Intra- and interatrial asynchrony in patients with heart failure

Research progress on the predictive value of electrocardiographic indicators in the diagnosis and prognosis of children with vasovagal syncope

Neurally mediated syncope (NMS) is a common type of syncope in children in clinical practice, among which vasovagal syncope (VVS) is the most frequent. In recent years, more and more studies have been carried out to assess the diagnosis and prognosis of VVS. The electrocardiographic indicators such as heart rate variability (HRV), QT dispersion (QTd), P-wave dispersion (Pd), ventricular late potentials (VLP), deceleration ability of heart rate (DC), etc., are easy to obtain and inexpensive. With the help of electrocardiographic indicators, the diagnostic procedure and individualized treatment strategies of pediatric VVS can be optimized. This article reviews the value of electrocardiographic indicators in the diagnosis and prognosis of children with VVS.

Assessment of right atrial dyssynchrony by 2D speckle-tracking in healthy young men following high altitude exposure at 4100 m

Background

High altitude exposure induces overload of right-sided heart and may further predispose to supraventricular arrhythmia. It has been reported that atrial mechanical dyssynchrony is associated with atrial arrhythmia. Whether high altitude exposure causes higher right atrial (RA) dyssynchrony is still unknown. The aim of study was to investigate the effect of high altitude exposure on right atrial mechanical synchrony.

Methods

In this study, 98 healthy young men underwent clinical examination and echocardiography at sea level (400 m) and high altitude (4100 m) after an ascent within 7 days. RA dyssynchrony was defined as inhomogeneous timing to peak strain and strain rate using 2D speckle-tracking echocardiography.

Results

Following high altitude exposure, standard deviation of the time to peak strain (SD-TPS) [36.2 (24.5, 48.6) ms vs. 21.7 (12.9, 32.1) ms, p<0.001] and SD-TPS as percentage of R–R’ interval (4.6 ± 2.1% vs. 2.5 ± 1.8%, p<0.001) significantly increased. Additionally, subjects with higher SD-TPS (%) at high altitude presented decreased right ventricular global longitudinal strain and RA active emptying fraction, but increased RA minimal volume index, which were not observed in lower group. Multivariable analysis showed that mean pulmonary arterial pressure and tricuspid E/A were independently associated with SD-TPS (%) at high altitude.

Conclusion

Our data for the first time demonstrated that high altitude exposure causes RA dyssynchrony in healthy young men, which may be secondary to increased pulmonary arterial pressure. In addition, subjects with higher RA dyssynchrony presented worse RA contractile function and right ventricular performance.

Tissue Doppler-derived atrial dyssynchrony predicts new-onset atrial fibrillation during hospitalization for ST-elevation myocardial infarction

BACKGROUND

Atrial dyssynchrony, but not atrial enlargement/dysfunction, reflects acute atrial histopathological changes. It has been shown to be associated with new-onset atrial fibrillation (NOAF) in various clinical conditions but was not studied in the acute phase of ST-elevation myocardial infarction (STEMI) which is the aim of the current study.

METHODS

A total of 440 STEMI patients underwent primary percutaneous coronary intervention (PCI) and were monitored for NOAF during hospitalization. Immediately after primary PCI, P-wave dispersion was calculated and conventional/tissue Doppler echocardiography was done.

RESULTS

During a median hospitalization period of 3 days, 80 (18.2%) patients developed NOAF. The group with NOAF showed significantly higher prevalence of hypertension (P = .049), higher P-wave dispersion (P = .018), higher post-PCI-corrected TIMI frame count (P < .001), and lower incidence of post-PCI myocardial blush grade 2-3 (P = .031). Indexed left atrial maximum volume (LAVI_max ), left atrial dyssynchrony, and inter-atrial dyssynchrony were significantly higher in NOAF group (P < .001, each). Using ROC curve analysis, inter-atrial dyssynchrony showed the highest diagnostic performance (AUC 85%, 95% CI: 0.77-0.94, P < .001). A cutoff value at 23.8 ms showed a good validity for predicting NOAF with a sensitivity of 93.8% and a specificity of 68.1%. Using binary logistic regression analysis, history of hypertension (OR = 10.72, P = .03), LAVI_max (OR = 7.47, P = .04), and inter-atrial dyssynchrony (OR = 45.58, P = .001) were independent determinants of NOAF.

CONCLUSIONS

In the acute phase after STEMI, history of hypertension, LAVI_max, and inter-atrial dyssynchrony were independent determinants of inhospital NOAF, with the latter being the strongest.

Atrial Dyssynchrony: A New Predictor for Atrial High-Rate Episodes in Patients with Cardiac Resynchronization Therapy

Background: Heart failure may induce atrial dyssynchrony. We aim to investigate whether preimplantation left atrial (LA) dyssynchrony could predict newly detected atrial high-rate episodes (AHRE) after receiving cardiac resynchronization therapy defibrillator (CRT-D). Methods: We conducted a retrospective analysis of consecutive patients who received CRT-D for standard indications and without a history of atrial fibrillation. The standard deviation of the time-to-peak strain in each LA segment during ventricular systole (SDs) and late diastole (SDa) were calculated to quantify LA dyssynchrony using two-dimensional speckle tracking echocardiography before device implantation. Patients were divided into the AHRE group and the AHRE-free group, depending on the presence of AHRE during device interrogation. Results: Thirty-one patients (28%) had newly detected AHRE during a mean follow-up of 21 ± 9 months. Patients in the AHRE group had higher SDs (8.2 ± 2.6% vs. 6.3 ± 2.3%, p < 0.001) and SDa (5.4 ± 1.8% vs. 4.1 ± 1.4%, p < 0.001) values before implantation than patients in the AHRE-free group. In the multivariate logistic analysis, both SDs (OR 1.325, 95% CI: 1.074–1.636, p =0.009) and SDa (OR: 1.499, 95% CI: 1.071–2.098, p= 0.018) were independent predictors of newly detected AHRE. At a cutoff value of 7.4% for SDs and 5.3% for SDa, the Kaplan-Meier survival analysis showed that patients with higher SDs and SDa had significantly increased risks of newly detected AHRE after receiving CRT-D. Conclusions: Dyssynchronous LA lengthening and contraction could assist in the prediction of newly detected AHRE in patients with CRT-D.

Relationship of left atrial mechanics to electrical activity on surface electrocardiography in idiopathic dilated cardiomyopathy

Aim: (1) Assess left atrial (LA) mechanics and electromechanical delay in patients with idiopathic dilated cardiomyopathy (IDCM), and (2) examine the relationship between atrial electromechanical delay and atrial electrical activity [P-wave duration, P-wave dispersion (PWD) and P terminal force (PTF)] on surface ECG. Methods: 73 IDCM patients (age 36  ±  17 years); 63% men,25 age & sex matched healthy subjects were studied. LA atrial electromechanical delay & mechanics (ε_sys, SR_sys, SR_e, SR_a) were measured with 2D-strain. From 12-lead electrocardiograms, P-wave duration, PWD and PTF calculated. Results: Reservoir, conduit and contractile functions were predominantly reduced compared to control (P < 0.001). Intra-atrial electromechanical delay was 88.9 ± 84.6 in IDCM versus 27.4 ± 16.5 in control (P < 0.0001). In IDCM, PWD (52.89 ± 15), P_max(98 ± 17.5) and PTF(58.2 ± 36) were significantly increased compared to control (36.20 ± 8.9, 79 ± 9.9, 25.22 ± 8.76) respectively (P < 0.0001). A positive correlation was detected between intra-atrial electromechanical delay and PWD &PTF (r = 0.5, P < 0.0001). By stepwise multiple linear regression analyses, LA reservoir function (LA ε_sys) [β = 0.754; CI at 95%:0.356-0.780, P < 0.001] and LA volume [β = 0.743; CI 95%:0.423-0.75, P < 0.001], and PWD [β=0.848; CI 95%:0.311-0.644, P < 0.0001], and PTF [β = 0.927; CI 95%: 0.357-0.722, P < 0.0001] are independent predictors for LA electromechanical delay in IDCM. Conclusion: In addition to altered LA mechanics, atrial electromechanical delay gets longer in IDCM and is correlated with PWD and PTF. Atrial electrical dispersion on surface ECG could be early index of LA dysfunction that deserves further study.

Incremental value of left atrial mechanical dispersion over CHA2 DS2 -VASc score in predicting risk of thrombus formation

PURPOSE

To assess the potential ability of two-dimensional speckle tracking analysis (STE) during atrial fibrillation (AF) to identify patients with LA appendage thrombi (LAAT).

METHODS

This study involved 93 patients with AF (39% female, 67.1 ± 9.5 years) who were referred for a clinical indication for transesophageal echocardiography (TEE). TEE revealed LAAT in 39 (42%) patients. We analyzed standard parameters of the left ventricle (LV) and LA in transthoracic echocardiography. Using STE, we assessed LV global longitudinal strain (LVGLS), peak atrial longitudinal strain (PALS), and intra-atrial asynchrony. The PALS was calculated using the global strain curve (GPALS) and as the mean of peaks derived from segmental strain curves (MPALS).

RESULTS

Patients were comparable with regard to the clinical data. A subgroup with LAAT had lower LV ejection fraction (LVEF) and a lower absolute value of the LVGLS, as well as greater impairment in the LA standard parameters, PALS, and asynchrony. Receiver operating characteristic curve analysis revealed that the LVEF of 30% (P < .001), the LVGLS of -7% (P < .0001), the GPALS of 11% (P < .005), and the LA asynchrony of 22% (P < .01) were the optimal cutoff values for distinguishing both subgroups. LA asynchrony, LVEF, and LVGLS were independently associated with the presence of LAAT in multivariate analyses, and PALS had additional significance over the CHA₂ DS₂ -VASc score.

CONCLUSIONS

Left ventricular systolic dysfunction characterized by both LVEF and LVGLS is an independent factor for LAAT. LA asynchrony provides additional diagnostic value for discriminating between patients with and without LAAT.

Early Reverse Cardiac Remodeling Effect of Laparoscopic Sleeve Gastrectomy

BACKGROUND

This study evaluated the early postoperative benefits of laparoscopic sleeve gastrectomy (LSG) on the left ventricular (LV) function and left atrial (LA) structural, mechanical, and electrical functions in severely obese patients.

METHODS

Thirty-two patients with severe obesity who were consecutively scheduled for LSG and 30 healthy controls were included in the study. LV global longitudinal strain (LGS), peak atrial longitudinal strain (PALS), and strain rates (S-Sr, E-Sr, and A-Sr) of the lateral and septal LA walls, and intra- and interatrial dyssynchrony periods for all subjects were evaluated using strain echocardiography. The measurements were repeated in patients 1 month after surgery.

RESULTS

LGS of the LV was significantly depressed in the patient group compared with the control group (p < 0.001). LA peak septal and lateral wall strain values were significantly lower in patients than in controls (both p values <0.001). LA intra- and interatrial dyssynchrony periods were longer in patients than in controls (p = 0.012 and p = 0.004, respectively). LGS significantly improved after LSG (p < 0.001). Significant reductions were noted in the LA antero-posterior diameter (p < 0.001), LA volume index (LAVI, p = 0.001), and in the mitral velocity to the early diastolic velocity of the mitral annulus ratio (E/e' ratio, p = 0.046). The PALS of the septal and lateral LA walls significantly increased (p = 0.001 and p < 0.001, respectively). S-Sr, E-Sr, and A-Sr values of the septal LA wall (p = 0.049, p < 0.001, and p = 0.001, respectively) and the lateral LA wall (p = 0.009, p = 0.007, and p = 0.002, respectively) significantly improved postoperatively. Intra- and interatrial dyssynchrony significantly decreased (p = 0.001 and p < 0.001, respectively). Weight loss positively correlated with changes in LGS (R = 0.39, p = 0.039), LAVI (R = 0.39, p = 0.034), intra-atrial dyssynchrony (R = 0.45, p = 0.021), interatrial dyssynchrony (R = 0.42, p = 0.038), septal LA wall peak strain (R = 0.44, p = 0.027), lateral LA wall peak strain (R = 0.46, p = 0.017), septal LA wall A-Sr (R = 0.43, p = 0.028), and lateral LA wall A-Sr (R = 0.46, p = 0.019). The comparison of postoperative findings of the patients with controls revealed that the LA diameter, both LA volume and volume index (LAVI), E/e' ratio, S-Sr and E-Sr of both lateral and septal LA walls, intra- and interatrial LA dyssynchrony of the patient group became similar to the control group (all p value >0.05). Postoperative A-Sr values of both LA walls (both p value <0.001) were higher in patients than controls.

CONCLUSION

The benefits of LSG on LV and LA function may be observed even in the early postoperative phase. The resulting weight loss correlates with LV and LA reverse remodeling in severely obese patients.

Assessment of left atrial mechanical function and synchrony in paroxysmal atrial fibrillation with two-dimensional speckle tracking echocardiography

BACKGROUND

The aim of this study was to investigate left atrial (LA) function and synchrony in paroxysmal atrial fibrillation (PAF) patients using two-dimensional speckle tracking echocardiography (STE).

METHODS

Forty-five PAF patients and 30 healthy controls were enrolled. LA peak ventricular systolic longitudinal strain (LA_S-S ) and strain rate (LA_SR-S ) and left atrial longitudinal strain (LA_S-A ) and strain rate (LA_SR-A ) during late diastole were determined using STE, and the standard deviation of the time to peak (TPSD) of the regional strains was calculated to quantify LA dyssynchrony. TPSD during ventricular systole and late diastole were named SDs and SDa, respectively.

RESULTS

Left atrial peak longitudinal strain during ventricular systole (LA_S-S ) (29.34±8.57 vs 36.73±6.13), LA_SR-S (1.27±0.311 vs 1.57±0.25), LA_S-A (13.11±4.91 vs 17.86±3.57), and LA_SR-A (-1.51±0.58 vs -1.90±0.30) were reduced in the PAF group compared with the controls (P<.05 for all). SDs (8.11±3.00% vs 4.67±1.48%) and SDa (5.57±2.26% vs 3.11±1.13%) were greater in PAF patients than in the controls (P<.05 for both). Furthermore, PAF patients with normal LA sizes exhibited lower LA_S-S (P<.05), LA_SR-S (P<.05), LA_S-A (P<.05), and LA_SR-A (P<.05) values and increased SDs (P<.05) and SDa (P<.05) values compared with the controls. Multivariate regression confirmed that SDs and SDa were powerful parameters for differentiating PAF patients from controls (SDs: sensitivity, 83%; specificity, 72%; SDa: sensitivity, 81%; specificity, 76%).

CONCLUSIONS

Left atrial (LA) dysfunction and dyssynchrony in PAF patients can be detected with STE even in the absence of LA enlargement. STE-derived SDs and SDa were powerful parameters for identifying PAF patients.

Early Changes in Atrial Electromechanical Coupling in Patients with Hypertension: Assessment by Tissue Doppler Imaging

BACKGROUND

Hypertension (HT) is associated with atrial electrophysiological abnormalities. Echocardiographic pulsed wave tissue Doppler imaging (TDI) is one of the noninvasive methods for evaluation of atrial electromechanical properties. The aims of our study were to investigate the early changes in atrial electromechanical conduction in patients with HT and to assess the parameters that affect atrial electromechanical conduction.

METHODS

Seventy-six patients with HT (41 males, mean age 52.6 ± 9.0 years) and 41 controls (22 males, mean age 49.8 ± 7.9 years) were included in the study. Atrial electromechanical coupling at the right (PRA), left (PLA), interatrial septum (PIS) were measured with TDI. Intra- (right: PIS-PRA, left: PLA-PIS) and inter-atrial (PLA-PRA) electromechanical delays were calculated. Maximum P-wave duration (Pmax) was calculated from 12-lead electrocardiogram.

RESULTS

Atrial electromechanical coupling at PLA (76.6 ± 14.1 ms vs. 82.9 ± 15.8 ms, P = 0.036), left intra-atrial (10.9 ± 5.0 ms vs. 14.0 ± 9.7 ms, P = 0.023), right intra-atrial (10.6 ± 7.8 ms vs. 14.5 ± 10.1 ms, P = 0.035), and interatrial electromechanical (21.4 ± 9.8 ms vs. 28.3 ± 12.7 ms, P = 0.003) delays were significantly longer in patients with HT. The linear regression analysis showed that left ventricular (LV) mass index and Pmax were significantly associated with PLA (P = 0.001 and P = 0.002, respectively), and the LV mass index was the only related factor for interatrial delay (P = 0.001).

CONCLUSIONS

Intra- and interatrial electromechanical delay, PLA were significantly prolonged in hypertensive patients. LV mass index and Pmax were significantly associated with PLA, and the LV mass index was the only related factor for interatrial delay. The atrial TDI can be a valuable method to assess the early changes of atrial electromechanical conduction properties in those patients.

Left ventricular longitudinal systolic dysfunction is associated with right atrial dyssynchrony in heart failure with preserved ejection fraction

OBJECTIVE

We aimed in this study to assess the role of longitudinal left ventricular (LV) systolic function in heart failure with preserved ejection fraction (HFpEF) in delayed intra- and interatrial conduction time.

METHODS

In 85 consecutive patients with HFpEF (age 60±11 years, ejection fraction [EF] ≥45%), a complete M-mode echocardiographic and tissue Doppler imaging (TDI) study was performed. The times from the onset of the P wave on the ECG to the beginning of the A' wave (PA) from the lateral and septal mitral and tricuspid annuli on TDI were recorded. The difference between these intervals gave the intra- and interatrial dyssynchrony. Based on mitral annular plane systolic excursion (MAPSE), patients were classified as having HFpEF with impaired (MAPSE ≤1.2 cm) or normal (MAPSE >1.2 cm) longitudinal systolic function.

RESULTS

Patients with impaired MAPSE were older (p<0.001), had higher LV mass index (p<0.001), greater left atrial (LA) minimum volume (p=0.007), reduced left atrial EF (p<0.001), higher E/e' ratio (p=0.002), reduced lateral and septal e' wave (p=0.005 and p=0.006, respectively), prolonged tricuspid PA' (p=0.03) and significantly increased right atrial (RA) dyssynchrony (p=0.001) compared with normal MAPSE. MAPSE correlated with RA dyssynchrony (r=-0.40, p<0.001) but not with interatrial and LA dyssynchrony.

CONCLUSION

In patients with HFpEF and impaired MAPSE, RA dyssynchrony is increased, compared to those with normal MAPSE. As patients with RA dyssynchrony are at higher risk for arrhythmia, assessment of this dyssynchrony may help to improve treatment, as well as to predict outcome in these patients.

Evaluating functional capacity, and mortality effects in the presence of atrial electromechanical conduction delay in patients with systolic heart failure

Objective:

Atrial functions are relatively suppressed in heart failure (HF). We aimed to investigate the associations of intra- and inter-atrial electromechanical conduction delay (EMCD) with functional class and mortality over a 12-month follow-up period.

Methods:

The prospective study included 65 patients with systolic HF and 65 healthy subjects with normal sinus rhythm. Left ventricular (LV) systolic functions and left atrial (LA) dimensions and volumes were evaluated by transthoracic echocardiography. Tissue Doppler imaging (TDI) signals at the lateral border of the mitral annulus (lateral PA’), septal mitral annulus (septal PA’), and tricuspid annulus (tricuspid PA’) were measured. Intra- and inter-atrial EMCD were calculated.

Results:

Mitral inflow velocities were studied using pulsed-wave Doppler after placing the sample volume at the leaflets’ tips. The peak early (E wave) and late (A wave) velocities were measured. The septal annular E/E’ ratio was relatively higher and lateral, septal, and right ventricular S, E’, and A’ waves were significantly lower in the HF group than in the control group (12.49±6.03 – 7.16±1.75, pE/E’ <0.0001). Intra-atrial EMCD was detected as 117.5 ms and inter-atrial EMCD as 127.5 ms in patients with prolonged atrial EMCD. A significant increase was found in prolonged intra- and inter-atrial EMCD according to functional capacity increase (p=0.012 and p=0.031, respectively). The incidence of mortality was significantly higher in patients with prolonged atrial EMCD (p=0.025), and 5 patients in the HF group died during the study over the 12-month follow-up period.

Conclusions:

In this study, we found a relationship between prolonged atrial conduction time and increased functional class and mortality in patients with systolic HF. (Anatol J Cardiol 2016; 16: 579-86)

Left atrial structure and functional quantitation using cardiovascular magnetic resonance and multimodality tissue tracking: validation and reproducibility assessment

BACKGROUND

Left atrium (LA) strain, volume and function are important markers of cardiovascular disease and myocardial impairment. We aimed to assess the accuracy of LA biplane volume and function measured by Multimodality Tissue Tracking (MTT). Also we assessed the inter-study reproducibility for cardiovascular magnetic resonance (CMR) derived LA volume and function parameters.

METHODS

Thirty subjects (mean age: 71.3 ± 8.7, 87% male) including twenty subjects with cardiovascular events and ten healthy subjects, with CMR were evaluated in the Multi-Ethnic Study of Atherosclerosis (MESA). LA volumes were computed by the modified biplane method from 2- and 4-chamber projections and the Simpson's method from short-axis slices using both methods - manual and semi-automated delineation using MTT. LA total, active and passive ejection fractions were calculated. Pearson's correlation and Bland-Altman analysis were used to compare the measurements. In a second sample of 25 subjects (age: 65.7 ± 7.1, 72% males) inter study, intra and inter reader reliability analysis was performed. The intra-class correlation coefficient (ICC) was evaluated.

RESULTS

Left atrial MTT structural and functional parameters were not different from manual delineation, yet image analysis was only half as time consuming on average with MTT. Maximal volume MTT was not different between the Simpson's and Biplane methods, functional parameters, however were different. MTT allowed us to measure multiple LA parameters with good-excellent (ICC; 0.88- 0.98, p < 0.001) intra-and inter reader reproducibility and fair-good (ICC; 0.44-0.82, p < 0.05-0.001) inter study reproducibility.

CONCLUSIONS

MTT derived LA biplane volume and function is accurate and reproducible and is suited for use in longitudinal studies.

Left atrial dyssynchrony time measured by tissue Doppler imaging to predict atrial fibrillation recurrences after pulmonary vein isolation

OBJECTIVE

In this study we assess the value of left atrial dyssynchrony time measured by tissue Doppler imaging (TDI) to predict recurrences after pulmonary vein isolation (PVI) in patients with paroxysmal and persistent atrial fibrillation (AF).

METHODS

One hundred sixty patients (57 ± 7.5 years, 122 males) with symptomatic drug-refractory paroxysmal and persistent AF, undergoing PVI were enrolled in our study. PA peak time by tissue Doppler imaging (PApeak-TDI) is defined as the time measured from the start of P wave in lead II to the peak of A wave on the tissue Doppler tracing. Left atrial dyssynchrony was measured by subtracting the PApeak-TDI time measured at the mid-inter atrial septum from the PA peak-TDI time measured at the left atrial midlateral free wall, (LA dyssynchrony = PApeak TDI lateral-PApeak TDI septal).

RESULTS

During a mean follow-up of 12 ± 3 months, recurrences occurred in 50 out of 160 patients. Patients with recurrence of atrial fibrillation had larger left atrial dyssynchrony time (26.5 ± 2.4 ms vs. 23.5 ± 2.3 ms, p < 0.001). Left atrial dyssynchrony time of 25 ms has the best combined sensitivity and specificity (74% and 63% respectively) along with positive predictive value 53% and negative predictive value 85.5%. LA dyssynchrony time ≥ 25 ms was found to discriminate patients prone to AF recurrences over time. Multivariate regression analysis showed that left atrial dyssynchrony time (HR per ms: 1.69, p<0.001) was identified as independent predictor of AF recurrence.

CONCLUSION

Left atrial dyssynchrony time is good clinical predictor of recurrence of AF after PVI in patients with paroxysmal and persistent AF.

Outcome of pulmonary vein isolation ablation for paroxysmal atrial fibrillation: predictive role of left atrial mechanical dyssynchrony by speckle tracking echocardiography

INTRODUCTION

Although few clinical variables have been associated with recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) the role of left atrial (LA) mechanical function in the outcome of catheter ablation of AF is not adequately defined. The aim of our study was to determine whether LA mechanical dyssynchrony as evaluated by speckle tracking echocardiography can predict outcome of PVI ablation procedure in patients with paroxysmal AF.

METHODS

Twenty-five patients (age 58 ± 11 years, [mean ± standard deviation], 17 males) with paroxysmal AF who met specific enrollment criteria pertaining to clinical presentation and follow-up, assessment of LA mechanical dyssynchrony, and strategy of catheter ablation procedure were enrolled. For LA mechanical dyssynchrony assessment, the time to peak longitudinal strain (TPk) in opposing walls in the midportion of the LA walls at peak atrial contraction in standard two- and four-chamber echocardiographic views by vector velocity imaging (VVI) was measured. Outcome of PVI procedure, whether no recurrence (NR) or AF recurrence (AFR) after 3 months of post-procedural blanking period, was evaluated based on AF-related symptoms and documentation of AF by electrocardiogram, continuous 24-h Holter, and intermittent event monitor recordings.

RESULTS

During a follow-up period of 20.3 ± 8.6 months, 18 out of 25 (72 %) patients had no recurrence (NR group), and 7 out of 25 (28 %) patients had recurrence of AF (AFR group). Significant gender difference was observed in terms of outcome such that all AFR patients were men and no woman had recurrence of AF. Between the NR and AFR groups, neither the left atrial diameter, 4.0 ± 0.3 and 4.2 ± 0.2 cm, respectively (p = 0.2), nor the left atrial volume indexes, 45 ± 15 and 48 ± 20 ml/m(2), respectively (p = 0.56), were statistically significantly different. For LA mechanical function, compared to the patients in NR group who had maximum opposing wall TPk delay of 39.9 ± 12.0 ms, those in the AFR group demonstrated significantly more LA mechanical dyssynchrony with maximum opposing wall TPk delay of 64.4 ± 17.0 ms prior to ablation (p = 0.007). Using receiver operative characteristic analyses of the data that had an area under the curve of 0.865, we identified a maximum opposing wall delay cutoff value of 51 ms which predicted AF recurrence with sensitivity and specificity values of 89 and 72 %, respectively (p = 0.005).

CONCLUSIONS

Speckle tracking strain analysis echocardiography can evaluate the LA mechanical dyssynchrony quantitatively. The severity of LA mechanical dyssynchrony by VVI can predict the outcome of PVI catheter ablation for paroxysmal AF.

Assessment of Inter and Intra-atrial Asynchrony in Patients with Systolic Heart Failure Using Velocity Vector Imaging

Background:

According to previous studies on the deformation properties of the left atrium, the systolic strain and strain rates represent the atrial reservoir function and the early and late diastolic strain rates show the conduit and booster functions, respectively.

Objectives:

We sought to evaluate the intra and interatrial asynchrony using strain/strain rate imaging in systolic heart failure patients.

Patients and Methods:

Twenty five patients with systolic heart failure (LVEF ≤ 40%) were enrolled into the study. Asynchrony quantifications were performed according to the standard deviation of time-to peak (TP-SD) of deformation of three segments manually located along the perimeter of the left atrium free wall, right atrium free wall and interatrial septum, as imaged in an apical four-chamber view. We also calculated classic echocardiography parameters such as LV end-diastolic dimension index, LA volume index, RA area, as well as deceleration time (DT) on transmitral pulsed wave Doppler and E/E’ ratio on mitral annular tissue Doppler imaging.

Results:

In heart failure patients either inter or intra-atrial asynchrony were far more common in comparison with normal subjects (P=0.008 and P=0.007 respectively).

Conclusions:

Left ventricular systolic heart failure, may result in inter and intra-atrial asynchrony even in clinically stable patients without significant pulmonary hypertension and diastolic dysfunction.

Evaluation of atrial conduction features with tissue Doppler imaging in patients with chronic obstructive pulmonary disease

BACKGROUND

The electrical activity of atria can be demonstrated by P waves on surface electrocardiogram (ECG). Atrial electromechanical delay (AEMD) measured with tissue Doppler imaging (TDI) echocardiography can be a useful non-invasive method for evaluating atrial conduction features. We investigated whether AEMD is prolonged in patients with chronic obstructive pulmonary disease (COPD).

PATIENTS AND METHODS

Study consisted of 41 (15 female, 26 male, mean age 62 + 12 years) patients with COPD and 41 healthy subjects. Pulmonary function tests,12 lead surface ECG and echocardiographic examination were performed and recorded. P wave changes on surface ECG, minimum (P (min)) and maximum (P (max)) duration of P wave and its difference as P wave dispersion (P (wd)) were measured and recorded. Atrial electromechanic delay (AEMD) was calculated from colored-TDI recordings.

RESULTS

Pulmonary functions were significantly lower in COPD group than the control group as expected. Right atrial areas and pulmonary arterial systolic pressures (PAP) were significantly higher in COPD group than the controls (right atrial area: 11.9 ± 3.4 cm(2) and 8.2 ± 2.2 cm(2), p < 0.0001 and PAP: 38.4 ± 12.2 and 19.0 ± 3.2 mmHg p < 0.0001, respectively). P wave intervals on surface ECG were significantly increased in COPD patients than the control group (P (max): 105 ± 11 and 90 ± 12 ms, p < 0.0001; P (min): 60 ± 12 and 51 ± 10 ms, p = 0.003 and P (wd): 39 ± 10 and 31 ± 7 ms, p < 0.0001). According to the AEMD measurements from different sites by TDI, there was a significant delay between the onset of the P wave on surface ECG and the onset of the late diastolic wave in patients with COPD when compared with controls measured from tricuspid lateral septal annulus (TAEMD) (COPD: 41.3 ± 9.8 ms, control: 36 ± 4.5 ms; p = 0.005). There was a positive correlation between TAEMD and right atrial area (r = 0.63, p < 0.0001) and also between TAEMD and PASP (r = 0.43, p < 0.0005) and a negative correlation between TAEMD and forced expiratory volume (FEV1) (r = -0.44, p = 0.04).

CONCLUSIONS

Right atrial electromechanical delay is significantly prolonged in patients with COPD. The right atrial area, PAP and FEV1 levels are important factors of this prolonged delay. Also the duration of atrial depolarization is significantly prolonged and propagation of depolarization is inhomogeneous in patients with COPD. These may be the underlying mechanisms to explain the atrial premature beats, multifocal atrial tachycardia, atrial flutter and fibrillation often seen in patients with COPD secondary to these changes.

Comprehensive risk reduction in patients with atrial fibrillation: emerging diagnostic and therapeutic options--a report from the 3rd Atrial Fibrillation Competence NETwork/European Heart Rhythm Association consensus conference

While management of atrial fibrillation (AF) patients is improved by guideline-conform application of anticoagulant therapy, rate control, rhythm control, and therapy of accompanying heart disease, the morbidity and mortality associated with AF remain unacceptably high. This paper describes the proceedings of the 3rd Atrial Fibrillation NETwork (AFNET)/European Heart Rhythm Association (EHRA) consensus conference that convened over 60 scientists and representatives from industry to jointly discuss emerging therapeutic and diagnostic improvements to achieve better management of AF patients. The paper covers four chapters: (i) risk factors and risk markers for AF; (ii) pathophysiological classification of AF; (iii) relevance of monitored AF duration for AF-related outcomes; and (iv) perspectives and needs for implementing better antithrombotic therapy. Relevant published literature for each section is covered, and suggestions for the improvement of management in each area are put forward. Combined, the propositions formulate a perspective to implement comprehensive management in AF.

[Cardiac resynchronization therapy: preoperative screening. How can we reliably predict response to CRT?]

Cardiac resynchronization therapy (CRT) is an established therapy for patients with advanced heart failure, depressed left ventricular function, and wide QRS complex. However, about 30 to 45% of patients do not respond to CRT. Assuming that the main therapeutic action of CRT is the correction of dyssynchronous myocardial contraction, a plethora of echocardiographic dyssynchrony parameters have been proposed to improve the prediction of response to CRT. However, one multicenter study has recently questioned the utility of any of these indexes. This review delineates the various causes of non-response to CRT, explains the different levels and mechanisms of dyssynchrony and gives a critical overview of currently available echocardiographic techniques for assessment of dyssynchrony. Based upon a discussion of the evidence coming from randomized multicenter studies and against the background of national and international cardiac societies' guideline recommendations on CRT, a rational basis for the evaluation of patients for CRT is proposed.

Relation of gender and interatrial dyssynchrony on tissue Doppler imaging to the prediction of the progression to chronic atrial fibrillation in patients with nonvalvular paroxysmal atrial fibrillation

This prospective study aimed to identify the relation of gender and interatrial dyssynchrony on tissue Doppler imaging (TDI) to the prediction of the progression to chronic atrial fibrillation (CAF) in nonvalvular paroxysmal AF (PAF) patients. Nineteen consecutive men and 19 women with nonvalvular PAF were prospectively followed after echocardiography. We measured the interval of time from initiation of the P wave on the electrocardiogram until the beginning of the late diastolic TDI signal at the lateral border of the mitral (P-A'(M)) and the tricuspid annulus (P-A'(T)). Interatrial dyssynchrony was defined as the difference between the P-A'(M) and P-A'(T) intervals (A'(M)-A'(T)). The study endpoint was the onset of CAF (>6 months). Six men developed CAF during a follow-up of 32 +/- 26 months, and 3 women developed CAF during a follow-up of 25 +/- 19 months. Compared to those without CAF, the patients with CAF had significantly longer A'(M)- A'(T) intervals (men: 41 +/- 10 vs 27 +/- 12 ms, women: 64 +/- 4 vs 23 +/- 9 ms; P < 0.01) in both genders. Kaplan-Meier analysis, using cutoff values determined by analysis of receiver-operating characteristics curves, revealed that the progression to CAF was significantly observed more often when A'(M)-A'(T) interval was >34 ms in men and >43 ms in women. This prospective study suggests that nonvalvular PAF men and women with a high risk of developing CAF have "interatrial dyssynchrony" on atrial TDI, whose cutoff values are shorter and may affect the vulnerability of AF in men.

Three-dimensional echocardiographic assessment of left atrial size and function and the normal range of asynchrony in healthy individuals

Left atrial size and function are very important prognostic factors. Our aim was to evaluate left atrial size, function and mechanical synchrony using three-dimensional echocardiography in order to establish normal reference values. The study involved 63 healthy individuals enrolled at two hospitals. All underwent two-dimensional and three-dimensional echocardiography. Mechanical asynchrony was assessed by determining the standard deviation of the time each left atrial segment took to reach the minimum volume during atrial systole, normalized by the RR interval. The mean value for this normalized standard deviation was 15.4+/-10.9. In conclusion, it is possible to analyze left atrial asynchrony, size and function using three-dimensional echocardiography.

Interatrial conduction time and left atrial function in patients with left ventricular systolic dysfunction: effects of cardiac resynchronization therapy

BACKGROUND

Prolonged interatrial conduction time (IACT) can be associated with abnormal left atrial (LA) function but has not been characterized in patients with left ventricular (LV) systolic dysfunction (LVSD) and QRS intervals >130 ms.

METHODS

Two-dimensional Doppler echocardiography and Doppler tissue imaging (DTI) were performed in 41 patients with LVSD (mean LV ejection fraction, 26 +/- 5%) and 41 similarly aged normal controls. Two-dimensional measurements included LV volume and ejection fraction and LA volume for the determination of LA emptying fraction and LA ejection fraction. IACT was defined as the time from the onset of the P wave to the onset of the DTI-derived late diastolic (A') velocity at the lateral mitral annulus. Two-dimensional Doppler measurements were reassessed in patients with LVSD 4 +/- 2 months after cardiac resynchronization therapy (CRT).

RESULTS

IACT was longer in patients with compared to controls (105 +/- 25 vs 74 +/- 12 ms, P < .001); none of the controls had an IACT > 100 ms. In patients with LVSD, IACT was correlated modestly with measurements of LA volume (r = .41-.48, all P values < .009) but not with measurements of LA function. Patients with LVSD with IACTs > 100 ms (n = 20) prior to CRT had larger LA volumes and lower indices of LA function after CRT compared to those with IACTs < or = 100 ms. Significant reductions in LV end-systolic volumes and increases in LV ejection fractions occurred in both groups after CRT.

CONCLUSION

DTI-derived IACT can be prolonged in patients with severe LVSD and wide QRS intervals. An IACT > 100 ms can affect LA remodeling and function at early follow-up after CRT but does not influence the response in LV end-systolic volume or ejection fraction.

Echocardiographic optimization of the atrioventricular and interventricular intervals during cardiac resynchronization

An optimized atrioventricular (AV) interval can maximize the benefits of cardiac resynchronization therapy (CRT). If programmed poorly, it may curtail beneficial effects of CRT. AV optimization will not convert non-responder to responder, but may convert under-responder to improved status. There are many echocardiographic techniques for AV optimization but there is no universally accepted gold standard. The optimal AV delay varies with time, necessitating periodic re-evaluation. As the optimal AV delay may lengthen on exercise, a rate-adaptive AV delay should not be routinely programmed. Intra- and interatrial conduction delays may require AV junctional ablation when AV optimization is impossible in patients with a poor clinical response. Fusion with the spontaneous QRS complex may be acceptable on a trial basis to seek a better clinical response or with a short PR interval. Routine VV optimization is presently controversial but programming may prove beneficial in some patients with a suboptimal CRT response where no cause is found. It may partially compensate for less than optimal left ventricular (LV) lead position and may correct for heterogeneous ventricular activation including a prolonged LV latency interval and slow conduction (scarring) near the LV pacing site. VV timing is generally programmed using the aortic velocity-time integral, and long-term variations of the optimal value necessitate periodic re-evaluation.

Using echocardiography in cardiac resynchronization therapy

Cardiac resynchronization therapy has become a therapeutic option for refractory heart failure. Several imaging techniques play an increasingly important role in patient selection during and after implantation. This manuscript reviews the current echocardiographic techniques available for guiding both patient selection and optimization of device programming following implantation.