Combined longitudinal and radial dyssynchrony predicts ventricular response after resynchronization therapy. J Am Coll Cardiol. 2007;50:1476-1483. [PMID: 17919568 DOI: 10.1016/j.jacc.2007.06.043]

Role of echocardiography in selection of patients for biventricular pacing therapy

Cardiac resynchronization therapy (CRT) has demonstrated improved quality of life, New York Heart Association class, left ventricular ejection fraction, and survival in patients with moderate to severe heart failure, left ventricular ejection fraction less than or equal to 35%, and a prolonged QRS duration. QRS duration remains the primary surrogate for mechanical dyssynchrony, defining the pathophysiology of abnormal regional mechanical activation. Studies have demonstrated that 30% to 40% of patients who meet current criteria for CRT are nonresponders. Therefore, there is great interest in the relationship between electrical and mechanical dyssynchrony, and the ability of each alone or together to predict response remains unknown. Echocardiographic approaches have emerged to quantify mechanical dyssynchrony with greater specificity than QRS duration alone. Although these methods are complex, exciting, and highly accurate for predicting response to CRT in single-center studies, they lack widespread applicability and validation to replace current criteria for device implantation. Use of echocardiography to define dyssynchrony and the impact of promising imaging methods for future patient selection for CRT are discussed.

Prediction of response to cardiac resynchronization therapy by speckle tracking echocardiography using different software approaches

BACKGROUND

Although several echocardiographic approaches exist to quantify mechanical dyssynchrony, the comparative ability of different manufacturers' speckle-tracking software programs to predict response to cardiac resynchronization therapy (CRT) is unknown.

METHODS

Eighty-four patients with heart failure referred for CRT were studied (mean age, 64 +/- 12 years; mean ejection fraction [EF], 26 +/- 7%; mean QRS duration, 157 +/- 26 ms). Dyssynchrony was assessed using the same midventricular short-axis digital cine loop for each patient with 3 different offline speckle-tracking strain analysis programs: software A, speckle-tracking two-dimensional strain; software B, velocity vector imaging strain; and software C, speckle-tracking strain. Significant dyssynchrony was defined as an anterior septum-to-posterior wall delay > or =130 ms. Follow-up was available for 57 patients (mean, 7 +/- 4 months). Response to CRT was defined as an EF increase > or =15%.

RESULTS

Variability between software results was observed when patients had large degrees of dyssynchrony (> or =200 ms), with limits of agreement from 123 to 214 ms. However, close agreement for identifying patients with significant dyssynchrony was observed: 91% for software A versus B, 96% for software A versus C, and 93% for software B versus C. Importantly, the 3 software approaches' ability to predict EF outcome had similar sensitivities, specificities, and areas under receiver operating characteristic curves: 0.87, 0.86, and 0.86, respectively.

CONCLUSIONS

Radial strain dyssynchrony analyses by 3 different speckle-tracking software programs were similarly able to predict EF response to CRT. Although variability in absolute values of dyssynchrony was observed, there was close agreement for determining the presence or absence of significant dyssynchrony. Speckle-tracking echocardiography has potential as a means to quantify dyssynchrony in a multicenter clinical trial or clinical practice.

Usefulness of multimodality imaging for detecting differences in temporal occurrence of left ventricular systolic mechanical events in healthy young adults

Detailed information about the absolute temporal occurrence of myocardial motion and deformation events during the cardiac cycle is still lacking. However, the normal time range of these parameters may be of great importance as a reference for detecting and interpreting mechanical dyssynchrony and for identifying a delayed contraction in case of left ventricular (LV) dysfunction. The aim of this study was to determine in young healthy subjects and for different LV segments the value of (1) time to peak systolic longitudinal velocity, displacement, strain rate, and strain using tissue Doppler imaging (TDI); (2) time to minimum systolic volume using real-time 3-dimensional echocardiography; and (3) time to maximum thickness using cardiac magnetic resonance imaging (MRI). Twenty 20 young healthy volunteers (13 men, mean age 32 +/- 4 years) underwent cardiac MRI and echocardiographic examination, including TDI and real-time 3-dimensional echocardiography. To define LV ejection time and isovolumic relaxation time, aortic valve closure and opening and mitral valve opening were identified. For all LV segments, longitudinal peak systolic velocity and strain rate were early systolic events. Peak systolic longitudinal displacement and strain in turn occurred in late systole, or in 20% to 30% of LV segments, during isovolumic relaxation time, similarly to minimum systolic volume and maximum myocardial thickness. In conclusion, the present study provides a systematic report of the normal time range of measurements obtained by TDI, real-time 3-dimensional echocardiography, and cardiac MRI. Peak systolic longitudinal velocity and strain rate significantly precede peak longitudinal displacement, strain, minimum systolic volume, and maximum thickness.

Speckle tracking in the evaluation of left ventricular dyssynchrony

A number of echocardiographic techniques have been introduced to determine left ventricular dyssynchrony (LVD) and to improve selection of patients for CRT. During the last years tissue Doppler imaging (TDI) has been used as the most preferred technique to quantify LVD, but results with nonresponder rates below 30% have been shown only in small studies based on high experience. Angle of incidence dependency, noise, artifacts, and tethering motion of adjacent segments are the main limitations of TDI influencing selection of patients for CRT. Although strain TDI is not affected by translation or tethering, accurate measurement of regional strain is also limited. Two-dimensional (2D) strain imaging based on novel speckle tracking echocardiography (STE) is a relatively new tool to define regional myocardial strain and to quantify dyssynchrony based on a more robust technique and avoiding angle of incidence. Current studies are promising to use strain or vector velocity imaging derived from STE for qualitative and quantitative assessment of LVD and follow-up studies as well. If one compare different types of strain components at present, radial strain imaging seems to be the most promising technique to determine LVD and to predict positive response to CRT. Furthermore, STE offers an insight into rotational mechanics of the dyssynchronous ventricle. Although clinical studies using 2D strain have analyzed LVD related to various conditions, measures are based on a 2D data set. Three-dimensional strain imaging, based on speckle tracking will probably open a new door to assess patients with heart failure and LVD.

Echocardiography for cardiac resynchronization therapy selection: fatally flawed or misjudged?

After the publication of the PROSPECT (Predictors of Response to CRT) trial, the use of echocardiography for the assessment of mechanical dyssynchrony and as a possible aid for selecting patients for cardiac resynchronization therapy has been heavily criticized. Calls have been made to observe the current guidelines and implant according to the entry criteria of recent major trials. However, although this approach is currently to be recommended, the attempt to identify patients who will not receive the benefits of cardiac resynchronization therapy and whose clinical condition may be worsened should continue. Devices are not analogous to drugs: initial costs are higher, complications are significant, and the device cannot readily be withdrawn. Professional resources and the costs to society are high and wasted if devices are implanted inappropriately. Rather that discarding the attempt to identify the most suitable patients pre-operatively, further work is needed to refine the techniques and new clinical trials performed. A combination of methods that include finding the site of latest mechanical activation, myocardial scar localization, and assessing venous anatomy pre-operatively may help to identify those who will not derive any benefit or be potentially worsened.

Strain and strain rate imaging by echocardiography - basic concepts and clinical applicability

Echocardiographic strain and strain-rate imaging (deformation imaging) is a new non-invasive method for assessment of myocardial function. Due to its ability to differentiate between active and passive movement of myocardial segments, to quantify intraventricular dyssynchrony and to evaluate components of myocardial function, such as longitudinal myocardial shortening, that are not visually assessable, it allows comprehensive assessment of myocardial function and the spectrum of potential clinical applications is very wide. The high sensitivity of both tissue Doppler imaging (TDI) derived and two dimensional (2D) speckle tracking derived myocardial deformation (strain and strain rate) data for the early detection of myocardial dysfunction recommend these new non-invasive diagnostic methods for extensive clinical use. In addition to early detection and quantification of myocardial dysfunction of different etiologies, assessment of myocardial viability, detection of acute allograft rejection and early detection of allograft vasculopathy after heart transplantation, strain and strain rate data are helpful for therapeutic decisions and also useful for follow-up evaluations of therapeutic results in cardiology and cardiac surgery. Strain and strain rate data also provide valuable prognostic information, especially prediction of future reverse remodelling after left ventricular restoration surgery or after cardiac resynchronization therapy and prediction of short and median-term outcome without transplantation or ventricular assist device implantation of patients referred for heart transplantation.The Review explains the fundamental concepts of deformation imaging, describes in a comparative manner the two major deformation imaging methods (TDI-derived and speckle tracking 2D-strain derived) and discusses the clinical applicability of these new echocardiographic tools, which recently have become a subject of great interest for clinicians.

Insights from a cardiac resynchronization optimization clinic as part of a heart failure disease management program

OBJECTIVES

Our aim was to determine the feasibility and value of a protocol-driven approach to patients with cardiac resynchronization therapy (CRT) who did not exhibit a positive response long after implant.

BACKGROUND

Up to one-third of patients with advanced heart failure do not exhibit a positive response to CRT.

METHODS

A total of 75 consecutive ambulatory patients with persistent advanced heart failure symptoms and/or adverse reverse remodeling and CRT implanted >6 months underwent a comprehensive protocol-driven evaluation to determine the potential reasons for a suboptimal response. Recommendations were made to maximize the potential of CRT, and adverse events were documented.

RESULTS

All patients (mean left ventricular [LV] ejection fraction 23 +/- 9%, LV end-diastolic volume 275 +/- 127 ml) underwent evaluation. Eighty-eight percent of patients had significantly better echocardiographic indexes of LV filling and LV ejection with optimal setting of their CRT compared with a temporary VVI back-up setting. Most patients had identifiable reasons for suboptimal response, including inadequate device settings (47%), suboptimal medical treatment (32%), arrhythmias (32%), inappropriate lead position (21%), or lack of baseline dyssynchrony (9%). Multidisciplinary recommendations led to changes in device settings and/or other therapy modifications in 74% of patients and were associated with fewer adverse events (13% vs. 50%, odds ratio: 0.2 [95% confidence interval: 0.07 to 0.56], p = 0.002) compared with those in which no recommendation could be made.

CONCLUSIONS

Routine protocol-driven approach to evaluate ambulatory CRT patients who did not exhibit a positive response is feasible, and changes in device settings and/or other therapies after multidisciplinary evaluation may be associated with fewer adverse events.

The role of echocardiography in cardiac resynchronization therapy

Echocardiography is the most important imaging tool for managing heart failure patients. With the advent of cardiac resynchronization therapy (CRT), its role has been broadened by data pertaining to patient selection, optimization of device settings, and outcome assessment. Beyond ejection fraction determination, echocardiographic methods that measure tissue velocity and strain may have the capability to determine degree of mechanical dyssynchrony and possibly predict likelihood of benefit with CRT. After implantation (as the ventricles are fully paced, adjusting the atrioventricular delay ), the timing of the right ventricular and left ventricular lead stimulation (ventricular-ventricular optimization) to achieve maximal cardiac filling or ejection may be clinically important. Atrioventricular and ventricular-ventricular optimization rely on echocardiography to determine optimal values. In long-term follow-up, serial measurement of left ventricular volume has significant correlation with mortality and is a reasonable measure of successful CRT; echocardiography is uniquely suited for this purpose.

Echocardiographic speckle tracking radial strain imaging to assess ventricular dyssynchrony in a pacing model of resynchronization therapy

BACKGROUND

Speckle tracking imaging is a promising new echocardiographic method to assess left ventricular (LV) mechanical dyssynchrony. Our aim was to assess a new speckle tracking regional strain algorithm by comparison with angle-corrected tissue Doppler (TD) in an animal model of left bundle branch block and cardiac resynchronization therapy.

METHODS AND RESULTS

Ten open-chest dogs had routine gray-scale and TD images of the mid-LV short-axis plane. Electrical activation was altered by pacing from right ventricular, LV free wall, and biventricular sites to create various degrees of mechanical dyssynchrony and alter regional function. Segmental time to peak strain, peak strain, and frame-by-frame strain were measured by angle-corrected TD, TD M-mode, and speckle tracking on the same digital cineloop. Of 240 possible paired TD and speckle tracking segments, data were available for 222 segments (93%); images with catheter artifacts were prospectively excluded. Comparative overall time to peak strain by each method correlated well: r = 0.96, bias = -6 +/- 20 ms. Of 80 possible paired M-mode TD and speckle tracking segments, strain data were available for 76 segments (95%). Comparative overall time to peak strain, peak strain, and frame-by-frame strain analysis in 1012 frames by each method correlated well: r = 0.98, bias of 1 +/- 14 ms; r = 0.82, bias of 3% +/- 7%; and r = 0.91, bias of 0% +/- 6%, respectively.

CONCLUSION

Regional strain analysis using echocardiographic speckle tracking radial strain strongly correlated with strain by angle-corrected TD imaging in an animal model of dyssynchrony. Speckle tracking radial strain has potential for clinical applications.

The role of tissue Doppler and strain imaging in predicting response to CRT

AIMS

Several echocardiographic methods have been proposed to assist in patient selection for cardiac resynchronization therapy (CRT). The prevailing hypothesis is that echocardiography may be superior to the electrocardiogram to qualify abnormalities in regional mechanical activation, because QRS widening is only a surrogate for ventricular dyssynchrony.

METHODS AND RESULTS

This review will focus on tissue Doppler (TD) and strain imaging, including their advantages and disadvantages for patient selection for CRT. Colour-coded TD remains to be one of the most promising means to quantify dyssynchrony. Tissue Doppler velocity data have a more favourable signal-to-noise ratio compared with TD strain or strain rate imaging. However, velocity data are affected by Doppler angle of incidence and passive or tethering motion. A newer promising method is speckle-tracking echocardiography to calculate strain. An opposing wall delay in peak TD velocity > or =65 ms has been associated with clinical and ventricular response to CRT. The initial experience with speckle tracking used the short-axis view to calculate radial strain. An anterior-septal to posterior wall peak strain delay > or =130 ms has been associated with an ejection fraction response to CRT.

CONCLUSION

Although no ideal echo-Doppler method has yet been discovered to select patients for CRT, technical refinements and advances in understanding of pathophysiology continue to favourably impact on potential clinical applications.

Results of the Prospective Minnesota Study of ECHO/TDI in Cardiac Resynchronization Therapy (PROMISE-CRT) study

BACKGROUND

Retrospective single-center studies have shown that measures of mechanical dyssynchrony before cardiac resynchronization therapy (CRT), or acute changes after CRT, predict response better than QRS duration. The Prospective Minnesota Study of Echocardiographic/TDI in Cardiac Resynchronization Therapy (PROMISE-CRT) study was a prospective multicenter study designed to determine whether acute (1 week) changes in mechanical dyssynchrony were associated with response to CRT.

METHODS AND RESULTS

Nine Minnesota Heart Failure Consortium centers enrolled 71 patients with standard indications for CRT. Left ventricular (LV) size, function, and mechanical dyssynchrony (echocardiography [ECHO], tissue Doppler imaging [TDI], speckle-tracking echocardiography [STE]) as well as 6-minute walk distance and Minnesota Living with Heart Failure Questionnaire scores were measured at baseline and 3 and 6 months after CRT. Acute change in mechanical dyssynchrony was not associated with clinical response to CRT. Acute change in STE radial dyssynchrony explained 73% of the individual variation in reverse remodeling. Baseline measures of mechanical dyssynchrony were associated with reverse remodeling (but not clinical) response, with 4 measures each explaining 12% to 30% of individual variation.

CONCLUSIONS

Acute changes in radial mechanical dyssynchrony, as measured by STE, and other baseline mechanical dyssynchrony measures were associated with CRT reverse remodeling. These data support the hypothesis that acute improvement in LV mechanical dyssynchrony is an important mechanism contributing to LV reverse remodeling with CRT.

Left ventricular torsion and recoil: implications for exercise performance and cardiovascular disease

In recent years, advancements in echocardiography assessment techniques have allowed for the quantification of left ventricular (LV) rotation. This information has provided new insight into LV function in health and disease. In this review, we discuss the importance of assessing LV circumferential rotation for understanding cardiac function in a wide range of populations. We provide a synopsis of LV rotational mechanics in the context of the various techniques currently available to assess LV rotation. We also highlight the factors that alter LV function at rest and during exercise. Finally, we discuss the influences of age, sex, and cardiac pathology on LV rotation. Collectively, this review highlights the importance of understanding LV rotation and its measurement in both health and disease.

Validation of an echocardiographic multiparametric strategy to increase responders patients after cardiac resynchronization: a multicentre study

AIMS

We sought to develop and validate a multiparametric algorithm by applying previously validated criteria to predict cardiac resynchronization therapy (CRT) response in a multicentre study. Thirty per cent of patients treated by CRT fail to respond to the treatment. Although dyssynchrony by echocardiography has been used to improve the selection of patients, the complexity of myocardial contraction has generated a moderate improvement using any of several individual parameters.

METHODS AND RESULTS

Two hundred end-stage heart failure patients [NYHA 3-4 and left ventricular ejection fraction (LVEF)<35%] with QRS>120 ms were included. Echocardiography analysis focused on the following parameters: atrioventricular dyssynchrony, interventricular dyssynchrony, and intraventricular dyssynchrony that integrated radial (PSAX M-mode) and longitudinal [tissue Doppler imaging (TDI)] evaluations for spatial (wall to wall) and temporal (wall end-systole to mitral valve opening) dyssynchrony diagnosis. Following CRT implantation, patients were monitored for 6 months with functional and echo evaluations defining responders by a 15% reduction in end-systolic volume. Mean QRS duration and LVEF were 152 +/- 17 ms and 25 +/- 8%. There was a CRT response in 57% of patients, independent of QRS width. Mean prevalence of positive criteria was 34 +/- 8%. Feasibility and variability averages were 81 +/- 20% and 9 +/- 4%. In a single parametric approach, ranges of sensitivities and specificities were 18-65% and 45-84% with a mean of 41% and 66%. A multiparametric approach by focusing on criteria combination decreased the mean rate of false-positive results to 14 +/- 12%, 5 +/- 4%, 2 +/- 2%, and 1 +/- 2% from one to four parameters, respectively. More than three parameters were associated with a specificity above 90% and a positive predictive value above 65%. Reproducibility of this global strategy was 91%.

CONCLUSION

A multiparametric echocardiographic strategy based on the association of conventional criteria is a better indicator of CRT response than the existing single parametric approaches.

New Echocardiographic Techniques for Evaluating Left Ventricular Myocardial Function

Ultrasound imaging of the heart continues to play an important role in diagnosis and management of patients with cardiovascular diseases. Recent advances in ultrasound technology and introduction of newer imaging modalities have enabled improved assessment of left ventricular myocardial function. Tissue Doppler imaging and 2-dimensional speckle tracking allow more objective quantification of myocardial function in the form of tissue velocities, displacement, strain, and strain rate. Similarly, contrast-enhanced echocardiography and 3-dimensional echocardiography have provided a unique insight into left ventricular form and function that was not possible by unenhanced 2-dimensional echocardiography. In this review, the authors discuss the clinical application of these new imaging techniques in the assessment of left ventricular myocardial function.

Contemporary pacemakers: what the primary care physician needs to know

Pacemaker therapy is most commonly initiated because of symptomatic bradycardia, usually resulting from sinus node disease. Randomized multicenter trials assessing the relative benefits of different pacing modes have made possible an evidence-based approach to the treatment of bradyarrhythmias. During the past several decades, major advances in technology and in our understanding of cardiac pathophysiology have led to the development of new pacing techniques for the treatment of heart failure in the absence of bradycardia. Left ventricular or biventricular pacing may improve symptoms of heart failure and objective measurements of left ventricular systolic dysfunction by resynchronizing cardiac contraction. However, emerging clinical data suggest that long-term right ventricular apical pacing may have harmful effects. As the complexity of cardiac pacing devices continues to grow, physicians need to have a basic understanding of device indications, device function, and common problems encountered by patients with devices in the medical and home environment.

Measures of left ventricular dyssynchrony and the correlation to clinical and echocardiographic response after cardiac resynchronization therapy

There is still no standardized measure of left ventricular (LV) dyssynchrony or definition of response in candidates of cardiac resynchronization therapy (CRT). Recipients of CRT underwent echocardiographic assessment of LV dyssynchrony before and immediately after implantation of a CRT device. Patients were followed for 6 months postimplantation. A total of 44 patients (64 +/- 12 years, 30 men, and 26 with ischemic cardiomyopathy) were included in this analysis. There was a significant decrease in both radial (304 +/- 137 vs 121 +/- 85 ms, p <0.001) and longitudinal (143 +/- 104 vs 95 +/- 43 ms, p = 0.02) measures of LV dyssynchrony immediately after CRT. The immediate post-CRT change in radial (r = -0.43, p = 0.015) but not longitudinal (r = -0.09, p = 0.61) LV dyssynchrony correlated with a significant improvement in the physical component of the quality-of-life score 6 months after CRT. Although a higher baseline longitudinal (p = 0.05) or radial (p = 0.025) LV dyssynchrony predicted a >or=1 improvement in New York Heart Association classification of heart failure 6 months after CRT, acute changes in neither radial (p = 0.71) nor longitudinal (p = 0.89) LV dyssynchrony were predictive of any improved echocardiographic outcomes in follow-up. Concordance between clinical and echocardiographic response to CRT was documented in 72% of patients. In conclusion, both longitudinal and radial measures of LV dyssynchrony improve after CRT. The change in longitudinal but not radial measures of LV dyssynchrony correlates with improved physical quality-of-life score in intermediate term follow-up.

Biventricular pacing worsened dyssynchrony in heart failure patient with right-bundle branch block

The use of a biventricular pacing system for patients with complete right-bundle branch block (CRBBB) is still controversial. Although cardiac resynchronization therapy-defibrillator (CRT-D) was implanted in a heart failure patient with CRBBB, dyssynchrony worsened and stroke volume decreased, and this patient was re-admitted due to exacerbated heart failure. Therefore, evaluation of dyssynchrony and cardiac function after implantation of a biventricular pacing system may be needed in patients with atypical indications for CRT.

Relation between left ventricular regional radial function and radial wall motion abnormalities using two-dimensional speckle tracking in children with idiopathic dilated cardiomyopathy

Left ventricular (LV) regional radial function and its relation to radial wall motion abnormalities have not been investigated in children with idiopathic dilated cardiomyopathy (IDC). Radial strain was measured using 2-dimensional speckle tracking to evaluate regional radial function and wall motion in 6 LV segments in 24 children (0 to 18 years old) with IDC and 16 healthy controls. Patients and controls were similar in age. Patients with IDC had higher heart rates (97 +/- 28 vs 77 +/- 19, p <0.05) and decreased ejection fraction (34 +/- 12% vs 66 +/- 7%, p <0.0001) compared with controls. Radial strain in all segments was significantly lower in patients with IDC. In IDC, average radial strain correlated well with ejection fraction (r = 0.8, p <0.0001). The SD of time to peak radial strain among 6 LV segments was significantly higher in patients with IDC than in controls (56 +/- 38 vs 15 +/- 12 ms, p <0.0001). Segmental peak radial strain correlated closely to time to peak radial strain in controls (r = 0.98, p = 0.0008), but less in patients with IDC (r = 0.76, p = 0.07). In conclusion, LV regional radial function is impaired in pediatric IDC, in association with increased radial dyssynchrony, revealing a possible important mechanism for LV dysfunction in these children.

Assessment of left ventricular dyssynchrony by speckle tracking strain imaging comparison between longitudinal, circumferential, and radial strain in cardiac resynchronization therapy

OBJECTIVES

The objective of this study was to assess the usefulness of each type of strain for left ventricular (LV) dyssynchrony assessment and its predictive value for a positive response after cardiac resynchronization therapy (CRT). Furthermore, changes in extent of LV dyssynchrony for each type of strain were evaluated during follow-up.

BACKGROUND

Different echocardiographic techniques have been proposed for assessment of LV dyssynchrony. The novel 2-dimensional (2D) speckle tracking strain analysis technique can provide information on radial strain (RS), circumferential strain (CS), and longitudinal strain (LS).

METHODS

In 161 patients, 2D echocardiography was performed at baseline and after 6 months of CRT. Extent of LV dyssynchrony was calculated for each type of strain. Response to CRT was defined as a decrease in LV end-systolic volume >/=15% at follow-up.

RESULTS

At follow-up, 88 patients (55%) were classified as responders. Differences in baseline LV dyssynchrony between responders and nonresponders were noted only for RS (251 +/- 138 ms vs. 94 +/- 65 ms; p < 0.001), whereas no differences were noted for CS and LS. A cut-off value of radial dyssynchrony >/=130 ms was able to predict response to CRT with a sensitivity of 83% and a specificity of 80%. In addition, a significant decrease in extent of LV dyssynchrony measured with RS (from 251 +/- 138 ms to 98 +/- 92 ms; p < 0.001) was demonstrated only in responders.

CONCLUSIONS

Speckle tracking radial strain analysis constitutes the best method to identify potential responders to CRT. Reduction in LV dyssynchrony after CRT was only noted in responders.

The associations between tricuspid annular plane systolic excursion (TAPSE), ventricular dyssynchrony, and ventricular interaction in heart failure patients

AIMS

Ventricular interactions may be mediated by loading conditions and biventricular timing and coordination. We sought to understand the relationships between right (RV) and left ventricular (LV) function and dyssynchrony, examine the RV correlates of LV dyssynchrony, and determine whether improved loading conditions affect inter-ventricular interaction.

METHODS AND RESULTS

In 25 heart failure patients [15 with left ventricular ejection fraction (LVEF) < 40%; 10 with LVEF >/= 50%], Doppler echocardiography and invasive bi-ventricular pressure-volume haemodynamics were obtained at baseline and 30 min after infusion of the recombinant B-type natriuretic peptide vasodilator nesiritide. RV and LV intra-ventricular dyssynchrony was measured invasively using a pressure-conductance catheter. Patients with reduced LVEF had greater LV dyssynchrony (31 +/- 3 vs. 24 +/- 7%; P = 0.003) compared to those with preserved LVEF. Tricuspid annular plane systolic excursion (TAPSE) had the highest correlation with LV dyssynchrony (r = -0.52; P = 0.0002) compared to other RV echocardiographic parameters. The association between TAPSE and LV dyssynchrony was independent of RVEF and LVEF (P = 0.008). There were no acute changes in the correlations between LV dyssynchrony and TAPSE after nesiritide.

CONCLUSION

TAPSE and LV dyssynchrony are strongly associated, independent of RV and LV ejection fraction. Of the RV echocardiographic parameters, TAPSE has the highest predictive value of LV dyssynchrony, and remained significant after vasodilator unloading.