmus–dependent) atrial flutter (IAAFL) may be seen in patients without structural heart disease and without previous cardiac surgery or ablation. ObjectiveThis study sought to determine the patient characteristics, electrophysiologic and electroanatomic properties, and clinical outcomes after ablation in patients with IAAFL. MethodsWe retrospectively compared IAAFL patients with cavotricuspid isthmus–dependent AFL (C-AFL) patients undergoing catheter ablation. The primary outcome was a composite of death from cardiovascular causes, ischemic stroke, and hospitalization for worsening of heart failure. ResultsOf 180 patients who underwent catheter ablation for AFL, 89 were included in this study (22 IAAFL and 67 C-AFL). Electrophysiologic study showed significantly longer intra-atrial conduction time and lower atrial voltage during sinus rhythm in the IAAFL group compared with the C-AFL group. The atrial scar was observed in all 22 IAAFL patients, with the most common sites being the posterior or lateral wall of the right atrium in 10 (45.5%) and the anterior wall of the left atrium in 8 (36.4%). During 3.5 ± 2.8 years of follow-up, the composite primary end point occurred significantly more frequently in the IAAFL group (hazard ratio [HR], 3.45; 95% confidence interval [CI], 1.20–9.89; P = .015). In multivariable analysis, brain natriuretic peptide levels (HR, 1.01; 95% CI, 1.00–1.01, per 1 pg/mL; P = .01) and IAAFL (HR, 4.14; 95% CI, 1.21–14.07; P = .02) were independently associated with the primary outcome. ConclusionIAAFL in patients had distinct electrophysiologic features suggestive of atrial cardiomyopathy. These patients are at risk for development of cardiovascular adverse events after ablation.

Simultaneous assessment of mechanical and electrical function in Langendorff-perfused ex-vivo mouse hearts.

The Langendorff-perfused ex-vivo isolated heart model has been extensively used to study cardiac function for many years. However, electrical and mechanical function are often studied separately-despite growing proof of a complex electro-mechanical interaction in cardiac physiology and pathology. Therefore, we developed an isolated mouse heart perfusion system that allows simultaneous recording of electrical and mechanical function. Isolated mouse hearts were mounted on a Langendorff setup and electrical function was assessed via a pseudo-ECG and an octapolar catheter inserted in the right atrium and ventricle. Mechanical function was simultaneously assessed via a balloon inserted into the left ventricle coupled with pressure determination. Hearts were then submitted to an ischemia-reperfusion protocol. At baseline, heart rate, PR and QT intervals, intra-atrial and intra-ventricular conduction times, as well as ventricular effective refractory period, could be measured as parameters of cardiac electrical function. Left ventricular developed pressure (DP), left ventricular work (DP-heart rate product) and maximal velocities of contraction and relaxation were used to assess cardiac mechanical function. Cardiac arrhythmias were observed with episodes of bigeminy during which DP was significantly increased compared to that of sinus rhythm episodes. In addition, the extrasystole-triggered contraction was only 50% of that of sinus rhythm, recapitulating the "pulse deficit" phenomenon observed in bigeminy patients. After ischemia, the mechanical function significantly decreased and slowly recovered during reperfusion while most of the electrical parameters remained unchanged. Finally, the same electro-mechanical interaction during episodes of bigeminy at baseline was observed during reperfusion. Our modified Langendorff setup allows simultaneous recording of electrical and mechanical function on a beat-to-beat scale and can be used to study electro-mechanical interaction in isolated mouse hearts.

The Effects of Laparoscopic Sleeve Gastrectomy on Cardiac Diastolic Function, Aortic Elasticity, and Atrial Electromechanics Delay.

Obesity is a well-known risk factor for cardiovascular diseases. The aim of this study was to prospectively investigate the short-term effects of laparoscopic sleeve gastrectomy (LSG) on cardiac functions. Forty-four morbidly obese patients who underwent LSG were included in the study. The aortic systolic and diastolic diameters, left ventricular (LV) diameter, LV cardiac output and cardiac index, LV ejection fraction, LV septal and lateral wall velocities, deceleration time of the E wave, the LA volume index and atrial mechanic functions, and atrial conduction times were evaluated. The patients' aortic stiffness index showed a significant improvement at postoperative control: 3.23 ± 0.58, 2.49 ± 0.36; p<0.001 for preoperative and postoperative aortic stiffness index, respectively. A significant reduction was observed in the LV mass and relative wall thickness (RWT) of the patients: 182.41 ± 36.87 g, 154.85 ± 24.32 g; p<0.001 and 0.42 ± 0.07, 0.39 ± 0.05; p=0.010 for the preoperative and postoperative LV mass and RWT, respectively. A statistically significant decrease was observed in total atrial conduction time and interatrial and intraatrial conduction time in the postoperative period: 120.95 ± 22.27 ms, 106.57 ± 20.46 ms; p=0.001; 13.82 ± 8.21 ms, 10.66 ± 6.78 ms; p=0.038, and 29.64 ± 14.18 ms, 24.09 ± 10.95 ms; p=0.047 for preoperative and postoperative total atrial conduction time, intraatrial electromechanical delay, and interatrial electromechanical delay, respectively. Weight loss reduced aortic stiffness, IVS and posterior wall thickness, LAV, LAVi, LA passive emptying fraction, and atrial electromechanical delays in morbidly obese patients.

Atrial conduction explains the occurrence of the P-wave dispersion phenomenon, but weakly.

BackgroundP‐wave dispersion (PWD) is believed to be caused by inhomogeneous atrial conduction. This statement, however, is based on limited little solid evidence. The aim of this study was to determine the relationship between atrial conduction and PWD by means of invasive electrophysiological studies.MethodsCross‐sectional study in 153 patients with accessory pathways and atrioventricular node reentry tachycardia (AVNRT) undergoing an electrophysiological study. Different atrial conduction times were measured and correlated with PWD.ResultsOnly the interatrial (P‐DCS) and left intra‐atrial conduction times (ΔDCS‐PCS) showed a significant correlation with PWD, but this correlation was weak. Multivariate linear regression analysis determined that both P‐DCS (β = 0.242; P = .008) and ΔDCS‐PCS (β = 0.295; P < .001) are independent predictors of PWD. Performing the multivariate analysis for arrhythmic substrates, it is observed that only ΔDCS‐PCS continued to be an independent predictor of PWD. Analysis of the receiver operating characteristic curves showed that regardless of the types of arrhythmic substrates, PWD discriminates significantly, but moderately, to patients with P‐DCS and ΔDCS‐PCS ≥75 percentile.ConclusionsInteratrial and intraleft atrial conduction times were directly and significantly correlated with PWD, but only weakly, and were independent predictors of PWD. In general, PWD correctly discriminates patients with high values in interatrial and intraleft atrial conduction times, but moderately. This is maintained in cases with accessory pathways; however, in patients with AVNRT it only does so for intraleft atrial conduction times. Interatrial and intraleft atrial conduction times weakly explains PWD.

Ranolazine depresses conduction of rapid atrial depolarizations in a beating rabbit heart model.

Previous clinical studies have shown that ranolazine (RAN) added to amiodarone (AMIO) might accelerate the termination of recent-onset atrial fibrillation. This study was undertaken to delineate possible mechanisms that contribute to the enhancement of the antiarrhythmic efficacy of RAN-AMIO coadministration. Ten rabbits were anesthetized and two monophasic action potential (MAP) catheters were sequentially inserted into the right atrium. One MAP electrode was used to pace and record; the other electrode was used only for recording MAP from an adjacent atrial region. Intraatrial conduction time (IACT), 2:1 intraatrial conduction block (IACB), and atrial post-repolarization refractoriness (aPRR) were consecutively determined by high-rate atrial burst pacing and programmed stimulation, respectively. All parameters were evaluated during baseline and following AMIO (3 mg/kg iv) or AMIO+RAN (2.4 mg/kg iv bolus +0.134 mg/kg/min maintenance infusion). The IACT remained unchanged post AMIO compared with baseline (37.6 ± 3.8 vs 36.4 ± 2.4 ms), whereas the addition of RAN to AMIO significantly prolonged IACT (50.4 ± 3.6 ms, p < .001). The pacing cycle length producing 2:1 IACB was 101.2 ± 21.7 ms at baseline , 117.5 ± 15 ms after AMIO (p = 0.265), and 150 ± 14 ms after AMIO+RAN (p < .001). Baseline aPRR was longer following AMIO treatment (35 ± 5 vs 50 ± 9 ms, p < .01) but remarkably prolonged with RAN supplementation (105 ± 11 ms, p < .001). RAN significantly prolonged the propagation time of rapid atrial depolarizations and potentiated the AMIO-induced moderate increases in aPRR. These mechanisms possibly contribute to the earlier termination of atrial fibrillation when RAN is co-administered with AMIO.

Interatrial conduction time is early marker of disturbed impulse propagation in adults with slightly elevated blood pressure

Background/Aim. Interatrial conduction time is early marker of disturbed impulse propagation in adult with elevated blood pressure. The aim of our study was to evaluate significance of noninvasive echocardiographic marker of slow sinus impulse propagation (atrial conduction time) for the identification of persons with slightly elevated blood pressure and hypertension in adults. Methods. One hundred and forty nine adults with normal and elevated blood pressure were studied: 46 normotensive adults (group 1), 28 adults with elevated blood pressure and hypertension stage 1 (group 2) and 75 adults with hypertension stage 2 (group 3), based on the Joint National Committee 8 (JNC-8) hypertension guidelines. We studied P wave dispersion, reservoir function of the left atrium (LA), total emptying volume of the LA and total emptying fraction of the LA (LATEF). The atrial conduction time (ACT) was evaluated by the pulsed tissue Doppler, and expressed as interatrial and intraatrial conduction time. Results. The LATEF decreased progressively from the group 3 (64.8 ? 4.4%) to the group 2 (59.8 ? 5.2%) and the group 1 (55.6 ? 7.3%) (p &lt; 0.001). The P wave dispersion (55.1 ? 9.8 ms vs. 46.8 ? 3.1 ms vs. 43.1 ? 2.6 ms; p &lt; 0.01) and intra ACT were significantly prolonged only in the group 3 compared to the other groups (22.7 ? 11.0 ms vs. 8.4 ? 4.7ms vs. 5.6 ? 2.4 ms, respectively; p &lt; 0.001). Inter ACT significantly increased from the group 1 to the group 2 and the group 3 (15.6 ? 3.9 ms vs. 24.6 ? 5.7 ms vs. 50.4 ? 20 ms, respectively; p &lt; 0.05). Using a cut-off level of 19.5 ms, inter ACT could separate adults in the group 2 from the group 1 with a sensitivity of 85%, and specificity of 89% [area under receiver operating characteristic (ROC) curve 0.911]. Conclusion. Prolonged ACT estimated with the tissue Doppler may be useful for identification persons with slighty elevated blood pressure, and hypertension stage 1.

Electrophysiological Cardiac Parameters and Results of Antiarrhythmic Treatment in Patients with Paroxysmal Atrial Fibrillation (Lone and Associated with Arterial Hypertension)

to assess cardiac electrophysiological parameters in patients with paroxysmal atrial fibrillation (AF), lone or with concomitant arterial hypertension (AH), and their prognostic significance relative to treatment effectiveness. We included in this study 184 patients with paroxysmal AF (84 with concomitant AH and 100 with presumed lone AF). Cardiac electrophysiological study was performed in accordance with standardized protocol that included assessment of sinus node recovery time, sinoatrial, intraatrial and interatrial conduction time, and effective refractory periods (ERP) of right and left atria and atrioventricular node. Patients with inducible supraventricular reentrant arrhythmias that could potentially trigger AF underwent catheter radiofrequency ablation of those arrhythmias. Other patients received either antiarrhythmic drug therapy (AAD; n=79) or catheter cryo-ablation (CBA; n=81). Treatment was considered ineffective in case of any symptomatic or asymptomatic AF episode documented by ECG or Holter ECG within 12 months of follow-up. Patients with lone AF compared with those with AH had shorter ERP of the right atrium (219±21 ms vs. 253±44 ms, respectively, p&lt;0.05) and more prominent dispersion of ERP of right and left atria (median 40 ms, interquartile range 10-50 ms vs. median 20 ms, interquartile range 10-22.5 ms, respectively, p&lt;0.05). There was no statistically significant difference in other electrophysiology parameters between the groups. Sustained supraventricular reentrant arrhythmias were induced in 9% (9 of 100) patients with presumed lone AF and in 1.2% (1 of 84) patients with AH (p&lt;0.05). All these arrhythmias were successfully ablated, and patients had no AF recurrence during 12-month follow-up. Among other patient treatment (CBA n=81, AAD n=79) was effective in 64% of those with lone AFib and in 34% - with AH (p&lt;0.05). In multivariate multiple regression analysis, none of electrophysiological parameters could be assumed as a factor associated with the efficacy of CBA or AAD. Patients with lone AF had more prominent atrial electrophysiological inhomogeneity compared with patients with concomitant AH. Cardiac electrophysiological parameters had no influence on effectiveness of antiarrhythmic treatment.

The effect of moderate altitude on Tp-e interval, Tp-e/QT, QT, cQT and P-wave dispersion

IntroductionLong-time exposure to high altitude leads to changing at the respiratory, cardiovascular and hematological systems. There is no sufficient study about cardiovascular changes in moderate altitude. The distance between the peak and the end of the T wave (Tp-e) is a measure of transmyocardial distribution of repolarization and may be associated to dangerous rhythm disorders and ventricular arrhythmias. Again, P-wave dispersion (PWD) described as the extension of interatrial and intraatrial conduction time and inhomogeneous spread of sinus pulses are well recognized electrophysiologic features in patients with atrial fibrillation. We aimed to compare repolarization parameters (Tp-e interval, Tp-e/QT ratio, QT, cQT) and P wave dispersion between healthy people living at moderate altitude and sea level. MethodsIn this study included 80 healthy people living at moderate altitude (1600 m, Group I) and 90 people living at sea level (0–4 m, Group II). All people were born and grew up at the same altitude area. Being migrant to living area, people with structural heart disease, rhythm disorders, pulmonary diseases or any systemic chronic disease were excluded criteria in the study. Tp-e interval, QT interval, cQT, Tp-e/QT ratio, P wave durations and PWD were measured from D2 and V5 leads with 20 mm/mV amplitude and 50 mm/s rate. All the measurements were repeated three times and were evaluated manually with a magnifying glass. ResultsThere were no differences in baseline demographic, laboratory, echocardiographic parameters and coronary artery risk factors. The QRS duration (94.2 ± 14.8 msn and 90.2 ± 9.3 msn, p = 0.05) and corrected QT time (415.8 ± 20.1 msn and 403.9 ± 20.5 msn; p = 0.001), Tp-e interval (86.5 ± 11.7 msn and 80.5 ± 10.4 msn p = 0.001) and Tp-e/QT ratio (0.23 ± 0.03 msn and 0.22 ± 0.03 msn p = 0.011) were statistically significantly higher in the moderate altitude group. P wave maximum, minimum time and PWD were similar in both groups (p > 0.05). ConclusionModerate altitude leads to subclinical electrocardiographic changes in healthy individuals such as high altitude. Repolarization parameters (Tp-e interval, Tp-e/QT ratio, and cQT) are prolonged without cardiac structural changes. It should be kept in mind that people living in moderate altitude may be more susceptible to arrhythmia in the future, and findings should be supported in large randomized trials.

P-Wave Morphology, Amplitude, Duration and Dispersion in Atrial Arrhythmias

The detailed analysis of the P-wave duration and dispersion by means of conventional electrocardiography with the 12 standard surface leads in the stratification of patients suffering from AF is a recognized universal approach. P-wave dispersion (PWD) has received increasing attention in the field of non-invasive electrophysiology studying atrial arrhythmias and has been examined in a broad range of clinical settings including cardiovascular and non-cardiovascular diseases. It is well accepted that, not only the P-wave duration, but also the P-wave morphology and dispersion have the potential to give information about the anatomical substrate predisposing to AF. Patients with diseased atrial myocardium with fibrotic changes may develop abnormal electrophysiological alterations. Therefore, these atrial anisotropic characteristics may play an important role in creating reentry circuits by causing inhomogeneous and discontinuous propagation of the impulse in the atrial tissue. The altered atrial myocardium may generate unidirectional block, conduction delay and reentrant atrial rhythms. The P-wave of the electrocardiogram may show alterations that can be associated with atrial arrhythmias and AF. PWD is considered a noninvasive electrocardiographic marker for atrial remodeling and predictor for AF. It has been shown that increased P-wave duration and PWD reflect prolongation of intra-atrial and inter-atrial conduction time. In patients prone to develop atrial arrhythmias and AF, PWD reflects prolonged, inhomogeneous and anisotropic distribution of connections between myocardial fibers resulting in discontinuous anisotropic propagation of sinus impulses and atrial conduction. PWD is considered as a sensitive and specific ECG marker and predictor of atrial arrhythmias and paroxysmal AF.

Simulated Obstructive Sleep Apnea Increases P-Wave Duration and P-Wave Dispersion.

BackgroundA high P-wave duration and dispersion (Pd) have been reported to be a prognostic factor for the occurrence of paroxysmal atrial fibrillation (PAF), a condition linked to obstructive sleep apnea (OSA). We tested the hypothesis of whether a short-term increase of P-wave duration and Pd can be induced by respiratory manoeuvres simulating OSA in healthy subjects and in patients with PAF.Methods12-lead-electrocardiography (ECG) was recorded continuously in 24 healthy subjects and 33 patients with PAF, while simulating obstructive apnea (Mueller manoeuvre, MM), obstructive hypopnea (inspiration through a threshold load, ITH), central apnea (AP), and during normal breathing (BL) in randomized order. The P-wave duration and Pd was calculated by using dedicated software for ECG-analysis.ResultsP-wave duration and Pd significantly increased during MM and ITH compared to BL in all subjects (+13.1ms and +13.8ms during MM; +11.7ms and +12.9ms during ITH; p<0.001 for all comparisons). In MM, the increase was larger in healthy subjects when compared to patients with PAF (p<0.05).ConclusionIntrathoracic pressure swings through simulated obstructive sleep apnea increase P-wave duration and Pd in healthy subjects and in patients with PAF. Our findings imply that intrathoracic pressure swings prolong the intra-atrial and inter-atrial conduction time and therefore may represent an independent trigger factor for the development for PAF.

Prolongation of atrio-ventricular node conduction in a rabbit model of ischaemic cardiomyopathy: Role of fibrosis and connexin remodelling

Conduction abnormalities are frequently associated with cardiac disease, though the mechanisms underlying the commonly associated increases in PQ interval are not known. This study uses a chronic left ventricular (LV) apex myocardial infarction (MI) model in the rabbit to create significant left ventricular dysfunction (LVD) 8weeks post-MI. In vivo studies established that the PQ interval increases by approximately 7ms (10%) with no significant change in average heart rate. Optical mapping of isolated Langendorff perfused rabbit hearts recapitulated this result: time to earliest activation of the LV was increased by 14ms (16%) in the LVD group. Intra-atrial and LV transmural conduction times were not altered in the LVD group. Isolated AVN preparations from the LVD group demonstrated a significantly longer conduction time (by approximately 20ms) between atrial and His electrograms than sham controls across a range of pacing cycle lengths. This difference was accompanied by increased effective refractory period and Wenckebach cycle length, suggesting significantly altered AVN electrophysiology post-MI. The AVN origin of abnormality was further highlighted by optical mapping of the isolated AVN. Immunohistochemistry of AVN preparations revealed increased fibrosis and gap junction protein (connexin43 and 40) remodelling in the AVN of LVD animals compared to sham. A significant increase in myocyte–non-myocyte connexin co-localization was also observed after LVD. These changes may increase the electrotonic load experienced by AVN muscle cells and contribute to slowed conduction velocity within the AVN.

Cryptogenic ischemic stroke and silent atrial fibrillation: What is the relationship?

Atrial fibrillation (AF) is responsible for up to one-third of ischemic strokes and associated with silent cerebral infarctions and transient ischemic attacks. Any method that predicts the stroke or unmasks the silent PAF would contribute to the treatment of ischemic stroke. Intraatrial conduction time (ICT) has been shown to be associated with intermittent AF. In this study, we evaluated the value of ICT detected by transthoracic echocardiography in normal population and in patients with cryptogenic stroke (CS) as a risk factor for stroke. The patients with CS and with normal left ventricular function without valvular disease are included in group 1. Patients with atypical symptoms admitted to cardiology clinics without any risk factor for cardiac disease and found to be normal constituted group 2. Age, gender, weight, height, echocardiographic parameters and ICT were compared between groups. 63 and 64 subjects were included in group 1 and 2, respectively. Two groups were similar according to age and gender. Among the parameters studied, left atrial diameter and height of the patients were significantly higher in group 1 (40 ± 2 vs 37 ± 4 mm, p < 0.001 and 167 ± 9 vs 163 ± 9 cm p = 0.027, respectively). ICT was significantly higher in group 1 (131 ± 15 vs 118 ± 13 ms, respectively, p < 0.000). According to ROC analysis, a cut point of 124 ms for ICT with a sensitivity of 74 % and specificity of 73 % in patients with CS (p < 0.001). This study show us, the measurements the ICT determined by means of echocardiography is longer in patients with CS. This simple and noninvasive technique can be applied widely and lead the clinicians to adopt the use of diagnostic and the treatment procedures.

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.

Left atrial and left atrial appendage functional recovery after cardioversion in patients with recent atrial fibrillation: Serial echocardiographic study.

The aim of this study is to point out timing of left atrium and its appendage functional recovery after cardioversion (CV) in recent onset atrial fibrillation (AF). Fifty patients; 27 within 48-h (group I) and 23 after 48-h (group II), of AF onset, who had successful CV underwent transthoracic echocardiography (TTE), before and immediately after CV, then 15, 30 and 90 days later. Transesophageal echocardiography (TEE) was performed for group II before and for all patients immediately after CV and 1 month later. Mitral peak A velocity and left atrial (LA) reversal (Ar) velocity, tissue Doppler imaging (TDI) of septal mitral annular velocity (A1) and LA free wall velocity (A3) were recorded. Absence or peak A velocity < 50 cm/s was taken as a cut off value for atrial stunning. Intra-atrial conduction time (IACT) was measured. LA appendage late emptying (LAALE) velocity was measured by TEE-pulsed TDI of LA appendage. Post CV, all group II and 34% of group I experienced stunning. In both groups, peak A, Ar, A1, A3 and LAALE velocities increased (p = 0.000), while IACT decreased (p = 0.000) progressively over time. Partial recovery occurred after 15 and 30 days, while full recovery occurred 30 and 90 days post CV in groups I and II, respectively. IACT1 and IACT2 correlated with LA diameter (r = 0.2778 and r = 0.227, respectively, p < 0.01). Stunning and functional recovery of the LA and its appendage are strongly determined by the duration being in AF. Serial IACT by TDI was a good new parameter for detection of functional recovery of LA and LA appendage.

Evaluation of atrial electromechanical conduction delay in case of hemodynamically insignificant rheumatic heart disease: A tissue Doppler study.

Atrial electromechanical delay (AEMD) that reflects delayed conduction may show us the clinical reflection of pathological changes in the atria. The main objective of the present study is to investigate AEMD in patients who had previous rheumatic carditis but without hemodynamically significant valvular disease. A total of 40 patients, previously diagnosed as rheumatic carditis but without significant valvular stenosis/regurgitation and atrial enlargement; and 39 age- and-sex matched controls were enrolled for the present study. Parameters of AEMD (lateral mitral annulus electromechanical delay, septal mitral annulus electromechanical delay and lateral tricuspid annulus electromechanical delay) were measured with tissue Doppler echocardiography and left intra-atrial and inter-atrial conduction times were calculated accordingly. A 24h ambulatory Holter monitoring was used in both groups to detect atrial fibrillation episodes and quantify atrial extrasystoles. Parameters of AEMD, including left intra-atrial and inter-atrial conduction times of subjects in the study group were longer compared to the control group (23.7 ± 7.0 vs. 18.3 ± 6.2). Increased AEMD is observed in patients with previous rheumatic carditis and no significant valvular stenosis/regurgitation and atrial enlargement, which may partly explain the increased incidence of atrial fibrillation observed in these patients.

Atrial conduction time, and left atrial mechanical and electromechanical functions in patients with polycystic ovary syndrome : interatrial conduction delay : cardiovascular topics

SummaryBackgroundPolycystic ovary syndrome (PCOS) is one of the most common endocrine disorders of women during the reproductive period. Cardiovascular risk factors are more frequent in patients with PCOS. We aimed to investigate the P-wave dispersion (Pd), inter- and intra-atrial conduction time and mechanical functions of the left atrium (LA) in patients with PCOS.MethodsForty-eight patients with PCOS and 38 normal healthy women were enrolled in this study. A 12-lead surface electrocardiogram was used to evaluate Pd. Left ventricular (LV) functions were measured using conventional and tissue Doppler imaging (TDI) methods. Inter- and intra-atrial conduction times were measured by TDI. LA volumes were measured echocardiographically with the biplane area–length method from the apical four-chamber view.ResultsHeart rate (82.02 ± 13.15 vs 74.24 ± 11.02 bpm, p = 0.014) and Pd were significantly increased in the PCOS patients [27 ± 5 vs 24 ± 6 ms, p = 0.035]. Transmitral E/A ratio was significantly lower in the PCOS patients than in the controls (1.5 ± 0.3 vs 1.7 ± 0.4 m/s, p = 0.023). Passive emptying volume (12.54 ± 4.39 vs 15.28 ± 3.85 ml/m2, p = 0.004) and passive emptying fraction [54.4 (21–69) vs 59.1% (28–74), p = 0.008] were significantly decreased in PCOS patients. Total emptying volume was significantly decreased (17.9 ± 5.49 vs 20.67 ± 4.29 ml/m2, p = 0.018) in PCOS patients. Interatrial (19 ± 7.4 vs 15 ± 6.4 ms, p = 0.035) and intra-atrial [8.5 (1–19) vs 5 ms (1–20), p = 0.026] electromechanical delays were found to be significantly higher in PCOS patients.ConclusionThis study showed that patients with PCOS had increased inter- and intra-atrial conduction delays, and decreased LA passive emptying volumes and fractions.

Atrial conduction abnormalities in patients with psoriasis vulgaris.

Psoriasis vulgaris is one of the most common chronic inflammatory skin disorders. Patients with psoriasis are at risk of developing atrial fibrillation (AF). The electromechanical delay (EMD) is the time interval from the onset of the P wave on surface electrocardiography (ECG) to the beginning of the A wave. Prolonged atrial EMD is an independent risk factor for the development of AF. This study investigated the intra- and interatrial EMD in patients with psoriasis. This study included 85 adults with psoriasis vulgaris (Group 1) and 46 age- and sex-matched healthy individuals (Group 2). ECGs were obtained from all subjects, and atrial EMD variables were calculated. Results are reported as means ± standard deviations and percentages. Continuous variables were analysed using Student's t-test. A p-value < 0.05 was considered statistically significant. Interatrial electromechanical delay (IA-EMD) and intra-left atrial electromechanical delay (ILA-EMD) were significantly longer in the psoriasis group compared with controls. A correlation analysis between psoriasis severity (PASI score) and the atrial conduction parameters revealed a significant positive correlation between PASI and IA-EMD (r = 0.261, p < 0.001). In addition, there was a positive correlation between high-sensitivity C-reactive protein (hsCRP) and IA-EMD (p = 0.022). The atrial conduction time was longer in patients with psoriasis vulgaris and it correlated with the severity of disease and hsCRP. Since the association between delayed conduction and AF is known, the measurement of intra-atrial conduction times could be a practical tool to estimate the AF risk in these patients.

Transmural dispersion of repolarization and atrial electromechanical coupling: complementary indices for quantifying cardiac electrical heterogeneity in patients with conversion disorder.

Dear editor We read with great interest the article entitled “P-wave and QT dispersion in patients with conversion disorder” by Izci et al1 in Therapeutics and Clinical Risk Management. In this well designed research, Izci et al studied QT dispersion (QTd) and P-wave dispersion (Pd) in patients with conversion disorder (CD). In conclusion, they reported that corrected QT (QTc) and QTd values were significantly altered in patients with CD when compared to healthy controls, but that there was no significant difference in terms of Pd. It has been postulated that the relationship between somatoform disorders and CD is related to altered autonomic functions.2 These changes may affect the refractory period and conduction velocity of the heart. In line with these assumptions, heterogeneity in the duration of the ventricular repolarization phase leading to arrhythmias may also be seen in patients with CD. As in this study, QTd is the most frequently used parameter to detect ventricular inhomogeneity. However, reproducibility of QT interval measurements is low in both manual and automatic measurements and interobserver and intraobserver variability of QTd is very high.3,4 Quantifying the inhomogeneity of the myocardium, transmural dispersion of repolarization (TDR) has also been used since the beginning of the 2000s in addition to QTd.5 There are three types of myocyte, ie, endocardial, epicardial, and midmyocardial M cells, each having different electrophysiological properties in the ventricular myocardium. Mid-myocardial M cells have typically the longest repolarization phase. The repolarization phase of the midmyocardial M cells continues until the end of the T-wave. However, the repolarization phase of the epicardial cells ends at the peak of the T-wave. The time between the peak and end of the T-wave is known as the Tp-e interval, and is an index of the TDR.5 In addition, the Tp-e/QT ratio has also been used as an electrical dispersion index for the myocardium, showing arrhythmic risk. The role of the TDR in evaluation of arrhythmic risk has been demonstrated in coronary artery disease and in the Brugada, short QT, and long QT syndromes. Previously, we showed that the Tp-e interval was increased in patients with obstructive sleep apnea.6 On the other hand, the basic electrophysiological characteristics of the atrium that predispose to atrial arrhythmias are prolongation of intra-atrial and interatrial conduction times and heterogeneous propagation of sinus impulses. Pd is an accepted marker of atrial depolarization heterogeneity and the altered propagation of sinus impulses found to be associated with increased risk of atrial fibrillation. Although prolonged Pd values were found to be correlated with atrial fibrillation, it is controversial whether Pd is related to heterogeneity of atrial conduction or to other factors. Furthermore, reproducibility of P-wave measurements is low in both manual and automatic measurements and interobserver and intraobserver variability is very high. Atrial electromechanical coupling (AEC) can be assessed by electrocardiography-integrated tissue Doppler imaging and provides a means to determine the atrial mechanical and electrical event. Analysis of AEC by tissue Doppler imaging allows precise analysis of AEC between different regions. Moreover, measurement of AEC may suggest an inhomogeneous propagation of sinus impulses in different cardiac sites. Autonomic dysregulation and altered sympathovagal balance, as in somatoform disorders, may account for heterogeneity in atrial conduction properties. Measurement of AEC has been done in patients with psoriasis, ankylosing spondylitis, hyperthyroidism, end-stage renal disease, and hypertension.7–9 Regarding these observations, autonomic imbalance may cause atrial depolarization and sinus impulse propagation abnormalities leading to altered AEC. Our opinion is that, if AEC intervals had been measured in this study, they may have been found to be altered in patients with CD. Further, regarding the forementioned observations, if Izci et al had measured the Tp-e interval and Tp-e/QT ratio in their study, they might have found an increased TDR in their patients with CD. Considering all the data about Pd, AEC, QTd, and TDR, their study might have revealed the effects of CD on electrical heterogeneity of the myocardium more completely in many respects.