High prevalence of left ventricular systolic and diastolic asynchrony in patients with congestive heart failure and normal QRS duration

Association of serum albumin with heart failure mortality with NYHA class IV in Chinese patients: Insights from PhysioNet database (version 1.3)

BACKGROUND

Studies have proved that low albumin level is associated with increased mortality in most diseases, such as chronic kidney disease and hepatic cirrhosis. However, the relationship between albumin and all-cause death in heart failure patients in China is still unclear.

OBJECTIVES

We aimed to investigate the association between albumin level and 28-day mortality in Chinese hospitalized patients with NYHA IV heart failure.

METHODS

A total of 2008 Chinese patients were included. The correlation between serum albumin level and mortality was tested using a cox proportional hazards regression model. The smooth curve fitting was used to identify non-linear relationships between serum albumin and mortality. The Forest plot analysis was used to assess the association between albumin and 28-day mortality in different groups.

RESULTS

Compared with patients with NYHA II-III, patients with NYHA IV had lower albumin level and higher mortality within 28 days. The albumin on admission was independently and inversely associated with the endpoint risk, which remained significant (hazard ratio: 0.80; 95 % confidence interval: 0.66 to 0.96; p = 0.0196) after multivariable adjustment. The smooth curve fitting showed with the increase of albumin, the mortality within 28 days would decrease. A subgroup analysis found that the inverse association between the albumin level and risk of the mortality was consistent across the subgroup stratified by possible influence factors.

CONCLUSION

Serum albumin level is negatively associated with 28-day mortality in hospitalized heart failure patients within NYHA IV in China, which can be used as an independent predictor.

The association of Pulmonary Hypertension and right ventricular systolic function - updates in diagnosis and treatment

Right ventricular (RV) systolic function is an essential but neglected component in cardiac evaluation, and its importance to the contribution to overall cardiac function is undermined. It is not only sensitive to the effect of left heart valve disease but is also more sensitive to changes in pressure overload than the left ventricle. Pulmonary Hypertension is the common and well-recognized complication of RV systolic dysfunction. It is also the leading cause of pulmonary valve disease and right ventricular dysfunction. Patients with a high pulmonary artery pressure (PAP) and a low RV ejection fraction have a seven-fold higher risk of death than heart failure patients with a normal PAP and RV ejection fraction. Furthermore, it is an independent predictor of survival in these patients. In this review, we examine the association of right ventricular systolic function with Pulmonary Hypertension by focusing on various pathological and clinical manifestations while assessing their impact. We also explore new 2022 ESC/ERS guidelines for diagnosing and treating right ventricular dysfunction in Pulmonary Hypertension.

Usefulness of phase analysis on ECG gated single photon emission computed tomography myocardial perfusion imaging

Electrocardiogram (ECG)-gated single photon emission computed tomography myocardial perfusion imaging (GSPECT-MPI) is widely used for assessing coronary artery disease. Phase analysis on GSPECT-MPI can assess left ventricular mechanical dyssynchrony quantitatively on standard GSPECT-MPI alongside myocardial perfusion and function assessment. It has been shown that phase variables by GSPECT-MPI correlate well with tissue Doppler imaging by echocardiography. Main phase variables quantified by GSPECT-MPI are entropy, bandwidth, and phase standard deviation. Although those variables are automatically obtained from several software packages including Quantitative Gated SPECT and Emory Cardiac Toolbox, the methods for their measurement vary in each package. Several studies have shown that phase analysis has predictive value for response to cardiac resynchronization therapy and prognostic value for future adverse cardiac events beyond standard GSPECT-MPI variables. In this review, we summarize the basics of phase analysis on GSPECT-MPI and usefulness of phase analysis in clinical practice.

Relationship between intraventricular mechanical dyssynchrony and left ventricular systolic and diastolic performance: An in vivo experimental study

Left ventricular mechanical dyssynchrony (LVMD) refers to the nonuniformity in mechanical contraction and relaxation timing in different ventricular segments. We aimed to determine the relationship between LVMD and LV performance, as assessed by ventriculo-arterial coupling (VAC), LV mechanical efficiency (LV_eff ), left ventricular ejection fraction (LVEF), and diastolic function during sequential experimental changes in loading and contractile conditions. Thirteen Yorkshire pigs submitted to three consecutive stages with two opposite interventions each: changes in afterload (phenylephrine/nitroprusside), preload (bleeding/reinfusion and fluid bolus), and contractility (esmolol/dobutamine). LV pressure-volume data were obtained with a conductance catheter. Segmental mechanical dyssynchrony was assessed by global, systolic, and diastolic dyssynchrony (DYS) and internal flow fraction (IFF). Late systolic LVMD was related to an impaired VAC, LV_eff , and LVEF, whereas diastolic LVMD was associated with delayed LV relaxation (logistic tau), decreased LV peak filling rate, and increased atrial contribution to LV filling. The hemodynamic factors related to LVMD were contractility, afterload, and heart rate. However, the relationship between these factors differed throughout the cardiac cycle. LVMD plays a significant role in LV systolic and diastolic performance and is associated with hemodynamic factors and intraventricular conduction.

Evaluation of Cardiac Mechanical Dyssynchrony in Heart Failure Patients Using Current Echo-Doppler Modalities

BACKGROUND

Current guidelines indicate electrical dyssynchrony as the major criteria for selecting patients for cardiac resynchronization therapy, and 25–35% of patients exhibit unfavorable responses to cardiac resynchronization therapy (CRT). We aimed to evaluate different cardiac mechanical dyssynchrony parameters in heart failure patients using current echo-Doppler modalities and we analyzed their association with electrical dyssynchrony.

METHODS

The study included 120 heart failure with reduced ejection fraction (HFrEF) who underwent assessments for left ventricular mechanical dyssynchrony (LVMD) and interventricular mechanical dyssynchrony (IVMD).

RESULTS

Patients were classified according to QRS duration: group I with QRS < 120 ms, group II with QRS 120–149 ms, and group III with QRS ≥ 150 ms. Group III had significantly higher IVMD, LVMD indices, TS-SD speckle-tracking echocardiography (STE) 12 segments (standard deviation of time to peak longitudinal strain speckle tracking echocardiography in 12 LV-segments), and LVMD score compared with group I and group II. Group II and group III were classified according to QRS morphology into left bundle branch block (LBBB) and non-LBBB subgroups. LVMD score, TS-SD 12 TDI, and TS-SD 12 STE had good correlations with QRS duration.

CONCLUSIONS

HFrEF patients with wide QRS duration (> 150 ms) had more evident LVMD compared with patients with narrow or intermediate QRS. Those patients with intermediate QRS duration (120–150 ms) had substantial LVMD assessed by both TDI and 2D STE, regardless of QRS morphology. Subsequently, we suggest that LVMD indices might be employed as additive criteria to predict CRT response in that patient subgroup. Electrical and mechanical dyssynchrony were strongly correlated in HFrEF patients.

A Comparative Study of Systolic and Diastolic Mechanical Synchrony in Canine, Primate, and Healthy and Failing Human Hearts

Aim: Mechanical dyssynchrony (MD) is associated with heart failure (HF) and may be prognostically important in cardiac resynchronization therapy (CRT). Yet, little is known about its patterns in healthy or diseased hearts. We here investigate and compare systolic and diastolic MD in both right (RV) and left ventricles (LV) of canine, primate and healthy and failing human hearts. Methods and Results: RV and LV mechanical function were examined by pulse-wave Doppler in 15 beagle dogs, 59 rhesus monkeys, 100 healthy human subjects and 39 heart failure (HF) patients. This measured RV and LV pre-ejection periods (RVPEP and LVPEP) and diastolic opening times (Q-TVE and Q-MVE). The occurrence of right (RVMDs) and left ventricular systolic mechanical delay (LVMDs) was assessed by comparing RVPEP and LVPEP values. That of right (RVMDd) and left ventricular diastolic mechanical delay (LVMDd) was assessed from the corresponding diastolic opening times (Q-TVE and Q-MVE). These situations were quantified by values of interventricular systolic (IVMDs) and diastolic mechanical delays (IVMDd), represented as positive if the relevant RV mechanical events preceded those in the LV. Healthy hearts in all species examined showed greater LV than RV delay times and therefore positive IVMDs and IVMDd. In contrast a greater proportion of the HF patients showed both markedly increased IVMDs and negative IVMDd, with diastolic mechanical asynchrony negatively correlated with LVEF. Conclusion: The present IVMDs and IVMDd findings have potential clinical implications particularly for personalized setting of parameter values in CRT in individual patients to achieve effective treatment of HF.

Mechanical dyssynchrony: How do we measure it, what it means, and what we can do about it

Left ventricular mechanical dyssynchrony (LVMD) is defined by a difference in the timing of mechanical contraction or relaxation between different segments of the left ventricle (LV). Mechanical dyssynchrony is distinct from electrical dyssynchrony as measured by QRS duration and has been of increasing interest due to its association with worse prognosis and potential role in patient selection for cardiac resynchronization therapy (CRT). Although echocardiography is the most used modality to assess LVMD, some limitations apply to this modality. Compared to echo-based modalities, nuclear imaging by gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) has clear advantages in evaluating systolic and diastolic LVMD. GSPECT MPI can determine systolic and diastolic mechanical dyssynchrony by the variability in the timing in which different LV segments contract or relax, which has prognostic impact in patients with coronary artery disease and heart failure. As such, by targeting mechanical dyssynchrony instead of electrical dyssynchrony, GSPECT MPI can potentially improve patient selection for CRT. So far, few studies have investigated the role of diastolic dyssynchrony, but recent evidence seems to suggest high prevalence and more prognostic impact than previously recognized. In the present review, we provide an oversight of mechanical dyssynchrony.

Clinical Significance of Right Ventricular Function in Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive disease characterized by increased pulmonary vascular resistance that leads to right ventricular (RV) failure, a condition that determines its prognosis. This review focuses on the clinical value of the evaluation of RV function in PH. First, the pathophysiology of PH, including hemodynamics, RV function, and their interaction (known as ventriculoarterial coupling), are summarized. Next, non-invasive imaging modalities and the parameters of RV function, mainly assessed by echocardiography, are reviewed. Finally, the clinical impacts of RV function in PH are described. This review will compare the techniques that yield comprehensive information on RV function and their roles in the assessment of PH.

Poorer Exercise Accommodation of Regional Systolic Myocardial Motion after Spironolactone Treatment in Heart Failure Patients with Preserved Ejection Fraction and Ventricular Dyssynchrony

Patients with heart failure and preserved ejection fraction (HFpEF) are known to have reduced systolic myocardial velocity (Sm) with impaired accommodation to exercise. We tested the impact of an aldosterone antagonist on Sm at rest and post-exercise. Forty-nine HFpEF patients (65 ± 11 years, 24 male) with HF signs/symptoms, mitral E/Ea (annular early diastolic velocity) > 8, and left ventricular (LV) EF > 50% were randomized to spironolactone (25 mg/day, 25 patients) or the Control. At baseline and 6 months, we analyzed Sm of basal LV segments at rest and after a 6 min treadmill exercise. At 6 months, post-exercise mean Sm in the spironolactone group became greater than that in the Control (9.2 ± 1.6 vs. 8.3 ± 1.0 cm/s, p = 0.021), mainly due to the increment of post-exercise % increase of lateral Sm (44 ± 30 vs. 30 ± 19% at baseline, p = 0.045). Further analyses showed the presence of systolic dyssynchrony (standard deviation of electromechanical delay of 6-basal LV segments > 35 ms) was independently associated with a poorer response to spironolactone, defined as a post-exercise % increase of lateral Sm < 50% (OR = 2.7, 95% CI = 1.8–4.2) and the increment of Ea < 1.5 cm/s (OR = 1.5, 95% CI = 1.1–2.3). Spironolactone could improve exercise accommodation of regional systolic myocardial velocity for HFpEF patients. However, its benefits could be decreased in those with ventricular dyssynchrony. This suggested possible therapeutic impacts from underlying heterogeneity within HFpEF patients.

Left ventricular dyssynchrony assessment using tissue synchronization imaging in acute myocardial infarction

Objectives:

To assess left ventricular (LV) dyssynchrony in patients with ST elevation myocardial infarction (STEMI).

Background:

Mechanical synchronization disorder leads to a decrease in LV ejection fraction (LVEF) and stroke volume, an abnormal distribution of wall tension, and increase in workload during cardiac contraction.

Methods:

We enrolled 56 participants, 36 with acute STEMI and 20 healthy controls. The automatically color-coded time to peak myocardial velocity was measured using a 6mm sample volume, manually positioned within the two-dimensional-tissue strain image of the 12 basal and middle LV segments.

Results:

A significant delay was found between the septal-lateral and septal-posterior walls in patients with STEMI compared to patients in the control group (36.36 vs. −6.0ms, P = 0.036; and 42.7 vs. 23.94ms, P = 0.042, respectively). Furthermore, all segment maximum differences and all segment standard deviation (SD; dyssynchrony index) were found to be significantly higher in the STEMI group (131.28 vs. 95.45ms, P = 0.013; and 44.47 vs. 26.45ms, P = 0.001, respectively). A significant delay between the septal-lateral walls and septal-posterior walls, all segment maximum difference, and all segment SD (dyssynchrony index) were found in patients with complicated STEMI (70.89 vs. 15.83ms, P = 0.038; 57.44 vs. 19.06ms, P = 0.040; 138.11 vs. 100.0ms, P = 0.035; and 45.44 vs. 32.50ms, P = 0.021, respectively). There was a significant negative correlation between tissue synchronization imaging parameters and LVEF, and a positive correlation with LV end systolic dimension.

Conclusion:

Patients with acute STEMI showed significant LV dyssynchrony, which was an independent predictor of inhospital complications.

The Effect of Clinical Characteristics and Stent Parameters on Left Ventricular Mechanical Dyssynchrony

Aim. To study short term effect of stent size and number on left ventricular mechanical dyssynchrony after elective percutaneous coronary intervention (PCI) to left anterior descending (LAD) artery.

Materials and methods. the study included 150 adult patients with LAD lesion treated with PCI using drug-eluting stent. Patients were evaluated pre PCI then 1 month and 3 months post PCI for evaluation of mechanical dyssynchrony using tissue synchronization image (TSI).

Results. Before revascularization mean left ventricular ejection fraction was 51.2±5.7 %, mean time to peak TSI was 213.6±10.9 ms; 1 month after PCI TSI improved significantly to 163.7±17.6 ms (p<0.001), 3 months after PCI showed more improvement to 120.7±26.9 ms (p<0.001). After 3m; 61 patients (40.7%) showed recovery to normal TSI value. The predictors of non-improvement of time to peak TSI after 3 months were diabetes mellitus (p=0.007), dyslipidemia (p=0.001) and stent length (p=0.001), number of stents (p=0.004). There were strong negative correlation between stent length and improvement of the time to peak TSI at 1 month (r=-0.352, p<0.001) and at 3 months (r=-0.509, p<0.001),and also with number of stent at 1 month (r= -0.173, p=0.034) and at 3 months (r=-0.499, p<0.001), but the correlation between stent diameter and improvement of the TSI wasn’t significant neither at 1 month nor at 3 months (r=0.055, p=0.504 and r= -0.018, p=0.827) respectively.

Conclusion. Increased number and length of the implanted stents were predictors to non-improvement of mechanical dyssynchrony, while stent diameter didn’t affects the recovery.

Cardiac Resynchronization Therapy in Patients with Heart Failure: What is New?

Cardiac resynchronization therapy (CRT) is an established treatment of patients with medically refractory, mild-to-severe systolic heart failure (HF), impaired left ventricular function, and wide QRS complex. The pathologic activation sequence observed in patients with abnormal QRS duration and morphology results in a dyssynchronous ventricular activation and contraction leading to cardiac remodeling, worsening systolic and diastolic function, and progressive HF. In this article, the authors aim to explore the current CRT literature, focusing their attentions on the promising innovation in this field.

Efficacy of Cardiac Resynchronization Therapy in Patients with a Narrow QRS Complex

Aims. In the guidelines for cardiac resynchronization therapy (CRT), there is a gap between the Japanese Circulation Society (JCS) criteria, which specify a QRS duration of ≥120 ms, and other countries, with a QRS ≥ 130 ms. The efficacy of CRT remains controversial in patients with a narrow QRS <130 ms. The aims of this study are to evaluate the response to CRT in patients with a narrow QRS and to identify predictors of mortality. Methods. We retrospectively studied 212 patients who received CRT. They were divided into narrow QRS (<130 ms) and wide QRS (≥130 ms) groups. We compared CRT response rates and investigated whether age, gender, baseline New York Heart Association (NYHA) class, ischemic etiology, atrial fibrillation, and ventricular arrhythmias are associated with response and also predictive of mortality. Results. The CRT response rate was not significantly different between the wide QRS group and the narrow QRS group (74.6% versus 77.2%, $p$  = 0.6876), and the response rate in the narrow QRS group was as good as that reported worldwide. NYHA class IV was shown to be a predictor of mortality (HR 9.38, 95% CI 5.35–16.3, $p$  < 0.0001). Conclusions. The present study demonstrated that patients with a narrow QRS complex responded well to CRT. Even with QRS <130 ms, CRT should be tried if no other effective treatment is available.

Changes in strain parameters at different deterioration levels of left ventricular function: A cardiac magnetic resonance feature-tracking study of patients with left ventricular noncompaction

BACKGROUND

There is a lack of cardiac MRI information on left ventricular (LV) strain and rotational parameters of left ventricular noncompaction (LVNC) patients with reduced ejection fraction (EF). Thus, we sought to use feature tracking (FT) to describe these changes at different levels of EF deterioration.

METHODS

We included 31 adult LVNC patients with reduced LV EF (Group B, EF < 50%) without any comorbidities or concomitant cardiac diseases, 31 age- and sex-matched LVNC patients with good EF (Group A, EF > 50%) and 31 healthy controls. Group B was divided according to LV EF into two subgroups (Group B-1: EF 35-50%, Group B-2: EF < 35%). Their global longitudinal, circumferential (GCS), and radial (GRS) strains; LV segmental strains; LV apical and basal rotation values; and patterns and degree of LV dyssynchrony were measured.

RESULTS

All of the global and mean segmental strain parameters were significantly worse in Groups B, B-1 and B-2 than in Group A and in the controls. The LV mechanical dispersion increased as LV EF decreased. The degree of apical rotation was the highest in the control group, almost the same in Group A and the lowest and in the reverse direction in Group B-2. A rotational pattern, clockwise-directed rigid body rotation (RBR), was found in 39% of the Group B patients, and a counterclockwise-directed RBR was found in 26% of the Group A patients.

CONCLUSIONS

The strain values and rotational parameters changed as the EF decreased. These changes affected the global LV, and we did not identify an LVNC-specific strain pattern.

Prognostic value of integrative analysis of electrical and mechanical dyssynchrony in patients with acute heart failure

BACKGROUND

Left ventricular mechanical dyssynchrony has been shown to provide significant clinical values for chronic heart failure (HF) and cardiac resynchronization therapy (CRT). The purpose of this study was to evaluate whether electrical dyssynchrony combined with mechanical dyssynchrony has an incremental benefit over electrical dyssynchrony or mechanical dyssynchrony alone to predict clinical events in patients with acute heart failure (AHF).

METHODS

Ninety-six AHF patients who received standard 12-lead ECG, gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), and echocardiography were enrolled. Thirty-two normal subjects were collected as the control group to get the normal database of mechanical dyssynchrony. The end point is the composite of all-cause death and heart transplantation. Electrical dyssynchrony was defined as QRS duration > 120 ms. Mechanical dyssynchrony was defined as > mean + 2 × SD phase standard deviation (PSD) or phase bandwidth (PBW) based on our normal database.

RESULTS

During the follow-up of 28 ± 10 months, complete data were obtained in 92 patients. 26 (28.3%) Patients who reached the end point were classified into the event group. There were no significant differences in PSD or PBW between the event and non-event groups. However, PBW > 77.76° was independently associated with the end point in the univariate and multivariate analysis (hazard ratio 2.92, 95% confidence interval 1.00-8.47, P = .049; hazard ratio 3.89, 95% confidence interval 1.01-14.97, P = .048). The Kaplan-Meier curve with a log-rank test showed that the end point rate was significantly higher in the patients with PBW > 77.76° (log-rank P = .039). Moreover, the ROC curve analysis showed that the area under the curve (AUC) for predicting end point events by the integrative analysis of QRS > 120 ms and PBW > 77.76° was significantly improved compared to QRS duration > 120 ms (AUC: 0.75 vs 0.68, P = .001) or PBW > 77.76° (AUC: 0.75 vs 0.62, P = .049), respectively. The model of combined electrical and mechanical dyssynchrony yielded a further significantly improved risk prediction for adverse events in the global χ2.

CONCLUSIONS

The combination of QRS duration > 120 ms and PBW > 77.76° was an independent predictor of all-cause death and heart transplantation in AHF patients. The integrative analysis of electrical and mechanical dyssynchrony provides incremental prognostic value for clinical use.

Optimal pacing sites in cardiac resynchronization by left ventricular activation front analysis

Cardiac resynchronization therapy (CRT) can substantially improve dyssynchronous heart failure and reduce mortality. However, about one-third of patients who are implanted, derive no measurable benefit from CRT. Non-response may partly be due to suboptimal activation of the left ventricle (LV) caused by electrophysiological heterogeneities. The goal of this study is to investigate the performance of a newly developed method used to analyze electrical wavefront propagation in a heart model including myocardial scar and compare this to clinical benchmark studies. We used computational models to measure the maximum activation front (MAF) in the LV during different pacing scenarios. Different heart geometries and scars were created based on cardiac MR images of three patients. The right ventricle (RV) was paced from the apex and the LV was paced from 12 different sites, single site, dual-site and triple site. Our results showed that for single LV site pacing, the pacing site with the largest MAF corresponded with the latest activated regions of the LV demonstrated during RV pacing, which also agrees with previous markers used for predicting optimal single-site pacing location. We then demonstrated the utility of MAF in predicting optimal electrode placements in more complex scenarios including scar and multi-site LV pacing. This study demonstrates the potential value of computational simulations in understanding and planning CRT.

Evaluation of right ventricular dyssynchrony in patients with acute inferior myocardial infarction and its relation with mortality

PURPOSE

The aim of this study was to evaluate right ventricle (RV) dyssynchrony and its relation with mortality using speckle-tracking echocardiography (STE) in patients with acute inferior myocardial infarction (IMI).

METHODS

One hundred and fifty-eight consecutive patients with acute IMI treated with primary percutaneous coronary intervention, and 44 healthy subjects were included. RV myocardial involvement (RVMI) was defined as an elevation >1 mm in V1 or V4R and/or the presence of a culprit lesion at the proximal portion of the first RV marginal branch after reviewing coronary angiography. Patients were followed for 3 years to determine the cardiovascular mortality.

RESULTS

Overall, 70 patients with IMI had RVMI. IMI patients had significantly higher RV peak systolic longitudinal strain dyssynchrony (PLSSD) index, lower peak longitudinal systolic strain (PLSS), longer time to PLSS, and time to PLSS differences compared to healthy controls while the patients with RVMI had significantly worse values compared to patients without RVMI and healthy controls. Twenty-seven patients (17.1%) died within 2 years. RVMI was more prevalent in mortality group, and they had significantly higher RV PSSD index, whereas they had lower RV free wall PLSS and longer time to PLSS differences. Receiver operating characteristics (ROC) analysis revealed that a RV PLSSD index > 65 ms predicted mortality with a sensitivity of 88.9% and specificity of 71.8% in IMI patients.

CONCLUSIONS

Intra- and inter-ventricular dyssynhcrony may develop in patients with acute IMI, especially in those with RV involvement, which might have a negative effect on the prognosis of these patients.

Left ventricular systolic dyssynchrony in patients with Kawasaki disease: a real-time three-dimensional echocardiography study

The left ventricular (LV) systolic dyssynchrony index (SDI) is an important prognostic indicator for many cardiovascular diseases; however, the characteristics of the SDI in patients with Kawasaki disease (KD) are unknown. In this study, we aimed to identify and quantify the SDI using real-time three-dimensional echocardiography (RT3DE) in KD patients during different phases. In addition, we intended to explore whether the SDI is associated with systolic dysfunction. Seventy consecutive KD patients and seventy age- and sex-matched controls were enrolled. The SDIs (percent of cardiac cycle) of 16 segments (16-SDI%) and 12 segments (12-SDI%) were calculated based on the defined standard deviation of each segment time from end diastole to the minimal systolic volume according to the 17-segment model (apex excluded). In the acute phase, the 16-SDI% and 12-SDI% were significantly higher in KD patients than in controls (4.40 ± 0.14 vs. 1.98 ± 0.12, P = 0.000; 3.55 ± 1.21 vs. 1.67 ± 0.93, P = 0.009, respectively), and patients with coronary artery aneurysm (CAA) exhibited higher 16-SDI% (P = 0.021) and 12-SDI% (P = 0.034) than patients without CAA. In the convalescent phase, patients with CAA still had higher 16-SDI% (P = 0.002) and 12-SDI% (P = 0.031) than controls, while the SDI in patients without CAA recovered to normal. The 16-SDI% was negatively correlated with the LV ejection fraction obtained from RT3DE (r = - 0.845, P = 0.000). Mechanical dyssynchrony is prevalent in KD patients during the acute phase and transient in patients without CAA, while patients with CAA still have impaired synchrony even in the convalescent phase. LV systolic dysfunction is associated with increased dyssynchrony. RT3DE is a valuable modality for identifying and quantifying dyssynchrony in KD patients.

Quantitative mechanical dyssynchrony in dilated cardiomyopathy measured by deformable registration algorithm

OBJECTIVES

To investigate the diagnostic value and reproducibility of deformable registration algorithm (DRA)-derived mechanical dyssynchrony parameters in dilated cardiomyopathy (DCM) patients.

METHODS

The present study included 80 DCM patients (40 with normal QRS duration (NQRS-DCM); 40 with left bundle branch block (LBBB-DCM)) and 20 healthy volunteers. The balanced steady-state free-precession (bSSFP) cine images were acquired using a 3.0T scanner. Mechanical dyssynchrony parameters were calculated based on DRA-derived segmental strain, including uniformity ratio estimate (URE) and standard derivation of time-to-peak (T2Psd) parameters in circumferential, radial, and longitudinal orientations.

RESULTS

DCM patients showed significant mechanical dyssynchrony reflected by both URE and T2Psd parameters compared with controls. Among DCM patients, LBBB-DCM showed decreased CURE (0.78 ± 0.21 vs. 0.93 ± 0.05, p < 0.001) and RURE (0.69 ± 0.14 vs. 0.83 ± 0.15, p = 0.001), and increased T2Psd-Ecc (median with interquartile range, 94.1 (54.4-123.2) ms vs. 63.7 (44.9-80.4) ms, p = 0.003) and T2Psd-Err (91.1 (61.1-103.2) ms vs. 62.3 (46.3-104.5) ms, p = 0.041) compared with NQRS-DCM patients. CURE showed a strong correlation with QRS duration (r = - 0.54, p < 0.001), with maximum AUC (0.791) to differentiate LBBB-DCM from NQRS-DCM patients. Improved intra- and inter-observer reproducibility was found using URE indices (coefficient of variation (CoV), 1.20-3.17%) than T2Psd parameters (CoV, 15.28-41.18%).

CONCLUSIONS

The DRA-based CURE showed significant correlation with QRS duration and the highest discriminatory value between LBBB-DCM and NQRS-DCM patients. URE indices showed greater reproducibility compared with T2Psd parameters for assessing myocardial dyssynchrony in DCM patients.

KEY POINTS

• The strain analyses based on DRA suggested that DCM patients have varying degrees of mechanical dyssynchrony and there is a significant difference from normal controls. • CURE showed the strongest correlation with QRS duration and was the best parameter for differentiating DCM patients with normal QRS duration from patients with LBBB, and with normal controls. • URE indices showed improved reproducibility compared with T2Psd parameters in all three orientations (circumferential, radial, and longitudinal).

Comparison of left ventricular and biventricular pacing: Rationale and clinical implications

Cardiac resynchronization therapy constitutes a cornerstone in advanced heart failure treatment, when there is evidence of dyssynchrony, especially by electrocardiography. However, it is plagued both by persistently high (~30%) rates of nonresponse and by deterioration of right ventricular function, owing to iatrogenic dyssynchrony in the context of persistent apical pacing to ensure delivery of biventricular pacing. Left ventricular pacing has long been considered an alternative to standard biventricular pacing and can be achieved as easily as inserting a single pacing electrode in the coronary sinus. Although monoventricular left ventricular pacing has been proven to yield comparable results with the standard biventricular modality, it is the advent of preferential left ventricular pacing, combining both the powerful resynchronization potential of multipolar coronary sinus and right-sided electrodes acting in concert and the ability to preserve intrinsic, physiological right ventricular activation. In this review, we aim to present the underlying principles and modes for delivering left ventricular pacing, as well as to highlight advantages of preferential over monoventricular configuration. Finally, current clinical evidence, following implementation of automated algorithms, regarding performance of left ventricular as compared with biventricular pacing will be discussed. It is expected that the field of preferential left ventricular pacing will grow significantly over the following years, and its combination with other advanced pacing modalities may promote clinical status and prognosis of patients with advanced dyssynchronous heart failure.

Global Left Ventricular Myocardial Work Efficiency in Healthy Individuals and Patients with Cardiovascular Disease

BACKGROUND

Global left ventricular (LV) myocardial work efficiency, the ratio of constructive to wasted work in all LV segments, reflects the efficiency by which mechanical energy is expended during the cardiac cycle. Global LV myocardial work efficiency can be derived from LV pressure-strain loop analysis incorporating both noninvasively estimated blood pressure recordings and echocardiographic strain data. The aim of this study was to characterize global LV myocardial work efficiency in healthy individuals and patients with cardiovascular (CV) risk factors or overt cardiac disease.

METHODS

We retrospectively included healthy individuals without structural heart disease or CV risk factors, who were selected from an ongoing database of normal individuals, and matched for age and sex with (1) individuals without structural heart disease but with CV risk factors, (2) postinfarct patients without heart failure, and (3) heart failure patients with reduced ejection fraction (HFrEF). Global LV myocardial work efficiency was estimated with a proprietary algorithm from speckle-tracking strain analyses, as well as noninvasive blood pressure measurements.

RESULTS

In total, 120 individuals (44% male, 53 ± 13 years) were included (n = 30 per group). In healthy individuals without structural heart disease or CV risk factors, global LV myocardial work efficiency was 96.0% (interquartile range, 95.0%-96.3%). Myocardial efficiency of the LV did not differ significantly between individuals without structural heart disease and those with CV risk factors (96.0% vs 96.0%; P = .589). Global LV myocardial work efficiency, however, was significantly decreased in postinfarct patients (96.0% vs 93.0%, P < .001) and in those with HFrEF (96.0% vs 69.0%; P < .001).

CONCLUSIONS

While global LV myocardial work efficiency was similar in normal individuals and in those with CV risk factors, it was decreased in postinfarct and HFrEF patients. The global LV myocardial work efficiency values presented here show distinct patterns in different cardiac pathologies.

Cardiac Resynchronisation Therapy and Cellular Bioenergetics: Effects Beyond Chamber Mechanics

Cardiac resynchronisation therapy is a cornerstone in the treatment of advanced dyssynchronous heart failure. However, despite its widespread clinical application, precise mechanisms through which it exerts its beneficial effects remain elusive. Several studies have pointed to a metabolic component suggesting that, both in concert with alterations in chamber mechanics and independently of them, resynchronisation reverses detrimental changes to cellular metabolism, increasing energy efficiency and metabolic reserve. These actions could partially account for the existence of responders that improve functionally but not echocardiographically. This article will attempt to summarise key components of cardiomyocyte metabolism in health and heart failure, with a focus on the dyssynchronous variant. Both chamber mechanics-related and -unrelated pathways of resynchronisation effects on bioenergetics – stemming from the ultramicroscopic level – and a possible common underlying mechanism relating mechanosensing to metabolism through the cytoskeleton will be presented. Improved insights regarding the cellular and molecular effects of resynchronisation on bioenergetics will promote our understanding of non-response, optimal device programming and lead to better patient care.

Diastolic dyssynchrony and its exercise-induced changes affect exercise capacity in patients with heart failure with reduced ejection fraction

BACKGROUND

Left ventricular diastolic dyssynchrony is common in patients with heart failure with reduced ejection fraction (HFREF). Little is known however, about its pathophysiology and clinical effects. Herein is hypothesized that presence of diastolic dyssynchrony at rest or at exercise may importantly contribute to HF symptoms. The aim was to investigate the influence of diastolic dyssynchrony and its exercise-induced changes on exercise capacity in HFREF patients.

METHODS

Patients with stable, chronic HF, left ventricular ejection fraction < 35%, sinus rhythm and QRS ≥ 120 ms were eligible for the study. Rest and cyclo-ergometer exercise echocardiography were performed. Diastolic dyssynchrony was defined as opposing-wall-diastolic-delay ≥ 55 ms measured in tissue-Doppler imaging. Exercise capacity was assessed by peak oxygen consumption (VO2peak). Association between diastolic dyssynchrony and VO2peak was assessed in univariate regression analysis and further adjusted for possible confounders.

RESULTS

Fourty eight patients were included (aged 63.7 ± 12.2). Twenty-seven (56.25%) had diastolic dyssynchrony at rest and 13 (27%) at exercise. Twenty-two (46%) experienced a change in diastolic dyssynchrony status during exercise. In univariate models diastolic dyssynchrony at rest or at exercise were associated with lower VO2peak (beta coefficient = -3.8, p = 0.004; beta coefficient = -3.6, p = 0.02, respectively). However, the ability to restore diastolic synchronicity during exercise was associated with higher VO2peak (beta coefficient = 3.4, p = 0.04) and remained an important predictor of exercise capacity after adjustment for age and HF etiology.

CONCLUSIONS

The ability to restore diastolic synchronicity at exercise predicts exercise capacity in patients with HFREF.

Benefits of Multisite/Multipoint Pacing to Improve Cardiac Resynchronization Therapy Response

This article provides a general overview of the underlying mechanisms that support pacing from more discrete points and/or a wider vector (multisite and multipoint pacing) to improve left ventricular resynchronization. We performed a critical overview of the current literature and to identify some remaining knowledge gaps to spur further research. It was not our goal to provide a systematic review with a comprehensive bibliography, but rather to focus on selected publications that, in our opinion, have either expertly reviewed a specific aspect of cardiac resynchronization therapy or have been landmark studies in the field.

Left ventricular phase entropy: Novel prognostic predictor in patients with dilated cardiomyopathy and narrow QRS

BACKGROUND

The prognostic impact and pathophysiology of global left ventricular mechanical dyssynchrony (LVMD), namely mechanical dyssynchrony of whole left ventricle, as assessed by phase analysis of electrocardiographically gated (ECG-gated) myocardial perfusion SPECT has not been clearly elucidated in patients with dilated cardiomyopathy (DCM) and narrow QRS complex (<120 ms).

METHODS AND RESULTS

Forty-six patients with DCM underwent ECG-gated myocardial 99mTc-sestamibi perfusion SPECT and endomyocardial biopsy. LV phase entropy was automatically calculated using a phase analysis of ECG-gated myocardial perfusion SPECT. The patients were divided into two groups according to the median phase entropy value: low-phase entropy (<0.61) (N = 23: LE group) and high-phase entropy (≥0.61) (N = 23: HE group). In the Kaplan-Meier survival analysis, the event-free survival rate was significantly lower in the HE group (log-rank P = 0.015). Moreover, high-phase entropy was an independent predictor of adverse cardiac events (hazard ratio, 5.77%; 95% confidence interval, 1.02-108.32; P = 0.047). Interestingly, the mRNA expression levels of sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) in endomyocardial biopsy specimens were significantly lower in the HE group (P = 0.015).

CONCLUSION

LV phase entropy, which may reflect impairment of Ca2+ handling caused by decreased SERCA2a mRNA levels, is a novel prognostic predictor in patients with DCM and narrow QRS complex.

The interaction of QRS duration with cardiac magnetic resonance derived scar and mechanical dyssynchrony in systolic heart failure: Implications for cardiac resynchronization therapy

Background

Trials using echocardiographic mechanical dyssynchrony (MD) parameters in narrow QRS patients have shown a negative response to CRT. We hypothesized MD in these patients may relate to myocardial scar rather than electrical dyssynchrony.

Methods

We determined the prevalence of cardiac magnetic resonance (CMR) derived measures of MD in 130 systolic heart failure patients with both broad (≥ 130 ms - BQRS) and narrow QRS duration (< 130 ms - NQRS). We assessed whether late gadolinium enhancement derived scar might explain the presence of MD amongst narrow QRS patients. Dyssynchrony was calculated on the basis of a systolic dyssynchrony index (SDI).

Results

Fifty-nine patients (45%) had a NQRS and the remaining had QRS ≥ 130 ms (BQRS group). 25% of NQRS patients had MD based on SDI. In all narrow and broad QRS patients with MD there was a significantly lower scar volume than those without MD (7.4 ± 10.5% vs 13.7 ± 13.3% vs. p < 0.01). This was the case in the BQRS group with a significantly lower scar burden in patients with MD (5.0 ± 7.7% vs 15.4 ± 15.6%, p < 0.01). Notably in the NQRS group this difference was absent with an equal scar burden in patients with MD 13.3 ± 13.9% and without MD 12.5 ± 11%, p = 0.92.

Conclusions

25% of patients with systolic heart failure and a NQRS (< 130 ms) have CMR derived mechanical dyssynchrony. Our findings suggest MD in this group may be secondary to myocardial scar rather than electrical dyssynchrony and therefore not amenable to correction by CRT. This may give insight into non-response and potential harm from CRT in this group.

Right ventricular dyssynchrony and its improvements after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

PURPOSE

Whether pathologic alterations of right ventricle (RV) in chronic obstructive pulmonary disease (COPD) affect intra- and interventricular dyssynchrony due to changes in mechanical activation of the septum and RV is unclear. The aim of this study was to determine mechanical activation and its changes after pulmonary rehabilitation program (PRP) with speckle tracking echocardiography (STE) in COPD patients.

METHODS

After the exclusion of 15 patients due to poor echogenicity and 5 patients not tolerating PRP out of 69 consecutive COPD patients undergoing PRP, the remaining 49 patients and 41 healthy subjects were enrolled. The mechanical activations of both ventricles were evaluated at admission and after PRP with STE.

RESULTS

Chronic obstructive pulmonary disease patients had intra- and interventricular dyssynchrony compared to controls. The interventricular dyssynchrony assessed by time to peak longitudinal systolic strain (PLSS) difference between RV free wall and left ventricle (LV) lateral wall and intraventricular dyssynchrony assessed by RV peak systolic strain dyssynchrony (PSSD) index were improved after PRP. In all, 18 patients were hospitalized due to symptoms of right heart failure within 1 year. The time to PLSS difference between RV free wall and LV lateral wall and RV PSSD index were independent predictors of hospitalization. Receiver operating characteristics (ROC) analysis revealed that a time to PLSS difference between RV free wall and LV lateral wall >15 ms predicted hospitalization within 1 year with 77.8% sensitivity and 64.5% specificity.

CONCLUSIONS

Chronic obstructive pulmonary disease was associated with intra- and interventricular dyssynchrony. PRP had an important impact on the improvement of both intra-, and interventricular dyssynchrony, which might be used in predicting hospitalization within 1 year.

Prognostic value of three-dimensional echocardiographic right ventricular ejection fraction in patients with pulmonary arterial hypertension

Background

Right ventricular (RV) function is an independent predictor of clinical outcomes in patients with pulmonary arterial hypertension (PAH). However, it remains controversial which RV parameter should be measured as an appropriate index for the treatment of PAH. The aim of this study was to identify the most useful parameter that correlates with hemodynamics and predicts clinical outcomes in PAH.

Results

Most of the clinical and echocardiographic RV parameters were significantly correlated with pulmonary vascular resistance (PVR) as well as mean pulmonary arterial pressure (mPAP). Among these, three dimensional right ventricular ejection fraction (3DRVEF) showed the strongest hemodynamic correlation, followed by 6-minute walk distance. Receiver operating characteristic analysis of association with cardiac events including death, hospitalization, and intervention revealed a greater area under the curve for 3DRVEF than for mPAP (0.78 vs. 0.74). Kaplan-Meier analysis showed that patients with 3DRVEF less than 38% had significantly shorter event-free survival than those with greater than 38% (P = 0.0007). Finally, the Cox proportional hazards analysis revealed that 3DRVEF, but not mPAP, was an independent predictor of clinical events in PAH.

Materials and Methods

Eighty-six consecutive patients were enrolled in this study. RV hemodynamic parameters were measured by right heart catheterization (RHC). RV function was assessed using two-dimensional speckle-tracking echocardiography and three-dimensional transthoracic echocardiography (3DTTE) to evaluate RV free wall global strain (RVFS) and RVEF.

Conclusions

RVEF measured by 3DTTE could be a useful parameter for noninvasively assessing RV hemodynamics and predicting the clinical outcomes in PAH patients.

Relationship between QRS measurements and left ventricular morphology and function in asymptomatic individuals

BACKGROUND AND AIM

QRS amplitude and duration are associated with increased left ventricular (LV) volume, mass and dysfunction. However, the diagnostic concordance between QRS measurements and LV morphology and function, as shown by Doppler echocardiography, is not well established. We investigated the relationships of QRS duration and amplitude with echocardiographic measurements of LV morphology and systolic and diastolic function in normal individuals.

METHODS

Individuals without signs or symptoms of coronary artery disease or heart failure, who underwent clinical examination as a part of a cross-sectional survey for the prevalence of coronary risk factors, randomly selected from the population list in Caltanissetta, Italy, were included in the study. QRS duration and amplitude were automatically measured using inbuilt software. LV ejection and filling patterns were studied using Doppler echocardiography.

RESULTS

We studied 184 individuals (96 men and 88 women), mean age 55.9 (11.3). QRS duration increased by 5.4 ms for every 100 g increase in LV mass, and by 4.6 ms for each 10 mm increase in LV end-diastolic diameter. The amplitude increased by 0.8 mm for every 100 g increase in LV mass. There was no relationship with LV dimensions. A nonlinear correlation was found between QRS amplitude and indexes of global dyssynchrony. The time-voltage QRS area correlated with LV mass, dimensions and indexes of dyssynchrony. There was no relationship between QRS measurements and ejection fraction.

CONCLUSIONS

QRS prolongation and increase in amplitude are strongly influenced by LV increased mass and volume, as well as by dyssynchrony, independently of ejection fraction.

Three-dimensional echocardiographic evaluation of mechanical dyssynchrony in systolic heart failure with narrow QRS complex

Objectives

To investigate the role of three-dimensional echocardiography (3DE) in evaluation of left ventricular mechanical dyssynchrony (LVMD) in heart failure (HF) patients with narrow QRS.

Methods

143 subjects (70 with HF and narrow QRS, 23 with HF and LBBB and 50 controls) were subjected to 3DE, evaluating global and regional dyssynchrony using systolic dyssynchrony index, maximum segmental dyssynchrony and opposite segment dyssynchrony. Spatial distribution of LVMD was studied in each patient using 3DE derived regional time volume curves. Extent of LVMD in HF patients with narrow QRS was compared to those with left bundle branch block (LBBB).

Results

Frequency of LVMD was similar in HF patients with narrow QRS or LBBB (55.7% vs. 47.8%, p = NS). There was no difference in the severity of LVMD between these two groups (10.7 ± 6.7% vs. 12.1 ± 7.4%, p = NS). Both HF groups had significantly more dyssynchrony than controls. A scattered pattern of distribution of asynchronous segments was seen in narrow QRS patients; 33.96% of them had their earliest contracting segment, instead of delayed segment, located in areas conventionally targeted for LV pacing i.e. anterolateral, inferolateral or inferior segments.

Conclusions

3DE confirmed significant dyssynchrony in  > 50% HF patients with narrow QRS as demonstrated by other imaging methods. 3D distribution patterns of asynchronous segments indicate possibility of left ventricular mechanics related reasons responsible for lack of CRT responsiveness, an observation that generates hypothesis on possible reasons of CRT non-responsiveness.

'Optimized' LV only pacing using a dual chamber pacemaker as a cost effective alternative to CRT

Background

Cardiac Resynchronization therapy (CRT) remains largely under-used in developing countries owing to the high cost of therapy. In this pilot study, we explore ‘optimized’ Left Ventricle Only Pacing (LVOP) as a cost effective alternative to cardiac resynchronization therapy in selected patients with heart failure.

Hypothesis

In economically poorer patients with heart failure, left bundle branch block (LBBB) and intact AV node conduction, synchronization can be obtained using a dual chamber pacemaker (leads in right atrium and Left ventricle) with the help of 2D strain imaging.

Methods and results

4 patients underwent LVOP for symptomatic heart failure. Post procedure ‘optimization’ was done using 12 lead electrocardiography and 2D- Strain imaging. Difference between Time to Peak longitudinal strain and Aortic valve Closure (Diff T_PL-AC) was calculated for each segment at different AV delays and the AV delay with the smallest Diff T_PL-AC was programmed. The mean AV delay that resulted in electrical and mechanical synchrony was 150 ms. After a mean follow up of 6 months, all patients had improved by at least 1 NYHA class. The mean reduction in QRS duration post procedure was −54.5 ± 22.82 ms and the mean improvement in EF was 7 ± 2.75%.

Conclusion

Optimized LVOP using 2D strain and ECG can be a cost-effective alternative to CRT in patients with LBBB, heart failure and normal AV node conduction.

Non-invasive, model-based measures of ventricular electrical dyssynchrony for predicting CRT outcomes

AIMS

Left ventricular activation delay due to left bundle branch block (LBBB) is an important determinant of the severity of dyssynchronous heart failure (DHF). We investigated whether patient-specific computational models constructed from non-invasive measurements can provide measures of baseline dyssynchrony and its reduction after CRT that may explain the degree of long-term reverse ventricular remodelling.

METHODS AND RESULTS

LV end-systolic volume reduction (ΔESV_LV) measured by 2D trans-thoracic echocardiography in eight patients following 6 months of CRT was significantly (P < 0.05) greater in responders (26 ± 20%, n = 4) than non-responders (11 ± 16%, n = 4). LV reverse remodelling did not correlate with baseline QRS duration or its change after biventricular pacing, but did correlate with baseline LV endocardial activation measured by electroanatomic mapping (R²=0.71, P < 0.01). Patient-specific models of LBBB ventricular activation with parameters obtained by matching model-computed vectorcardiograms (VCG) to those derived from standard patient ECGs yielded LV endocardial activation times that correlated well with those measured from endocardial maps (R²=0.90). Model-computed 3D LV activation times correlated strongly with the reduction in LVESV (R²=0.93, P < 0.001). Computed decreases due to simulated CRT in the time delay between LV septal and lateral activation correlated strongly with ΔESV_LV (R²=0.92, P < 0.001). Models also suggested that optimizing VV delays may improve resynchronization by this measure of activation delay.

CONCLUSIONS

Patient-specific computational models constructed from non-invasive measurements can compute estimates of LV dyssynchrony and their changes after CRT that may be as good as or better than electroanatomic mapping for predicting long-term reverse remodelling.

Ventricular dyssynchrony in pregnant women: A tissue Doppler study

OBJECTIVE

The aim of the study was to assess the left ventricular (LV) synchronicity in pregnant women and to identify the main determinants of LV dyssynchrony in asymptomatic pregnant women.

METHODS

One hundred sixty-seven pregnant women consecutively and 48 age-matched nonpregnant controls were enrolled. For the assessment of LV systolic dyssynchrony, the standard deviation of the time from QRS onset to peak systolic (Tps-LV- standard deviation [SD]) velocity and the maximal difference of the time from QRS onset to peak systolic velocity (Tps-LV) from 12 segments at the apical views. For the LV diastolic dyssynchrony, the standard deviation of the time from QRS onset to peak diastolic (Tpe-LV-SD) velocity and the maximal difference of the time from QRS onset to peak diastolic velocity (Tpe-LV) were calculated.

RESULTS

Both systolic and diastolic dyssynchrony indexes were significantly higher in pregnant women than in the normal controls (Tps-LV; P<.01, Tps-LV-SD; P<.03, Tpe-LV, P<.05 and Tpe-LV-SD; P<.02). A total of 28 (16.8%) of the pregnant women had a dyssynchrony index above the accepted value for LV dyssynchrony (>34.4 msec). There was a significant correlation between LV dyssynchrony indexes with, multiparty, multifetal pregnancies, systolic blood pressure in pregnant women with LV dyssynchrony. Additionally LV dyssynchrony was significantly associated with elevated E/e" and brain natriuretic peptide (BNP).

CONCLUSIONS

Both systolic synchronicity and diastolic synchronicity were affected in pregnant women compared to nonpregnant women. LV dyssynchrony was significantly correlated with age, multiparity, and BNP level. Early detectable changes in systolic and diastolic synchrony may be present in pregnant women at higher risk of peripartum cardiomyopathy.

Diastolic Dyssynchrony in Acute ST Segment Elevation Myocardial Infarction and Relationship with Functional Recovery of Left Ventricle

Background

Incidence of diastolic dyssynchrony (DD) and its impact on functional recovery of left ventricle (LV) after ST segment elevation myocardial infarction (STEMI) is not known.

Methods

Consecutive patients with STEMI who underwent successful revascularization were prospectively enrolled. Echocardiography with tissue Doppler imaging was performed within 48 hours of admission and at 6 months. LV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), ejection fraction (EF), and left atrial volume index (LAVI) were calculated. Diastolic delay was calculated from onset of QRS complex to peak of E wave in tissue Doppler image and presented as maximal temporal difference between peak early diastolic velocity of 6 basal segments of LV (TeDiff). Study patients were compared with demographically matched control group.

Results

Forty eight consecutive patients (55 ± 10 years, 88% male) and 24 controls (56 ± 6 years, 88% male) were included. TeDiff was higher in STEMI than in controls (35.9 ± 19.9 ms vs. 26.3 ± 6.8 ms, p = 0.025). Presence of DD was higher in STEMI than controls (58% vs. 33%, p = 0.046) according to calculated cut-off value (≥ 29 ms). There was no correlation between TeDiff and change in EDVI, ESVI, and LAVI at 6 months, however TeDiff and change in EF at 6 months was positively correlated (r = 0.328, p = 0.023). Patients with baseline DD experienced remodeling less frequently compared to patients without baseline DD (11% vs. 38%, p = 0.040) during follow-up.

Conclusion

STEMI disrupts diastolic synchronicity of LV. However, DD during acute phase of STEMI is associated with better recovery of LV thereafter. This suggests that DD is associated with peri-infarct stunned myocardium that is salvaged with primary intervention as well as infarct size.

Changes in Right Ventricular Dysfunction After Balloon Pulmonary Angioplasty in Patients With Chronic Thromboembolic Pulmonary Hypertension

The aim was to investigate the effect of balloon pulmonary angioplasty (BPA) on right ventricular (RV) function in chronic thromboembolic pulmonary hypertension. Twenty-six patients with chronic thromboembolic pulmonary hypertension were enrolled and were divided into 2 groups, group H with high (>30 mm Hg) mean pulmonary arterial pressure and group L with low (25 to 30 mm Hg) mean pulmonary arterial pressure. RV function was assessed using 2-dimensional speckle-tracking echocardiography as well as 3-dimensional echocardiography, and RV dyssynchrony was assessed by the RV strain curves. Exercise capacity was evaluated by the 6-minute walk distance. RV dilatation was significantly reduced after BPA. In group H, RV ejection fraction, RV free wall longitudinal strain and RV dyssynchrony were all impaired before BPA and were ameliorated after BPA. In group L, RV ejection fraction as well as RV dyssynchrony were impaired without the reduction of RV free wall longitudinal strain and were improved after BPA, indicating that RV dysfunction may be attributable to the RV dyssynchrony in group L. Furthermore, RV dyssynchrony at baseline was the only parameter that was correlated with improvement in the 6-minute walk distance after BPA. RV dyssynchrony may affect RV function and could be the useful parameter for clinical outcome after BPA.

Reference values for left ventricular systolic synchrony according to phase analysis of ECG-gated myocardial perfusion SPECT

BACKGROUND

The aim of this study was to define reference values for left ventricular systolic synchrony and for the volume parameters of the left ventricle using myocardial perfusion SPECT-derived phase analysis method.

METHODS

We evaluated data of 433 patients who underwent myocardial perfusion SPECT/CT during January 2012-February 2013 in Kuopio University Hospital. The final study population consisted of 52 patients (aged 42-84 years) who met the criteria: (1) no previously diagnosed cardiac disease, (2) normal ECG at rest, (3) no advanced coronary artery disease in CT and 4) normal myocardial perfusion in stress/rest myocardial perfusion SPECT/CT. The severity of mechanical dyssynchrony was assessed by phase analysis of gated myocardial SPECT at stress stage after pharmacological exercise and at rest using Quantitative Gated SPECT (QGS) software. Volume parameters of the left ventricle were also assessed.

RESULTS

The phase histogram bandwidth at rest was 28.0 [63.7] degrees (median [95th percentile]). The standard deviation of phase histogram at rest was 7.8 [26.5] degrees. Entropy at the rest study was 54.0 [63.7] %. All left ventricular dyssynchrony parameters were statistically significantly higher at stress compared to rest. There were no statistically significant differences in dyssynchrony values between men and women. In volume parameters, reference values in male were expectedly higher than in female. Cardiac output did not differ significantly between genders.

CONCLUSION

In subjects without signs of cardiac diseases, the left ventricular systolic function is well synchronized. Phase analysis measurement does not depend on gender, age, BMI or blood pressure, but the values of dyssynchrony parameters increase during pharmacological stress.

QRS fragmentation: its role in sherlocking the arrhythmogenic heart

The electrocardiogram (ECG) is a commonly available basic diagnostic modality in in-patient, out-patient, and emergency departments. In patients with coronary artery disease (CAD), the presence of a fragmented QRS (f-QRS), which is an extra R wave (R′), notching of the single R wave, notching of the S wave in at least two contiguous leads on the 12-lead ECG, is associated with a myocardial scar from previous myocardial injury. Furthermore, the presence of f-QRS has been shown to be associated with adverse outcomes in CAD and non-CAD patients. In the present paper, we will solely focus on the usefulness and utilization of f-QRS in predicting ventricular tachyarrhythmia in many heart diseases, that is, ischemic cardiomyopathy, non-ischemic cardiomyopathy, hypertrophic obstructive cardiomyopathy, Brugada syndrome, and arrhythmogenic right ventricular cardiomyopathy. In the majority of such cases, ventricular tachyarrhythmia results in sudden cardiac death. Diagnosing them beforehand can lead to prevention and/or early treatment of these arrhythmias to prevent potential morbidity and mortality.