Atrial Electromechanical Interval Research Articles

Evaluation of atrial fibrillation risk in patients with vasovagal syncope.

This study aimed to determine whether autonomic dysfunction in patients with vasovagal syncope with a positive tilt test may cause an alteration in atrial electromechanical properties and pose a risk for subsequent atrial arrhythmias, especially atrial fibrillation. The data of 27 patients with vasovagal syncope and a matched control group comprising 28 healthy individuals were compared. All patients underwent a tilt table test. Atrial electromechanical intervals (PA) were measured from the mitral lateral annulus, mitral septal annulus, and tricuspid annulus with tissue Doppler imaging. Left atrium volumes were measured with the disc method in apical four-chamber imaging. Although atrial electromechanical intervals such as lateral PA, septal PA, and tricuspid PA durations were significantly longer (p = 0.009, p = 0.002, p = 0.011, respectively), interatrial, right intra-atrial, and left intra-atrial durations were similar in the vasovagal syncope group and the control group (p = 0.298, p = 0.388, p = 0.069, respectively). Left atrial volumes (maximum, minimum, and presystolic) were significantly increased in the vasovagal syncope group when compared with the control group (p = 0.001, p = 0.001, p = 0.007, respectively). There was no difference between vasovagal syncope types in terms of atrial electromechanical intervals. Interatrial and intra-atrial intervals were similar in the vasovagal syncope group and the control group. However, an increase in atrial volumes and a prolongation of certain atrial electromechanical intervals were observed in patients with vasovagal syncope. These findings suggest an alteration in atrial electromechanics caused by autonomic dysfunction that can lead to subsequent atrial arrhythmias, especially atrial fibrillation.

Atrial electromechanical delay and p wave dispersion associated with severity of chronic obstructive pulmonary disease.

The aim of this study was to evaluate atrial electromechanical delay (AEMD) with both electrocardiography (ECG) and echocardiography in patients with Chronic Obstructive Pulmonary Disease (COPD). Total of 110 patients were included in this cross-sectional case-control study. P-wave dispersion (PWD) was measured on a 12-lead ECG. Atrial electromechanical intervals (PA) were measured as the time interval between the onset of the P wave on the ECG and the beginning of the late diastolic A wave. PWD was found to be 40.9±9.2 ms in the healthy control group, 45.6±8.2 ms in the mild COPD and 44.8±8.7 ms in the severe COPD group (p<0.05). Intra-right atrial EMD was found to be 10.7±5.8 ms in mild COPD, 11.0±7 ms in severe COPD, and it was 16.4±7.3 ms in healthy control group (p<0.001). Interatrial EMD was detected to be 29.5±9.1 ms in the control group, 24.1±9 ms in mild COPD group, and 23.9±11.1 ms in the severe COPD group (p<0.001). Both mild and severe COPD groups decreased PWD, increased tricuspid PA and significantly decreased interand right intra-AEMD times in comparison to the control group.

Detection of atrial electromechanical dysfunction in obesity.

Obesity is associated with atrial fibrillation and is known as an independent risk factor. The aim of our study was to investigate if there was any association between the body mass index and atrial electromechanical intervals in obese and non-obese patients. Seventy patients were enrolled in the study. Body mass index (BMI), functional capacity, and fasting blood sugar were evaluated; then, these patients were divided into two groups, patients who had a BMI ≥ 30 were known as obese (35 patients) and those who had a BMI < 30 were known as non-obese patients. All patients were evaluated by transthoracic echocardiography. LA volumes were measured by the discs method in the apical four-chamber view. LA active and passive emptying volumes and fraction were calculated. Using TDI, atrial electromechanical coupling (PA) was measured from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum), and right ventricular tricuspid annulus (PA tricuspid). LA diameter was significantly higher in obese patients (P = 0.021). LA passive emptying volume and fraction were significantly decreased in obese patients (P = 0.038 and P = 0.011). LA active emptying volume and fraction were significantly increased in obese patients (P = 0.001 and P = 0.001). Left intraatrial and interatrial electromechanical delay were significantly higher in obese patients (18.9 ± 3.8 vs 11.9 ± 2.0, P < 0.001 and 29.5 ± 4.1 vs 17.9 ± 2.5, P < 0.001). Also interatrial electromechanical delay correlated positively with BMI. This study revealed that delayed atrial electromechanical interval and impaired LA mechanical functions were related to BMI in obese-patients. These findings may be an early sign of subclinical atrial dysfunction and arrhythmias in obese patients.

Efficacy of atorvastatin in prevention of atrial fibrillation after heart valve surgery in the PROFACE trial (PROphylaxis of postoperative atrial Fibrillation After Cardiac surgEry)

BackgroundTo evaluate the efficacy of perioperative atorvastatin administration for prophylaxis of postoperative atrial fibrillation (POAF) after heart valve surgery. MethodsOur study included 90 patients with heart valve disease who were scheduled to undergo elective cardiac surgery. Cases with previous AF or preoperative beta-blocker therapy were excluded. Patients were randomized into the atorvastatin group, which included 47 patients who received 40mg/day of atorvastatin 7 days before and after the surgery and the control group, which included 43 patients. Primary endpoint was the occurrence of POAF. Secondary endpoints included modifications in the preoperative and postoperative levels of the markers of inflammation (C-reactive protein [CRP]), myocardial injury (ultrasensitive troponin T and creatinine phosphokinase MB [CPK-MB]), and cardiac dysfunction (pro-brain natriuretic peptide [proBNP]) related to POAF and changes in the echocardiographic parameters, such as atrial electromechanical interval, A wave, E/A ratio, and Doppler imaging systolic velocity wave amplitude, related to POAF. ResultsNo relationship between atorvastatin administration and reduction in the incidence of POAF was observed (42.6% in the atorvastatin vs. 30.2% in the control group) (p=0.226). No difference in the levels of CPK-MB, ultrasensitive troponin T, CRP, or proBNP and in the analyzed echocardiographic parameter was detected between both groups. ConclusionsAtorvastatin in the described dose, was not adequate for the prophylaxis of POAF after heart valve surgery. It was ineffective in controlling the inflammatory phenomena, myocardial injury, and echocardiographic predictors of POAF.

Assessment of atrial electromechanical interval using echocardiography after catheter ablation in patients with persistent atrial fibrillation.

We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler (PW) and pulse tissue Doppler imaging (PW-TDI). A total of 25 consecutive in-patients with persistent atrial fibrillation, who restored sinus rhythm after ablation procedure, were recruited in our cardiac center. Echocardiography was performed on each patient at 2 hours, 1 day, 5 days, 1 month and 3 months after the ablation therapy, and atrial electromechanical delay was measured simultaneously by PW and PW-TDI. There was no significant difference between PW and TDI in measuring atrial electromechanical delay. However, at postoperative 2 hours, peak A detection rates were mathematically but nonsignificantly greater by PW-TDI than by PW. Second, there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months, but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time. Lastly, patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval, by the PW or by PW-TDI, respectively. In patients with persistent atrial fibrillation, atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later, and was significantly related to patients’ duration of atrial fibrillation. Atrial electromechanical interval, as a potential predicted factor, is recommended to be measured by either PW or TDI after 24 hours, when patients had recovered sinus rhythm by radiofrequency ablation.

Detection of atrial electromechanical dysfunction in obesity

Introduction Obesity is associated with atrial fibrillation and is known as an independent risk factor. The aim of our study was to investigate if there was any association between the body mass index and atrial electromechanical intervals in obese and non-obese patients.Methods Seventy patients were enrolled in the study. Body mass index (BMI), functional capacity, and fasting blood sugar were evaluated; then, these patients were divided into two groups, patients who had a BMI ≥ 30 were known as obese (35 patients) and those who had a BMI < 30 were known as non-obese patients. All patients were evaluated by transthoracic echocardiography. LA volumes were measured by the discs method in the apical fourchamber view. LA active and passive emptying volumes and fraction were calculated. Using TDI, atrial electromechanical coupling (PA) was measured from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum), and right ventricular tricuspid annulus (PA tricuspid).Results LA diameter was significantly higher in obese patients (P = 0.021). LA passive emptying volume and fraction were significantly decreased in obese patients (P = 0.038 and P = 0.011). LA active emptying volume and fraction were significantly increased in obese patients (P = 0.001 and P = 0.001). Left intraatrial and interatrial electromechanical delay were significantly higher in obese patients (18.9 ± 3.8 vs 11.9 ± 2.0, P < 0.001 and 29.5 ± 4.1 vs 17.9 ± 2.5, P < 0.001). Also interatrial electromechanical delay correlated positively with BMI.Conclusion This study revealed that delayed atrial electromechanical interval and impaired LA mechanical functions were related to BMI in obese patients. These findings may be an early sign of subclinical atrial dysfunction and arrhythmias in obese patients.

67. Clinical and echocardiographic predicators of postoperative atrial fibrillation

Background Postoperative atrial fibrillation is the most common arrhythmia after coronary artery bypass grafting, with a reported incidence of 10–60%. Preoperative clinical and echocardiographic data, especially the atrial electromechanical interval, predict postoperative atrial fibrillation in elective coronary artery bypass patients. Methods A prospective study evaluated preoperative clinical and echocardiographic data in 192 patients who underwent elective coronary artery bypass from 2010 to 2012. Results 18 (9.37%) patients developed postoperative atrial fibrillation. Compared to patients without postoperative atrial fibrillation, these 18 had significantly longer intensive care unit and hospital stays, they were significantly older (58.62±10.02 vs. 53.22±8.23years; p 3 , p p −1 ; p p Conclusion Older hypertensive patients are at higher risk of developing postoperative atrial fibrillation. Preoperative measurement of atrial electromechanical interval by tissue Doppler echocardiography is a useful predictor of postoperative atrial fibrillation in coronary artery bypass patients.

Evaluation of left atrial mechanical function and atrial conduction abnormalities in Maras powder (smokeless tobacco) users and smokers.

SummaryObjectiveIn Turkey, a type of smokeless tobacco called Maras powder (MP) is widely used in the south-eastern region. Smokeless tobacco is found in preparations for chewing and for absorption by the nasal and oral mucosae. The purpose of this study was to investigate whether MP damages intra- and inter-atrial conduction delay and left atrial (LA) mechanical function as much as cigarette smoking.MethodA total of 150 chronic MP users (50 males, 32.5 ± 5.4 years), smokers (50 males, 32.1 ± 6.0 years) and controls (50 males, 30.1 ± 5.8 years) were included in the study. LA volumes were measured echocardiographically according to the biplane area–length method. Atrial electromechanical coupling was measured with tissue Doppler imaging and LA mechanical function parameters were calculated.ResultsThe LA passive emptying fraction was significantly decreased and LA active emptying volume (LAAEV) was significantly increased in the MP group (p = 0.012 and p = 0.024, respectively), and the LA active emptying fraction (LAAEF) was significantly increased in the smokers (p = 0.003). There was a positive correlation between the amount of MP used and smoking (pack years) with LAAEV and LAAEF (r = 0.26, p = 0.009 and r = 0.25, p = 0.013, respectively). Lateral atrial electromechanical intervals (PA) were significantly higher in MP users, and the septal mitral PA was statistically higher in the smokers (p = 0.05 and p = 0.04, respectively).ConclusionWe suggest that atrial electromechanical coupling intervals were prolonged and LA mechanical function was impaired in MP users and smokers, but there was no significant difference between the MP users and smokers. These findings may be markers of subclinical cardiac involvement and tendency for atrial fibrillation.

Relationship between CHA2DS2-VASc score and atrial electromechanical function in patients with paroxysmal atrial fibrillation: A pilot study

BackgroundCHA2DS2-VASc score is the most widely preferred method for prediction of stroke risk in patients with atrial fibrillation. We hypothesized that CHA2DS2-VASc score may represent atrial remodeling status, and therefore echocardiographic evaluation of left atrial electromechanical remodeling can be used to identify patients with high risk. MethodsA total of 65 patients who had documented diagnosis of paroxysmal atrial fibrillation (PAF) were divided into three risk groups according to the CHA2DS2-VASc score: patients with low risk (score=0, group 1), with moderate risk (score=1, group 2), and with high risk score (score ≥2, group 3). We compared groups according to atrial electromechanical intervals and left atrium mechanical functions. ResultsAtrial electromechanical intervals including inter-atrial and intra-atrial electromechanical delay were not different between groups. However, parameters reflecting atrial mechanical functions including LA phasic volumes (Vmax, Vmin and Vp) were significantly higher in groups 2 and 3 compared with group 1. Likewise, LA passive emptying volume (LATEV) in the groups 2 and 3 was significantly higher than low-risk group (14.12±8.13ml/m2, 22.36±8.78ml/m2, 22.89±7.23ml/m2, p: 0.031). Univariate analysis demonstrated that Vmax, Vmin and Vp were significantly correlated with CHA2DS2-VASc score (r=0.428, r=0.456, r=0.451 and p<0.001). Also, LATEV (r=0.397, p=0.016) and LA active emptying volume (LAAEV) (r=0.281, p=0.023) were positively correlated with CHA2DS2-VASc score. In the ROC analysis, Vmin≥11ml/m2 has the highest predictive value for CHA2DS2-VASc score ≥2 (88% sensitivity and 89% specificity; ROC area 0.88, p<0.001, CI [0.76–0.99]). ConclusionEchocardiographic evaluation of left atrial electromechanical function might represent a useful method to identify patients with high risk.

Assessment of atrial electromechanical interval and P wave dispersion in patients with polycystic ovary syndrome.

Objective:Polycystic ovary syndrome (PCOS) is associated with increased cardiovascular risk, including ischemic stroke. Prolonged atrial electromechanical interval (EMI) is related to increased atrial fibrillation (AF) risk. The aim of the study is to evaluate atrial EMI and electrocardiographic P-wave indices related to increased AF risk in patients with PCOS.Methods:Forty PCOS patients diagnosed on the basis of the Rotterdam criteria and 20 age-matched controls were prospectively included. patients with atrioventricular or intraventricular conduction abnormalities, dysrhythmia or taking antiarrhythmic drugs, atherosclerotic heart disease, cardiomyopathies, valvular lesions, pericardial disease, a history of pulmonary emboli or pulmonary hypertension, and abnormal thyroid function were excluded. Intra and interatrial EMI were measured by tissue Doppler imaging and P-wave dispersion (Pd) was calculated on 12-lead electrocardiography (ECG). The Isovolumetric relaxation time was the interval between the aortic valve closure artifact at the end of the LV outflow envelope and the mitral valve opening artifact at the beginning of the mitral E wave.Results:Patients with PCOS had significantly higher interatrial [38 (24-65) ms vs. 16 (9-19) ms p<0.001], left-sided intra-atrial (14.8±6.1 vs. 7±1.7 ms, p<0.001), and right-sided intra-atrial (22.3±8.1 vs. 8.6±3.6 ms, p<0.001) EMI compared with the control group. Pd was significantly greater in the PCOS group compared with control group [45 (27-60) ms vs. 30 (26–38) ms, p<0.001]. Echocardiographic parameters of atrial EMI were significantly correlated with body mass index, Pd, and isovolumetric relaxation time in patients with PCOS.Conclusion:PCOS is associated with prolonged inter- and intra-atrial conduction times, which are related to increased AF risk.

Atrial conduction times and left atrium mechanical functions in patients with active acromegaly.

The aim of this study was to evaluate atrial electromechanical delay (EMD), P wave dispersion (Pwd), and left atrial (LA) mechanical functions in patients with active acromegaly. Twenty-three patients with active acromegaly and 27 age- and sex-matched controls were included in this study. All atrial electromechanical interval parameters (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) were measured from mitral lateral annulus, mitral septal annulus, and right ventricular tricuspid annulus by tissue Doppler imaging. LA volumes were measured by the disk method in the apical four-chamber view and were indexed to the body surface area. Mechanical function parameters of LA were calculated. Pwd was performed by 12-lead electrocardiograms. Atrial electromechanical intervals (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) and Pwd were similar between patients with acromegaly and control subjects (all p>0.05). LA volumes (maximum, minimum, and presystolic) and LA mechanical functions were not significantly different between the groups (all p>0.05). Additionally, serum levels of growth hormone and insulin-like growth factor-1 were not correlated with atrial electromechanical parameters and LA mechanical functions. Atrial electrical conduction times were not prolonged and LA mechanical functions were not impaired in patients with active acromegaly compared with controls. And the prevalence of supraventricular arrhythmia risk may not increase in this population.

The association between atrium electromechanical interval and pericardial fat.

ObjectivesPericardial fat (PCF) may induce local inflammation and subsequent structural remodeling of the left atrium (LA). However, the adverse effects of PCF on LA are difficult to be evaluated and quantified. The atrial electromechanical interval determined by transthoracic echocardiogram was shown to be a convenient parameter which can reflect the process of LA remodeling. The goal of the present study was to investigate the association between the electromechanical interval and PCF.Methods and ResultsA total of 337 patients with mean age of 51.9±9.0 years were enrolled. The electromechanical interval (PA-PDI) defined as the time interval from the initiation of the P wave deflection to the peak of the mitral inflow A wave on the pulse wave Doppler imaging was measured for every patient. The amount of PCF was determined by multi-detector computed tomography. The PA-PDI interval was significantly correlated with the amount of PCF (r = 0.641, p value <0.001). Graded prolongation of PA-PDI interval was observed across 3 groups of patients divided according to the tertile values of PCF. The AUC for the PA-PDI interval in predicting an increased amount of PCF (third tertile) was 0.796. At a cutoff value of 130 ms identified by the ROC curve, the sensitivity and specificity of PA-PDI interval in identifying patients with a highest tertile of PCF were 63.4% and 85.3%, respectively.ConclusionsThe PA-PDI intervals were longer in patients with an increased amount of PCF. It may be a useful parameter to represent the degree of PCF-related atrial remodeling.

Changes over time in echocardiographic variables and atrial electromechanical intervals after ablation for atrial fibrillation

IntroductionAcute and mid-term effects of ablation for atrial fibrillation (AF) on left atrial (LA) and left ventricular (LV) function and the atrial electromechanical interval are controversial. MethodsEchocardiographic variables and the PA-TDI interval (time from ECG lead II P-wave onset to lateral a′ wave on tissue Doppler tracings, indicating the total atrial conduction time [TACT]) were evaluated in 33 paroxysmal AF patients before, 1 day, and 3, 6, and 12 months after ablation. ResultsDuring a 12-month follow-up, 10 (30.3%) patients had recurrent AF, associated with a greater baseline LA volume (LAV) (48.4±19.3mm3 vs. 38.7±11.4mm3, P=0.0811) and PA-TDI interval (163.9±11.0ms vs. 151.1±14.6ms, P=0.0189) than in patients without AF recurrence. By 6 months after ablation, LAV had decreased progressively in the non-recurrence group (27.9±8.1mm3, P<0.0001 vs. baseline), but the decrease was modestly significant in the recurrence group (36.3±7.5cm3, P=0.0380). LV ejection fraction (LVEF) modestly increased 1 day after ablation in both groups and remained unchanged in the non-recurrence group (67.9±8.1% at baseline to 70.5±5.9% at 12 months, P=0.1711), whereas it decreased gradually below the baseline value in the recurrence group (68.2±11.3% to 60.9±13.6%, P=0.1025). The PA-TDI interval did not change during follow-up in either group, but remained longer in the recurrence group. ConclusionsThe PA-TDI interval may be useful for predicting post-ablation AF recurrences. The patterns of time-course changes in LAV, LVEF, and TACT differ, but the effects of ablation were better in patients without AF recurrence after ablation.

OP-033 Assessment of Atrial Electromechanical Interval and P-Wave Dispersion in Patients with Polycystic Ovary Syndrome

Objective: Polycystic ovary syndrome (PCOS) is associated with increased cardiovascular risk, including ischemic stroke. Prolonged atrial electromechanical interval (EMI) is related to increased atrial fibrillation (AF) risk. The aim of the study is to evaluate atrial EMI and electrocardiographic P-wave indices related to increased AF risk in patients with PCOS. Methods: Forty patients with PCOS and 20 age-matched controls were included. Intra and interatrial EMI were measured by tissue Doppler imaging and P-wave dispersion (Pd) was calculated on 12-lead electrocardiography (ECG). Results: Patients with PCOS had significantly higher interatrial [38 (24-65) ms vs. 16 (9-19) ms p<0.001], left-sided intra-atrial (14.8±6.1 vs. 7±1.7 ms, p<0.001), and right-sided intra-atrial (22.3±8.1 vs. 8.6±3.6 ms, p<0.001) EMI compared with the control group. Pd was significantly greater in the PCOS group compared with control group [45 (27-60) ms vs. 30 (26–38) ms, p<0.001]. Echocardiographic parameters of atrial EMI were significantly correlated with body mass index, Pd, and isovolumetric relaxation time in patients with PCOS. Conclusion: PCOS is associated with prolonged interand intra-atrial conduction times, which are related to increased AF risk. (Anatol J Cardiol 2015; 15(0): 000-000)

Clinical and echocardiographic predicators of postoperative atrial fibrillation.

Postoperative atrial fibrillation is the most common arrhythmiaafter coronary artery bypass grafting,with a reported incidence of 10% to 60%. Preoperative clinical and echocardiographic data, especially the atrial electromechanical interval, predict postoperative atrial fibrillation in elective coronary artery bypass patients. A prospective study evaluated preoperative clinical and echocardiographic data in 192 patients who underwent elective coronary artery bypass from 2010 to 2012. 18 (9.37%) patients developed postoperative atrial fibrillation. Compared to patients without postoperative atrial fibrillation, these 18 had significantly longer intensive care unit and hospital stays, they were significantly older (58.62 ± 10.02 vs. 53.22 ± 8.23 years; p = 0.02), with a larger left atrial volume (83.39 ± 8.31 vs. 55.47 ± 8.37 cm(3), p = 0.001), longer atrial electromechanical interval (133.67 ± 8.15 vs. 98.05 ± 6.71 ms p < 0.0001), and lower tissue Doppler imaging systolic velocity wave amplitude (6.6 ± 1 vs. 9.4 ± 2.2 cm·s(-1); p = 0.001); they also had a higher prevalence of hypertension (61.11% vs. 38.5%; p = 0.04). Using 115 ms as the cutoff value of atrial electromechanical interval enabled us to detect patients who developed postoperative atrial fibrillation with 100% sensitivity, 77% specificity, 78% positive predictive value, and 100% negative predictive value. Older hypertensive patients are at higher risk of developing postoperative atrial fibrillation. Preoperative measurement of atrial electromechanical interval by tissue Doppler echocardiography is a useful predictor of postoperative atrial fibrillation in coronary artery bypass patients.

Detection of atrial electrical and mechanical dysfunction in non-dipper pre-hypertensive subjects

Introduction: A relationship between atrial conduction time and hypertension was shown in previous studies. Increased atrial electromechanical intervals used to predict atrial fibrillation by measured tissue Doppler imaging (TDI). So we aimed to search if there was any association between the non-dipping status and atrial electromechanical intervals in pre-hypertensive patients.Methods: Forty-one non-dipper and 33 dipper pre-hypertensive subjects enrolled in the study. Systolic and diastolic blood pressures were measured with a mercury sphygmomanometer. Twenty-four hours blood pressure was measured with cuff-oscillometric method. All patients were evaluated by transthoracic echocardiography. Using tissue Doppler imaging (TDI), atrial electromechanical coupling (PA) was measured from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum) and right ventricular tricuspid annulus (PA tricuspid).Results: Systolic and diastolic blood pressures were significantly higher in subjects with non-dipper phenomenon than dipper ones at night. Twenty-four hours average systolic and diastolic blood pressures were higher in non-dipper pre-hypertensive subjects, but this elevation was not significant. Left and right intraatrial (PA lateral-PA septum and PA septum-PA tricuspid) and interatrial (PA lateral-PA tricuspid) electromechanical coupling intervals were measured significantly higher in non-dipper pre-hypertensive patients (31.3 ± 3.9 versus 24.1 ± 2.3, p = 0.001; 19.5 ± 4.3 versus 13.8 ± 2.1, p = 0.001; and 11.4 ± 2.8 versus 8.8 ± 1.5, p = 0.001). Also, interatrial electromechanical delay was negatively correlated with dipping levels.Conclusion: This study showed that prolonged atrial electromechanical intervals were related non-dipper pattern in pre-hypertensive patients. Prolonged electromechanical intervals may be an early sign of subclinical atrial dysfunction and arrhythmias’ in non-dipper pre-hypertensive patients.

Atrial electromechanical interval may predict cardioembolic stroke in apparently low risk patients with paroxysmal atrial fibrillation

Purpose: Considerable number of patients with atrial fibrillation (AF) develop cardioembolic stroke (CE) despite low CHADS2 score. We examined the possibility that use of the atrial electromechanical interval (AEMI) improves prediction of CE in patients with paroxysmal AF (PAF), particularly those with low CHADS2 score. Methods: We consecutively enrolled 122 patients with nonvalvular PAF (72±10 years, 83 men) and 52 healthy subjects as controls (70±6 years, 27 men). The PAF patients were divided into two groups depending on presence (n=43) or absence (n=79) of history of CE. Left atrial (LA) volume index (LAVI), peak myocardial velocity during late diastole (a') and AEMI (defined as time from onset of P-wave to onset of lateral a') were measured. Results: Patients with PAF had significantly larger LAVI (p 32 ml/m2 for LA volume index, 73 msec for AEMI. Using these thresholds, sensitivities and specificities of prediction of patients with PAF were 58% and 75% for LAVI, 49% and 75% for lateral a', 82% and 90% for AEMI, respectively. The sensitivity of AEMI for prediction of patients with PAF were significantly higher (p<0.05) than those of LAVI and lateral a'. Multivariate logistic regression analysis indicated that age (p<0.05), CHADS2 score (p<0.01), use of β-blockers (p<0.05), use of antiarrhythmic drugs (p<0.05), and AEMI (p<0.05), but not LAVI or a', were independently associated with history of CE in PAF patients. In PAF patients categorized into low risk by CHADS2 score (i.e.,CHADS2 score = 0 or 1, n=61), those with prolonged AEMI (≥82 msec) had significantly higher rates of CE than those with <82 msec (45% vs. 15%, p<0.05). Conclusions: As compared with echocardiographic parameters of LA size and LA function, AEMI appears to be more useful for identifying PAF patients. AEMI may enable to detect high risk PAF patients, especially those categorized into low risk by CHADS2 score.

Atrial Electromechanical Interval May Predict Cardioembolic Stroke in Apparently Low Risk Elderly Patients with Paroxysmal Atrial Fibrillation

A considerable number of patients with atrial fibrillation (AF) develop cardioembolic stroke (CE) despite low CHADS2 score. We examined the possibility that use of the atrial electromechanical interval (AEMI) improves prediction of CE in patients with paroxysmal AF (PAF), particularly those with low CHADS2 score. We consecutively enrolled 108 patients with nonvalvular PAF and 52 healthy subjects as controls. The PAF patients were divided into 2 groups depending on presence (n = 36) or absence (n = 72) of the history of CE. Left atrial (LA) volume index (LAVI), peak myocardial velocity during late diastole (a'), and AEMI as time from onset of P-wave to onset of lateral a' were measured. Patients with PAF had significantly larger LAVI, longer AEMI, and lower lateral a' than those in controls. Area under the curves for LAVI, lateral a', and AEMI for identifying patients with PAF were 0.70, 0.69, and 0.88, respectively. Multivariate logistic regression analysis indicated that age, use of antiarrhythmic drugs, and AEMI, but not LAVI or a', were independently associated with history of CE in patients with PAF. PAF patients were categorized into low risk by CHADS2 score (i.e. CHADS2 score = 0 or 1, n = 60), those with prolonged AEMI (>82 msec) had significantly higher rates of CE than those with ≤ 82 msec (48% vs. 15%, P < 0.05). As compared with echocardiographic parameters of LA size and LA function, AEMI appears to be more useful for identifying PAF patients. AEMI may enable to detect high risk PAF patients, especially those categorized into low risk by CHADS2 score.

Prolonged Atrium Electromechanical Interval Is Associated with Stroke in Patients with Atrial Fibrillation After Catheter Ablation

Atrial fibrillation (AF) is associated with increased risk of embolic stroke. Catheter ablation of AF provides an effective therapy for patients with symptomatic and drug-refractory AF. The aim of this study was to evaluate whether the atrial electromechanical interval is useful in identifying patients at risk of stroke after successful catheter ablation. A total of 279 AF patients who received catheter ablation and showed no evidence of recurrences were enrolled. Electromechanical interval (PA-PDI) was determined as the time interval from the initiation of P wave deflection to the peak of mitral inflow A wave on pulse wave Doppler imaging. The PA-PDI interval was measured for each patient after the 3-month blanking period of catheter ablation. The clinical endpoint was the occurrence of ischemic stroke. During the follow-up of 46.5 ± 17.2 months, 6 patients suffered from ischemic strokes. Patients with strokes had higher CHA2DS2-VASc scores and longer PA-PDI intervals (138.7 ± 12.4 ms vs 161.2 ± 7.7 ms, P value < 0.001) compared to those without strokes. At a cutoff point of 150 ms identified by ROC curve, the positive and negative predictive values of the PA-PDI interval to predict stroke were 86.7% and 100%, respectively. The PA-PDI interval improved the predictive performance of the CHA2DS2-VASc score, and the area under the ROC curve increased from 0.75 to 0.85. Our results suggest that the PA-PDI interval is a useful tool to identify patients with high risk of stroke after successful catheter ablation of AF.

Detection of subclinical atrial dysfunction by two-dimensional echocardiography in patients with overt hyperthyroidism

Hyperthyroidism is an important cardiovascular risk factor in the development of atrial fibrillation and heart failure. Increased atrial electromechanical intervals are used to predict atrial fibrillation, measured by tissue Doppler imaging (TDI). To evaluate atrial electromechanical delay (EMD) and left atrial (LA) mechanical function in patients with overt hyperthyroidism. Thirty-four patients with overt hyperthyroidism and 34 controls were included. A diagnosis of overt hyperthyroidism was reached with decreased serum thyroid-stimulating hormone (TSH) and increased free T4 (fT4) concentrations. Using TDI, atrial electromechanical coupling (PA) was obtained from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum) and right ventricular tricuspid annulus (PA tricuspid). LA volumes (maximum, minimum and presystolic) were measured by the disks method in apical four-chamber view and indexed to body surface area. LA active and passive emptying volumes and fractions were calculated. LA diameter was significantly higher in hyperthyroid patients (P=0.001). LA passive emptying volume and fraction were significantly decreased in hyperthyroid patients (P=0.038 and P<0.001). LA active emptying volume and fraction were significantly increased in hyperthyroid patients (P<0.001 and P<0.001). Left and right intra-atrial (PA lateral-PA septum and PA septum-PA tricuspid) and interatrial (PA lateral-PA tricuspid) EMDs were significantly higher in hyperthyroid patients (29.2 ± 4.4 vs 18.1 ± 2.6, P<0.001; 18.7 ± 4.3 vs 10.6 ± 2.0, P<0.001; and 10.5 ± 2.9 vs 7.1 ± 1.2, P<0.001, respectively). Stepwise linear regression analysis demonstrated that fT4 and TSH concentrations were independent predictors of interatrial EMD (β=0.436, P<0.001 and β=-0.310, P=0.005, respectively). This study showed prolonged atrial electromechanical intervals and impaired LA mechanical function in patients with overt hyperthyroidism, which may be an early sign of subclinical cardiac involvement and dysrhythmias in overt hyperthyroidism.