Impaired subendocardial wall thickening and post-systolic shortening are signs of critical myocardial ischemia in patients with flow-limiting coronary stenosis

Impaired hemodynamic forces assessed by routine CMR and its determinants in different duration T2DM patients with normal LV function and myocardial strain

Background

Early detection of subclinical myocardial dysfunction in asymptomatic patients with type 2 diabetes mellitus (T2DM) is essential before overt changes in left ventricular ejection fraction (LVEF) and myocardial strain occur. The objective of this study is to quantitatively assess hemodynamic forces (HDFs) using a rigorous mathematical model based on conventional cine cardiac magnetic resonance (CMR) images in patients with T2DM, and investigate their correlation with late gadolinium enhancement (LGE) and duration of diabetes.

Methods

We recruited 63 T2DM patients and 50 healthy volunteers to undergo contrast-enhanced CMR examinations. T2DM patients were divided into three groups according to the course of disease: early, middle and later stage (time <5 years, 5 ≤ time <10 years, time ≥10 years, respectively). LV deformation parameters, global circumferential strain (LVGCS), radial strain (LVGRS), longitudinal strain (LVGLS) and HDFs parameters such as longitudinal (apical-basal/A-B), transversal (lateral-septal/L-S) HDF strength (RMS) were measured and compared among the three groups.

Results

Compared with healthy volunteers, no significant differences in LV function and strains were observed (P > 0.05), while HDF Strength (RMS) L-S (%) were significantly higher in T2DM patients (p < 0.001). LVGLS was significantly decreased in late T2DM patients (p < 0.05), but HDF Strength (RMS) L-S (%) was significantly increased compared with early T2DM patients. Both HDF Strength (RMS) L-S (%) and HDF Strength (RMS) A-B (%) value were independently related to the extent of LGE (β = 0.435, p = 0.001; β = -0.329, p = 0.006, respectively). In addition, HDF Strength (RMS) L-S (%) was also independently correlated with insulin treatment(β = 0.291, p = 0.013).

Conclusions

HDF analysis can provide valuable insights into subclinical myocardial dysfunction prior to changes in ejection fraction and myocardial strain, suggesting that HDF analysis may be a potential early marker of subclinical myocardial dysfunction. LVGLS damage is gradually obvious with the prolongation of diabetes duration in T2DM patients. HDFs parameters are associated with the extent of LGE, and the transversal component of HDF increased with the duration of diabetes.

Association of postsystolic shortening on stress echocardiography and significant coronary artery stenosis: A single-centre retrospective cohort study

BACKGROUND

Postsystolic shortening (PSS) is one of the proposed quantitative measures to predict myocardial ischaemia in the stress echocardiographic (SE) evaluation. It is previously known that hypo-/akinesia (HA) correlates well with coronary stenosis. However, some patients undergoing SE only present with PSS, and their risk of significant coronary stenosis is less clear. This study aimed to evaluate the association between PSS and significant coronary stenosis compared with HA.

METHODS

This was a retrospective cohort study at the hospital of S:t Görans, Stockholm, Sweden. All patients who underwent SE to investigate inducible ischaemia between 1 January 2018 and 15 October 2021 were eligible for inclusion. Exclusion criteria were normal SE and inconclusive test. Pathological SE were divided into two groups, patients with HA and those with PSS. Outcome was significant coronary artery stenosis visualized by invasive coronary angiography.

RESULTS

The final study population consisted of 108 patients (73 PSS, 35 HA). The presence of HA was associated with a higher risk of significant stenosis compared to those with PSS (63% vs. 23%, p < 0.001). This relationship was observed among males (p < 0.001), but not among females (p = 0.133). Nonsignificant stenosis trended to be more common among patients with PSS (21% vs. 6%, p = 0.053) CONCLUSIONS: The finding of PSS without HA was associated with a lower risk of significant coronary stenosis than HA. However, patients with PSS still often had nonsignificant coronary stenosis and PSS in the evaluation for nonobstructive coronary artery disease (CAD) should be further investigated.

Multiparametric CMR imaging of myocardial structure and function changes in diabetic mini-pigs with preserved LV function: a preliminary study

Background

The purpose of this study is to dynamically monitor the myocardial structure and function changes in diabetic mini-pigs by 1.5 T cardiac magnetic resonance.

Methods

Three male mini-pigs underwent cardiac magnet resonance (CMR) imaging, and histologic examination. T1-mapping was acquired at basal, mid and apical segments. CMR feature-tracking (CMR-FT) is used to quantify left ventricle global longitudinal (LVGLS), circumferential (LVGCS) and radial strain (LVGRS). Epicardial adipose tissue (EAT) was evaluated using a commercially available software.

Results

Left ventricular mass (LVM), myocardial native T1 value, extracellular volume (ECV) value and EAT were increased gradually after 6 months of modeling, while LVGLS decreased gradually after 6 months of modeling (LVM: 24.5 (23.4, 26.7) vs. 42.7 (41.4, 44.6) g/m², p < 0.001; Native T1: 1005.5 (992.6, 1010.7) vs. 1028.7 (1015.5, 1035.6) ms, p = 0.041; EAT: 16.1 (14.5, 18.2) vs. 24.6 (20.8, 26.9) mL, p = 0.020; ECV: 21.4 (20.2, 23.9) vs. 28.9 (26.7, 30.3) %, p = 0.011; LVGLS: − 22.8 (− 21.4, − 23.9) vs. − 17.4 (− 17.2, − 19.2)%, p = 0.008). The diffuse myocardial interstitial fibrosis was found in histology samples.

Conclusion

The progressive impairments in LV structure and myocardial deformation occurs in diabetic mini-pigs. T1 mapping and CMR-FT technology are promising to monitor abnormal changes of diabetic myocardium in the early stage of diabetic cardiomyopathy.

Rapidly and Accurately Detecting Significant Coronary Artery Stenosis in Patients with Suspected Stable Coronary Artery Disease and Normal Segmental Wall Motion by Speckle Tracking Automated Functional Imaging

This study was performed to explore the value of a machine with built-in speckle tracking automated functional imaging (AFI) in predicting the severity of coronary artery lesions in patients with suspected stable coronary artery disease (SCAD) with normal wall motion. One hundred forty-three consecutive patients with clinically suspected SCAD with normal wall motion were included. Multiple parameters, including global longitudinal peak strain, post-systolic index (PSI) and peak strain dispersion, were automatically analyzed with AFI. Territorial longitudinal strain (TLS) and territorial PSI (TPSI) were also calculated. Receiver operating characteristic curve analyses revealed that global longitudinal peak strain and PSI were superior to other parameters in detecting left main or three-vessel SCAD. A combination of TLS and TPSI could improve diagnostic performance in identifying significant stenotic left anterior descending and right coronary arteries. In conclusion, 2-dimensional speckle tracking AFI can rapidly provide multiple parameters for detecting significant coronary artery stenosis with high accuracy in patients suspected of having SCAD with normal wall motion.

Additional diagnostic accuracy of global longitudinal strain at peak dobutamine stress in patients with moderate pretest probability of coronary artery disease

BACKGROUND

Previous studies confirmed the feasibility of 2D speckle tracking echocardiography (2D STE) during dobutamine stress echocardiography (DSE) in assessing myocardial ischemia in patients with previous myocardial infarction. It is unknown whether it improves the diagnostic accuracy in young patients with intermediate pretest probability for coronary artery disease (CAD) and no prior cardiovascular events.

METHODS

We prospectively studied 101 patients by DSE and STE, followed by coronary angiography within 1 month. Significant CAD was defined as diameter stenosis ≥ 50%. Receiver operating characteristic analysis obtained global longitudinal strain (GLS) cutoff values of significant area under the curve (AUC).

RESULTS

Mean age: 53 ± 8 years, 56% females, 49 had significant CAD (group 1) and 52 had normal/mild CAD (group 2); no significant baseline differences except more males in group 1 (P: .002). DSE sensitivity and specificity for CAD were 79.6% and 92.3%, respectively, positive predictive value (PPV): 90.6%, negative predictive value (NPV): 82.7%, and diagnostic accuracy: 86%. At peak stress, all strain parameters were significantly lower in group 1. However, GLS had the highest AUC: 0.88, P: <.001. GLS cutoff value ≤ -20.5 had 89.8% sensitivity, 84.6% specificity, 84.6% PPV, 89.8% NPV, and 87% diagnostic accuracy. Combining GLS cutoff with DSE had higher AUC than either alone (0.9, P < .001): 95.9% sensitivity, 84.6% specificity, 85.5% PPV, 95.7% NPV, and 90% diagnostic accuracy.

CONCLUSION

2D-STE-derived GLS increases DSE precision to detect CAD in intermediate pretest probability patients: It improves DSE sensitivity, NPV, and accuracy. It is reproducible and has comparable specificity.

Duration of myocardial early systolic lengthening for diagnosis of coronary artery disease

Objective

Myocardial early systolic lengthening (ESL) duration is prolonged in patients with coronary artery disease (CAD). However, the relationship between the fractional flow reserve (FFR), the current gold standard for evaluating physiological myocardial ischaemia, and ESL has not been studied. The aims of this study were to investigate whether left ventricular (LV) ESL duration could identify patients with CAD, and to examine the relationship between FFR and LV ESL duration.

Methods

In this single-centre, cross-sectional, prospective study of 75 patients with suspected or known CAD, we performed two-dimensional speckle tracking echocardiography at rest on the day before coronary angiography or percutaneous coronary intervention. Apical 3 views were used to examine ESL duration, defined as time from onset of the Q wave to maximum myocardial systolic lengthening.

Results

Thirty-five patients had non-significant stenosis. Forty patients with CAD underwent FFR testing: 17 had an FFR≥0.8 and 23 had an FFR<0.8. Global ESL duration was 20.9±22.2 ms in patients with non-significant stenosis, 36.4±23.2 ms in patients with FFR≥0.8 and 39.6±29.5 ms in patients with FFR<0.8 (p=0.020). However, global and regional ESL durations were not significantly correlated with FFR and demonstrated poor reproducibility.

Conclusion

Although myocardial ESL duration was significantly prolonged in patients with CAD compared with patients without CAD, ESL at rest showed poor reproducibility, and this new parameter did not predict FFR in patients with suspected CAD.

Summed thickening score by myocardial perfusion imaging: A risk factor of left ventricular remodeling in patients with myocardial infarction

BACKGROUND

Left ventricular (LV) remodeling has adverse effects on the prognosis of patients with myocardial infarction (MI). The aim of this study is to identify the risk factors of LV remodeling in MI patients by radionuclide myocardial imaging.

METHODS AND RESULTS

This retrospective study consisted of 92 patients who had a history of definite prior MI on ECG and underwent both resting gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) and positron emission tomography (PET) myocardial metabolism imaging. LV remodeling was defined as > mean + 2SD of LV end-diastolic volume index (LVEDVi) in the normal database. LV enlargement, cardiac dysfunction, wall thickening abnormalities expressed as summed thickening score (STS) were more severe in the old MI patients as compared to those with subacute MI. STS (Odds ratio, 1.296; P = .004) and the proportion of segments with reduced wall thickening in segments with normal perfusion (Odds ratio, 1.110; P = .001) were identified as the independent factors of LV remodeling in subacute and old MI patients in the multivariate binary regression model. Total perfusion deficit (TPD), viable myocardium, scar, and the proportion of segments with reduced wall thickening in segments with decreased perfusion showed strong correlation with LV remodeling in the univariate regression model as well.

CONCLUSIONS

LV remodeling in old MI patients is more extensive and severe than that in subacute MI patients. LV wall thickening abnormalities as expressed by STS and the proportion of segments with reduced wall thickening in segments with normal perfusion are the independent risk factors of LV remodeling in MI patients.

Postsystolic Shortening by Speckle Tracking Echocardiography Is an Independent Predictor of Cardiovascular Events and Mortality in the General Population

Background

Postsystolic shortening (PSS) has been proposed as a novel marker of contractile dysfunction in the myocardium. Our objective was to assess the prognostic potential of PSS on cardiovascular events and death in the general population.

Methods and Results

The study design consisted of a prospective cohort study of 1296 low‐risk participants from the general population, who were examined by speckle tracking echocardiography. The primary end point was the composite of heart failure, myocardial infarction, and cardiovascular death, defined as major adverse cardiovascular events (MACEs). The secondary end point was all‐cause death. The postsystolic index (PSI) was defined as follows: [(maximum strain in cardiac cycle−peak systolic strain)/(maximum strain in cardiac cycle)]×100. PSS was regarded as present if PSI >20%. During a median follow‐up of 11 years, 149 participants (12%) were diagnosed as having MACEs and 236 participants (18%) died. Increasing number of walls with PSS predicted both end points, an association that persisted after adjustment for age, sex, estimated glomerular filtration rate, global longitudinal strain, hypertension, heart rate, left ventricular ejection fraction, LV mass index, pro‐B‐type natriuretic peptide, previous ischemic heart disease, systolic blood pressure, average peak early diastolic longitudinal mitral annular velocity (e′), ratio between peak transmitral early and late diastolic inflow velocity (E/A), and left atrial volume index: MACEs (hazard ratio, 1.35; 95% confidence interval, 1.09–1.67; P=0.006 per 1 increase in walls displaying PSS) and death (hazard ratio, 1.30; 95% confidence interval, 1.08–1.57; P=0.006 per 1 increase in walls displaying PSS). The strongest predictor of end points was ≥2 walls exhibiting PSS. The PSI also predicted increased risk of the end points, and the associations remained significant in multivariable models: MACEs (per 1% increase in PSI: hazard ratio, 1.18; 95% confidence interval, 1.02–1.36; P=0.024) and death (per 1% increase in PSI: hazard ratio, 1.18; 95% confidence interval, 1.05–1.33; P=0.005).

Conclusions

Presence of PSS in the general population provides independent and long‐term prognostic information on the occurrence of MACEs and death.

Layer-specific analysis of left ventricular myocardial contractility in patients with coronary slow-flow phenomenon

PURPOSE

Coronary slow-flow phenomenon (CSFP) is an angiographic diagnosis characterized by delayed coronary opacification in the absence of significant epicardial coronary stenosis. We previously reported impaired left ventricular (LV) function in patients with CSFP. However, the LV wall comprises three myocardial layers whose contractility can be differently affected. Therefore, we evaluated layer-specific (endocardial, mid-myocardial, and epicardial) LV myocardial contractility and assessed its relationships with the number of affected coronary arteries and their flow.

METHODS

We studied 60 patients with CSFP and 46 controls. CSFP was diagnosed by thrombolysis in myocardial infarction frame count. Echocardiography was performed within 72 hours after the coronary angiography. LV layer-specific longitudinal strain (LS) was measured using two-dimensional speckle-tracking echocardiography.

RESULTS AND CONCLUSIONS

The LS of all three myocardial layers was lower in patients with CSFP than in controls. In patients with CSFP, LS of all three myocardial layers and transmural LS gradient correlated negatively with the number of affected coronary arteries and the mean thrombolysis in myocardial infarction frame count. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:429-436, 2016.

Layer-specific analysis of dobutamine stress echocardiography for the evaluation of coronary artery disease

Although dobutamine stress echocardiography (DSE) is a well-defined tool for the diagnosis of coronary artery disease (CAD), false-negative and false-positive results still occur. This study investigated the diagnostic role of layer-specific analysis using 2-dimensional speckle-tracking echocardiography (STE) during DSE.A total of 121 patients who underwent DSE and showed normal wall motion and ejection fraction during baseline echocardiography were enrolled. All patients underwent coronary angiography after DSE within 2 weeks. The patients were divided into the following 4 groups according to DSE results and CAD status: negative DSE with no significant CAD (n = 73), positive DSE with significant CAD (n = 16), negative DSE with significant CAD (n = 17), and positive DSE with no significant CAD (n = 15). Layer-specific global longitudinal strain (GLS) was assessed in the endocardium, mid-myocardium, and epicardium by STE techniques.Patients with significant CAD were older, more male and showed higher glucose level compared to patients without CAD. But coronary risk factors and previous medications were not different between patients with and without CAD. There were no significant differences in whole myocardium or layer-specific GLS found in the baseline echocardiography. During recovery echocardiography, endocardial GLS was significantly different between patients with and without CAD, regardless of the DSE results. A receiver-operating characteristic curve analysis showed that endocardial GLS (>-16%) was superior for identifying significant CAD during the DSE recovery stage. Diagnostic accuracy was improved by applying the results of endocardial GLS compared with visual estimation of DSE.The assessment of layer-specific strain by STE during DSE was feasible, and the evaluation of poststress endocardial function is a more sensitive tool for the detection of CAD.

Subendocardial Systolic Dysfunction in Asymptomatic Normotensive Diabetic Patients

BACKGROUND

It remains uncertain whether diabetes itself causes specific echocardiographic features of myocardial morphology and function in the absence of hypertension or ischemic heart disease. The purpose of the present study was to determine the characteristics of pure diabetic cardiomyopathy-related echocardiographic morphology and function using layer-by-layer evaluation with myocardial strain echocardiography.

METHODS AND RESULTS

We enrolled 104 patients with poorly controlled type 2 diabetes mellitus (mean HbA1c level, 10%) with (n=74) or without (n=40) hypertension and 24 age- and sex-matched healthy volunteers. Patients with coronary artery stenosis or structural heart disease were excluded. Myocardial layer-specific strain was analyzed by speckle tracking echocardiography. Compared with the healthy control group, the normotensive diabetes group showed no significant difference in ejection fraction, left ventricular mass index, diastolic properties, left atrial volume index, or B-type natriuretic protein (BNP) level, but global longitudinal strain and subendocardial radial strain were significantly deteriorated. The deterioration of longitudinal strain correlated with body mass index (R=0.49, P<0.01) and blood pressure (R=0.36, P<0.01) in the normotensive diabetes group.

CONCLUSIONS

Deterioration of left ventricular longitudinal shortening accompanied by decreased subendocardial wall thickening are the characteristic functional abnormalities of diabetic cardiomyopathy in patients without hypertrophy, diastolic dysfunction, or elevated BNP. Obesity and blood pressure may also play important roles in this strain abnormality in asymptomatic patients with type 2 diabetes.

Myocardial function in aortic stenosis--insights from radial multilayer Doppler strain

Background

Left ventricular (LV) radial tissue Doppler imaging (TDI) strain increases gradually from the subepicardial to the subendocardial layer in healthy individuals. A speckle tracking echocardiography study suggested this gradient to be reduced in parallel with increasing aortic stenosis (AS) severity.

Methods

We used TDI strain in 84 patients with AS (mean age 73 ± 10 years, 56% hypertensive) for superior assessment of layer strain. 38 patients had non-severe and 46 severe AS by aortic valve area corrected for pressure recovery. Peak systolic radial TDI strain was measured in the subendocardial, mid-myocardial and subepicardial layers of the basal inferior LV wall, each within a region of interest of 2 × 6 mm (strain length 2 mm).

Results

Radial strain was lower in the subepicardial layer (33.4 ± 38.6%) compared to the mid-myocardial and subendocardial layers (50.3 ± 37.3% and 53.0 ± 40.0%, respectively, both p < 0.001 vs. subepicardial). In the subendo- and midmyocardium, radial strain was lower in patients with severe AS compared to those with non-severe AS (p < 0.05). In multivariate regression analyses including age, heart rate, inferior wall thickness, hypertension, and AS severity, radial strain in the mid-myocardium was primarily attenuated by presence of hypertension (β = −0.23) and AS severity (β = −0.26, both p < 0.05), while radial strain in the subendocardium was significantly influenced by AS severity only (β = −0.35, p < 0.01).

Conclusions

In AS, both the AS severity and concomitant hypertension attenuate radial TDI strain in the inferior LV wall. The subendocardial radial strain is mainly influenced by AS severity, while midmyocardial radial strain is attenuated by both hypertension and AS severity.

Myocardial layer-specific analysis of ischemic memory using speckle tracking echocardiography

The assessment of post-systolic shortening (PSS) by speckle tracking echocardiography allows myocardial ischemic memory imaging. Because the endocardial layer is more vulnerable to ischemia, the assessment of this layer might be useful for detecting ischemic memory. Serial echocardiographic data were acquired from nine dogs with 2 min of coronary occlusion followed by reperfusion. Regional deformation parameters were measured in the risk and normal areas. Using speckle tracking echocardiography, circumferential strain was analyzed in the endocardial, mid-wall, and epicardial layers; and radial strain was analyzed in the inner half, outer half and entire (transmural) layers. In the risk area, peak systolic and end-systolic strain in the circumferential and radial directions significantly decreased during occlusion, but recovered to the baseline levels immediately after reperfusion in all layers. However, circumferential post-systolic strain index (PSI), a parameter of PSS, significantly increased during occlusion, and the significant increases persisted until 20 min after reperfusion in the endocardial and mid-wall layers. Radial PSI tended to increase after reperfusion in the inner half and entire layers but these increases were not significant compared with baseline. In the normal area, systolic strains and PSI in the radial and circumferential directions hardly changed before and after occlusion/reperfusion in all layers. In layer-specific analysis with speckle tracking echocardiography, circumferential PSS in the endocardial and mid-wall layers may be useful for detecting ischemic memory.

Two-dimensional speckle tracking imaging as a novel strategy for accurately identifying the accessory pathway

A 14-year-old patient was diagnosed with hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome. The two-dimensional speckle tracking strain method showed normal left ventricular local contraction, but the peak systolic longitudinal strain of the right ventricular (RV) anterior wall was earlier than that of the septal wall. As expected, the location of the accessory pathway was at the RV anterior wall. The patient's RV local contraction was normalized by successful radiofrequency application.

Effects of biventricular pacing on left heart twist and strain in a porcine model of right heart failure

BACKGROUND

Biventricular pacing (BiVP) improves cardiac output (CO) in selected cardiac surgery patients, but response remains variable, necessitating a better understanding of the mechanism. Accordingly, we used speckle tracking echocardiography (STE) to analyze BiVP during acute right ventricular pressure overload (RVPO).

MATERIALS AND METHODS

In nine pigs, the inferior vena cava (IVC) was snared to decrease CO and establish a control model. Heart block was induced, the pulmonary artery snared, and BiVP initiated. Echocardiograms of the left ventricular midpapillary level were taken at varying atrioventricular delay (AVD) and interventricular delay (VVD) for STE analysis of regional circumferential strain (CS) and radial strain (RS). Echocardiograms were taken of the left ventricular base, midpapillary, and apex during baseline, IVC occlusion, and each BiVP setting for STE analysis of twist, apical and basal rotations, CS, RS, and synchrony. Indices were correlated against CO with mixed linear models.

RESULTS

During IVC occlusion, CO correlated with twist, apical rotation, RS, RS synchrony, and CS (P < 0.05). During RVPO with BiVP, CO only correlated with RS synchrony and CS (P < 0.05). During AVD and VVD variations, CO was associated with free wall RS (P < 0.008). CO correlated with septal wall CS during AVD variation and free wall CS during VVD variation (P < 0.008).

CONCLUSIONS

In an open chest model, twist, RS, RS synchrony, and CS analyzed by STE may be noninvasive surrogates for changes in CO. During RVPO, changes in RS synchrony and CS with varying regional strain contributions may be the primary mechanism in which BiVP improves CO. Lack of correlation of remaining indices may reflect postsystolic function.

Regional and global strain changes during biventricular pacing in a porcine model of acute left ventricular volume overload

OBJECTIVES

Biventricular pacing may ameliorate symptoms of acute heart failure. Speckle-tracking echocardiography can assess cardiac function to elucidate mechanisms of benefit. Accordingly, radial and circumferential strain and radial and circumferential strain synchrony were measured with speckle-tracking echocardiography during biventricular pacing in a model of left ventricular (LV) volume overload.

METHODS

Heart block was established in 4 open-chest anesthetized pigs. Left ventricular volume overload was induced with an ascending aorta-LV apex conduit. Measurements included cardiac output by an aortic flow probe, the maximum derivative of LV pressure versus time (dP/dtmax), and transseptal pressure synchrony. Biventricular pacing was performed for combinations of 3 interventricular delays and 3 LV pacing sites. Speckle-tracking echocardiographic analysis was applied to short-axis images at the midpapillary LV for 9 pacing combinations. Strain and synchrony parameters were correlated with hemodynamics.

RESULTS

Increased cardiac output correlated with improved global circumferential strain (P = .002) but not changes in global radial strain or radial strain synchrony. Increased LV dP/dtmax was associated with improved circumferential strain in the septum (P < .001) and radial strain in the lateral wall (P = .046). Improved transseptal pressure synchrony was associated with improved global circumferential strain, but primarily in the septum (P < .001). Aortic valve closure occurred before peak radial strain in 62% of beats and before peak circumferential strain in 6%.

CONCLUSIONS

During acute LV volume overload, hemodynamic improvement with biventricular pacing was associated with improved circumferential strain primarily in the septum. Radial strain and radial strain synchrony did not correlate with improvement, possibly due to delayed systolic contraction. An increase in circumferential strain in the septum associated with optimum transseptal pressure synchrony suggested improvement by interventricular assist from the right ventricle.