Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse

Arrhythmogenic Mitral Valve Prolapse: Can We Risk Stratify and Prevent Sudden Cardiac Death?

Ventricular arrhythmias associated with mitral valve prolapse (MVP) and the capacity to cause sudden cardiac death (SCD), referred to as 'malignant MVP', are an increasingly recognised, albeit rare, phenomenon. SCD can occur without significant mitral regurgitation, implying an interaction between mechanical derangements affecting the mitral valve apparatus and left ventricle. Risk stratification of these arrhythmias is an important clinical and public health issue to provide precise and targeted management. Evaluation requires patient and family history, physical examination and electrophysiological and imaging-based modalities. We provide a review of arrhythmogenic MVP, exploring its epidemiology, demographics, clinical presentation, mechanisms linking MVP to SCD, markers of disease severity, testing modalities and management, and discuss the importance of risk stratification. Even with recently improved understanding, it remains challenging how best to weight the prognostic importance of clinical, imaging and electrophysiological data to determine a clear high-risk arrhythmogenic profile in which an ICD should be used for the primary prevention of SCD.

Echocardiographic assessment of left ventricular mechanics in individuals with mitral valve prolapse: a systematic review and meta-analysis

PURPOSE

During the last decade, a number of echocardiographic studies have employed speckle tracking echocardiography (STE) for assessing myocardial deformation properties in individuals with mitral valve prolapse (MVP), reporting not univocal results. Accordingly, we performed a systematic review and meta-analysis to summarize the main findings of these studies and to examine the overall influence of MVP on left ventricular (LV) global longitudinal strain (GLS).

METHODS

All echocardiographic studies assessing conventional echoDoppler parameters and myocardial strain indices in MVP individuals vs. controls without MVP, selected from PubMed and EMBASE databases, were included. The risk of bias was assessed by using the National Institutes of Health (NIH) Quality Assessment of Case-Control Studies. Continuous data (LV-GLS) were pooled as a standardized mean difference (SMD) comparing MVP group with healthy controls. The overall SMD of LV-GLS was calculated using the random-effect model.

RESULTS

The full-texts of 15 studies with 1088 individuals with MVP and 591 healthy controls were analyzed. Average LV-GLS magnitude was significantly, even though modestly, reduced in MVP individuals in comparison to controls (19.4 ± 3.4% vs. 21.1 ± 2.8%, P < 0.001). The overall effect of MVP on LV-GLS was small-to-medium (SMD - 0.54, 95%CI -0.76,-0.32, P < 0.001). Substantial heterogeneity was detected for the included studies, with an overall I2 statistic value of 75.9% (P < 0.001). Egger's test for a regression intercept gave a P-value of 0.58, indicating no publication bias. On meta-regression analysis, none of the moderators (the age, the percentage of females among MVP individuals, body mass index, heart rate and systolic blood pressure of MVP individuals, the degree of mitral regurgitation, the type of ultrasound machine employed for strain echocardiographic imaging and finally the beta blocker treatment) was significantly associated with effect modification (all P < 0.05). Regional strain analysis, performed by two-third of the studies, highlighted a more enhanced reduction in myocardial strain parameters at level of the LV basal infero-lateral segments in all directions (longitudinal, circumferential and radial), with apical sparing.

CONCLUSIONS

The longitudinal strain impairment detected in MVP individuals is more regional than global, with peculiar involvement of the LV basal infero-lateral segments and relative apical sparing pattern.

When annuloplasty is not enough: a case report of ventricular arrhythmias stepwise abolition after mitral valve re-repair

Background

Some patients affected by mitral valve (MV) prolapse (MVP) are at higher risk of ventricular arrhythmias (VAs), but the underlying pathogenesis, as well as the effects of surgery on VA, remain not fully understood. Mitral valve repair, however, represents a privileged point of view to deepen the understanding of arrhythmogenesis in this context. Hence, we report an interesting case of MV re-repair.

Case summary

A 52-year-old man was referred to our institution for severe mitral regurgitation (MR) due to P2 prolapse in the context of myxomatous MV degeneration. Pre-operative imaging showed systolic mitral annular disjunction, left ventricular (LV) wall curling, Pickelhaube's sign, and a prolapsing tricuspid valve (TV) with only mild regurgitation. Twenty-four-hour electrocardiogram (ECG) Holter revealed a significant burden of premature ventricular contractions (PVCs), most of them originating from anterior papillary muscle (APM), posterior papillary muscle (PPM), and mitral annulus (MA). Quadrangular resection of P2 and mitral annuloplasty were performed. One year later, relapse of severe MR due to a residual P2M1 prolapse occurred. Twenty-four-hour ECG Holter showed no PVCs from PPM and MA, while those from APM persisted. A central edge-to-edge repair was effectively used to fix the residual prolapse. After 1 year from REDO surgery, a third ECG Holter confirmed the absence of any remaining LV PVCs, but still few ectopic beats originating from TV were recorded.

Discussion

Here, we report a case of VA resolution after specific, anatomical triggers addressing surgical gestures. Our experience confirms that MV surgery may have a role in MVP patients' arrhythmias correction.

Subclinical impairment of left ventricular myocardium function in type 2 diabetes mellitus patients with or without hypertension

BACKGROUND

Cardiovascular disease has been the leading cause of morbidity and mortality for type 2 diabetes mellitus (T2DM) patients over the last decade.

AIM

To determine whether layer-specific global longitudinal strain (GLS) combined with peak strain dispersion (PSD) can be used to assess left ventricle (LV) myocardium systolic dysfunction in T2DM patients or without hypertension (HP).

METHODS

We enrolled 97 T2DM patients, 70 T2DM + HP patients and 101 healthy subjects. Layer-specific GLS and PSD were calculated by EchoPAC software in apical three-, four- and two-chamber views. GLS of the epimyocardial, middle-layer and endomyocardial (GLSepi, GLSmid, and GLSendo) were measured and recorded. Receiver operating characteristic analysis was performed to detect LV myocardium systolic dysfunction in T2DM patients.

RESULTS

There were significant differences in GLSepi, GLSmid, GLSendo, and PSD between healthy subjects, T2DM patients and T2DM patients with HP (P < 0.001). Trend tests yielded the ranking of healthy subjects > T2DM patients > T2DM with HP patients in the absolute values of GLSepi, GLSmid and GLSendo (P < 0.001), while PSD was ranked healthy subjects < T2DM < T2DM with HP (P < 0.001). Layer-specific GLS and PSD had high diagnostic efficiency for detecting LV myocardium systolic dysfunction in T2DM patients, however, the area under the curve (AUC) for layer-specific GLS and PSD combined was significantly higher than the AUCs for the individual indices (P < 0.05).

CONCLUSION

Layer-specific GLS and PSD were associated with LV myocardium systolic dysfunction in T2DM patients, T2DM patients with HP. T2DM patients with HP have more severe LV myocardium systolic dysfunction than T2DM patients without HP and normal control patients. The combination of layer-specific GLS and PSD may provide additional prognostic information for T2DM patients with or without HP.

Primary Atriopathy in Mitral Valve Prolapse: Echocardiographic Evidence and Clinical Implications

BACKGROUND

Prominent multi-scallop systolic leaflet displacement toward the left atrium (atrialization) is typically observed in bileaflet mitral valve prolapse (MVP) with mitral annular disjunction. We hypothesized that mitral leaflet atrialization is associated with an underlying left atrial (LA) myopathy characterized by progressive structural and functional abnormalities, irrespective of mitral regurgitation (MR) severity.

METHODS

We identified 334 consecutive patients with MVP, no prior atrial fibrillation, and comprehensive clinical and echocardiographic data. LA function was assessed by LA reservoir strain, LA function index, and LA emptying fraction. We also classified the stage of LA remodeling based on LA enlargement and LA reservoir strain (stage 1: no remodeling; stage 2: mild remodeling; stage 3: moderate remodeling; and stage 4: severe remodeling). The primary end point was the composite risk of sudden arrhythmic death, heart failure hospitalization, or the new onset of atrial fibrillation.

RESULTS

Bileaflet MVP with no or mild MR had a lower LA reservoir strain (P=0.04) and LA function index (P<0.001) compared with other MVP subtypes. In multivariable linear regression adjusted for cardiovascular risk factors and MR ≥moderate, bileaflet MVP remained significantly associated with lower LA function parameters (all P<0.05). There was a significant increase in the risk of events as the LA reservoir strain and LA remodeling stage increased (P<0.001). In multivariable analysis, stage 4 of LA remodeling remained significantly associated with a higher risk of events compared with stage 1 (hazard ratio, 6.09 [95% CI, 1.69-21.9]; P=0.006).

CONCLUSIONS

In a large MVP registry, bileaflet involvement is associated with reduced LA function regardless of MR severity, suggesting a primary atriopathy in this MVP subtype. Abnormal LA function, particularly when assessed through a multiparametric approach, is linked to a higher risk of cardiovascular events and may improve risk stratification in MVP, even in those without significant MR.

Mitral Annular Disjunction in the Context of Mitral Valve Prolapse: Identifying the At-Risk Patient

Mitral annular disjunction (MAD), a separation between the left atrium/mitral valve annulus and the left ventricular myocardium, is frequently seen in patients with arrhythmic mitral valve prolapse. Although an association exists between MAD and ventricular arrhythmias, little is known regarding the identification of individuals at high risk. Multimodality imaging including echocardiography, computed tomography, cardiac magnetic resonance, and positron emission tomography can play an important role in both the diagnosis and risk stratification of MAD. Due to a paucity of data, clinical decision making in a patient with MAD is challenging and remains largely empirical. Although MAD itself can be corrected surgically, the prevention and treatment of associated arrhythmias may require medical therapy, catheter ablation, and an implantable cardioverter-defibrillator. Prospective data are required to define the role of implantable cardioverter-defibrillators, targeted catheter ablation, and surgical correction in selected, at-risk patients.

Arrhythmic mitral valve prolapse: a practical approach for asymptomatic patients

Mitral valve prolapse (MVP) is usually regarded as a benign condition though the proportion of patients with a life-threatening arrhythmic MVP form remains undefined. Recently, an experts' consensus statement on arrhythmic MVP has proposed approaches for risk stratification across the spectrum of clinical manifestation. However, sudden cardiac death may be the first presentation, making clinicians focused to early unmasking this subset of asymptomatic patients. Growing evidence on the role of cardiac imaging in the in-deep stratification pathway has emerged in the last decade. Pathology findings have suggested the fibrosis of papillary muscles and inferobasal left ventricular wall as the malignant hallmark. Cardiac magnetic resonance, while of limited availability, allows the identification of this arrhythmogenic substrate. Therefore, speckle-tracking echocardiography may be a gateway to prompt referring patients to further advanced imaging investigation. Our review aims to summarize the phenotypic features linked to the arrhythmic risk and to propose an image-based algorithm intended to help stratifying asymptomatic MVP patients.

Arrhythmic risk profile in mitral valve prolapse: A systematic review and metanalysis of 1715 patients

INTRODUCTION

Mitral valve prolapse (MVP) is a common clinical condition in the general population. A subgroup of patients with MVP may experience ventricular arrhythmias and sudden cardiac death ("arrhythmic mitral valve prolapse" [AMVP]) but how to stratify arrhythmic risk is still unclear. Our meta-analysis aims to identify predictive factors for arrhythmic risk in patients with MVP.

METHODS

We systematically searched Medline, Cochrane, Journals@Ovid, Scopus electronic databases for studies published up to December 28, 2022 and comparing AMVP and nonarrhythmic mitral valve prolapse (NAMVP) for what concerns history, electrocardiographic, echocardiographic and cardiac magnetic resonance features. The effect size was estimated using a random-effect model as odds ratio (OR) and mean difference (MD).

RESULTS

A total of 10 studies enrolling 1715 patients were included. Late gadolinium enhancement (LGE) (OR: 16.67; p = .005), T-wave inversion (TWI) (OR: 2.63; p < .0001), bileaflet MVP (OR: 1.92; p < .0001) and mitral anulus disjunction (MAD) (OR: 2.60; p < .0001) were more represented among patients with AMVP than in NAMVP. Patients with AMVP were shown to have longer anterior mitral leaflet (AML) (MD: 2.63 mm; p < .0001), posterior mitral leaflet (MD: 2.96 mm; p < .0001), thicker AML (MD: 0.49 mm; p < .0001), longer MAD length (MD: 1.24 mm; p < .0001) and higher amount of LGE (MD: 1.41%; p < .0001) than NAMVP. AMVP showed increased mechanical dispersion (MD: 8.04 ms; 95% confidence interval: 5.13-10.96; p < .0001) compared with NAMVP.

CONCLUSIONS

Our meta-analysis proved that LGE, TWI, bileaflet MVP, and MAD are predictive factors for arrhythmic risk in MVP patients.

High-risk phenotypes of arrhythmic mitral valve prolapse: a systematic review and meta-analysis

BACKGROUND

Mitral valve prolapse (MVP) is associated with aggravated risk of ventricular tachycardia (VT), ventricular fibrillation (VF) and sudden cardiac death (SCD). There is a lack of specific guideline recommendation regarding risk stratification and management, despite multiple proposed high-risk phenotypes. We performed systematic review and meta-analysis to evaluate high-risk phenotypes for malignant arrhythmias in patients with MVP.

METHODS

We comprehensively searched the databases of MEDLINE, SCOPUS, and EMBASE from inception to April 2023. Included studies were cohort and case-control comparing between MVP patients with and without VT, VF, cardiac arrest, ICD placement, or SCD. Data from each study were combined using the random-effects. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

Nine studies from 1985 to 2023 were included involving 2,279 patients with MVP. We found that T-wave inversion (OR 2.52; 95% CI: 1.90-3.33; p < 0.001), bileaflet involvement (OR 2.28; 95% CI: 1.69-3.09; p < 0.001), late gadolinium enhancement (OR 17.05; 95% CI: 3.41-85.22; p < 0.001), mitral annular disjunction (OR 3.71; 95% CI: 1.63-8.41; p < 0.002), and history of syncope (OR 6.96; 95% CI: 1.05-46.01; p = 0.044), but not female (OR 0.96; 95% CI: 0.46-2.01; p = 0.911), redundant leaflets (OR 4.30; 95% CI: 0.81-22.84; p = 0.087), or moderate-to-severe mitral regurgitation (OR 1.24; 95% CI: 0.65-2.37; p = 0.505), were associated with those events.

CONCLUSION

Bileaflet prolapse, T-wave inversion, mitral annular disjunction, late gadolinium enhancement, and history of syncope are high-risk phenotypes among population with MVP. Further research is needed to validate the risk stratification model and justify the role of primary prophylaxis against malignant arrhythmias.

Arrhythmic Mitral Valve Prolapse: A Comprehensive Review

Mitral valve prolapse (MVP) is a prevalent cardiac disorder that impacts approximately 2% to 3% of the overall population. While most patients experience a benign clinical course, there is evidence suggesting that a subgroup of MVP patients face an increased risk of sudden cardiac death (SCD). Although a conclusive causal link between MVP and SCD remains to be firmly established, various factors have been associated with arrhythmic mitral valve prolapse (AMVP). This study aims to provide a comprehensive review encompassing the historical background, epidemiology, pathology, clinical manifestations, electrocardiogram (ECG) findings, and treatment of AMVP patients. A key focus is on utilizing multimodal imaging techniques to accurately diagnose AMVP and to highlight the role of mitral annular disjunction (MAD) in AMVP.

Genetic mechanisms underlying arrhythmogenic mitral valve prolapse: Current and future perspectives

Mitral valve prolapse (MVP) is a heart valve disease that is often familial, affecting 2%-3% of the general population. MVP with or without mitral regurgitation can be associated with an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). Research on familial MVP has specifically focused on genetic factors, which may explain the heritable component of the disease estimated to be present in 20%-35%. Furthermore, the structural and electrophysiological substrates underlying SCD/ventricular arrhythmia risk in MVP have been studied postmortem and in the electrophysiology laboratory, respectively. Understanding how familial MVP and rhythm disorders are related may help patients with MVP by individualizing risk and working to develop effective management strategies. This contemporary, state-of-the-art, expert review focuses on genetic factors and familial components that underlie MVP and arrhythmia and encapsulates clinical, genetic, and electrophysiological issues that should be the objectives of future research.

Identifying Mitral Valve Prolapse at Risk for Arrhythmias and Fibrosis From Electrocardiograms Using Deep Learning

BACKGROUND

Mitral valve prolapse (MVP) is a common valvulopathy, with a subset developing sudden cardiac death or cardiac arrest. Complex ventricular ectopy (ComVE) is a marker of arrhythmic risk associated with myocardial fibrosis and increased mortality in MVP.

OBJECTIVES

The authors sought to evaluate whether electrocardiogram (ECG)-based machine learning can identify MVP at risk for ComVE, death and/or myocardial fibrosis on cardiac magnetic resonance (CMR) imaging.

METHODS

A deep convolutional neural network (CNN) was trained to detect ComVE using 6,916 12-lead ECGs from 569 MVP patients from the University of California-San Francisco between 2012 and 2020. A separate CNN was trained to detect late gadolinium enhancement (LGE) using 1,369 ECGs from 87 MVP patients with contrast CMR.

RESULTS

The prevalence of ComVE was 28% (160/569). The area under the receiver operating characteristic curve (AUC) of the CNN to detect ComVE was 0.80 (95% CI: 0.77-0.83) and remained high after excluding patients with moderate-severe mitral regurgitation [0.80 (95% CI: 0.77-0.83)] or bileaflet MVP [0.81 (95% CI: 0.76-0.85)]. AUC to detect all-cause mortality was 0.82 (95% CI: 0.77-0.87). ECG segments relevant to ComVE prediction were related to ventricular depolarization/repolarization (early-mid ST-segment and QRS from V1, V3, and III). LGE in the papillary muscles or basal inferolateral wall was present in 24% patients with available CMR; AUC for detection of LGE was 0.75 (95% CI: 0.68-0.82).

CONCLUSIONS

CNN-analyzed 12-lead ECGs can detect MVP at risk for ventricular arrhythmias, death and/or fibrosis and can identify novel ECG correlates of arrhythmic risk. ECG-based CNNs may help select those MVP patients requiring closer follow-up and/or a CMR.

Predictors of Ventricular Arrhythmias in Patients With Mitral Valve Prolapse: A Meta-analysis

Mitral valve prolapse (MVP) has an estimated prevalence of 2-3% in the general population. Patients with MVP have an increased risk of ventricular arrhythmic events. The aim of this meta-analysis was to identify easily obtained markers that can be used for the arrhythmic risk stratification of MVP patients. This meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement). The search strategy identified 23 studies that were finally included in the study. The quantitative synthesis showed that late gadolinium enhancement (LGE) [RR 6.40 (2.11-19.39), I2 77%, P = 0.001], longer QTc interval [mean difference: 14.2 (8.92-19.49) I2 0%, P < 0.001], T-wave inversion in inferior leads [RR 1.60 (1.39-1.86), I2 0%, P < 0.001], mitral annular disjunction (MAD) [RR 1.77 (1.29-2.44), I2 37%, P = 0.0005], lower left ventricular ejection fraction (LVEF) [mean difference: -0.77 (-1.48, -0.07) I2 0%, P = 0.03], bileaflet MVP [RR 1.32 (1.16-1.49), I2 0%, P < 0.001], increased anterior [mean difference: 0.45 (0.28, 0.61), I2 0%, P < 0.001] and posterior [mean difference: 0.39 (0.26, 0.52), I2 0%, P < 0.001] mitral leaflet thickness were significantly associated with ventricular arrhythmias in MVP patients. On the other hand, gender, QRS duration, anterior, and posterior mitral leaflet length were not associated with increased risk of arrhythmias. In conclusion, inferior T-wave inversions, QTc interval, LGE, LVEF, MAD, bileaflet MVP, anterior, and posterior mitral leaflet thickness are easily obtained markers that can be used for the risk stratification of patients with MVP. Prospective studies should be designed for the better stratification of this population.

Additional value of cardiac magnetic resonance feature tracking parameters for the evaluation of the arrhythmic risk in patients with mitral valve prolapse

OBJECTIVES

The identification of patients with mitral valve prolapse (MVP) presenting high arrhythmic risk remains challenging. Cardiovascular Magnetic Resonance (CMR) feature tracking (FT) may improve risk stratification. We analyzed the role of CMR-FT parameters in relation to the incidence of complex ventricular arrhythmias (cVA) in patients with MVP and mitral annular disjunction (MAD).

METHODS

42 patients with MVP and MAD who underwent 1.5 T CMR were classified as MAD-cVA (n = 23, 55%) in case of cVA diagnosed on a 24-h Holter monitoring and as MAD-noVA in the absence of cVA (n = 19, 45%). MAD length, late gadolinium enhancement (LGE), basal segments myocardial extracellular volume (ECV) and CMR-FT were assessed.

RESULTS

LGE was more frequent in the MAD-cVA group in comparison with the MAD-noVA group (78% vs 42%, p = 0.002) while no difference was observed in terms of basal ECV. Global longitudinal strain (GLS) was reduced in MAD-cVA compared to MAD-noVA (- 18.2% ± 4.6% vs - 25.1% ± 3.1%, p = 0.004) as well as global circumferential strain (GCS) at the mid-ventricular level (- 17.5% ± 4.7% vs - 21.6% ± 3.1%, p = 0.041). Univariate analysis identified as predictors of the incidence of cVA: GCS, circumferential strain (CS) in the basal and mid infero-lateral wall, GLS, regional longitudinal strain (LS) in the basal and mid-ventricular inferolateral wall. Reduced GLS [Odd ratio (OR):1.56 (confidence interval (CI) 95%: 1.45-2.47; p < 0.001)] and regional LS in the basal inferolateral wall [OR: 1.62 (CI 95%: 1.22-2.13; p < 0.001)] remained independent prognostic factors in multivariate analysis.

CONCLUSION

In patients with MVP and MAD, CMR-FT parameters are correlated with the incidence of cVA and may be of interest in arrhythmic risk stratification.

Mechanical Dispersion Discriminates between Arrhythmic and Non-Arrhythmic Sudden Death: From the POST SCD Study

Background

Global longitudinal strain (GLS) and mechanical dispersion (MD) by speckle-tracking echocardiography can predict sudden cardiac death (SCD) beyond left ventricular ejection fraction (LVEF) alone. However, prior studies have presumed cardiac cause from EMS records or death certificates rather than gold-standard autopsies.

Objectives

We sought to investigate whether abnormal GLS and MD, reflective of underlying myocardial fibrosis, are associated with autopsy-defined sudden arrhythmic death (SAD) in a comprehensive postmortem study.

Methods

We identified and autopsied all World Health Organization-defined (presumed) SCDs ages 18-90 via active surveillance of out of hospital deaths in the ongoing San Francisco POstmortem Systematic InvesTigation of Sudden Cardiac Death (POST SCD) Study to refine presumed SCDs to true cardiac causes. We retrieved all available pre-mortem echocardiograms and assessed LVEF, LV-GLS, and MD. The extent of LV myocardial fibrosis was assessed and quantified histologically.

Results

Of 652 autopsied subjects, 65 (10%) had echocardiograms available for primary review, obtained at a mean 1.5 years before SCD. Of these, 37 (56%) were SADs and 29 (44%) were non-SADs; fibrosis was quantified in 38 (58%). SADs were predominantly male, but had similar age, race, baseline comorbidities, and LVEF compared to non-SADs (all p>0.05). SADs had significantly reduced LV-GLS (median: -11.4% versus -18.5%, p=0.008) and increased MD (median: 14.8 ms versus 9.4 ms, p=0.006) compared to non-SADs. MD was associated with total LV fibrosis by linear regression in SADs (r=0.58, p=0.002).

Conclusion

In this countywide postmortem study of all sudden deaths, autopsy-confirmed arrhythmic deaths had significantly lower LV-GLS and increased MD than non-arrhythmic sudden deaths. Increased MD correlated with higher histologic levels of LV fibrosis in SADs. These findings suggest that increased MD, which is a surrogate for the extent of myocardial fibrosis, may improve risk stratification and specification for SAD beyond LVEF.

PERSPECTIVES

Competency in medical knowledge: Mechanical dispersion derived from speckle tracking echocardiography provides better discrimination between autopsy-defined arrhythmic vs non-arrhythmic sudden death than LVEF or LV-GLS. Histological ventricular fibrosis correlates with increased mechanical dispersion in SAD.Translational outlook: Speckle tracking echocardiography parameters, in particular mechanical dispersion, may be considered as a non-invasive surrogate marker for myocardial fibrosis and risk stratification in SCD.

Mitral and Tricuspid Valve Disease in Athletes

Observing mitral or tricuspid valve disease in an athlete raises many considerations for the clinician. Initially, the etiology must be clarified, with causes differing depending on whether the athlete is young or a master. Notably, vigorous training in competitive athletes leads to a constellation of structural and functional adaptations involving cardiac chambers and atrioventricular valve systems. In addition, a proper evaluation of the athlete with valve disease is necessary to evaluate the eligibility for competitive sports and identify those requiring more follow-up. Indeed, some valve pathologies are associated with an increased risk of severe arrhythmias and potentially sudden cardiac death. Traditional and advanced imaging modalities help clarify clinical doubts, allowing essential information about the athlete's physiology and differentiating between primary valve diseases from those secondary to training-related cardiac adaptations. Remarkably, another application of multimodality imaging is evaluating athletes with valve diseases during exercise to reproduce the sport setting and better characterize the etiology and valve defect mechanism. This review aims to analyze the possible causes of atrioventricular valve diseases in athletes, focusing primarily on imaging applications in diagnosis and risk stratification.

Strain Imaging and Ventricular Arrhythmia

Ventricular arrhythmia is one of the main causes of sudden cardiac death. Hence, identifying patients at risk of ventricular arrhythmias and sudden cardiac death is important but can be challenging. The indication for an implantable cardioverter defibrillator as a primary preventive strategy relies on the left ventricular ejection fraction as a measure of systolic function. However, ejection fraction is flawed by technical constraints and is an indirect measure of systolic function. There has, therefore, been an incentive to identify other markers to optimize the risk prediction of malignant arrhythmias to select proper candidates who could benefit from an implantable cardioverter defibrillator. Speckle-tracking echocardiography allows for a detailed assessment of cardiac mechanics, and strain imaging has repeatedly been shown to be a sensitive technique to identify systolic dysfunction unrecognized by ejection fraction. Several strain measures, including global longitudinal strain, regional strain, and mechanical dispersion, have consequently been proposed as potential markers of ventricular arrhythmias. In this review, we will provide an overview of the potential use of different strain measures in the context of ventricular arrhythmias.

Left Ventricle Segmental Longitudinal Strain and Regional Myocardial Work Index Could Help Determine Mitral Valve Prolapse Patients with Increased Risk of Ventricular Arrhythmias

Mitral valve prolapse (MVP) could associate with malignant ventricular arrhythmias (VAs). Mitral annular disjunction, a putative mechanism for an arrhythmic substrate, leads to excessive mobility, stretch, and damage of some segments. Speckle tracking echocardiography (STE), with particular attention to the segmental longitudinal strain and myocardial work index (MWI), could be an indicator of the segments we aimed to check. Seventy-two MVP patients and twenty controls underwent echocardiography. Complex VAs documented prospectively after the enrollment was qualified as the primary endpoint, which was noticed in 29 (40%) patients. Pre-specified cut-off values for peak segmental longitudinal strain (PSS) and segmental MWI for basal lateral (-25%, 2200 mmHg%), mid-lateral (-25%, 2500 mmHg%), mid-posterior (-25%, 2400 mmHg%), and mid-inferior (-23%, 2400 mmHg%) segments were accurate predictors of complex VAs. A combination of PSS and MWI increased the probability of the endpoint, reaching the highest predictive value for the basal lateral segment: odds ratio 32.15 (3.78-273.8), p < 0.001 for PSS ≥ -25% and MWI ≥ 2200 mmHg%. STE may be a valuable tool for assessing the arrhythmic risk in MVP patients. Excessively increased segmental longitudinal strain with an augmented regional myocardial work index identifies patients with the highest risk of complex VAs.

Abnormal Mechanics Relate to Myocardial Fibrosis and Ventricular Arrhythmias in Patients With Mitral Valve Prolapse

BACKGROUND

The relation between ventricular arrhythmia and fibrosis in mitral valve prolapse (MVP) is reported, but underlying valve-induced mechanisms remain unknown. We evaluated the association between abnormal MVP-related mechanics and myocardial fibrosis, and their association with arrhythmia.

METHODS

We studied 113 patients with MVP with both echocardiogram and gadolinium cardiac magnetic resonance imaging for myocardial fibrosis. Two-dimensional and speckle-tracking echocardiography evaluated mitral regurgitation, superior leaflet and papillary muscle displacement with associated exaggerated basal myocardial systolic curling, and myocardial longitudinal strain. Follow-up assessed arrhythmic events (nonsustained or sustained ventricular tachycardia or ventricular fibrillation).

RESULTS

Myocardial fibrosis was observed in 43 patients with MVP, predominantly in the basal-midventricular inferior-lateral wall and papillary muscles. Patients with MVP with fibrosis had greater mitral regurgitation, prolapse, and superior papillary muscle displacement with basal curling and more impaired inferior-posterior basal strain than those without fibrosis (P<0.001). An abnormal strain pattern with distinct peaks pre-end-systole and post-end-systole in inferior-lateral wall was frequent in patients with fibrosis (81 versus 26%, P<0.001) but absent in patients without MVP with basal inferior-lateral wall fibrosis (n=20). During median follow-up of 1008 days, 36 of 87 patients with MVP with >6-month follow-up developed ventricular arrhythmias associated (univariable) with fibrosis, greater prolapse, mitral annular disjunction, and double-peak strain. In multivariable analysis, double-peak strain showed incremental risk of arrhythmia over fibrosis.

CONCLUSIONS

Basal inferior-posterior myocardial fibrosis in MVP is associated with abnormal MVP-related myocardial mechanics, which are potentially associated with ventricular arrhythmia. These associations suggest pathophysiological links between MVP-related mechanical abnormalities and myocardial fibrosis, which also may relate to ventricular arrhythmia and offer potential imaging markers of increased arrhythmic risk.

Arrhythmogenic Mitral Valve Prolapse and Sudden Cardiac Death: An Update and Current Perspectives

Mitral valve prolapse (MVP) affects about 2% to 3% of the general population, mostly women, and is the most common cause of primary chronic mitral regurgitation (MR) in western countries. The natural history is heterogeneous and widely determined by the severity of MR. Although most patients remain asymptomatic with a near-normal life expectancy, approximately 5% to 10 % progress to severe MR. As largely recognized, left ventricular (LV) dysfunction due to chronic volume overload per se identifies a subgroup at risk of cardiac death. However, there is rising evidence of a link between MVP and life threating ventricular arrhythmias (VAs)/sudden cardiac death (SCD) in a small subset of middle-aged patients without significant MR, heart failure and remodeled hearts. The present review focuses on the underlying mechanism of electric instability and unexpected cardiac death in this subset of young patients, from the myocardial scarring of the LV infero-lateral wall due to mechanical stretch exerted by the prolapsing leaflets and mitral annular disjunction, to the inflammation's impact on fibrosis pathways along with a constitutional hyperadrenergic state. The heterogeneity of clinical course reveals a necessity of risk stratification, preferably through noninvasive multimodality imaging, that will help to identify and prevent adverse scenarios in young MVP patients.

Echocardiographic Parameters to Predict Malignant Events in Arrhythmic Mitral Valve Prolapse Population

Bileaflet Mitral Valve Prolapse (bMVP) has been linked to major arrhythmic events and sudden cardiac death (SCD). Consistent predictors in this field are still lacking. Echocardiography is the best tool for the analysis of the prolapse and its impact on the ventricular mechanics. The aim of this study was to find new echocardiographic predictors of malignant events within an arrhythmic MVP population. We evaluated 22 patients with arrhythmic bMVP with a transthoracic echocardiogram focused on mitral valve anatomy and ventricular contraction. Six of them had major arrhythmic events that required ICD implantation (ICD-MVP group), while sixteen presented with a high arrhythmic burden without major events (A-MVP group). The best predictors of malignant events were the Anterior Mitral Leaflet (AML) greater length and greater Mechanical Dispersion (MD) of basal and mid-ventricular segments, while other significant predictors were the larger mitral valve annulus (MVA) indexed area, lower MVA anteroposterior diameter/AML length ratio, higher inferolateral basal segment S3 velocity.

Advanced echocardiographic assessment in adults with repaired aortic coarctation: myocardial work analysis provides novel insights on left ventricular mechanics

AIM

To analyze left ventricular (LV) mechanics through advanced echocardiography, including speckle tracking analysis and myocardial work (MW) in a cohort of adults with repaired aortic coarctation (CoA).

METHODS

Data on standard echocardiography, LV speckle-tracking and MW analysis were collected in CoA patients > 18 years with no significant recoartation or valvular disease and normal LV ejection fraction at the time of the exam. MW indices were calculated using the blood pressure measured in the right arm. A group of healthy subjects with comparable sex, age and body surface area was included for comparison.

RESULTS

Eighty-nine CoA patients and 70 healthy subjects were included. Patients had higher systolic blood pressure (p < 0.0001), LV mass index (p < 0.0001), left atrial volume index (p = 0.005) and E/E' ratio (p = 0.001). Despite similar LV ejection fraction, speckle tracking analysis revealed lower global longitudinal strain (GLS: - 18.3[17-19] vs - 20.7[19-22]%, p < 0.0001) and increased peak systolic dispersion (PSD: 45[40-54] vs 37.5[32-43] ms, p < 0.0001) in CoA patients. Global work index (GWI) and global constructive work were similar to healthy controls (p = 0.6 and 0.5, respectively), whereas CoA patients showed significant increased wasted work (GWW: 125[90-185] vs 89.5[64-127]mmHg%, p < 0.0001) and a mild but significant reduction in global work efficiency (GWE: 93%[92-95] vs 95%[94-97], p < 0.0001). Moreover, when stratifying for GLS values, MW analysis showed increased GWW and PSD with impaired GWE in 54(61%) patients with normal GLS compared to healthy individuals. Spearman's linear method illustrated an inverse relation between GWE and PSD (r: - 0.53, p < 0.0001), while GCW was associated with peak (r: 0.2, p = 0.01) and mean gradient across the descending aorta (r: 0.3, p = 0.004) and with systolic blood pressure (r: 0.48, p < 0.0001). PSD was the sole univariate predictor of GWE on linear regression analysis (β: - 0.1 [- 0.16 to - 0.07], p < 0.0001), whereas female sex, SBP and gradients across the descending aorta were independently associated with higher GCW values. When CoA patients were divided based on the history of redo CoA repair and arterial hypertension, no significant differences in MW indices were found.

CONCLUSIONS

MW is a novel echocardiographic tool, which provides additional information on LV performance in CoA patients over GLS allowing a more comprehensive understanding of LV dysfunction mechanisms in a setting of increased afterload.

Characterization of ventricular arrhythmias and sudden cardiac death in subjects with mitral valve prolapse and mitral annular disjunction

Sudden cardiac death is reported as the leading cause of mortality in developed nations. Arrhythmic mitral valve disease, encompassing mitral valve prolapse and/or mitral annular disjunction, is thought to be responsible in a sizable portion of these deaths. Despite this evidence, there are no reliable methods or clinically useful risk stratification schemes to determine which group of patients are at higher risk or may benefit from interventions such as catheter ablation or prophylactic implantation of a defibrillator. The reasons for this lack of guidance include our incomplete understanding of the mechanisms of ventricular arrhythmias and the fact that mitral valve prolapse and disjunction are frequently diagnosed, yet carry an overall low risk of sudden cardiac death. This heterogeneity makes the development of a reliable prediction model based on the presence of common risk factors very difficult. In this review, we summarize the relevant literature regarding the epidemiology, diagnosis, pathophysiology, and management of mitral valve prolapse and mitral annular disjunction and elucidate their role in sudden cardiac death.

The evaluation of coronary microvascular obstruction in patients with STEMI by cardiac magnetic resonance T2-STIR image and layer-specific analysis of 2-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography

This study was designed to assess coronary microvascular obstruction (MVO) in patients with acute ST-segment elevation myocardial infarction (STEMI) by cardiac magnetic resonance T2-weighted short tau inversion recovery (T2-STIR) image and layer-specific analysis of 2-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography (LDDSE-LS2D-STE). 32 patients were enrolled to perform cardiac magnetic resonance and echocardiography 5-7 days after primary percutaneous coronary intervention. Infarcted myocardium was categorized into MVO⁺ group and MVO^- group by late gadolinium enhancement as gold standard. At T2-weighted image, the area of hyper-intense region and hypo-intense core inside were marked as A1, A2 and A2/A1 > 0 represented MVO. Strain parameters were composed of longitudinal strain (LS), circumferential strain and radial strain at rest and dobutamine stress. There were 94 MVO⁺ segments, 136 MVO^- segments according to gold standard. 96 segments had hypo-intense core at T2-STIR image. The sensitivity and specificity of T2-STIR in detecting MVO were 91.49 and 92.65%. Endocardial LS was superior to other parameters, and stress endocardial LS was higher than that of resting endocardial LS (sensitivity: 77.11% vs 72.29%, specificity: 93.28% vs 83.19%, AUC: 0.87 vs 0.82, P < 0.05). The combination of T2-STIR and stress endocardial LS in parallel test could improve sensitivity significantly (98.05% vs 91.49%). T2-STIR has higher diagnostic value in detecting MVO with some limitations. However, LDDSE-LS2D-STE with cost-effective and handling may be a good alternative to T2-STIR. It provides additional and reliable diagnostic tools to identify MVO in STEMI patients after reperfusion.

Research Opportunities in the Treatment of Mitral Valve Prolapse: JACC Expert Panel

In light of the adverse prognosis related to severe mitral regurgitation, heart failure, or sudden cardiac death in a subset of patients with mitral valve prolapse (MVP), identifying those at higher risk is key. For the first time in decades, researchers have the means to rapidly advance discovery in the field of MVP thanks to state-of-the-art imaging techniques, novel omics methodologies, and the potential for large-scale collaborations using web-based platforms. The National Heart, Lung, and Blood Institute recently initiated a webinar-based workshop to identify contemporary research opportunities in the treatment of MVP. This report summarizes 3 specific areas in the treatment of MVP that were the focus of the workshop: 1) improving management of degenerative mitral regurgitation and associated left ventricular systolic dysfunction; 2) preventing sudden cardiac death in MVP; and 3) understanding the mechanisms and progression of MVP through genetic studies and small and large animal models, with the potential of developing medical therapies.

Mitral Annular Disjunction: Associated Pathologies and Clinical Consequences

PURPOSE OF REVIEW

To provide an overview of mitral annular disjunction (MAD) and to discuss important challenges in diagnosis and management of MAD.

RECENT FINDINGS

MAD has regained interest in the context of sudden cardiac death (SCD) in patients with mitral valve prolapse (MVP), coined as the "arrhythmic" MVP syndrome. In addition, MAD in isolation was recently suggested to be associated with severe arrhythmia and SCD. There is a lack of consensus on the definition of MAD and the imaging modality to be used for diagnosing MAD, and the therapeutic implications of MAD remain uncertain. Furthermore, the exact mechanism underlying the association of MAD with SCD remains largely unexplored.

Imaging Considerations and Clinical Implications of Mitral Annular Disjunction

Mitral annular disjunction is increasingly recognized as an important anatomic feature of mitral valve disease. The presence of mitral annular disjunction, defined as separation between the left atrial wall at the point of mitral valve insertion and the left ventricular free wall, has been associated with increased degeneration of the mitral valve and increased incidence of sudden cardiac death. The clinical importance of this entity necessitates standard reporting on cardiovascular imaging reports if patients are to receive adequate risk stratification and management. We provide a narrative review of the literature pertaining to mitral annular disjunction, its clinical implications, and areas needing further research.

Mitral Valve Prolapse and Mitral Annular Disjunction Arrhythmic Syndromes: Diagnosis, Risk Stratification and Management

Although mitral valve prolapse (MVP) is usually considered a benign clinical condition, it has been linked with ventricular arrhythmias and sudden cardiac death in patients with a certain "arrhythmic" phenotype, raising awareness and mandating a specific risk stratification protocol. Mitral annular disjunction (MAD) is considered a "red flag" in malignant MVP syndrome along with bileaflet myxomatous prolapse, female gender, negative or biphasic T waves in the inferior leads, fibrosis in the papillary muscles or inferobasal wall detected by cardiac magnetic resonance imaging and complex arrhythmias of right bundle branch morphology. MAD seems to play a critical role in the chain of morphofunctional abnormalities which lead to increased mechanical stretch and subsequent fibrosis mainly in the papillary muscles, forming the vulnerable anatomic substrate prone to arrhythmogenesis, and associated with long-term severe ventricular arrhythmias. Arrhythmogenesis in MVP/MAD patients is not fully understood but a combination between a substrate and a trigger has been established with premature ventricular contraction triggered ventricular fibrillation being the main mechanism of sudden cardiac death (SCD). Certain characteristics mostly recognized by non-invasive imaging modalities serve as risk factors and can be used to diagnose and identify high risk patients with MAD, while treatment options include catheter ablation, device therapy and surgical intervention. This review focuses on the clinical presentation, the arrhythmogenic substrate, and the incidence of ventricular arrhythmias and SCD in MAD population. The current risk stratification tools in MAD arrhythmogenic entity are discussed.

Transthoracic echocardiography for arrhythmic mitral valve prolapse: Phenotypic characterization as first step

Mitral valve prolapse (MVP) is the most frequent valvulopathy with a prevalence of 1.2%-2.4% in general population and it is characterized by a benign course. Although it can be associated with some complications, ventricular arrhythmias (VA) and sudden cardiac death (SCD) as ultimate expressions, are the most worrying. The estimated risk of SCD in MVP is between 0.2% and 1.9% per year including both MVP patients with left ventricular (LV) dysfunction due to severe MR and MVP patients without significant MR. The latter ones constitute a particular phenotype called "malignant MVP" characterized by bileaflet myxomatous prolapse, ECG repolarization abnormalities and complex VAs (c-VAs) with polymorphic/right bundle branch block morphology (RBBB) and LV fibrosis of the papillary muscles (PMs) and inferobasal wall secondary to mechanical stretching visualized as late gadolinium enhancement (LGE) areas by cardiac magnetic resonance (CMR). In MVP, the first diagnostic approach is transthoracic echocardiography (TTE) that defines the presence of mitral annular disjunction (MAD) which seems to be associated with "arrhythmic MVP" (AMVP). From an ECG point of view, AMVP is characterized by frequent premature ventricular contractions (PVCs) arising from one or both PMs, fascicular tissue, and outflow tract, as well as by T-wave inversion in the inferolateral leads. The aim of the present paper is to describe TTE red flags that could identify MVP patients at high risk to develop complex arrhythmias as supported by the corresponding findings of LGE-CMR and anatomy studies. TTE could be a co-partner in phenotyping high-risk arrhythmic MVP patients.

Mitral Valve Prolapse-The Role of Cardiac Imaging Modalities

Mitral valve prolapse (MVP) is the most common nonischemic mitral regurgitation etiology and mitral abnormality requiring surgery in the Western world. There is an increasing awareness that pathological findings in MVP are not confined to the valve tissue; rather, it is a complex disease, involving the mitral valve apparatus, cardiac hemodynamics, and cardiac structure. Imaging has played a fundamental role in the understanding of the diagnosis, prevalence, and consequences of MVP. The diagnosis of MVP by imaging is based upon demonstrating valve leaflets ascending into the left atrium through the saddle-shaped annulus. Transthoracic and transesophageal echocardiography are the primary modalities in the diagnosis and assessment of MVP patients and must include careful assessment of the leaflets, annulus, chords, and papillary muscles. High-spatial-resolution imaging modalities such as cardiac magnetic resonance images and cardiac computed tomography play a secondary role in this regard and can demonstrate the anatomical relation between the mitral valve annulus and leaflet excursion for appropriate diagnosis. Ongoing development of new methods of cardiac imaging can help us to accurately understand the mechanism, diagnose the disease, develop an appropriate treatment plan, and estimate the risk for sudden death. Recently, several new observations with respect to prolapse have been derived from cardiac imaging including three-dimensional echocardiography and tissue-Doppler imaging. The aim of this article is to present these new imaging-derived insights for the diagnosis, risk assessment, treatment, and follow-up of patients with MVP.

Malignant Mitral Valve Prolapse: Risk and Prevention of Sudden Cardiac Death

Purpose of review

The purpose of this review is to explore the prevalence and risk factors for a malignant phenotype in mitral valve prolapse (MVP) characterized by life-threatening ventricular arrhythmias and sudden cardiac arrest and death (SCD), including mechanistic and pathophysiologic findings and mechanism-based potential therapies.

Recent findings

A malignant phenotype in MVP characterized by life-threatening arrhythmias has long been recognized, although MVP is often benign. Efforts to identify this malignant phenotype have revealed potential risk factors for SCD that include elongated, myxomatous leaflets, ECG changes and complex ventricular ectopy. More recently, malignant MVP has been associated with myocardial fibrosis in the papillary muscles and inferobasal left ventricular wall. This localization suggests a central role of prolapse-induced mechanical forces on the myocardium in creating an arrhythmogenic substrate and triggering life-threatening arrhythmias. This mechanism for fibrosis is also consistent with imaging evidence of prolapse-induced mechanical changes in the papillary muscles and inferobasal left ventricular wall. Currently, no therapy to prevent SCD in malignant MVP has been established and limited clinical data are available. Mechanistic information and prospective study have the potential to identify patients at risk of SCD and preventive strategies.

Summary

Malignant MVP relates to unique properties and mechanical abnormalities in the mitral valve apparatus and adjacent myocardium. Increased understanding of disease mechanisms and determinants of arrhythmias is needed to establish effective therapies.

Recent Non-Invasive Parameters to Identify Subjects at High Risk of Sudden Cardiac Death

Cardiovascular diseases remain among the leading causes of death worldwide and sudden cardiac death (SCD) accounts for ~25% of these deaths. Despite its epidemiologic relevance, there are very few diagnostic strategies available useful to prevent SCD mainly focused on patients already affected by specific cardiovascular diseases. Unfortunately, most of these parameters exhibit poor positive predictive accuracy. Moreover, there is also a need to identify parameters to stratify the risk of SCD among otherwise healthy subjects. This review aims to provide an update on the most relevant non-invasive diagnostic features to identify patients at higher risk of developing malignant ventricular arrhythmias and SCD.

Developing a Mechanistic Approach to Sudden Death Prevention in Mitral Valve Prolapse

Sudden cardiac death (SCD) from ventricular fibrillation (VF) can occur in mitral valve prolapse (MVP) in the absence of other comorbidities including mitral regurgitation, heart failure or coronary disease. Although only a small proportion with MVP are at risk, it can affect young, otherwise healthy adults, most commonly premenopausal women, often as the first presentation of MVP. In this review, we discuss arrhythmic mechanisms in MVP and mechanistic approaches for sudden death risk assessment and prevention. We define arrhythmogenic or arrhythmic MVP (AMVP) as MVP associated with complex and frequent ventricular ectopy, and malignant MVP (MMVP) as MVP with high risk of SCD. Factors predisposing to AMVP are myxomatous, bileaflet MVP and mitral annular disjunction (MAD). Data from autopsy, cardiac imaging and electrophysiological studies suggest that ectopy in AMVP is due to inflammation, fibrosis and scarring within the left ventricular (LV) base, LV papillary muscles and Purkinje tissue. Postulated mechanisms include repetitive injury to these regions from systolic papillary muscle stretch and abrupt mitral annular dysmotility (excursion and curling) and diastolic endocardial interaction of redundant mitral leaflets and chordae. Whereas AMVP is seen relatively commonly (up to 30%) in those with MVP, MVP-related SCD is rare (2-4%). However, the proportion at risk (i.e., with MMVP) is unknown. The clustering of cardiac morphological and electrophysiological characteristics similar to AMVP in otherwise idiopathic SCD suggests that MMVP arises when specific arrhythmia modulators allow for VF initiation and perpetuation through action potential prolongation, repolarization heterogeneity and Purkinje triggering. Adequately powered prospective studies are needed to assess strategies for identifying MMVP and the primary prevention of SCD, including ICD implantation, sympathetic modulation and early surgical mitral valve repair. Given the low event rate, a collaborative multicenter approach is essential.

Arrhythmic Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical Features, Pathophysiology, Risk Stratification, and Management

Mitral valve prolapse (MVP) is a common cause of valvular heart disease. Although many patients with MVP have a benign course, there is increasing recognition of an arrhythmic phenotype associated with ventricular arrhythmias and sudden cardiac death (SCD). Pathophysiologic mechanisms associated with arrhythmias include cardiac fibrosis, mechanical stress induced changes in ventricular refractory periods, as well as electrophysiologic changes in Purkinje fibers. Clinically, a variety of risk factors including demographic, electrocardiographic, and imaging characteristics help to identify patients with MVP at the highest at risk of SCD and arrhythmias. Once identified, recent advances in treatment including device therapy, catheter ablation, and surgical interventions show promising outcomes. In this review, we will summarize the incidence of ventricular arrhythmias and SCD in patients with MVP, the association with mitral annular disjunction, mechanisms of arrhythmogenesis, methods for arrhythmic and SCD risk stratification including findings with multimodality imaging, and treatments for the primary and secondary prevention of SCD.

Diagnosis of Mitral Valve Prolapse: Much More than Simple Prolapse. Multimodality Approach to Risk Stratification and Therapeutic Management

Mitral valve prolapse (MVP) is the most common valvular disease with a prevalence of 2%. It has generally a benign course; however, recent findings suggested an association between MVP and complex arrhythmias and eventually cardiac arrest and for this reason, it is also called arrhythmogenic MVP. Subjects who experience this complication are in general young women, with thickened mitral leaflets or bileaflet prolapse not necessarily associated with severe mitral regurgitation (MR). The nature of the relation between MVP and cardiac arrest is not clearly understood. Actually, the challenging task is to find the cluster of prognostic factors including T-wave inversion, polymorphic premature ventricular contractions, bileaflet prolapse, MR severity, but most importantly, those parameters of hypercontractility, mitral annulus disjunction (MAD), and myocardial fibrosis using a multimodality approach. Transthoracic echocardiography is the first-line imaging modality for the diagnosis of MVP, but also for detecting MAD and hypercontractility, followed by cardiac magnetic resonance for tissue characterization and detection of myocardial and papillary muscle fibrosis, using either late gadolinium enhancement (at the basal segment of the inferolateral wall and papillary muscles) (macro-fibrosis), or diffuse fibrosis by T1 mapping (native and post contrast T1). Moreover, there are also preliminary data on positron emission tomography utilizing 18F-fluorodeoxyglucose as a tool for providing evidence of early myocardial inflammation. The objective of this review article is to provide the clinician with an overview and a practical clinical approach to MVP for risk stratification and treatment guidance.

Reproducibility and its confounders of CMR feature tracking myocardial strain analysis in patients with suspected myocarditis

Objectives

Cardiovascular magnetic resonance feature tracking (CMR-FT) is an emerging technique for assessing myocardial strain with valuable diagnostic and prognostic potential. However, the reproducibility of biventricular CMR-FT analysis in a large cardiovascular population has not been assessed. Also, evidence of confounders impacting reader reproducibility for CMR-FT in patients is unknown and currently limits the clinical implementation of this technique.

Methods

From a dual-center database of patients referred to CMR for suspected myocarditis, 125 patients were randomly selected to undergo biventricular CMR-FT analysis for 2-dimensional systolic and diastolic measures, with additional 3-dimensional analysis for the left ventricle. All image analysis was replicated by a single reader and by a second reader for intra- and inter-reader analysis (Circle Cardiovascular Imaging). Reliability was tested with intraclass correlation (ICC) tests, and the impact of imaging confounders on agreement was assessed through multivariable analysis.

Results

Left and right ventricular ejection fractions were reduced in 34% and 37% of the patients, respectively. Good to excellent reliability was shown for 2D (all ICC > 0.85) and 3D (all ICC > 0.70) peak strain and early diastolic strain rate for both ventricles in longitudinal orientation as well as circumferential orientations for the left ventricle. An increased slice number improved agreement while the presence of pericardial effusion compromised diastolic strain rate agreement, and arrhythmia compromised right ventricular agreement.

Conclusion

In a large clinical cohort, we could show CMR-FT yields excellent inter-reader and intra-reader reproducibility. Multi-parametric CMR-FT of the right and left ventricles appears to be a robust tool in cardiovascular patients referred to CMR.

Clinical trial registration.

ClinicalTrials.gov Identifier: NCT03470571, NCT04774549.

Key Points

• Cardiovascular magnetic resonance feature tracking (CMR-FT) is an emerging technique to measure myocardial strain in cardiovascular patients referred for CMR; however, the evaluation of its reproducibility in a large cohort has not yet been performed.

• In a large clinical cohort, CMR-FT yields excellent inter-reader and intra-reader reproducibility for both left and right ventricular systolic and diastolic parameters.

• Arrhythmia and pericardial effusion compromise agreement of select FT parameters, but poor ejection fraction does not.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08416-5.

Mitral Valve Prolapse Induces Regionalized Myocardial Fibrosis

Background Mitral valve prolapse (MVP) is one of the most common forms of cardiac valve disease and affects 2% to 3% of the population. Previous imaging reports have indicated that myocardial fibrosis is common in MVP and described its association with sudden cardiac death. These data combined with evidence for postrepair ventricular dysfunction in surgical patients with MVP support a link between fibrosis and MVP. Methods and Results We performed histopathologic analysis of left ventricular (LV) biopsies from peripapillary regions, inferobasal LV wall and apex on surgical patients with MVP, as well as in a mouse model of human MVP (Dzip1S14R/+). Tension-dependent molecular pathways were subsequently assessed using both computational modeling and cyclical stretch of primary human cardiac fibroblasts in vitro. Histopathology of LV biopsies revealed regionalized fibrosis in the peripapillary myocardium that correlated with increased macrophages and myofibroblasts. The MVP mouse model exhibited similar regional increases in collagen deposition that progress over time. As observed in the patient biopsies, increased macrophages and myofibroblasts were observed in fibrotic areas within the murine heart. Computational modeling revealed tension-dependent profibrotic cellular and molecular responses consistent with fibrosis locations related to valve-induced stress. These simulations also identified mechanosensing primary cilia as involved in profibrotic pathways, which was validated in vitro and in human biopsies. Finally, in vitro stretching of primary human cardiac fibroblasts showed that stretch directly activates profibrotic pathways and increases extracellular matrix protein production. Conclusions The presence of prominent regional LV fibrosis in patients and mice with MVP supports a relationship between MVP and progressive damaging effects on LV structure before overt alterations in cardiac function. The regionalized molecular and cellular changes suggest a reactive response of the papillary and inferobasal myocardium to increased chordal tension from a prolapsing valve. These studies raise the question whether surgical intervention on patients with MVP should occur earlier than indicated by current guidelines to prevent advanced LV fibrosis and potentially reduce residual risk of LV dysfunction and sudden cardiac death.

Arrhythmic mitral valve prolapse: Diagnostic parameters for high-risk patients: A systematic review and meta-analysis

BACKGROUND

Although frequently considered a benign condition, new evidence has shown that mitral valve prolapse (MVP) is associated with complex ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Therefore, we conducted a systematic review and meta-analysis of the relevant studies to investigate the parameters that could identify MVP patients at higher risk of experiencing complex VAs.

METHOD

We performed a systematic literature search of PubMed for potential studies between January 2010 and January 2021. Our meta-analysis included studies comparing MVP patients with complex VAs (A-MVP) and those without (NA-MVP). We used the fixed-effects model to obtain the odds ratio (OR), risk ratio (RR), or mean difference (MD) and 95% confidence interval (CI) for each analyzed parameter.

RESULTS

Six studies with 848 individuals were included in the meta-analysis. As compared to the NA-MVP patients, A-MVP patients had a higher prevalence of inverted T-wave (OR: 2.73; 95% CI: 1.85-4.02; p < .00001) and longer QTc interval on the resting ECG (MD: 14.73; 95% CI: 9.39-20.08; p < .00001), longer anterior mitral leaflet length (MD: 2.67; 95% CI: 2.02-3.31; p < .00001), bi-leaflet prolapse (OR: 1.65; 95% CI: 1.22-2.24; p = .001), and mitral annulus disjunction (MAD) on echocardiogram (RR: 1.90; 95% CI: 1.50-2.40; p < .00001), and late gadolinium enhancement (LGE) on cardiac magnetic resonance (RR: 4.38; 95% CI: 1.77-10.86; p = .001).

CONCLUSION

Our comprehensive meta-analysis suggests that risk factors related to A-MVP are T-wave inversion, longer QTc interval, bi-leaflet prolapse, longer anterior mitral valve leaflet, MAD, and LGE.

Left ventricular characteristics of noncompaction phenotype patients with good ejection fraction measured with cardiac magnetic resonance

OBJECTIVE

We describe left ventricular (LV) volumes, myocardial and trabeculated muscle mass and strains with Cardiac magnetic resonance of a large cohort (n=81) who fulfilled the morphologic criteria of left ventricular noncompaction (LVNC) and had good ejection fraction (EF >55%) and compare them with healthy controls (n=81). Male and female patients were compared to matched controls and to each other. We also investigated the LV trabeculated muscle mass cutoff in male and female patients with LVNC.

METHODS

81 participants with LVNC and 81 healthy controls were included. Male and female patients were compared to matched controls and to each other. We also investigated the left ventricular trabeculated muscle mass cut-off in male and female LVNC patients.

RESULTS

The LV parameters of the LVNC population were normal, but they had significantly higher volumes, myocardial and trabeculated muscle mass, and a significantly smaller EF than the controls. Similar differences were observed after stratifying by sex. The optimal LV trabeculated muscle mass cutoffs were 25.8 g/m2 in men (area under the curve: 0.81) and 19.0 g/m2 in women (area under the curve: 0.87). The patients had normal global strains but a significantly worse global circumferential strain (patients vs controls: -29.9±4.9 vs. -35.8±4.7%, p<0.05) and significantly higher circumferential mechanical dispersion than the controls (patients vs. controls: 7.6±4.2 vs. 6.1±2.8%; p<0.05). No disease-related strain differences were noted between men and women.

CONCLUSION

The LV functional and strain characteristics of the LVNC cohort differed significantly from those of healthy participants; this might be caused by increased LV trabeculation, and its clinical relevance might be questionable. The LV trabeculated muscle mass was very different between men and women; thus, the use of sex-specific morphologic diagnostic criteria should be considered.

Evaluation of left ventricular systolic synchrony by peak strain dispersion in patients with rheumatoid arthritis

Objective

To investigate the clinical value of the peak strain dispersion (PSD) in evaluating left ventricular (LV) systolic synchrony in patients with rheumatoid arthritis (RA).

Methods

One hundred eleven patients with RA were divided into two groups according to their disease duration: <5 years (Group I, n = 60) and ≥5 years (Group II, n = 51). The control group comprised 57 healthy subjects without RA. All three groups were examined by transthoracic two-dimensional echocardiography. Traditional parameters were measured by conventional echocardiography. Two-dimensional speckle tracking imaging was used to analyze the PSD and LV global longitudinal strain (LVGLS). Related ultrasound and blood test results were analyzed and compared.

Results

The PSD gradually increased in the order of the control group, Group I, and Group II, and the difference among the groups was statistically significant. The LVGLS gradually decreased in the order of the control group, Group I, and Group II, and the difference among the groups was statistically significant. The PSD was negatively correlated with the LVGLS.

Conclusions

LV systolic synchrony in patients with RA gradually decreases as the disease course progresses. The PSD can be used as a new reliable index to evaluate LV systolic synchrony.

Feature tracking myocardial strain analysis in patients with bileaflet mitral valve prolapse: relationship with LGE and arrhythmias

OBJECTIVES

Anatomical substrate and mechanical trigger co-act in arrhythmia's onset in patients with bileaflet mitral valve prolapse (bMVP). Feature tracking (FT) may improve risk stratification provided by cardiac magnetic resonance (CMR). The aim was to investigate differences in CMR and FT parameters in bMVP patients with and without complex arrhythmias (cVA and no-cVA).

METHODS

In this retrospective study, 52 patients with bMVP underwent 1.5 T CMR and were classified either as no-cVA (n = 32; 12 males; 49.6 ± 17.4 years) or cVA (n = 20; 3 males; 44.7 ± 11.2 years), the latter group including 6 patients (1 male; 45.7 ± 12.7 years) with sustained ventricular tachycardia or ventricular fibrillation (SVT-FV). Twenty-four healthy volunteers (11 males, 36.2 ± 12.5 years) served as control. Curling, prolapse distance, mitral annulus disjunction (MAD), and late gadolinium enhancement (LGE) were recorded and CMR-FT analysis performed. Statistical analysis included non-parametric tests and binary logistic regression.

RESULTS

LGE and MAD distance were associated with cVA with an odds ratio (OR) of 8.51 for LGE (95% CI 1.76, 41.28; p = 0.008) and of 1.25 for MAD (95% CI 1.02, 1.54; p = 0.03). GLS 2D (- 11.65 ± 6.58 vs - 16.55 ± 5.09 1/s; p = 0.04), PSSR longitudinal 2D (0.04 ± 1.62 1/s vs - 1.06 ± 0.35 1/s; p = 0.0001), and PSSR radial 3D (3.95 ± 1.97 1/s vs 2.64 ± 1.03 1/s; p = 0.0001) were different for SVT-VF versus the others. PDSR circumferential 2D (1.10 ± 0.54 vs. 0.84 ± 0.34 1/s; p = 0.04) and 3D (0.94 ± 0.42 vs. 0.69 ± 0.17 1/s; p = 0.04) differed between patients with and without papillary muscle LGE.

CONCLUSIONS

CMR-FT allowed identifying subtle myocardial deformation abnormalities in bMVP patients at risk of SVT-VF. LGE and MAD distance were associated with cVA.

KEY POINTS

• CMR-FT allows identifying several subtle myocardial deformation abnormalities in bMVP patients, especially those involving the papillary muscle. • CMR-FT allows identifying subtle myocardial deformation abnormalities in bMVP patients at risk of SVT and VF. • In patients with bMVP, the stronger predictor of cVA is LGE (OR = 8.51; 95% CI 1.76, 41.28; p = 0.008), followed by MAD distance (OR = 1.25; 95% CI 1.02, 1.54; p = 0.03).

Mitral Valve Prolapse, Arrhythmias, and Sudden Cardiac Death: The Role of Multimodality Imaging to Detect High-Risk Features

Mitral valve prolapse (MVP) was first described in the 1960s, and it is usually a benign condition. However, a subtype of patients are known to have a higher incidence of ventricular arrhythmias and sudden cardiac death, the so called “arrhythmic MVP.” In recent years, several studies have been published to identify the most important clinical features to distinguish the benign form from the potentially lethal one in order to personalize patient’s treatment and follow-up. In this review, we specifically focused on red flags for increased arrhythmic risk to whom the cardiologist must be aware of while performing a cardiovascular imaging evaluation in patients with MVP.

Multimodality imaging predictors of sudden cardiac death

Sudden cardiac death (SCD) is the worst clinical event occurring in the clinical context of cardiomyopathies. Current guidelines recommend using LV ejection fraction as the only imaging-derived parameter to identify patients who may benefit from ICD implantation in cardiomyopathies with reduced ejection fraction; however, a relevant proportion of high-risk population is left with unmet therapeutic goal. In case of dilated, hypertrophic, or arrhythmogenic cardiomyopathies, there is still a room for more sensitive and specific risk markers for identifying a cluster at higher risk of SCD. In this paper, we reviewed the evidence supporting the use of advanced echocardiography, CMR, and nuclear cardiology for SCD stratification in patients with the most common cardiomyopathies. The added value of these modalities may be explained on the basis of tissue characterization, especially scar detection, a central player in the pathogenesis of arrhythmias. Therefore, integration of these modalities to our everyday clinical practice may help in dealing with the gray zones where current guidelines are still ineffective for patient selection.

Exercise Participation for Patients with Valvular Heart Disease: a Review of the Current Guidelines

PURPOSE OF REVIEW

Valvular heart disease affects many individuals who aspire to partake in competitive or recreational sports. This manuscript reviews the most recent European and American guidelines related to exercise and sport participation in individuals with valvular heart disease (VHD) and identifies areas not addressed by these guidelines.

RECENT FINDINGS

Exercise recommendations for individuals with VHD have been presented since at least 1984. There is limited data on the impact of intensive physical activity on the progression and outcomes of VHD. Therefore, current recommendations are based on consensus opinion. Most recent consensus guidelines address exercise participation in young and active older individuals. Exercise guidelines for patients with VHD have become progressively less restrictive to allow exercise participation for many VHD patients. These more progressive recommendations should be included in clinical decision-making when evaluating physical activity levels for athletes and active adults with VHD.

Arrhythmic Mitral Valve Prolapse: Introducing an Era of Multimodality Imaging-Based Diagnosis and Risk Stratification

Mitral valve prolapse is a common cardiac condition, with an estimated prevalence between 1% and 3%. Most patients have a benign course, but ever since its initial description mitral valve prolapse has been associated to sudden cardiac death. Although the causal relationship between mitral valve prolapse and sudden cardiac death has never been clearly demonstrated, different factors have been implicated in arrhythmogenesis in patients with mitral valve prolapse. In this work, we offer a comprehensive overview of the etiology and the genetic background, epidemiology, pathophysiology, and we focus on the state-of-the-art imaging-based diagnosis of mitral valve prolapse. Going beyond the classical, well-described clinical factors, such as young age, female gender and auscultatory findings, we investigate multimodality imaging features, such as alterations of anatomy and function of the mitral valve and its leaflets, the structural and contractile anomalies of the myocardium, all of which have been associated to sudden cardiac death.