Left Ventricular Asynchrony Research Articles

Interrelationships between Peak Strain Dispersion, Myocardial Work Indices, Isovolumetric Relaxation and Systolic-Diastolic Coupling in Middle-Aged Healthy Subjects.

In echocardiography, peak strain dispersion (PSD) is the standard deviation of the time to peak longitudinal strain for each left ventricular (LV) segment during systole. It assesses the coordination and synchrony of LV segment contractility. Global work efficiency (GWE) and global wasted work (GWW) quantify LV myocardial work and, if impaired, the coupling between LV systolic contraction and early relaxation. Isovolumetric relaxation (IVRT) measures the duration of initial LV relaxation, while the ratio of early diastolic recoil to systolic excursion (E'VTI/S'VTI) describes systolic-diastolic coupling. We evaluated these parameters in 69 healthy subjects and found that PSD correlated negatively with GWE (r = -0.49, p < 0.0001) and E'VTI/S'VTI (r = -0.44, p = 0.0002), but positively with GWW (r = 0.4, p = 0.0007) and IVRT (r = 0.53, p < 0.0001). GWE correlated negatively with GWW (r = -0.94, p < 0.0001) and IVRT (r = -0.30, p = 0.0127), but positively with E'VTI/S'VTI (r = 0.3, p = 0.0132). In addition, E'VTI/S'VTI was negatively correlated with GWW (r = -0.35, p = 0.0032) and IVRT (r = -0.36, p = 0.0024). These associations remained significant after adjustment for sex, age and LV mass index of the subjects. In conclusion, there is an interaction between measures of LV asynchrony, myocardial work, diastolic function and its systolic-diastolic coupling in middle-aged healthy subjects. The clinical value of these interactions requires further investigation.

Success rates, challenges and troubleshooting of left bundle branch area pacing as a cardiac resynchronization therapy for treating patients with heart failure.

Cardiac resynchronization therapy (CRT) is an important treatment of heart failure patients with reduced left ventricular ejection fraction (LVEF) and asynchrony of cardiac electromechanical activity. Left bundle branch area pacing (LBBaP) is a novel physiological pacing modality that appears to be an effective method for CRT. LBBaP has several advantages over the traditional biventricular-CRT (BiV-CRT), including a low and stable pacing capture threshold, a high success rate of implantation, a short learning curve, and high economic feasibility. However, LBBaP is not suitable for all heart failure patients needing a CRT and the success rates of LBBaP in heart failure patients is lower because of myocardial fibrosis, non-specific intraventricular conduction disturbance (IVCD), enlargement of the right atrium or right ventricle, etc. In this literature review, we summarize the success rates, challenges, and troubleshooting of LBBaP in heart failure patients needing a CRT.

Assessment of Left Ventricular Asynchrony after Insertion of Dual Chamber Pacemaker by Using Two-Dimensional Speckle Tracking Echocardiography

Assessment of Left Ventricular Asynchrony after Insertion of Dual Chamber Pacemaker by Using Two-Dimensional Speckle Tracking Echocardiography

Early onset of left ventricular regional asynchrony in arteries with sub-clinical stenosis

BackgroundAsynchrony has been reported to be a marker of ischemic-induced left ventricular dysfunction, the magnitude of which correlates with extent of epicardial coronary disease. We wished to determine whether normal-appearing arterial territories with mild degrees of asynchrony have lower 82Rb PET absolute myocardial blood flow (MBF) and/or lower myocardial flow reserve (MFR). Methods and ResultsData were examined retrospectively for 105 patients evaluated for known/suspected CAD who underwent rest/regadenoson-stress 82Rb PET/CT and quantitative coronary angiography. Rest and stress absolute MBF and MFR were quantified from first-pass 82Rb PET curves. Regional relative myocardial perfusion summed stress score (SSS), summed rest score (SRS), regional phase bandwidth (BW), and regional semi-quantitative asynchrony visual scores of (Asynch) were assessed. We found that in apparently normal arteries (SSS < 4, SRS < 4 and stenosis < 70%), those with abnormally low MFR < 2.0 compared to those with MFR ≥ 2.0 had larger phase BW (186 ± 79° vs 158 ± 67°, P = .02), and more visually apparent Asynch (5.7 ± 4.2 vs 3.9 ± 3.6, P = .02), which was associated with increasing stenosis values (ρ = 0.44, P < .0001). ConclusionA subgroup of coronary territories with normal relative perfusion and normal or non-obstructive coronary disease may have reduced MFR, which is signaled physiologically by a mild degree of left ventricular asynchrony.

Left ventricular myocardial deformation pattern, mechanical dispersion, and their relation with electrocardiogram markers in the large population-based STANISLAS cohort: insights into electromechanical coupling.

Mechanical alterations in patients with electrical conduction abnormalities are reported to have prognostic value in patients with left ventricular asynchrony or long QT syndrome beyond electrocardiogram (ECG) variables. Whether conduction and repolarization patterns derived from ECG are associated with speckle tracking echocardiography parameters in subjects without overt cardiac disease is yet to be investigated. To report ranges of longitudinal deformation according to conduction and repolarization values in a population-based cohort. One thousand, one hundred, and forty subjects (48.6 ± 14.0 years, 47.7% men) enrolled in the fourth visit of the STANISLAS cohort (Lorraine, France) were studied. Echocardiography strain was performed in all subjects. RR, PR, QRS, and QT intervals were retrieved from digitalized 12-lead ECG. Echocardiographic data were stratified according to quartiles of QRS and QTc duration values. Full-wall global longitudinal strain (GLS) was -21.1 ± 2.5% with a mechanical dispersion (MD) value of 34 ± 12 ms. Absolute GLS value was lower in the longest QRS quartile and shortest QTc quartile (both P < 0.001). Time-to-peak of strain was not significantly different according to QRS duration although significantly higher in patients with higher QTc (P < 0.001). MD was significantly greater in patients with longer QTc (32 ± 12 ms for QTc < 396 ms vs. 36 ± 12 ms for QTc > 421 ms; P = 0.002). Longer QTc is related to increased MD and better longitudinal strain values. In a population-based setting, QRS is not associated with MD, suggesting that echocardiography-based dyssynchrony does not largely overlap with ECG-based dyssynchrony.

How His bundle pacing prevents and reverses heart failure induced by right ventricular pacing.

Ideal heart performance demands vigorous systolic contractions and rapid diastolic relaxation. These sequential events are precisely timed and interdependent and require the rapid synchronous electrical stimulation provided by the His-Purkinje system. Right ventricular (RV) pacing creates slow asynchronous electrical stimulation that disrupts the timing of the cardiac cycle and results in left ventricular (LV) mechanical asynchrony. Long-term mechanical asynchrony produces LV dysfunction, remodeling, and clinical heart failure. His bundle pacing preserves synchronous electrical and mechanical LV function, prevents or reverses RV pacemaker-induced remodeling, and reduces heart failure.

Assessment of Left Ventricular Asynchrony after Permanent Cardiac Pacing by Using Speckle Tracking Echocardiography

AbstractBackground: Echocardiography is important in assessing Left Ventricular (LV) Mechanical Dysynchrony (LVMD) and left ventricular function after permanent pacemaker. At present, Real-Time Three Dimensional Echocardiography (RT3DE) and tissue Doppler imaging (TDI) are the most sensitive and commonly used techniques for the quantification of LVMD. Global longitudinal strain (GLS) and LV dyssynchrony as-sessment enables us to detect early signs of LV dysfunction after cardiac pacing.Aim of Study: To evaluate LV mechanical dyssynchrony and LV function in different pacing modes after permanent cardiac pacing by using TDI and speckle tracking echocardi-ography and to correlate these changes with other clinical, electrocardiographic and echocardiographic data.Patients and Methods: Seventy patients were enrolled in this prospective cross sectional observational study, (mean age 60.99±13.77 years, 42 females), in Mansoura Specialized Medical Hospital over a period of 1 year from April 2018 to April 2019. All patients were assessed by thorough history taking, clinical examination, 12 lead surface ECG, echocar-diography, 2D speckle tracking echocardiography STE to assess GLS and tissue Doppler imaging TDI.Results: Regarding diastolic function by pulsed wave Doppler PWD: There was significant decrease in E/e¢ ratio (p<0.001 *), significant increase in myocardial performance index Tei index (p<0.001 *). Regarding internal dimensions and systolic function: There was significant increase in the following: Left Atrial Dimension (LAD) (p=0.001*), Left Ventricular End Systolic Dimension LVESD (p<0.001*) and Left Ventricular End Diastolic Dimension LVEDD (p<0.001 *) while there was significant decrease in ejection fraction EF (p<0.001 *) and fractional shortening FS (p<0.001 *). Regarding parameters of LV dysynchrony: There was significant increase in the following: Aortic preejection delay APED (p<0.001*), interventricular mechanical delay (p<0.001 *) and septal posterior wall motion delay SPWMD by M mode (p<0.001 *). Regarding parameters assessed by tissue synchronization imaging TSI: There was significant increase in the following: SD-Ts (p=0.001 *) and all segments Max delay (p=0.027*). Regarding parameters assessed by STE: There was significant decrease in global longitudinal strain GLS (p=0.034*) while there was significant increase in TP-SD by STE (p<0.001*).Also, there was significant decrease in global longitudinal strain GLS (p<0.001*) and significant increase in TP-SD by STE (p=0.001*) in DDD group. While there was significant decrease in global longitudinal strain GLS (p<0.001 *) and significant increase in TP-SD by STE (p<0.001*) in VVI group.Conclusion: GLS and 2D STE can help in the detection of subclinical left ventricular dysfunction after permanent pacemaker implantation before appearance of symptoms. Also, cardiac pacing leads to LVMD whatever the pacing mode is which may needs later on upgrading to cardiac resynchronization therapy CRT.

Left ventricular myocardial deformation pattern, mechanical dispersion and their relation with ecg markers in the large population-based stanislas cohort: Insights into electro-mechanical coupling

Background: Mechanical alterations in patients with electrical conduction abnormalities are reported to have prognostic value in patients with left ventricular asynchrony or long QT syndrome beyond ECG variables. Whether conduction and repolarization patterns derived from ECG are associated with speckle tracking echocardiography (STE) parameters in patients without overt disease has not been previously investigated. To report ranges of longitudinal deformation according to conduction and repolarization values in a population-based cohort. In total, 1140 subjects (48.6 ± 14.0 years,) enrolled in the STANISLAS cohort were studied. Echocardiography with layer-specific strain was performed in all subjects. RR, PR, QRS and QT intervals were retrieved from digitalized twelve-lead ECG. Echocardiographic data were stratified according to quartiles of QRS and QTc duration values. Full-wall peak longitudinal strain (PLS) was −21.1% ± 2.5% with a mechanical dispersion value of 33.6 ± 11.7ms. Absolute PLS value was lower in the longest QRS quartile and shortest QTc quartile (both P < 0.001). Time-to-peak of strain was not significantly different according to QRS duration although significantly higher in patients with higher QTc ( P < 0.001). Mechanical dispersion was significantly greater in patients with longer QTc (32.45 ± 11.68 ms for QTc < 396 ms versus 35.88 ± 11.94 ms for QTc > 421ms; P = 0.002). QTc is associated with variations in normal values of the deformation pattern of longitudinal systolic strain such that mechanical dispersion and QTc-specific normal values should preferentially be used. In a population-based setting, QRS is not associated with mechanical dispersion suggesting that echocardiography-based dyssynchrony does not largely overlap with ECG-based dyssynchrony.

Clinical Influence and Predictors of Pacing-Induced Mechanical Asynchrony in Patients with Normal Cardiac Function with Ventricular Lead Placed in Non-Apical Position.

Right ventricular apical (RVA) pacing often causes left ventricular (LV) mechanical asynchrony, which is enhanced by impaired cardiac contraction and intrinsic conduction abnormality. However, data on patients with normal cardiac function and under RV non-apical (non-RVA) pacing are limited.We retrospectively investigated 97 consecutive patients with normal ejection fraction who received pacemaker implantation for atrioventricular block with the ventricular lead placed in a non-RVA position. We defined mechanical asynchrony as discoordinate contraction between opposing regions of the LV wall evaluated by echocardiography. Asynchrony was detected in 9 (9%) patients at baseline and in 38 (39%) under non-RVA pacing (P < 0.001). Asynchrony at baseline was significantly associated with complete left bundle branch block (CLBBB) [odds ratio (OR) = 20.8, P < 0.001]. Asynchrony under non-RVA pacing was significantly associated with left anterior fascicular block (LAFB) (OR = 7.14, P < 0.001) and CLBBB (OR = 13.3, P = 0.002) at baseline. New occurrence of asynchrony was significantly associated with LAFB at baseline (OR = 5.88, P = 0.001). During a median follow-up period of 4.8 years, the incidence of device-detected atrial fibrillation (AF) was more frequent in patients who developed asynchrony than in those who did not (53.3% versus 27.5%, hazard ratio = 2.17, 95% confidence interval = 1.02-4.61, P = 0.03).In patients with normal cardiac function, LAFB at baseline was significantly associated with new occurrence of mechanical asynchrony under non-RVA pacing. Abnormal contraction had a significant influence on the incidence of device-detected AF.

Evaluation of left and right ventricular systolic and diastolic electromechanical synchrony in older people: a population-based observational study.

It is unknown whether physiological ageing also goes along with electromechanical asynchrony of contraction. Aim of the study was to evaluate synchrony of contraction in older people with ("non-healthy") or without ("healthy") evidence for structural cardiac disease. In 547 persons (age 76.7+/-5.5 years, 306 male, 241 female) recruited from a population-based cohort of the ActiFE-Ulm study including a random sample of people >/=65 years old living in the region of Ulm, Germany, various PW- and TDI-Doppler based markers for asynchrony were obtained by echocardiography. Within a subgroup of 84 healthy subjects, at most minimal systolic and diastolic asynchrony was found. Concerning systolic asynchrony, similar observations were made within the non-healthy subgroup. However, extent of diastolic left ventricular intraventricular asynchrony and also - by tendency - diastolic interventricular asynchrony was increased in comparison to the healthy subgroup. To conclude, no evidence that physiological ageing might go along with relevant left or right ventricular systolic or diastolic electromechanical asynchrony was found in our study. Furthermore, our population-based data support the results from other clinical studies with rather selected cohorts that structural heart diseases might go along with increased diastolic asynchrony.

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

It is now well recognized that heart failure (HF) patients with left bundle branch block (LBBB) derive substantial clinical benefits from cardiac resynchronization therapy (CRT), and LBBB has become one of the important predictors for CRT response. The conventional tachypacing-induced HF model has several major limitations, including absence of stable LBBB and rapid reversal of left ventricular (LV) dysfunction after cessation of pacing. Hence, it is essential to establish an optimal model of chronic HF with isolated LBBB for studying CRT benefits. In the present study, a canine model of asynchronous HF induced by left bundle branch (LBB) ablation and 4 weeks of rapid right ventricular (RV) pacing is established. The RV and right atrial (RA) pacing electrodes via the jugular vein approach, together with an epicardial LV pacing electrode, were implanted for CRT performance. Presented here are the detailed protocols of radiofrequency (RF) catheter ablation, pacing leads implantation, and rapid pacing strategy. Intracardiac and surface electrograms during operation were also provided for a better understanding of LBB ablation. Two-dimensional speckle tracking imaging and aortic velocity time integral (aVTI) were acquired to validate the chronic stable HF model with LV asynchrony and CRT benefits. By coordinating ventricular activation and contraction, CRT uniformed the LV mechanical work and restored LV pump function, which was followed by reversal of LV dilation. Moreover, the histopathological study revealed a significant restoration of cardiomyocyte diameter and collagen volume fraction (CVF) after CRT performance, indicating a histologic and cellular reverse remodeling elicited by CRT. In this report, we described a feasible and valid method to develop a chronic asynchronous HF model, which was suitable for studying structural and biologic reverse remodeling following CRT.

Patients with left bundle branch block and left axis deviation show a specific left ventricular asynchrony pattern: Implications for left ventricular lead placement during CRT implantation

BackgroundLeft bundle branch block (LBBB) and left axis deviation (LAD) patients may have poor response to resynchronization therapy (CRT). We sought to assess if LBBB and LAD patients show a specific pattern of mechanical asynchrony. MethodsCRT candidates with non-ischemic cardiomyopathy and LBBB were categorized as having normal QRS axis (within −30° and +90°) or LAD (within −30° and −90°). Patients underwent tissue Doppler imaging (TDI) to measure time interval between onset of QRS complex and peak systolic velocity in ejection period (Q-peak) at basal segments of septal, inferior, lateral and anterior walls, as expression of local timing of mechanical activation. ResultsThirty patients (mean age 70.6years; 19 males) were included. Mean left ventricular ejection fraction was 0.28±0.06. Mean QRS duration was 172.5±13.9ms. Fifteen patients showed LBBB with LAD (QRS duration 173±14; EF 0.27±0.06). The other 15 patients had LBBB with a normal QRS axis (QRS duration 172±14; EF 0.29±0.05).Among patients with LAD, Q-peak interval was significantly longer at the anterior wall in comparison to each other walls (septal 201±46ms, inferior 242±58ms, lateral 267±45ms, anterior 302±50ms; p<0.0001). Conversely, in patients without LAD Q-peak interval was longer at lateral wall, when compared to each other (septal 228±65ms, inferior 250±64ms, lateral 328±98ms, anterior 291±86ms; p<0.0001). ConclusionsPatients with heart failure, presenting LBBB and LAD, show a specific pattern of ventricular asynchrony, with latest activation at anterior wall. This finding could affect target vessel selection during CRT procedures in these patients.

Relationships between left ventricular asynchrony and myocardial blood flow

Objective82Rb PET protocols enable determination of left ventricular asynchrony (LVAS) at rest and stress, along with myocardial blood flow (MBF). We hypothesized that in patients with resting LVAS, MBF differs between those with stress-induced LVAS improvement and those with stress-induced LVAS deterioration. MethodsWe retrospectively analyzed 82Rb rest/regadenoson stress PET studies of 195 patients evaluated for known or suspected coronary artery disease. MBF was computed from first-pass data; function and relative perfusion were computed from myocardial equilibrium data. LVAS was defined as phase contraction bandwidth (BW) above 82Rb gender-specific normal limits, with changes defined as BW moving into or out of normal ranges. ResultsAmong the 195 patients, 64 had LVAS at rest, of whom 13 reverted to normal and 51 continued to have LVAS with stress. Patients who did not improve had lower stress MBF (1.04 ± 0.69 vs 1.58 ± 0.67, p = .02) and coronary flow reserve (1.94 ± 1.16 vs 3.04 ± 1.22, p = .01) than those who did improve. ROC analysis indicated that the parameter most strongly associated with improvement in asynchrony for patients with resting LVAS was reduction in MBF heterogeneity (ROC area (accuracy) = 84%, sensitivity = 92%, and specificity = 67%). ConclusionLVAS is highly correlated with MBF and CVR, with stress-induced improvement in synchronicity most strongly associated with improved MBF homogeneity.

Regional wall motion abnormalities during early diastole in patients with hypertensive left ventricular hypertrophy: a Doppler tissue echocardiographic study.

To investigate left ventricular wall motion asynchrony in patients with hypertensive heart disease, we measured regional myocardial velocity in hypertensive patients with left ventricular hypertrophy and in normotensive individuals using tissue Doppler imaging. The endocardial velocity and the myocardial velocity gradient were measured in the basal and mid segments of the septal and posterior walls. The dilating velocity of the left ventricular cavity were determined for the basal and mid ventricular segments of left ventricle. The peak myocardial velocity gradient was significantly lower in the hypertensive group than in the control group for all regions. The peak endocardial velocity during early diastole in the mid ventricular septum was significantly lower in the hypertensive group (Hypertensive vs Controls; 3.8 +/- 1.3 vs 5.1 +/1.6 cm/s, P < 0.05), whereas the peak endocardial velocity at the other three sites were similar in the two groups. The peak dilating velocity was significantly lower in the hypertensive group only in the mid portion of the left ventricle (Hypertensive vs Controls; 7.2 +/- 2.4 vs 9.8 +/- 1.3 s(-1), P < 0.005). These results suggest that there were regional wall motion abnormalities and nonuniformity during the early diastolic phase in the hypertensive hearts with left ventricular hypertrophy.

Assessment of subclinical cardiac damage in chronic plaque psoriasis patients: a case control study

IntroductionEpidemiological studies have suggested that patients with psoriasis are at an increased risk of developing cardiovascular diseases. Chronic inflammation may play a role in the pathogenesis of atherosclerosis in psoriasis patients. Recent studies have evaluated the expression of plasma endocan and homocysteine levels. Endocan is a marker of vascular endothelial damage, and homocysteine plays a role in the development of atherosclerosis. Plasma endocan and homocysteine levels, as well as echocardiographic parameters, were evaluated in patients with psoriasis to assess cardiovascular disease risk.Material and methodsThis was a prospective cohort analysis of 40 patients who were diagnosed with psoriasis and 40 healthy controls matched to the patient group according to demographic and biochemical parameters.ResultsSerum endocan and homocysteine concentrations were significantly higher in the psoriasis group than the control group (p < 0.001). Serum endocan concentrations correlated positively with disease duration (p < 0.001; r = 0.725). The Tei index (myocardial performance) was elevated in psoriasis patients (p < 0.001). Additionally, the E/A (mitral valve early diastolic peak flow velocity/mitral valve late diastolic peak flow velocity) and E/Em (early diastolic myocardial velocity) ratios were reduced in psoriasis patients (p < 0.001). Parameters indicative of left ventricular asynchrony were elevated significantly in the psoriasis group versus the control group (p < 0.001).ConclusionsWe observed a substantial increase in serum endocan and homocysteine concentrations, and significant differences in key parameters of cardiac function, in psoriasis patients relative to controls. These results are consistent with the hypothesis that subclinical cardiac damage is increased in patients with psoriasis and that psoriasis itself may be a cardiovascular risk factor.

Left ventricular remodeling in patients with right ventricular myocardial infarction

Aim . To study left ventricular (LV) remodeling, interventricular and intraventricular asynchrony in isolated inferior LV myocardial infarction (MI) or combined inferior LV MI with right ventricular (RV) MI. Material and methods. 57 patients with inferior LV MI with or without RV MI (n=57) were included in a 6-month prospective study. The patients were divided into 2 groups: Group 1 - patients with inferior LV MI (n=30); Group 2 - patients with inferior LV MI in combination with RV MI (n=27). Electrocardiography and echocardiography were performed in all patients at admission, on days 3, 30 and 180 after MI. Results. Significant signs of diastolic dysfunction (RV end-diastolic area 29.21±2.0 cm2) were found in group 2 on the third day after MI. A significant increase in the LV volume indices and diastolic sphericity index (from 0.54±0.02 to 0.59±0.03 units) and an increase in interventricular asynchrony (from 37.4±4.2 to 44.6±4.2 ms) were found in group 2 in 30 days after MI. Increasing tendency towards intraventricular and interventricular asynchrony, despite the absence of pathological LV remodeling, occurred in group 2 in 6 months after MI. Conclusion. Patients with RV MI have more pronounced maladaptive LV remodeling, intraventricular and interventricular asynchrony and greater LV diastolic dysfunction.

Upgrading and replacement in CRT devices: experience counts.

Cardiac resynchronisation therapy has proven to be highly effective in patients with heart failure and an asynchronous contraction pattern of the left ventricle, due to late activation of the posterolateral wall with left bundle branch block configuration on the ECG of more than 150 ms [1]. In pacemaker patients with a high percentage of right ventricular pacing, pacing-induced left ventricular (LV) dysfunction can appear. This newly developing heart failure is most probably the result of pacing-induced LV asynchrony. These patients with pacing-induced heart failure and ICD patients with heart failure who develop a wide QRS complex during follow-up account for the majority of patients who are eligible for an upgrade to a CRT device. In an European survey, up to 25 % of CRT implants were upgrading procedures [2]. The REPLACE registry demonstrated a high percentage of complications in upgrade and revision procedures in 434 CRT patients from 71 centres. It was not stated how many centres actually contributed to this total number of CRT upgrades [3]. Their conclusion ‘pacemaker and implantable cardioverter-defibrillator generator replacements are associated with a notable complication risk, particularly those with lead additions’ made cardiologists somewhat cautious and even reluctant to perform a therapeutic upgrade to CRT. These REPLACE data support careful decision making before device replacement when managing device advisories and when considering upgrades to more complex systems, concluded the authors [3]. And indeed, an upgrade procedure can be complicated and is in need of an experienced skilled operator or at least her or his direct supervision during the procedure. As experience is a major factor in reducing complications during and after device implantation [4], it is reasonable that experience is an even stronger denominator in complicated procedures as primary CRT implants and CRT upgrades. In this issue, the retrospective data of upgrading procedures to CRT devices were compared with the complications in primary CRT implants during the same period [5]. These retrospective data originate from one tertiary centre with a high patient load. Only three experienced operators performed the majority of procedures or supervised them. A: Total number of individual implants of 165 (62 %), including 82 upgrade procedures. Thirty assists of which 16 assists in an upgrade procedure. B: Total number of individual implants of 30 (11 %), including 13 upgrade procedures. Six assists of which 4 assists in an upgrade procedure. C: Total number of individual implants of 18 (7 %), including 9 upgrade procedures. Three assists of which 0 assists in an upgrade procedure. Though these data are retrospective, the complication rate is considerably lower when compared with the literature [3]. The most determining factor in the difference of complication rate is most likely skill, which comes from experience and cooperation during these complicated procedures. It was not investigated whether the determining factor was cooperation or experience or its combination.

Comparative study on ultrasonic assessments of left ventricular systolic synchronicity under different cardiac pacing modes

Objective To compare left ventricular (LV) synchronization of direct His-bundle pacing(DHBP) and right ventricular apical pacing (RVAP) with two-dimensional speckle tracking imaging (2D-STI) and tissue Doppler imaging (TDI), and discuss the diagnostic value of 2D-STI and TDI in evaluation of left ventricular systolic synchronicity. Methods Twenty-four patients implanted with DHBP and RVAP were observed. Conventional echocardiography examination were undergone both at the mode of DHBP or RVAP respectively. The time to peak radial strain of LV 18 segments were derived from the parasternal short-axis views by 2D-STI, then calculated the standard deviations (SD) and the maximal temporal difference of LV 18 segments (Trs-SD and Trs-Dif), and the interval of time to peak radial strain between the anteroseptal wall and the posterior wall(Tas-post). The time to peak systolic velocity of LV 12 segments were derived from the apical axis views by TDI. The SD and the maximal temporal difference of 12 segments (Ts-SD and Ts-Dif) were calculated as the LV dyssynchrony index. Results All the systolic synchrony parameters derived from 2D-STI and TDI were more significantly shortened in DHBP than in RVAP (all P<0.01). For DHBP, the detection rate of LV synchronization was higher by 2D-STI than by TDI. For RVAP the detection rate of LV dyssynchronization was also higher by 2D-STI than by TDI with RVAP lead (all P<0.05). Conclusions DHBP is more beneficial than RVAP in LV syschronization and LV function, RVAP may induce left ventricular systolic asynchrony. Both 2D-STI and TDI can assess the LV synchronization quantitatively, but 2D-STI may be more superior on the detection rate than TDI. Key words: Echocardiography; Cardiac pacing, artificial; Ventricular function, left

Improvement of Left Ventricular Asynchrony: Cases of Functional Recovery After Revascularization.

Assessment of regional contraction is considered important for diagnosis of coronary artery disease (CAD). We evaluated the synchronicity in regional contraction and assessed recovery from contraction insufficiency after revascularizations. Myocardial contraction parallel to the left ventricular (LV) wall was calculated using the method called quantification of segmental function by solving the Poisson equation (QSFP) from an electrocardiogram (ECG)-gated (99m)Tc-methoxyisobutylisonitrile (MIBI) single-photon emission computed tomographic (ECG-SPECT) image. Myocardial synchronous contraction was quantified using the synchronous contraction index (SCI), defined as the temporal correlation coefficient between LV volume and regional myocardial shortening. SCI was evaluated in 20 subjects, of whom 10 had CAD and 10 were normal. ECG-SPECT was performed in all the CAD patients before and after revascularization. In the 10 patients with CAD, the mean SCI before the revascularization was 62.7 ± 19.1%, which was significantly lower than that in the normal subjects (95.0 ± 3.0%, p = 0.002). After revascularization, a significant improvement in SCI was recorded (74.8 ± 11.1%, p = 0.01). The territorial improvement in SCI was 12.0 ± 15.6% (p = 0.03). Locations of abnormal cardiac contraction due to CAD were delineated by using QSFP. Therefore, SCI can be considered a valuable index for cardiac function assessment.

SAT0173 Assessment of Left Ventricular Dyssynchrony in Patients with Familial Mediterranean Fever

BackgroundFamilial Mediterranean fever (FMF) is a disease characterized by recurrent and sustained increased inflammatory activity. Various clinical and subclinical cardiovascular involvements have been reported in FMF patients. However, there is...