Acute recoordination rather than functional hemodynamic improvement determines reverse remodelling by cardiac resynchronisation therapy.

PURPOSE: Cardiac resynchronisation therapy (CRT) improves left ventricular (LV) function acutely, with further improvements and reverse remodelling during chronic CRT. The current study investigated the relation between acute improvement of LV systolic function, acute mechanical recoordination, and long-term reverse remodelling after CRT. METHODS: In 35 patients, LV speckle tracking longitudinal strain, LV volumes & ejection fraction (LVEF) were assessed by echocardiography before, acutely within three days, and 6 months after CRT. A subgroup of 25 patients underwent invasive assessment of the maximal rate of LV pressure rise (dP/dtmax,) during CRT-implantation. The acute change in dP/dtmax, LVEF, systolic discoordination (internal stretch fraction [ISF] and LV systolic rebound stretch [SRSlv]) and systolic dyssynchrony (standard deviation of peak strain times [2DS-SD18]) was studied, and their association with long-term reverse remodelling were determined. RESULTS: CRT induced acute and ongoing recoordination (ISF from 45 ± 18 to 27 ± 11 and 23 ± 12%, p < 0.001; SRS from 2.27 ± 1.33 to 0.74 ± 0.50 and 0.71 ± 0.43%, p < 0.001) and improved LV function (dP/dtmax 668 ± 185 vs. 817 ± 198 mmHg/s, p < 0.001; stroke volume 46 ± 15 vs. 54 ± 20 and 52 ± 16 ml; LVEF 19 ± 7 vs. 23 ± 8 and 27 ± 10%, p < 0.001). Acute recoordination related to reverse remodelling (r = 0.601 and r = 0.765 for ISF & SRSlv, respectively, p < 0.001). Acute functional improvements of LV systolic function however, neither related to reverse remodelling nor to the extent of acute recoordination. CONCLUSION: Long-term reverse remodelling after CRT is likely determined by (acute) recoordination rather than by acute hemodynamic improvements. Discoordination may therefore be a more important CRT-substrate that can be assessed and, acutely restored.

Echocardiographic Prediction of Cardiac Resynchronization Therapy Response Requires Analysis of Both Mechanical Dyssynchrony and Right Ventricular Function: A Combined Analysis of Patient Data and Computer Simulations.

BACKGROUND: Pronounced echocardiographically measured mechanical dyssynchrony is a positive predictor of response to cardiac resynchronization therapy (CRT), whereas right ventricular (RV) dysfunction is a negative predictor. The aim of this study was to investigate how RV dysfunction influences the association between mechanical dyssynchrony and left ventricular (LV) volumetric remodeling following CRT. METHODS: One hundred twenty-two CRT candidates (mean LV ejection fraction, 19 ± 6%; mean QRS width, 168 ± 21 msec) were prospectively enrolled and underwent echocardiography before and 6 months after CRT. Volumetric remodeling was defined as percentage reduction in LV end-systolic volume. RV dysfunction was defined as RV fractional area change < 35%. Mechanical dyssynchrony was assessed as time to peak strain between the septum and LV lateral wall, interventricular mechanical delay, and septal systolic rebound stretch. Simulations of heart failure with an LV conduction delay in the CircAdapt computer model were used to investigate how LV and RV myocardial contractility influence LV dyssynchrony and acute CRT response. RESULTS: In the entire patient cohort, higher baseline septal systolic rebound stretch, time to peak strain between the septum and LV lateral wall, and interventricular mechanical delay were all associated with LV volumetric remodeling in univariate analysis (R = 0.599, R = 0.421, and R = 0.410, respectively, P < .01 for all). The association between septal systolic rebound stretch and LV volumetric remodeling was even stronger in patients without RV dysfunction (R = 0.648, P < .01). However, none of the mechanical dyssynchrony parameters were associated with LV remodeling in the RV dysfunction subgroup. The computer simulations showed that low RV contractility reduced CRT response but hardly affected mechanical dyssynchrony. In contrast, LV contractility changes had congruent effects on mechanical dyssynchrony and CRT response. CONCLUSIONS: Mechanical dyssynchrony parameters do not reflect the negative impact of reduced RV contractility on CRT response. Echocardiographic prediction of CRT response should therefore include parameters of mechanical dyssynchrony and RV function.

Mechanistic evaluation of echocardiographic dyssynchrony indices: patient data combined with multiscale computer simulations.

BACKGROUND: The power of echocardiographic dyssynchrony indices to predict response to cardiac resynchronization therapy (CRT) appears to vary between indices and between studies. We investigated whether the variability of predictive power between the dyssynchrony indices can be explained by differences in their operational definitions. METHODS AND RESULTS: In 132 CRT-candidates (left ventricular [LV] ejection fraction, 19 ± 6%; QRS width, 170 ± 22 ms), 4 mechanical dyssynchrony indices (septal systolic rebound stretch [SRSsept], interventricular mechanical dyssynchrony [IVMD], septal-to-lateral peak shortening delay [Strain-SL], and septal-to-posterior wall motion delay [SPWMD]) were quantified at baseline. CRT response was quantified as 6-month percent change of LV end-systolic volume. Multiscale computer simulations of cardiac mechanics and hemodynamics were used to assess the relationships between dyssynchrony indices and CRT response within wide ranges of dyssynchrony of LV activation and reduced contractility. In patients, SRSsept showed best correlation with CRT response followed by IVMD, Strain-SL, and SPWMD (R=-0.56, -0.50, -0.48, and -0.39, respectively; all P<0.01). In patients and simulations, SRSsept and IVMD showed a continuous linear relationship with CRT response, whereas Strain-SL and SPWMD showed discontinuous relationships characterized by data clusters. Model simulations revealed that this data clustering originated from the complex multipeak pattern of septal strain and motion. In patients and simulations with (simulated) LV scar, SRSsept and IVMD retained their linear relationship with CRT response, whereas Strain-SL and SPWMD did not. CONCLUSIONS: The power to predict CRT response differs between indices of mechanical dyssynchrony. SRSsept and IVMD better represent LV dyssynchrony amenable to CRT and better predict CRT response than the indices assessing time-to-peak deformation or motion.

Septal rebound stretch is a strong predictor of outcome after cardiac resynchronization therapy.

BACKGROUND: Septal rebound stretch (SRSsept) is a distinctive characteristic of discoordination-related mechanical inefficiency. We assessed how intermediate- and long-term outcome after cardiac resynchronization therapy (CRT) relate to baseline SRSsept. METHODS AND RESULTS: A total of 101 patients (age 65 ± 11 years, 69 men, 18 New York Heart Association (NYHA) class IV, QRS 173 ± 23 ms) scheduled for CRT underwent clinical assessment, echocardiography, and brain-type natriuretic peptide (BNP) measurements before and 6.4 ± 2.3 months after CRT. Baseline SRSsept (all systolic stretch after initial shortening in the septum) was quantified by speckle tracking echocardiography. Primary composite end point was death, urgent cardiac transplantation, or left ventricular assist device implantation at the end of the study. Secondary end points were intermediate-term (6 months) response, quantified as decreases in left ventricular end-systolic volume (ΔLVESV) and BNP (ΔBNP). After a mean clinical follow-up of 15.6 ± 9.0 months; 23 patients had reached the primary end point. Baseline SRSsept (hazard ratio [HR] 0.742; 95% confidence intervals [CI] 0.601-0.916, P < .01]) was independently associated with a better outcome and NYHA class (HR 5.786: 95% CI 2.341-14.299, P < .001) with a worse outcome. Contrary to baseline NYHA class, baseline SRSsept was an independent predictor of both ΔLVESV (beta 0.53; P < .001) and ΔBNP (beta 0.29; P < .01). Intermediate-term ΔLVESV and ΔBNP were associated with a favorable long-term outcome. CONCLUSIONS: SRSsept at baseline is a strong, independent predictor of long-term prognosis after CRT and of improvements in left ventricular remodeling and neurohormonal activation at intermediate term.

Septal deformation patterns delineate mechanical dyssynchrony and regional differences in contractility: analysis of patient data using a computer model.

BACKGROUND: Response to cardiac resynchronization therapy depends both on dyssynchrony and (regional) contractility. We hypothesized that septal deformation can be used to infer integrated information on dyssynchrony and regional contractility, and thereby predict cardiac resynchronization therapy response. METHODS AND RESULTS: In 132 cardiac resynchronization therapy candidates with left bundle branch block (LBBB)-like electrocardiogram morphology (left ventricular ejection fraction 19±6%; QRS width 170±23 ms), longitudinal septal strain was assessed by speckle tracking echocardiography. To investigate the effects of dyssynchronous activation and differences in septal and left ventricular free wall contractility on septal deformation pattern, we used the CircAdapt computer model of the human heart and circulation. In the patients, 3 characteristic septal deformation patterns were identified: LBBB-1=double-peaked systolic shortening (n=28); LBBB-2=early systolic shortening followed by prominent systolic stretching (n=34); and LBBB-3=pseudonormal shortening with less pronounced late systolic stretch (n=70). LBBB-3 revealed more scar (2 [2-5] segments) compared with LBBB-1 and LBBB-2 (both 0 [0-1], P<0.05). In the model, imposing a time difference of activation between septum and left ventricular free wall resulted in pattern LBBB-1. This transformed into pattern LBBB-2 by additionally simulating septal hypocontractility, and into pattern LBBB-3 by imposing additional left ventricular free wall or global left ventricular hypocontractility. Improvement of left ventricular ejection fraction and reduction of left ventricular volumes after cardiac resynchronization therapy were most pronounced in LBBB-1 and worst in LBBB-3 patients. CONCLUSIONS: A double-peaked systolic septal deformation pattern is characteristic for LBBB and results from intraventricular dyssynchrony. Abnormal contractility modifies this pattern. A computer model can be helpful in understanding septal deformation and predicting cardiac resynchronization therapy response.

Cardiovascular magnetic resonance imaging for diagnosis and clinical management of suspected cardiac masses and tumours.

AIMS: To evaluate the diagnostic accuracy of cardiovascular magnetic resonance (CMR) imaging from a risk-stratification and therapeutic-management perspective in patients with suspected cardiac tumours. METHODS AND RESULTS: Cardiovascular magnetic resonance exams of 41 consecutive patients (aged 61 ± 14 years, 21 men) referred for evaluation of a suspected cardiac mass were reviewed for tumour morphology and signal characteristics in various unenhanced and contrast-enhanced sequences. Cardiovascular magnetic resonance-derived diagnosis and treatment were compared with clinical outcome and histology in patients undergoing surgery or autopsy (n = 20). In 18 of 41 patients, CMR excluded masses or reclassified them as normal variants; all were treated conservatively. In 23 of 41 patients, CMR diagnosed a neoplasm (14 'benign', 8 'malignant', and 1 'equivocal'); 18 of these patients were operated on, 2 managed conservatively, and 3 by palliation. During follow-up of 705 (inter-quartile range 303-1472) days, 13 patients died. No tumour-related deaths occurred in conservatively managed patients. Patients with a CMR-based diagnosis and treatment of benign tumour had a similar survival as patients without detectable tumour. Compared with histology, CMR correctly classified masses as 'benign or malignant' in 95% of the cases. Tumour perfusion, invasiveness, localization, and pericardial fluid were valuable to distinguish between malignant and benign tumours. Soft tissue contrast and signal intensity patterns in various sequences were valuable for excluding neoplastic lesions and helped to obtain tissue characterization at the histological level in selected tumour cases, respectively. CONCLUSION: Comprehensive CMR provides a confident risk-stratification and clinical-management tool in patients with suspected tumours. Patients where CMR excludes tumours can be managed conservatively.

Mechano-energetics of the asynchronous and resynchronized heart.

Abnormal electrical activation of the ventricles creates major abnormalities in cardiac mechanics. Local contraction patterns, as reflected by measurements of local strain, are not only out of phase, but often also show opposing length changes in early and late activated regions. As a consequence, the efficiency of cardiac pump function (the amount of stroke work generated by a unit of oxygen consumed) is approximately 30% lower in asynchronous than in synchronous hearts. Moreover, the amount of work performed in myocardial segments becomes considerably larger in late than in early activated regions. Cardiac Resynchronization Therapy (CRT) improves mechano-energetics of the previously asynchronous heart in various ways: it alleviates impediment of the abnormal contraction on blood flow, it increases myocardial efficiency, it recruits contraction in the previously early activated septum and it creates a more uniform distribution of myocardial blood flow. These factors act together to increase the range of cardiac work that can be delivered by the patients' heart, an effect that can explain the increased exercise tolerance and quality of life reported in several CRT trials.

Detection and quantification by deformation imaging of the functional impact of septal compared to free wall preexcitation in the Wolff-Parkinson-White syndrome.

Pacing experiments in healthy animal hearts have suggested a larger detrimental effect of septal compared to free wall preexcitation. We investigated the intrinsic relation among the site of electrical preexcitation, mechanical dyssynchrony, and dysfunction in human patients. In 33 patients with Wolff-Parkinson-White (WPW) syndrome and 18 controls, regional myocardial deformation was assessed by speckle tracking mapping (ST-Map) to assess the preexcitation site, shortening sequences and dyssynchrony, and the extent of local and global ejecting shortening. The ST-Map data in patients with accessory atrioventricular pathways correctly diagnosed as located in the interventricular septum (IVS) (n = 11) or left ventricular free wall (LFW) (n = 12) were compared to the corresponding control values. A local ejecting shortening of <2 SD of the control values identified hypokinetic segments. The localization of the atrioventricular pathways by ST-Map matched with the invasive electrophysiology findings in 23 of 33 patients and was one segment different in 5 of 33 patients. In both WPW-IVS and WPW-LFW, local ejecting shortening was impaired at the preexcitation site (p <0.01). However, at similar electrical and mechanical dyssynchrony, WPW-IVS had more extensive hypokinesia than did WPW-LFW (3.6 +/- 0.9 vs 1.8 +/- 1.3 segments, p <0.01). Compared to controls, the left ventricular function was significantly reduced only in WPW-IVS (global ejecting shortening 17 +/- 2% vs 19 +/- 2%, p = 0.01; ejection fraction 55 +/- 5% vs 59 +/- 3%, p = 0.02). In conclusion, preexcitation is associated with local hypokinesia, which at comparable preexcitation is more extensive in WPW-IVS than in WPW-LFW and could adversely affect ventricular function. ST-Map might have a future role in detecting and guiding treatment of septal pathways with significant mechanical effects.

Effects of on-pump and off-pump coronary artery bypass grafting on left ventricular relaxation and compliance: a comprehensive perioperative echocardiography study.

AIMS: The short-term effect of coronary artery bypass grafting (CABG) on diastolic function is only moderately investigated. Furthermore, it remains unknown whether avoidance of cardioplegic arrest by an off-pump CABG procedure has advantages over on-pump procedure regarding diastolic relaxation and compliance. We investigated whether components of diastolic function would be improved the day after CABG depending on the type of the surgical procedure. METHODS AND RESULTS: Spontaneously breathing on-pump (n = 20) and off-pump CABG (n = 12) patients underwent a comprehensive transthoracic echocardiography examination the day before and the day after elective CABG, including transmitral and pulmonary vein flow parameters, colour M-mode flow propagation velocity (Vp) and tissue Doppler assessment of the average mitral annulus diastolic velocity (Em). Isovolumic relaxation and E-wave deceleration time were corrected for heart rate (IVRTcHR and DTcHR). Left ventricular (LV) relaxation time (τ) and LV operating stiffness (LVOS) were calculated. Overall and independent from operation type and preload, CABG decreased IVRTcHR (107 ± 20 vs. 93 ± 15 ms) (P < 0.01) and τ (54 ± 10 vs. 45 ± 10 ms) (P < 0.01), increased Vp (49 ± 22 vs. 75 ± 37 cm/s) (P < 0.01), and increased Em (6.6 ± 2.0 vs. 7.3 ± 1.3 cm/s, P = 0.06), indicating improved relaxation. LVOS increased (0.13 ± 0.06 vs. 0.22 ± 0.05 mmHg/mL) (P < 0.01), compatible with an impaired compliance. A similar improvement in relaxation and impairment in compliance were observed in both groups. CONCLUSION: Myocardial relaxation improved the day after CABG irrespective of the use of cardiopulmonary bypass with cardioplegic arrest. Impairment in compliance could not be prevented by the avoidance of cardioplegia.

Effect of long term and intensive endurance training in athletes on the age related decline in left and right ventricular diastolic function as assessed by Doppler echocardiography.

The aim of this study was to evaluate (1) the effect of endurance training on left ventricular and right ventricular diastolic function and (2) whether the normal aging effect on left ventricular and right ventricular diastolic function is slowed by endurance training. A total of 269 healthy subjects were prospectively enrolled for echocardiographic evaluation. Five groups were defined on the basis of age and athletic activities: (1) young (18 to 39 years) nonathletes (n = 62), (2) veteran (>or=40 years) nonathletes (n = 33), (3) young regular athletes (9 to 18 hours of sports/week; n = 58), (4) young elite athletes (>18 hours of sports/week; n = 63), and (5) veteran athletes (>or=40 years and >or=9 hours of sports/week; n = 53). Pulsed-wave Doppler indexes for diastolic function in the left and right ventricles were obtained at rest. No significant differences were found among the young controls, regular athletes, and elite athletes in left ventricular and right ventricular pulsed-wave and tissue Doppler diastolic parameters. These were also comparable between the veteran athletes and controls. In athletes and controls, similar and significant correlations were found between age and diastolic parameters. Age was the most important determinant in almost all parameters in multivariate analysis, while the influence of the amount of training did not account for >2% of the observed variance in any of these parameters. In conclusion, the amount of endurance training did not alter diastolic parameters in either ventricle in the young. Furthermore, the biventricular decreases in diastolic function observed in healthy, nonathletic subjects with age was also observed in aging athletes' hearts.

Septal rebound stretch reflects the functional substrate to cardiac resynchronization therapy and predicts volumetric and neurohormonal response.

AIMS: To develop a novel myocardial deformation index that is highly sensitive to the effect of cardiac resynchronization therapy (CRT) and that can be used to predict response to CRT. METHODS AND RESULTS: Before and 6.5 +/- 2.3 months after implantation of a CRT device, longitudinal shortening and stretch were timed and quantified by speckle tracking echocardiography in a cohort of 62 patients. Distinction was made between systolic total stretch (STS; all systolic stretch) and systolic rebound stretch (SRS; only systolic stretch following initial shortening). Systolic total stretch and SRS could be measured in all wall segments in 41 of 62 patients. Septal SRS quantification was possible in all 62 patients and was performed by a blinded observer. Cardiac resynchronization therapy reduced STS (-55 +/- 30%) but reduced SRS (-77 +/- 21%) significantly more (P < 0.01). The largest amount of baseline SRS and the largest reductions in SRS (-90 +/- 22%) were found in the septum. Reductions in local SRS were paralleled by increases in local systolic shortening that were twice as large (r = 0.79), thereby strongly improving septal function. Baseline values of septal SRS correlated with reductions in left ventricular end-systolic volume index (Delta LVESVi; r = 0.62) and brain-type natriuretic peptide (BNP) (Delta log(10)BNP; r = 0.57). Septal SRS was an independent predictor of CRT response in linear regression analysis and predicted Delta LVESVi of >or=15% with a sensitivity and specificity of 81% at ROC analysis (areas under the curve 0.89 +/- 0.04). CONCLUSION: Septal rebound stretch appears to be a sensitive and practical diagnostic criterion to quantify the functional substrate amenable to CRT and to predict response.

Development of strategies for guiding cardiac resynchronization therapy.

This article illustrates the highly interesting possibilities of cardiac resynchronization therapy (CRT) yet also discusses several problems for optimal implementation. The authors have presented possible strategies to improve CRT by designing and using better measurements of mechanical dyssynchrony or discoordination, leading to better patient selection. In addition, application of CRT can be improved by developing techniques to reach the optimal pacing site(s) easier and algorithms for easier programming of optimal atrioventricular delay and interventricular interval. Also, application of CRT in patients with less severe heart failure deserves further attention. Finally, the mechanism of ventricular interaction may open new fields of application of left ventricle-based pacing in patients who have heart failure, even with a narrow QRS complex.

Three-dimensional mapping of mechanical activation patterns, contractile dyssynchrony and dyscoordination by two-dimensional strain echocardiography: rationale and design of a novel software toolbox.

BACKGROUND: Dyssynchrony of myocardial deformation is usually described in terms of variability only (e.g. standard deviations SD's). A description in terms of the spatio-temporal distribution pattern (vector-analysis) of dyssynchrony or by indices estimating its impact by expressing dyscoordination of shortening in relation to the global ventricular shortening may be preferential. Strain echocardiography by speckle tracking is a new non-invasive, albeit 2-D imaging modality to study myocardial deformation. METHODS: A post-processing toolbox was designed to incorporate local, speckle tracking-derived deformation data into a 36 segment 3-D model of the left ventricle. Global left ventricular shortening, standard deviations and vectors of timing of shortening were calculated. The impact of dyssynchrony was estimated by comparing the end-systolic values with either early peak values only (early shortening reserve ESR) or with all peak values (virtual shortening reserve VSR), and by the internal strain fraction (ISF) expressing dyscoordination as the fraction of deformation lost internally due to simultaneous shortening and stretching. These dyssynchrony parameters were compared in 8 volunteers (NL), 8 patients with Wolff-Parkinson-White syndrome (WPW), and 7 patients before (LBBB) and after cardiac resynchronization therapy (CRT). RESULTS: Dyssynchrony indices merely based on variability failed to detect differences between WPW and NL and failed to demonstrate the effect of CRT. Only the 3-D vector of onset of shortening could distinguish WPW from NL, while at peak shortening and by VSR, ESR and ISF no differences were found. All tested dyssynchrony parameters yielded higher values in LBBB compared to both NL and WPW. CRT reduced the spatial divergence of shortening (both vector magnitude and direction), and improved global ventricular shortening along with reductions in ESR and dyscoordination of shortening expressed by ISF. CONCLUSION: Incorporation of local 2-D echocardiographic deformation data into a 3-D model by dedicated software allows a comprehensive analysis of spatio-temporal distribution patterns of myocardial dyssynchrony, of the global left ventricular deformation and of newer indices that may better reflect myocardial dyscoordination and/or impaired ventricular contractile efficiency. The potential value of such an analysis is highlighted in two dyssynchronous pathologies that impose particular challenges to deformation imaging.

Practical and conceptual limitations of tissue Doppler imaging to predict reverse remodelling in cardiac resynchronisation therapy.

BACKGROUND: Recent, conflicting results about the use of tissue Doppler imaging derived (TDI-) asynchrony indices to predict reverse remodelling after cardiac resynchronisation therapy (CRT) have raised questions about their physiological meaning and methodological limitations. METHODS: In 41 patients, baseline TDI-derived septal to lateral delays of peak velocities (TDI-SL), standard deviation of peak velocities over 12 segments (Ts-SD), and peak 2D longitudinal strain (strain-SL) were compared with volumetric response (reduction in end-systolic volume of > or =15%) after at least 6 months of CRT. Timing of peak TDI velocities was compared to timing of 2DS velocities and strain-SL. Influence of sample position, transverse motion, and interobserver inconsistency of the chosen peak velocities was assessed. Diagnostic accuracy of TDI-based delays was compared to accuracy of visual and 2D strain-based assessment. RESULTS: After 7.0+/-3.2 months of CRT, 24 patients were classified as responders. TDI-SL and Ts-SD were similar between responders and nonresponders at baseline, did not predict response, and were unaffected by CRT. Visual asynchrony scoring and strain-SL were better predictors of response than TDI-SL and Ts-SD. TDI measurements were highly susceptible to sample location and transverse motion components and poorly correlated with the timing of longitudinal contraction. There was a considerably poor agreement between observers with regard to scoring of TDI-SL and Ts-SD. CONCLUSION: TDI-based measurements of asynchrony do not appear robust predictors of volume response to CRT.

Reversible 18-FDG-uptake defects on myocardial PET: Is this myocardial resurrection?

Because it can accurately detect preserved glucose metabolism even in the hypoperfused or stunned myocardium, 18-FDG-PET is considered as the gold standard of myocardial viability assessment. In tako-tsubo cardiomyopathy, a presumed condition of stunning, absence of glucose metabolism however is not a marker of death. This sheds a critical light on 18-FDG-PET as a gold standard for viability.

Echocardiographic assessment of regional right ventricular function: a head-to-head comparison between 2-dimensional and tissue Doppler-derived strain analysis.

OBJECTIVE: We sought to compare the feasibility and results of Doppler tissue imaging-derived and 2-dimensional strain echocardiography-derived deformation assessment of the right ventricular (RV) free wall. METHODS: Absolute values and timing of strain and strain rate (SR) obtained by both techniques in the basal, mid, and apical segments of the RV free wall were prospectively analyzed and compared in individuals with varying RV function and geometry: patients with an impaired RV function (n = 23), endurance athletes (n = 22), and control subjects (n = 22). RESULTS: Both techniques yielded a 93% technical feasibility and had a similar interobserver and intraobserver variability. The overall correlation for onset strain values was 0.59, with better correlation in the pathologic RV (r = 0.77). The overall correlation of peak strain was moderately good for strain values (r = 0.73) and timing (r = 0.56). Over the entire range of systolic and diastolic values, SR correlated closely (r = 0.90). Systolic SR correlated moderately (r = 0.59), but its timing poorly (r = 0.35). There was a small bias toward higher values of strain and SR when using Doppler tissue imaging, except in the basal segment. CONCLUSION: Overall, in the assessment of RV deformation, Doppler tissue imaging and 2-dimensional strain echocardiography correlate moderately well and display a comparable feasibility.

Echocardiographic quantification of myocardial function using tissue deformation imaging, a guide to image acquisition and analysis using tissue Doppler and speckle tracking.

Recent developments in the field of echocardiography have allowed the cardiologist to objectively quantify regional and global myocardial function. Regional deformation (strain) and deformation rate (strain-rate) can be calculated non-invasively in both the left and right ventricle, providing information on regional (dys-)function in a variety of clinical settings. Although this promising novel technique is increasingly applied in clinical and preclinical research, knowledge about the principles, limitations and technical issues of this technique is mandatory for reliable results and for implementation both in the clinical as well as the scientific field. In this article, we aim to explain the fundamental concepts and potential clinical applicability of strain and strain-rate for both tissue Doppler imaging (TDI) derived and speckle tracking (2D-strain) derived deformation imaging. In addition, a step-by-step approach to image acquisition and post processing is proposed. Finally, clinical examples of deformation imaging in hypertrophic cardiomyopathy (HCM), cardiac resynchronization therapy (CRT) and arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) are presented.

Colour M-mode velocity propagation: a glance at intra-ventricular pressure gradients and early diastolic ventricular performance.

The physiology of early-diastolic filling comprises ventricular performance and fluid dynamical principles. Elastic recoil and myocardial relaxation rate determine left ventricular early diastolic performance. The integrity of left ventricular synchrony and geometry is essential to maintain the effect of their timely action on early diastolic left ventricular filling. These factors not only are prime determinants of left ventricular pressure decay during isovolumic relaxation and immediately after mitral valve opening; they also instigate the generation of a sufficient intra-ventricular pressure gradient, which enhances efficient early diastolic left ventricular filling. Accurate assessment of diastolic (dys)function by non-invasive techniques has important therapeutic and prognostic implications but remains a challenge to the cardiologist. The evaluation of left ventricular relaxation by the standard Doppler echocardiographic parameters is hindered by their preload dependency. The colour M-mode velocity propagation of early diastolic inflow (Vp) correlates with intra-ventricular pressure gradients and is a largely preload independent index of ventricular diastolic performance. In this article, the physiologic background, utility and limitations of this promising new tool for the study of early diastolic filling are reviewed.