Dilated cardiomyopathy evaluation with Imagenomics: combining multimodal cardiovascular imaging and genetics

Dilated cardiomyopathy (DCM) is a clinical diagnosis characterized by the presence of left ventricular dilatation and systolic dysfunction unexplained by abnormal loading conditions or coronary artery disease. However, a broad range of phenotypic manifestations, encompassing isolated scar, DCM with preserved ejection fraction, and overt DCM, should be regarded as a diagnostic classification representing a broad spectrum of underlying aetiologies, including both inherited and acquired heart muscle disorders. A multimodal non-invasive imaging approach is essential for accurate morpho-functional assessment of cardiac chambers and is key to establish the cardiac phenotype and to rule out an underlying ischaemic aetiology. Furthermore, advanced imaging techniques enable deep cardiovascular phenotyping and non-invasive tissue characterization. The aim of this review is to propose a systematic approach to the diagnosis of DCM, emphasizing the importance of genetics and clinical findings for a precise and practical clinical approach. Also, we strive to qualify the role of cardiac imaging in the diagnosis of DCM, particularly on the relevance of novel techniques and clinical utility of actionable parameters to improve current diagnostic schemes and risk stratification algorithms. We further elaborate on the role of cardiac imaging to deliver optimal guidance to aetiology-based therapeutic approaches, verification of treatment response and disease progression monitoring.

Epidemiology, Pathophysiology, and Management of Native Atrioventricular Valve Regurgitation in Heart Failure Patients

Atrioventricular regurgitation is frequent in the setting of heart failure. It is due to atrial and ventricular remodelling, as well as rhythmic disturbances and loss of synchrony. Once atrioventricular regurgitation develops, it can aggravate the underlying heart failure, and further participate and aggravate its own severity. Its presence is therefore concomitantly a surrogate of advance disease and a predictor of mortality. Heart failure management, including medical therapy, cardiac resynchronization therapy, and restoration of sinus rhythm, are the initial steps to reduce atrioventricular regurgitation. In the current review, we analyse the current data assessing the epidemiology, pathophysiology, and impact of non-valvular intervention on atrioventricular regurgitation including medical treatment, cardiac resynchronization and atrial fibrillation ablation.

Progression of cardiac disease in patients with lamin A/C mutations

Aims

We aimed to study the progression of cardiac dysfunction in patients with lamin A/C mutations and explore markers of adverse cardiac outcome.

Methods and results

We followed consecutive lamin A/C genotype-positive patients divided into tertiles according to age. Patients underwent repeated clinical examinations, electrocardiograms (ECGs), and echocardiograms. We followed left ventricular (LV) and right ventricular (RV) size and function, and the severity atrioventricular-valve regurgitations. Outcome was death, LVAD implant, or cardiac transplantation. We included 101 patients [age 44 (29–54) years, 39% probands, 50% female]. We analysed 576 echocardiograms and 258 ECGs during a follow-up of 4.9 (interquartile range 2.5–8.2) years. The PR-interval increased at young age from 204 ± 73 to 212 ± 69 ms (P < 0.001), LV ejection fraction (LVEF) declined from middle age from 50 ± 12% to 47 ± 13% (P < 0.001), while LV volumes remained unchanged. RV function and tricuspid regurgitation worsened from middle age with accelerating rates. Progression of RV dysfunction [odds ratio (OR) 1.3, 95% confidence interval (CI) (1.03–1.65), P = 0.03] and tricuspid regurgitation [OR 4.9, 95% CI (1.64–14.9), P = 0.004] were associated with outcome when adjusted for age, sex, comorbidities, LVEF, and New York Heart Association functional class.

Conclusion

In patients with lamin A/C genotype, electrical disease started at young age. From middle age, LV function deteriorated progressively, while LV size remained unchanged. Worsening of RV function and tricuspid regurgitation accelerated in older age and were associated with outcome. Our systematic map on cardiac deterioration may help optimal monitoring and prognostication in lamin A/C disease.

The role of strut chordae in mitral valve competence during annular dilation

Strut chordae, on their own, are not typically thought to aid mitral valve competence. The aim of this study is to assess whether strut chordae aid mitral valve competence during acute annular dilation. Twelve porcine hearts were dissected and tested using an in vitro simulator, with the mitral annulus tested in either a 'normal' or a dilated configuration. The normal configuration included a diameter of 30 mm, a posterior leaflet 'radius' of 15 mm and a commissural corner 'radius' of 7.5 mm; the dilated annular template instead used dimensions of 50 mm, 25 mm and 12.5 mm, respectively. Each mitral valve underwent ten repeat tests with a target systolic pressure of 100 mmHg. No significant difference in the pressure was detected between the dilated and regular annuli for the mitral valves tested (95 ± 3 mmHg cf. 95 ± 2 mmHg). However, the volume of regurgitation for a dilated annulus was 28 ml greater than for a valve with a normal annulus. Following severing of strut chordae, there was a significant reduction in the systolic pressure withstood before regurgitation by mitral valves with dilated annuli (60 ± 29 mmHg cf. 95 ± 2 mmHg for normal annular dimensions; p < 0.05). In conclusion, strut chordae tendineae may play a role in aiding mitral valve competence during pathophysiology.

The role of strut chordae in mitral valve competence during annular dilation

Strut chordae, on their own, are not typically thought to aid mitral valve competence. The aim of this study is to assess whether strut chordae aid mitral valve competence during acute annular dilation. Twelve porcine hearts were dissected and tested using an in vitro simulator, with the mitral annulus tested in either a 'normal' or a dilated configuration. The normal configuration included a diameter of 30 mm, a posterior leaflet 'radius' of 15 mm and a commissural corner 'radius' of 7.5 mm; the dilated annular template instead used dimensions of 50 mm, 25 mm and 12.5 mm, respectively. Each mitral valve underwent ten repeat tests with a target systolic pressure of 100 mmHg. No significant difference in the pressure was detected between the dilated and regular annuli for the mitral valves tested (95 ± 3 mmHg cf. 95 ± 2 mmHg). However, the volume of regurgitation for a dilated annulus was 28 ml greater than for a valve with a normal annulus. Following severing of strut chordae, there was a significant reduction in the systolic pressure withstood before regurgitation by mitral valves with dilated annuli (60 ± 29 mmHg cf. 95 ± 2 mmHg for normal annular dimensions; p < 0.05). In conclusion, strut chordae tendineae may play a role in aiding mitral valve competence during pathophysiology.

Multi-Modality Imaging in Dilated Cardiomyopathy: With a Focus on the Role of Cardiac Magnetic Resonance

Heart failure (HF) is recognized as a leading cause of morbidity and mortality worldwide. Dilated cardiomyopathy (DCM) is a common phenotype in patients presenting with HF. Timely diagnosis, appropriate identification of the underlying cause, individualized risk stratification, and prediction of clinical response to treatment have improved the prognosis of DCM over the last few decades. In this article, we reviewed the current evidence on available imaging techniques used for DCM patients. In this direction, we evaluated appropriate scenarios for the implementation of echocardiography, nuclear imaging, and cardiac computed tomography, and we focused on the primordial role that cardiac magnetic resonance (CMR) holds in the diagnosis, prognosis, and tailoring of therapeutic options in this population of special clinical interest. We explored the predictive value of CMR toward left ventricular reverse remodeling and prediction of sudden cardiac death, thus guiding the decisions for device therapy. Principles underpinning the use of state-of-the-art CMR techniques such as parametric mapping and feature-tracking strain analysis are also provided, along with expectations for the anticipated future advances in this field. We also attempted to correlate the evidence with clinical practice, with the intent to address questions on selecting the optimal imaging method for different indications and clinical needs. Overall, we recommend a comprehensive assessment of DCM patients at baseline and at follow-up intervals depending on the clinical status, with the addition of CMR as a second-line modality to other imaging techniques. We also provide an algorithm to guide the detailed imaging approach of the patient with DCM. We expect that future guidelines will upgrade their clinical recommendations for the utilization of CMR in DCM, which is expected to further improve the quality of care and the outcomes. This review provides an up-to-date perspective on the imaging of dilated cardiomyopathy patients and will be of clinical value to training doctors and physicians involved in the area of heart failure.

A novel 3D-Printed preferential posterior mitral annular dilation device delineates regurgitation onset threshold in an ex vivo heart simulator

Mitral regurgitation (MR) due to annular dilation occurs in a variety of mitral valve diseases and is observed in many patients with heart failure due to mitral regurgitation. To understand the biomechanics of MR and ultimately design an optimized annuloplasty ring, a representative disease model with asymmetric dilation of the mitral annulus is needed. This work shows the design and implementation of a 3D-printed valve dilation device to preferentially dilate the posterior mitral valve annulus. Porcine mitral valves (n = 3) were sewn into the device and mounted within a left heart simulator that generates physiologic pressures and flows through the valves, while chordal forces were measured. The valves were incrementally dilated, inducing MR, while hemodynamic and force data were collected. Flow analysis demonstrated that MR increased linearly with respect to percent annular dilation when dilation was greater than a 25.6% dilation threshold (p < 0.01). Pre-threshold, dilation did not cause significant increases in regurgitant fraction. Forces on the chordae tendineae increased as dilation increased prior to the identified threshold (p < 0.01); post-threshold, the MR resulted in highly variable forces. Ultimately, this novel dilation device can be used to more accurately model a wide range of MR disease states and their corresponding repair techniques using ex vivo experimentation. In particular, this annular dilation device provides the means to investigate the design and optimization of novel annuloplasty rings.

Contrasting Effects of Pharmacological, Procedural, and Surgical Interventions on Proportionate and Disproportionate Functional Mitral Regurgitation in Chronic Heart Failure

Two distinct pathways can lead to functional mitral regurgitation (MR) in patients with chronic heart failure and a reduced ejection fraction. When remodeling and enlargement of the left ventricle (LV) cause annular dilatation and tethering of the mitral valve leaflets, there is a linear relationship between LV end-diastolic volume and the effective regurgitant orifice area of the mitral valve. These patients, designated as having proportionate MR, respond favorably to treatments that lead to reversal of LV remodeling and a decrease in LV volumes (eg, neurohormonal antagonists and LV assist devices), but they may not benefit from interventions that are directed only at the mitral valve leaflets (eg, transcatheter mitral valve repair). In contrast, when ventricular dyssynchrony causes functional MR attributable to unequal contraction of the papillary muscles, the magnitude of regurgitation is greater than that predicted by LV volumes. These patients, designated as having severe but disproportionate MR, respond favorably to treatments that are directed to the mitral valve leaflets or their supporting structures (eg, cardiac resynchronization or transcatheter mitral valve repair), but they may derive little benefit from interventions that act only to reduce LV cavity size (eg, pharmacological treatments). This novel conceptual framework reflects the important interplay between LV geometry and mitral valve function in determining the clinical presentation of patients, and it allows characterization of the determinants of functional MR to guide the most appropriate therapy in the clinical setting.

An Echocardiographic Evaluation of Dilated Cardiomyopathy in a Tertiary Care Hospital

INTRODUCTION

Cardiomyopathies are diseases of heart muscle that may originate from genetic defects, cardiac myocyte injury or infiltration of myocardial tissues. Dilated cardiomyopathy is the most common phenotype and is often a final common pathway of numerous cardiac insults. Mostly it remains unknown in the absence of echocardiography, histopathology and genetic evaluation. Though common it is underdiagnosed with not much of data available in our setup.

METHODS

This study was analytical cross-sectional study of hospital data on Echocardiographic findings in 65 patients of DCM visiting cardiology unit for Echocardiographic evaluation from 1st of February to 31st July 2018 for the period of six months in Shree Birendra Hospital, a tertiary care military hospital at Chhauni, Kathmandu. Pediatric age group patients and those who refused to give consent were excluded. Data obtained were entered in Microsoft Excel 2010 and analyzed by IBM SPSS 21.

RESULTS

Among 65 patients enrolled 40 (61%) were male and 25 (39%) female with male to female ratio of 1.6:1. Elderly people (61-75 years) with an average age of 65 were commonly involved and they presented mostly with congestive heart failure, 32 (49%). Echocardiographic evaluation showed 36 (55%) with mildly dilated Left Ventricle (5.6-6.0cm). Majority had reduced Left ventricular systolic function with an average Ejection fraction (EF) of 39.6%. No significant difference between male and female with the average EF% (P=0.990) and there was no significant relation between age and average EF% (P=0.091).

CONCLUSIONS

Dilated Cardiomyopathy is the commonest cardiomyopathy phenotype mostly presenting with congestive heart failure. It is often underdiagnosed in our part of the world, however echocardiography will easily detect the condition.

Genetic deletion of the alamandine receptor MRGD leads to dilated cardiomyopathy in mice

We have recently described a new peptide of the renin-angiotensin system, alamandine, a derivative of angiotensin-(1–7). Mas-related G protein-coupled receptor member D (MrgD) was identified as its receptor. Although similar cardioprotective effects of alamandine to those of angiotensin-(1–7) have been described, the significance of this peptide in heart function is still elusive. We aimed to evaluate the functional role of the alamandine receptor MrgD in the heart using MrgD-deficient mice. MrgD was localized in cardiomyocytes by immunofluorescence using confocal microscopy. High-resolution echocardiography was performed in wild-type and MrgD-deficient mice (2 and 12 wk old) under isoflurane anesthesia. Standard B-mode images were obtained in the right and left parasternal long and short axes for morphological and functional assessment and evaluation of cardiac deformation. Additional heart function evaluation was performed using Langendorff isolated heart preparations and inotropic measurements of isolated cardiomyocytes. Immunofluorescence indicated that the MrgD receptor is expressed in cardiomyocytes, mainly in the membrane and perinuclear and nuclear regions. Echocardiography showed left ventricular remodeling and severe dysfunction in MrgD-deficient mice. Strikingly, MrgD-deficient mice presented a pronounced dilated cardiomyopathy with a marked decrease in systolic function. Echocardiographic changes were supported by the data obtained in isolated hearts and inotropic measurements in cardiomyocytes. Our data add new evidence for a major role for alamandine/MrgD in the heart. Furthermore, our results indicate that we have identified a new gene implicated in dilated cardiomyopathy, unveiling a new target for translational approaches aimed to treat heart diseases.

NEW & NOTEWORTHY The renin-angiotensin system is a key target for cardiovascular therapy. We have recently identified a new vasodepressor/cardioprotective angiotensin, alamandine. Here, we unmasked a key role for its receptor, Mas-related G protein-coupled receptor member D (MrgD), in heart function. The severe dilated cardiomyopathy observed in MrgD-deficient mice warrants clinical and preclinical studies to unveil its potential use in cardiovascular therapy.

Listen to this article’s corresponding podcast at https://ajpheart.podbean.com/e/mrgd-deficiency-leads-to-dilated-cardiomyopathy/ .

The ventricular residence time distribution derived from 4D flow particle tracing: a novel marker of myocardial dysfunction

4D flow cardiac magnetic resonance (CMR) imaging allows visualisation of blood flow in the cardiac chambers and great vessels. Post processing of the flow data allows determination of the residence time distribution (RTD), a novel means of assessing ventricular function, potentially providing additional information beyond ejection fraction. We evaluated the RTD measurement of efficiency of left and right ventricular (LV and RV) blood flow. 16 volunteers and 16 patients with systolic dysfunction (LVEF < 50%) underwent CMR studies including 4D flow. The RTDs were created computationally by seeding virtual 'particles' at the inlet plane in customised post-processing software, moving these particles with the measured blood velocity, recording and counting how many exited per unit of time. The efficiency of ventricular flow was determined from the RTDs based on the time constant (RTDc = - 1/B) of the exponential decay. The RTDc was compared to ejection fraction, T1 mapping and global longitudinal strain (GLS). There was a significant difference between groups in LV RTDc (healthy volunteers 1.2 ± 0.13 vs systolic dysfunction 2.2 ± 0.80, p < 0.001, C-statistic = 1.0) and RV RTDc (1.5 ± 0.15 vs 2.0 ± 0.57, p = 0.013, C-statistic = 0.799). The LV RTDc correlated significantly with LVEF (R = - 0.84, P < 0.001) and the RV RTDc had significant correlation with RVEF (R = - 0.402, p = 0.008). The correlation between LV RTDc and LVEF was similar to GLS and LVEF (0.926, p < 0.001). The ventricular residence time correlates with ejection fraction and can distinguish normal from abnormal systolic function. Further assessment of this method of assessment of chamber function is warranted.

Prediction of the ischemic origin of functional mitral regurgitation in patients with systolic heart failure through posterior mitral leaflet angle

BACKGROUND

Differentiating ischemic from non-ischemic functional mitral regurgitationý (FMR) in patients with cardiomyopathy is important in terms of the therapeutic decision-making and prognosis, but might be clinically challenging. In this study, the deformation of mitral valve (MV) indices in the prediction of the etiology of FMR was assessed using 2D transthoracic and tissue Doppler echocardiography.

METHODS

This case-control study was conducted from April 2015 to January 2016 in Imam Reza Hospital in Mashhad, Iran. The participants consisted of 40 patients with ischemic cardiomyopathy (ICM) and 22 with non-ischemic dilated cardiomyopathy (DCM) who referred to the heart failure clinic. Transthoracic echocardiography was performed using the conventional 2D and tissue Doppler imaging (TDI). MV tenting area (TA), coaptation distance (CD), anterior and posterior mitral leaflet angles (AMLA and PMLA), and regional systolic myocardial velocity (Sm) were measured.

RESULTS

There were no significant differences in echocardiographic indices between the two groups, besides Sm and PMLA which were significantly lower and higher, respectively, in ICM subjects in comparison with DCM patients (P = 0.002). PMLA ≥ 40 degrees and Sm ≤ 4 cm/second have a relatively high value for discriminating the ischemic from non-ischemic origin of functional MR in subjects with systolic heart failure (sensitivity: 80.0% and 70.0%, specificity: 73.0% and 77.3%; P = 0.001 and P < 0.001; respectively). Multivariable logistic regression identified PMLA and anterior Sm as major determinants for ischemic MR {Odds ratio (OR) [95% confidence interval (CI)] = 0.89 (0.82-0.96), P = 0.003, OR (95% CI) = 0.29 (0.14-0.60), P = 0.001, respectively}.

CONCLUSION

The present study showed that PMLA and Sm had an independent significant association with the mechanism of FMR. These findings are suggestive of the predictive role of mitral deformation echocardiographic indices in the determination of the etiology of FMR in systolic heart failure.

Functional Mitral Regurgitation: An Interventional Cardiologist's Perspective

Functional mitral regurgitation (FMR) is common in patients with heart failure and portends a poor prognosis. The etiology is secondary to nonischemic or ischemic (postmyocardial infarction) adverse remodeling. Treatment includes guideline-directed medical therapy, cardiac resynchronization therapy, and in some cases, surgical repair or replacement. Transcatheter mitral valve (MV) repair with the MitraClip device is approved in patients with degenerative MR and is currently under investigation for use in FMR, as are several transcatheter MV replacement devices. This review discusses the basis of FMR pathophysiology, classification, and prognosis; provides an overview of current therapeutic approaches; examines the available literature on the use of MitraClip in patients with FMR; and provides insight into ongoing clinical trials and new investigational devices for the treatment of FMR.

Torsion Mechanics as an Indicator of More Advanced Left Ventricular Systolic Dysfunction in Secondary Mitral Regurgitation in Patients with Dilated Cardiomyopathy: A 2D Speckle-Tracking Analysis

Left ventricular (LV) twist serves as a compensatory mechanism in systolic dysfunction and its degree of reduction may reflect a more advanced stage of disease. Aim: The aim was to investigate twist alterations depending on the degree of functional mitral regurgitation (MR) by speckle-tracking echocardiography. Methods: Sixty-three patients with symptomatic dilated cardiomyopathy (DCM) were included. Patients were divided according to MR vena contracta width (VCW): group 1 with VCW <7 mm (mild/moderate MR) and group 2 with VCW ≥7 mm (severe MR). Results: There were no differences in LV geometry and function between groups. Group 2 showed lower endocardial basal rotation (BR) (–2.04° ± 1.83° vs. –3.23° ± 1.83°, p = 0.012); epicardial BR (–1.54° ± 1.18° vs. –2.31° ± 1.22°, p = 0.015); endocardial torsion (0.41°/cm ± 0.36°/cm vs. 0.63°/cm ± 0.44°/cm, p = 0.033) and mid-level circumferential strain (CSmid) (–6.12% ± 2.64% vs. –7.75% ± 2.90%, p = 0.028), when compared with group 1. Multivariable linear regression analysis identified endocardial BR, torsion and CSmid, as the best predictors of larger VCW. In the ROC curve analysis, endocardial BR and CSmid values greater than or equal to –3.63° and –9.35%, respectively, can differentiate patients with severe MR. Conclusions: In DCM patients, torsional profile was more altered in severe MR. Endocardial BR, endocardial torsion, and CSmid, can be used as indicators of advanced structural wall architecture damage.

Creation of nonischemic functional mitral regurgitation by annular dilatation and nonplanar modification in a chronic in vivo swine model

BACKGROUND

Mechanisms and treatments of nonischemic functional mitral regurgitation (NIMR) are not fully established, in part, because of a lack of proper large animal models. We developed a novel technique of NIMR creation in a swine model by making multiple small incisions in the mitral annulus.

METHODS AND RESULTS

Ex vivo experiments using isolated swine hearts (n=10) showed a 15% increase in annular area (6.8-7.8 cm(2)) after 16 incisions were made along the posterior mitral annulus of a pressurized left ventricle. In an in vivo swine model (n=7; 46.4 ± 2.2 kg), NIMR was created by making fourteen to twenty-six 2-mm incisions in the atrial aspect of the mitral annulus using a cardioport video-assisted imaging system in the beating heart. Animals were euthanized at 4 weeks (n=4) and 6 weeks (n=3). Three-dimensional (3D) echocardiography was obtained before and immediately after NIMR creation and at euthanasia; vena contracta area, mitral annular dimension, left ventricular volume, and inter-papillary muscle distance were measured. The mitral annular incisions resulted in mild to moderate mitral regurgitation and an increased vena contracta area. NIMR creation altered mitral valve geometry by decreasing mitral annular nonplanarity and increasing annular area, primarily in the anteroposterior dimension. NIMR creation did not significantly change left ventricular volume or inter-papillary muscle distance. Longer follow-up period did not significantly affect these outcomes.

CONCLUSIONS

NIMR can successfully be created in a beating heart swine model and results in dilatation and 3D changes in mitral annular geometry. This model can enhance the experimental validation of new valve repair devices and techniques.

Review on CFD simulation in heart with dilated cardiomyopathy and myocardial infarction

The heart is a sophisticated functional organ that plays a crucial role in the blood circulatory system. Hemodynamics within the heart chamber can be indicative of exert cardiac health. Due to the limitations of current cardiac imaging modalities, computational fluid dynamics (CFD) have been widely used for the purposes of cardiac function assessment and heart disease diagnosis, as they provide detailed insights into the cardiac flow field. An understanding of ventricular hemodynamics and pathological severities can be gained through studies that employ the CFD method. In this research the hemodynamics of two common myocardial diseases, dilated cardiomyopathy (DCM) and myocardial infarction (MI) were investigated, during both the filling phase and the whole cardiac cycle, through a prescribed geometry and fluid structure interaction (FSI) approach. The results of the research indicated that early stage disease identification and the improvement of cardiac assisting devices and therapeutic procedures can be facilitated through the use of the CFD method.

Role of dyssynchrony on functional mitral regurgitation in patients with idiopathic dilated cardiomyopathy: a comparison study with geometric parameters of mitral apparatus

Background

Functional mitral regurgitation (FMR) occurs commonly in patients with dilated cardiomyopathy (DCM). This study was conducted to explore the role of left ventricular (LV) dyssynchrony in developing FMR in patients with DCM in comparison with geometric parameters of the mitral apparatus.

Methods

Twenty patients without FMR and 33 patients with FMR [effective regurgitant orifice area (ERO) = 0.17 ± 0.10 cm²] were enrolled. MR severity was estimated with ERO area. Dyssynchrony indices (DI) were measured using the standard deviations of time to peak myocardial systolic velocity between eight segments. Using real time 3D echocardiography, mitral valve tenting area (MVTa), anterior (APMD) and posterior papillary muscle distances (PPMD), LV sphericity, and tethering angle of anterior (Aα) and posterior leaflets (Pα) were estimated. All geometrical measurements were corrected (c) by the height of each patient.

Results

The patient with FMR had significantly higher cDI, cMVTa, cAPMD and cPPMD, LV sphericity, Aα, and Pα than the patients without FMR (all p < 0.05). With multiple logistic regression analysis, cMVTa (p = 0.017) found to be strongest predictor of FMR development. In patients with FMR, cMVTa (r = 0.868), cAPMD (r = 0.801), cPPMD (r = 0.742), Aα (r = 0.454), LV sphericity (r = 0.452), and DI (r = 0.410) showed significant correlation with ERO. On multivariate regression analysis, cMVTa and cAPMD (p < 0.001, p = 0.022, respectively) remained the strongest determinants of the degree of ERO and cAPMD (p < 0.001) remained the strongest determinant of the degree of cMVTa.

Conclusion

Displacement of anterior papillary muscle and consequent mitral valve tenting seem to play a major role in developing FMR in DCM, while LV dyssynchrony seems to have no significant role.

The importance of papillary muscle dyssynchrony in predicting the severity of functional mitral regurgitation in patients with non-ischaemic dilated cardiomyopathy: a two-dimensional speckle-tracking echocardiography study

AIMS

In our study, we investigated the impact of papillary muscle systolic dyssynchrony (DYS-PAP) and the configuration of mitral leaflets in the prediction of significant functional mitral regurgitation (MR) with two-dimensional (2D) speckle-tracking strain analysis in non-ischaemic dilated cardiomyopathy (DCM) patients with sinus rhythm.

METHODS

Thirty-six non-ischaemic DCM patients (left ventricular ejection fraction <40%) with sinus rhythm were recruited. The quantification of functional MR was performed using the proximal isovelocity surface area method. The configuration of mitral leaflets [mitral annulus, coaptation height (CH), and tethering distances for papillary muscles] was evaluated in the parasternal long-axis and apical four-chamber views. The assessment of DYS-PAP was performed by applying 2D speckle-tracking imaging to the apical four-chamber view for anterolateral papillary muscle and to the apical long-axis view for posteromedial papillary muscle.

RESULTS

Fifteen (41.6%) patients had mild MR and 21 (58.3%) patients had moderate or moderate-to-severe MR. Patients with higher levels of MR had larger mitral annulus size (P = 0.02), tethering-AL (P = 0.04), higher MR volume (P < 0.0001), effective regurgitant orifice area (P < 0.0001), and DYS-PAP (P < 0.0001) values, but lower CH (P = 0.001), global longitudinal (P = 0.005), radial (P = 0.03), and circumferential strain (P = 0.01) than those with mild MR. Receiver operating characteristic analysis was performed to assess the utility of DYS-PAP to predict moderate or moderate-to-severe functional MR. A DYS-PAP value >30 ms predicted moderate-to-severe MR with 85% sensitivity and 87% specificity [area under the curve: 0.897, 95% confidence interval (CI): 0.781-0.999, P < 0.0001]. Logistic regression analysis revealed that DYS-PAP (odds ratio: 3.2, 95% CI: 1.22-47.7, P = 0.037) was the only independent predictor of moderate or moderate-to-severe functional MR.

CONCLUSION

DYS-PAP is correlated with functional MR in non-ischaemic DCM patients with sinus rhythm. A DYS-PAP cut-off value of 30 ms is a useful tool to identify patients with moderate-to-severe functional MR.

The role of echocardiography in guiding management in dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a common and malignant condition, which carries a poor long-term prognosis. Underlying disease aetiologies are varied, and often carry specific implications for treatment and prognosis. The role of echocardiography is essential in not only establishing the diagnosis, but also in defining the aetiology, and understanding the pathophysiology. This article therefore explores the pivotal role of echocardiography in the evaluation and management of patients with DCM.

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.