Right ventricular mechanical dispersion is related to malignant arrhythmias: a study of patients with arrhythmogenic right ventricular cardiomyopathy and subclinical right ventricular dysfunction

Multimodality imaging in arrhythmogenic cardiomyopathy - From diagnosis to management

Arrhythmogenic Cardiomyopathy (AC), an inherited cardiac disorder characterized by myocardial fibrofatty replacement, carries a significant risk of sudden cardiac death (SCD) due to ventricular arrhythmias. A comprehensive multimodality imaging approach, including echocardiography, cardiac magnetic resonance imaging (CMR), and cardiac computed tomography (CCT), allows for accurate diagnosis, effective risk stratification, vigilant monitoring, and appropriate intervention, leading to improved patient outcomes and the prevention of SCD. Echocardiography is primary tool ventricular morphology and function assessment, CMR provides detailed visualization, CCT is essential in early stages for excluding congenital anomalies and coronary artery disease. Echocardiography is preferred for follow-up, with CMR capturing changes over time. The strategic use of these imaging methods aids in confirming AC, differentiating it from other conditions, tracking its progression, managing complications, and addressing end-stage scenarios.

Additive Prognostic Value of Left Ventricular Dispersion and Deformation in Patients With Severe Aortic Stenosis

BACKGROUND

Speckle tracking strain echocardiography allows one to visualize the timing of maximum regional strain and quantifies left ventricular-mechanical dispersion (LV-MD). Whether LV-MD and LV-global longitudinal strain (LV-GLS) provide similar or complementary information in mortality risk stratification in patients with severe aortic stenosis (SAS) remains unknown.

OBJECTIVES

The authors hypothesized that LV mechanical dyssynchrony assessed by LV-MD is associated with an increased risk of mortality and provides additional prognostic information on top of LV-GLS in patients with SAS.

METHODS

A total of 364 patients with SAS (aortic valve area indexed ≤0.6 cm2/m2 and/or aortic valve area ≤1 cm2), LV ejection fraction ≥50% and no or mild symptoms were enrolled. The endpoint was overall mortality.

RESULTS

During a median follow-up period of 41 months, 149 patients died. After adjustment, LV-MD ≥68 ms was significantly associated with an increased risk of mortality (adjusted HR: 1.41; 95% CI: 1.01-1.96; P = 0.044). Adding LV-MD ≥68 ms to a multivariable Cox regression model including LV-GLS ≥-15% improved predictive performance in terms of overall mortality, with improved global model fit, reclassification, and better discrimination. Patients with both criteria had an important increase in mortality compared to patients with none or one criterion (adjusted HR: 2.02; 95% CI: 1.34-3.03; P = 0.001). Interobserver reproducibility of LV-MD was good with an intraclass correlation coefficient of 0.90 (95% CI: 0.72-0.97).

CONCLUSIONS

LV-MD is a reproducible parameter independently associated with an increased risk of mortality in SAS. Increased LV-MD associated with depressed LV-GLS identifies a subgroup of patients with an increased mortality risk. Whether early aortic valve replacement improves the outcome of these patients deserves further studies.

Preoperative and mid-term right ventricular systolic function assessment, at rest and during exercise, with speckle-tracking echocardiography after left ventricular assist device implantation

OBJECTIVES

The study aimed to compare pre- and postoperative resting as well as postprocedural resting and exertional right ventricular speckle-tracking echocardiographic parameters at a mid-term follow-up after left ventricular assist device (LVAD) implantation.

METHODS

Patients with implanted third-generation LVADs with hydrodynamic bearings were prospectively enrolled (NCT05063006). Myocardial deformation was evaluated before pump implantation and at least three months after the procedure, both at rest and during exercise.

RESULTS

We included 22 patients, 7.3 months (IQR, 4.7-10.2) after the surgery. The mean age was 58.4 ± 7 years, 95.5% were men, and 45.5% had dilated cardiomyopathy. The RV strain analysis was feasible in all subjects both at rest and during exercise. The RV free wall strain (RVFWS) worsened from -13% (IQR, -17.3 to -10.9) to -11.3% (IQR, -12.9 to -6; p = 0.033) after LVAD implantation with a particular decline in the apical RV segment [-11.3% (IQR, -16.4 to -6.2) vs -7.8% (IQR, -11.7 to -3.9; p = 0.012)]. The RV four-chamber longitudinal strain (RV4CSL) remained unchanged [-8.5% (IQR, -10.8 to -6.9) vs -7.3% (IQR, -9.8 to -4.7; p = 0.184)]. Neither RVFWS (-11.3% (IQR, -12.9 to -6) vs -9.9% (IQR, -13.5 to -7.5; p = 0.077) nor RV4CSL [-7.3% (IQR, -9.8 to -4.7) vs -7.9% (IQR, -9.8 to -6.3; p = 0.548)] changed during the exercise test.

CONCLUSIONS

In patients who are pump-supported, the right ventricular free wall strain tends to worsen after LVAD implantation and remains unchanged during a cycle ergometer stress test.

Right Ventricular Function in Arrhythmogenic Right Ventricular Cardiomyopathy: Potential Value of Strain Echocardiography

Arrhythmogenic right ventricular cardiomyopathy is an inherited cardiomyopathy, characterized by abnormal cell adhesions, disrupted intercellular signaling, and fibrofatty replacement of the myocardium. These changes serve as a substrate for ventricular arrhythmias, placing patients at risk of sudden cardiac death, even in the early stages of the disease. Current echocardiographic criteria for diagnosing arrhythmogenic right ventricular cardiomyopathy lack sensitivity, but novel markers of cardiac deformation are not subject to the same technical limitations as current guideline-recommended measures. Measuring cardiac deformation using speckle tracking allows for meticulous quantification of global systolic function, regional function, and dyssynchronous contraction. Consequently, speckle tracking to quantify myocardial strain could potentially be useful in the diagnostic process for the determination of disease progression and to assist risk stratification for ventricular arrhythmias and sudden cardiac death. This narrative review provides an overview of the potential use of different myocardial right ventricular strain measures for characterizing right ventricular dysfunction in arrhythmogenic right ventricular cardiomyopathy and its utility in assessing the risk of ventricular arrhythmias.

Enhancing Arrhythmogenic Right Ventricular Cardiomyopathy Detection and Risk Stratification: Insights from Advanced Echocardiographic Techniques

INTRODUCTION

The echocardiographic diagnosis criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) are highly specific but sensitivity is low, especially in the early stages of the disease. The role of echocardiographic strain in ARVC has not been fully elucidated, although prior studies suggest that it can improve the detection of subtle functional abnormalities. The purposes of the study were to determine whether these advanced measures of right ventricular (RV) dysfunction on echocardiogram, including RV strain, increase diagnostic value for ARVC disease detection and to evaluate the association of echocardiographic parameters with arrhythmic outcomes.

METHODS

The study included 28 patients from the Heart Institute of São Paulo ARVC cohort with a definite diagnosis of ARVC established according to the 2010 Task Force Criteria. All patients were submitted to ECHO's advanced techniques including RV strain, and the parameters were compared to prior conventional visual ECHO and CMR.

RESULTS

In total, 28 patients were enrolled in order to perform ECHO's advanced techniques. A total of 2/28 (7%) patients died due to a cardiovascular cause, 2/28 (7%) underwent heart transplantation, and 14/28 (50%) patients developed sustained ventricular arrhythmic events. Among ECHO's parameters, RV dilatation, measured by RVDd (p = 0.018) and RVOT PSAX (p = 0.044), was significantly associated with arrhythmic outcomes. RV free wall longitudinal strain < 14.35% in absolute value was associated with arrhythmic outcomes (p = 0.033).

CONCLUSION

Our data suggest that ECHO's advanced techniques improve ARVC detection and that abnormal RV strain can be associated with arrhythmic risk stratification. Further studies are necessary to better demonstrate these findings and contribute to risk stratification in ARVC, in addition to other well-known risk markers.

Utility of Left and Right Ventricular Strain in Arrhythmogenic Right Ventricular Cardiomyopathy: A Prospective Multicenter Registry

BACKGROUND

Imaging evaluation of arrhythmogenic right ventricular cardiomyopathy (ARVC) remains challenging. Myocardial strain assessment by echocardiography is an increasingly utilized technique for detecting subclinical left ventricular (LV) and right ventricular (RV) dysfunction. We aimed to evaluate the diagnostic and prognostic utility of LV and RV strain in ARVC.

METHODS

Patients with suspected ARVC (n = 109) from a multicenter registry were clinically phenotyped using the 2010 ARVC Revised Task Force Criteria and underwent baseline strain echocardiography. Diagnostic performance of LV and RV strain was evaluated using the area under the receiver operating characteristic curve analysis against the 2010 ARVC Revised Task Force Criteria, and the prognostic value was assessed using the Kaplan-Meier analysis.

RESULTS

Mean age was 45.3±14.7 years, and 48% of patients were female. Estimation of RV strain was feasible in 99/109 (91%), and LV strain was feasible in 85/109 (78%) patients. ARVC prevalence by 2010 ARVC Revised Task Force Criteria is 91/109 (83%) and 83/99 (84%) in those with RV strain measurements. RV global longitudinal strain and RV free wall strain had diagnostic area under the receiver operating characteristic curve of 0.76 and 0.77, respectively (both P<0.001; difference NS). Abnormal RV global longitudinal strain phenotype (RV global longitudinal strain > -17.9%) and RV free wall strain phenotype (RV free wall strain > -21.2%) were identified in 41/69 (59%) and 56/69 (81%) of subjects, respectively, who were not identified by conventional echocardiographic criteria but still met the overall 2010 ARVC Revised Task Force Criteria for ARVC. LV global longitudinal strain did not add diagnostic value but was prognostic for composite end points of death, heart transplantation, or ventricular arrhythmia (log-rank P=0.04).

CONCLUSIONS

In a prospective, multicenter registry of ARVC, RV strain assessment added diagnostic value to current echocardiographic criteria by identifying patients who are missed by current echocardiographic criteria yet still fulfill the diagnosis of ARVC. LV strain, by contrast, did not add incremental diagnostic value but was prognostic for identification of high-risk patients.

The added value of abnormal regional myocardial function for risk prediction in arrhythmogenic right ventricular cardiomyopathy

AIMS

A risk calculator for individualized prediction of first-time sustained ventricular arrhythmia (VA) in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients has recently been developed and validated (www.ARVCrisk.com). This study aimed to investigate whether regional functional abnormalities, measured by echocardiographic deformation imaging, can provide additional prognostic value.

METHODS AND RESULTS

From two referral centres, 150 consecutive patients with a definite ARVC diagnosis, no prior sustained VA, and an echocardiogram suitable for deformation analysis were included (aged 41 ± 17 years, 50% female). During a median follow-up of 6.3 (interquartile range 3.1-9.8) years, 37 (25%) experienced a first-time sustained VA. All tested left and right ventricular (LV and RV) deformation parameters were univariate predictors for first-time VA. While LV function did not add predictive value in multivariate analysis, two RV deformation parameters did; RV free wall longitudinal strain and regional RV deformation patterns remained independent predictors after adjusting for the calculator-predicted risk [hazard ratio 1.07 (95% CI 1.02-1.11); P = 0.004 and 4.45 (95% CI 1.07-18.57); P = 0.040, respectively] and improved its discriminative value (from C-statistic 0.78 to 0.82 in both; Akaike information criterion change > 2). Importantly, all patients who experienced VA within 5 years from the echocardiographic assessment had abnormal regional RV deformation patterns at baseline.

CONCLUSIONS

This study showed that regional functional abnormalities measured by echocardiographic deformation imaging can further refine personalized arrhythmic risk prediction when added to the ARVC risk calculator. The excellent negative predictive value of normal RV deformation could support clinicians considering the timing of implantable cardioverter defibrillator implantation in patients with intermediate arrhythmic risk.

Arrhythmic risk stratification in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable cardiomyopathy characterized by a predominantly arrhythmic presentation. It represents the leading cause of sudden cardiac death (SCD) among athletes and poses a significant morbidity threat in the general population. As a causative treatment for ARVC is still not available, the placement of an implantable cardioverter defibrillator represents the current cornerstone for SCD prevention in this setting. Thanks to international ARVC-dedicated efforts, significant steps have been achieved in recent years towards an individualized, patient-centred risk stratification approach. A novel risk calculator algorithm estimating the 5-year risk of arrhythmias of patients with ARVC has been introduced in clinical practice and subsequently validated. The purpose of this article is to summarize the body of evidence that has allowed the development of this tool and to discuss the best way to implement its use in the care of an individual patient.

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.

The prognostic value of right ventricular strain and mechanical dispersion on mortality in patients with normal left ventricle function

AIMS

We aimed to assess if right ventricular (RV) 4-chamber longitudinal strain (RV4CLS), RV free wall longitudinal strain (RVFWLS) and RV mechanical dispersion index (RVMDI) have prognostic independent value in patients with preserved ejection fraction (pEF), without clearly elevated LV filling pressure.

METHODS

Retrospective analysis of Peak RV4CLS, RVFWLS, RVMDI and comprehensive echocardiographic assessment including left ventricle (LV), atrium (LA) strain and RV parameters in patients with pEF (EF ≥ 50%; E/e' < 14). Multivariate Cox regression hazards model were used to determine the independent association between RV strain parameters to all-cause mortality and cardiovascular events.

RESULTS

We analyzed 224 consecutive patients with pEF (age 65.2 ± 19.8, 44% female, Charlson Comorbidity Index median = 3.8), with all-cause mortality of 64 patients and 28 cardiovascular events, during a median follow-up of 8.2 years (interquartile range: 6.8 to 8.4 years). The best strain univariate predictors of mortality were RV4CSL [1.16 (1.07-1.26); p = 0.0001] and RVMDI [1.01 (1.001-1.02); p = 0.02] being superior to LV and LA strain, or other RV functional indices. Moreover, after adjustment for clinical (age, gender, Charlson Comorbidity Index), conventional echocardiographic parameters (LA volume, E/e' average, LVEDD, routine RV functional indices), LV and LA STE, RV4CLS and RVFWLS remained statistically significant associates of all-cause mortality and cardiac events. RV4CLS, or RVFWLS remained statistically significant associated for all-cause mortality, after additional adjustment for RVFAC and RVMDI.

CONCLUSIONS

RV4CSL and RVMDI provide significant prognostic additive value in patients with preserved ejection fraction with excellent reproducibility, incremental to routine clinical, hemodynamic and LV and LA STE parameters.

Characterisation of patients referred to a tertiary-level inherited cardiac condition clinic with suspected arrhythmogenic right ventricular cardiomyopathy (ARVC)

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) or arrhythmogenic cardiomyopathy is a rare inherited disease with incomplete penetrance and an environmental component. Although a rare disease, ARVC is a common cause of sudden cardiac death in young adults. Data on the different stages of ARVC remains scarce. The purpose of this study is to describe the initial presentation and cardiac phenotype of definite and non-definite ARVC for patients seen at a tertiary service.

METHODS

This is a single centre, observational cohort study of patients with definite and non-definite ARVC seen at the Inherited Cardiac Conditions services at University Hospital Birmingham (UHB) in the period 2010-2021. Patients were identified by interrogation of digital health records, medical history, imaging and by examining 12-lead electrocardiograms (ECG).

RESULT

The records of 1451 patients were reviewed; of those, 165 patients were at risk of ARVC (mean age 41 ± 17 years, 56% male). 60 patients fulfilled task force criteria for definite ARVC diagnosis (n = 40, 67% males), and 38 (72%) of them carried a known pathogenic variant. The remaining 105 patients (50% males) were non-definite, and of these 45 (62%) carried a known pathogenic variant. Patients in the definite group were more symptomatic, with palpitations (57% vs. 17%), syncope (35% vs. 6%) and shortness of breath (28% vs. 5%, p < 0.001). T-wave inversion in V1-V3 and epsilon waves were observed only in the definite group. Both PR interval and QRS duration were longer in the definite (170 ± 34 ms and 100 ± 19 ms, p < 0.001) compared to (149 ± 25 and 91 ± 14 ms, p = 0.005). Patients with definite ARVC had significantly larger RV end diastolic areas and significantly reduced biventricular function (RVEDA = 27 ± 10 cm², RVFAC = 37 ± 11% and EF = 56 ± 12%) compared to the non-definite group (RVEDA = 18 ± 4 cm², RVFAC 49 ± 6% and LVEF 64 ± 7%, p < 0.001). Sustained ventricular tachycardia (VT) occurred more frequently in the definite group compared to the non-definite group (27% vs. 2%, p < 0.001). Ventricular fibrillation was observed in the definite group only (8 of 60 patients, 13%).

CONCLUSION

Our study showed differences between definite and non-definite ARVC patients in terms of clinical, electrophysiological and imaging features. Major adverse cardiac events occurred more commonly in the definite group, but also were observed in non-definite ARVC. This single centre observational cohort study forms a basis for further prospective multicentre interventional studies.

Young athlete's growing heart: sex differences in cardiac adaptation to exercise training during adolescence

BACKGROUND

Athlete's heart is a condition of exercise-induced cardiac remodelling. Adult male endurance athletes more often remodel beyond reference values. The impact of sex on remodelling through adolescence remains unclear. Paediatric reference values do not account for patient sex or exercise history. We aimed to study the effect of sex on cardiac remodelling throughout adolescence.

METHODS

We recruited 76 male (M) and female (F) 12-year-old cross-country skiers in a longitudinal cohort study. Echocardiography was performed and analysed according to guidelines at age 12 (48 M, 28 F), 15 (34 M, 14 F) and 18 (23 M, 11 F). Repeated echocardiographic measurements were analysed by linear mixed model regression.

RESULTS

Males displayed greater indexed left ventricular end-diastolic volumes (LV EDVi) from age 12 (M 81±7 vs F 76±7, mL/m², p≤0.01), and progressed further until follow-up at age 18 (M 2.3±9.7 vs F -3.9±4.5 ΔmL/m², p≤0.01). LV EDVi remained above adult upper reference values in both groups. Males increased LV Mass Index from age 12 to 18 (M 33±27 vs F 4±19, Δg/m², p≤0.01). Males displayed LV mass above paediatric reference values at ages 15 and 18. A subset of males (35%) and females (25%) displayed wall thickness above paediatric reference values at age 12. Cardiac function was normal. There was no sex difference in exercise hours.

CONCLUSION

Sex-related differences in athlete's heart were evident from age 12, and progressed throughout adolescence. Remodelling beyond reference values was more frequent than previously reported, particularly affecting males. Age, sex and exercise history may assist clinicians in distinguishing exercise-induced remodelling from pathology in adolescents.

Arrhythmogenic Right Ventricular Cardiomyopathy Prevalence and Arrhythmic Outcomes in At-Risk Family Members: A Systematic Review and Meta-Analysis

Background:

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a complex cardiomyopathy with autosomal dominant inheritance and age-related incomplete penetrance, characterized by a high risk of sudden cardiac death. Recent professional consensus guidelines recommend clinical cardiac lifelong serial screening for at-risk family members refined only by age, but family genotype might influence necessary screening. Although numerous studies report prevalence of disease and arrhythmia in family members and explore predictors of penetrance and arrhythmic risk, a systematic review consolidating this evidence is lacking.

Methods:

We searched Medline (PubMed), Embase, The Cochrane Library, and Web of Science for studies that reported prevalence of (1) diagnosis of ARVC per 2010 Task Force Criteria and/or (2) sustained ventricular arrhythmias (VA) in at least 10 family members of definite patients with ARVC.

Results:

We identified 41 studies, including 36 that reported diagnosis by Task Force Criteria and 22 VA. Meta-analysis of 1359 family members, from 13 unique cohorts showed an average prevalence estimate of 25% for diagnosis as per Task Force Criteria (95% CI, 0.15–0.35, I 2 = 96.44%). Overall prevalence of VA among gene-positive family members was 18% (95% CI, 0.13–0.23, I 2 =33.25%) in 7 independent studies (n=597). Family genotype was a significant risk factor for diagnosis of both ARVC (odds ratio, 6.91 [95% CI, 1.27–37.70]; P =0.0005) and VA (odds ratio, 13.62 [95% CI, 0.91–204.13]; P =0.06). Male gender was not associated with disease prevalence (odds ratio, 1.18 [95% CI, 0.72–1.95]; P =0.42) or VA (odds ratio, 0.81 [95% CI, 0.51–1.29]; P =0.91).

Conclusions:

The prevalence of ARVC and VA in at-risk family members differs significantly based on family genotype. Although recent recommendations provide a guideline based only on age, we propose screening every 1 to 2 years for gene-positive family members and every 3 to 5 years for first-degree relatives of gene-elusive cases, as long as they are asymptomatic and not athletes.

Contemporary Diagnosis and Management of Hypertrophic Cardiomyopathy: The Role of Echocardiography and Multimodality Imaging

Hypertrophic cardiomyopathy (HCM) is an underdiagnosed genetic heart disease with an estimated prevalence of 0.2–0.5%. Although the prognosis of HCM is relatively good, with an annual general mortality of ~0.7%, some patients have an increased risk of sudden death, or of developing severe heart failure requiring heart transplantation or left ventricular (LV) assist device therapy. Therefore, earlier diagnosis and proper identification of high-risk patients may reduce disease-related morbidity/mortality by promoting timely treatment. Echocardiography is the primary imaging modality for patients with suspected HCM; it plays central roles in differential diagnosis from other causes of LV hypertrophy and in evaluating morphology, hemodynamic disturbances, LV function, and associated valvular disease. Echocardiography is also an essential tool for the continuous clinical management of patients with confirmed HCM. Other imaging modalities, such as cardiac computed tomography (CT) and cardiac magnetic resonance imaging (MRI), can supplement echocardiography in identifying high-risk as well as milder HCM phenotypes. The role of such multimodality imaging has been steadily expanding along with recent advancements in surgical techniques and minimally invasive procedures, and the emergence of novel pharmacotherapies directly targeting pathogenic molecules such as myosin inhibitors. Here we review essential knowledge surrounding HCM with a specific focus on structural and functional abnormalities assessed by imaging modalities, leading to treatment strategies.

Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) encompasses a group of conditions characterized by right ventricular fibrofatty infiltration, with a predominant arrhythmic presentation. First described in the late 1970s and early 1980s, it is now frequently recognized to have biventricular involvement. The prevalence is ∼1:2,000 to 1:5,000, depending on geographic location, and it has a slight male predominance. The diagnosis of ARVC is determined on the basis of fulfillment of task force criteria incorporating electrophysiological parameters, cardiac imaging findings, genetic factors, and histopathologic features. Risk stratification of patients with ARVC aims to identify those who are at increased risk of sudden cardiac death or sustained ventricular tachycardia. Factors including age, sex, electrophysiological features, and cardiac imaging investigations all contribute to risk stratification. The current management of ARVC includes exercise restriction, β-blocker therapy, consideration for implantable cardioverter-defibrillator insertion, and catheter ablation. This review summarizes our current understanding of ARVC and provides clinicians with a practical approach to diagnosis and management.

Echocardiographic predictors of ventricular arrhythmias in patients with non-ischemic cardiomyopathy

Objective

Methods

Results

Conclusion

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.

Echocardiographic Deformation Imaging for Early Detection of Genetic Cardiomyopathies: JACC Review Topic of the Week

Clinical screening of the relatives of patients with genetic cardiomyopathies is challenging, as they often lack detectable cardiac abnormalities at presentation. Life-threatening adverse events can already occur in these early stages of disease, so sensitive tools to reveal the earliest signs of disease are needed. The utility of echocardiographic deformation imaging for early detection has been explored for this population in multiple studies but has not been broadly implemented in clinical practice. The authors discuss contemporary evidence on the utility of deformation imaging in relatives of patients with genetic cardiomyopathies. The available body of data shows that deformation imaging reveals early disease-specific abnormalities in dilated cardiomyopathy, hypertrophic cardiomyopathy, and arrhythmogenic cardiomyopathy. Deformation imaging seems promising to enhance the screening and follow-up protocols in relatives, and the authors propose measures to accelerate its implementation in clinical care.

Prevalence of Right Ventricle Strain Changes following Anthracycline Therapy

Background: Anthracycline (ANT) is the most recognized therapy known to cause cardiotoxicity, mainly left ventricle (LV) dysfunction. Global Longitudinal Strain (GLS) is the optimal tool for assessment of subclinical LV dysfunction. Right ventricle (RV) function has been recognized as an independent factor for cardiac outcomes; however, data evaluating RV GLS is limited. We aimed to evaluate the change in RV GLS following ANT therapy. Methods: The study cohort is part of the Israel Cardio-Oncology Registry (ICOR). All patients performed echocardiography before (T1) and at the end (T3) of ANT therapy. A significant reduction was defined as a relative reduction of ≥10% in RV GLS values. Results: The study included 40 female patients with breast cancer treated with ANT. During follow-up, both RV GLS and free wall longitudinal strain systolic peak (RV FWLS PK) decreased significantly (p < 0.001 and p = 0.002). Altogether, 30 (75%) and 23 (58%) patients showed RV GLS and RV FWLS PK ≥ 10% relative reduction. At T3, LV ejection fraction and LV GLS were within normal range. Conclusions: RV GLS and RV FWLS PK reduction following ANT exposure is extremely frequent, comparing to LV GLS reduction.

Multimodality Imaging in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare, heritable myocardial disease associated with the development of ventricular arrhythmias, heart failure, and sudden cardiac death in early adulthood. Multimodality imaging is a central component in the diagnosis and evaluation of ARVC. Diagnostic criteria established by an international task force in 2010 include noninvasive parameters from echocardiography and cardiac magnetic resonance imaging. These criteria identify right ventricular structural abnormalities, chamber and outflow tract dilation, and reduced right ventricular function as features of ARVC. Echocardiography is a widely available and cost-effective technique, and it is often selected for initial evaluation. Beyond fulfillment of diagnostic criteria, features such as abnormal tricuspid annular plane excursion, increased right ventricular basal diameter, and abnormal strain patterns have been described. 3-dimensional echocardiography may also expand opportunities for structural and functional assessment of ARVC. Cardiac magnetic resonance has the ability to assess morphological and functional cardiac features of ARVC and is also a core modality in evaluation, however, tissue characterization of the right ventricle is limited by spatial resolution and low specificity for detection of pathological changes. Nonetheless, the ability of cardiac magnetic resonance to identify left ventricular involvement, offer high negative predictive value, and provide a reproducible structural evaluation of the right ventricle enhance the ability and scope of the modality. In this review, the prognostic significance of multimodality imaging is outlined, including the supplemental value of multidetector computed tomography and nuclear imaging. Strengths and weaknesses of imaging techniques, as well as future direction of multimodality assessment, are also described.

Multimodality Cardiac Imaging in Cardiomyopathies: From Diagnosis to Prognosis

Cardiomyopathies are a group of structural and/or functional myocardial disorders which encompasses hypertrophic, dilated, arrhythmogenic, restrictive, and other cardiomyopathies. Multimodality cardiac imaging techniques are the cornerstone of cardiomyopathy diagnosis; transthoracic echocardiography should be the first-line imaging modality due to its availability, and diagnosis should be confirmed by cardiovascular magnetic resonance, which will provide more accurate morphologic and functional information, as well as extensive tissue characterization. Multimodality cardiac imaging techniques are also essential in assessing the prognosis of patients with cardiomyopathies; left ventricular ejection fraction and late gadolinium enhancement are two of the main variables used for risk stratification, and they are incorporated into clinical practice guidelines. Finally, periodic testing with cardiac imaging techniques should also be performed due to the evolving and progressive natural history of most cardiomyopathies.

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.

Left Ventricular Longitudinal Dyssynchrony by CMR Feature Tracking Is Related to Adverse Prognosis in Advanced Arrhythmogenic Cardiomyopathy

Objectives: Left ventricular (LV) involvement has been associated with unfavorable prognosis in arrhythmogenic cardiomyopathy (ACM). We aim to evaluate LV mechanics by cardiovascular magnetic resonance-feature tracking (CMR-FT) in ACM patients with right ventricular (RV) dysfunction. Methods: We retrospectively recruited ACM patients diagnosed according to the revised Task Force Criteria (rTFC) from January 2015 to July 2017. All patients underwent CMR examinations and collections of clinical, electrocardiographic data. The strain and dyssynchrony parameters of LV and RV were analyzed. These patients were followed, and primary study outcome was defined as a composite of cardiovascular events (arrhythmic events and heart transplantation), secondary study outcome included arrhythmic events. Results: Eighty-nine ACM patients (40.40 ± 13.98 years, 67.42% male) were included. LV and RV ejection fractions were 49.12 ± 12.02% and 22.28 ± 10.11%, respectively. During a median (IQR) follow-up for 18.20 (11.60-30.04) months, 30 patients experienced cardiovascular events which included 22 patients who experienced arrhythmic events. Patients with cardiovascular events had impaired LV global longitudinal strain (-10.82 ± 2.77 vs. -12.61 ± 3.18%, p = 0.010), impaired LV global circumferential strain (-11.81 ± 2.40 vs. -13.04 ± 2.83%, p = 0.044), and greater LV longitudinal dyssynchrony (LVLD) (80.98 ± 30.98 vs. 64.23 ± 25.51 ms, p = 0.012) than those without. After adjusting for age, sex, and other confounding factors, LVLD ≥89.15 ms was an independent risk factor for cardiovascular events (HR: 4.50, 95% CI: 1.94 to 10.42; p = 0.001) and for arrhythmic events (HR: 4.79, 95% CI: 1.74 to 13.20; p = 0.003). Conclusions: LVLD by CMR-FT was an independent risk factor for cardiovascular and arrhythmic events in ACM patients in advanced stage, which could provide prognostic value for this subtype.

Long-term follow-up and sex differences in adults operated for tetralogy of Fallot

OBJECTIVE

Adults operated for tetralogy of Fallot (TOF) have high risk of ventricular arrhythmias (VA). QRS duration >180 ms is an established risk factor for VA. We aimed to investigate heart function, prevalence of arrhythmias and sex differences in patients with TOF at long-term follow-up.

METHODS

We included TOF-operated patients≥18 years from our centre's registry. We reviewed medical records and the most recent echocardiographic exam. VA was recorded on ECGs, 24-hour Holter registrations and from implantable cardioverter defibrillator.

RESULTS

We included 148 patients (age 37±10 years). Left ventricular global longitudinal strain (LV GLS, -15.8±3.1% vs -18.8±3.2%, p=0.001) and right ventricular (RV) GLS (-15.8±3.9% vs -19.1±4.1%, p=0.001) were lower in men at all ages compared with women. Higher RV D1 (4.3±0.5 cm vs 4.6±0.6 cm, p=0.01), lower ejection fraction (55%±8% vs 50%±9%, p=0.02), lower RV GLS (-18.1±4.0 ms vs -16.1±4.8 ms, p=0.04) and N-terminal pro-brain natriuretic peptide (NT-proBNP) over reference range (n=27 (23%) vs n=8 (77%), p<0.001) were associated with higher incidence of VA. QRS duration was longer in men (151±30 ms vs 128±25 ms, p<0.001). No patients had QRS duration >180 ms. QRS duration did not differ in those with and without VA (143±32 ms vs 137±28 ms, p=0.06).

CONCLUSIONS

Our results confirmed reduced RV function in adults operated for TOF. Male patients had impaired LV and RV function expressed by lower LV and RV GLS values at all ages. Reduced cardiac function and elevated NT-proBNP were associated with higher incidence of VA and may be important in risk assessment.

Uncertainty Quantification of Regional Cardiac Tissue Properties in Arrhythmogenic Cardiomyopathy Using Adaptive Multiple Importance Sampling

Introduction: Computational models of the cardiovascular system are widely used to simulate cardiac (dys)function. Personalization of such models for patient-specific simulation of cardiac function remains challenging. Measurement uncertainty affects accuracy of parameter estimations. In this study, we present a methodology for patient-specific estimation and uncertainty quantification of parameters in the closed-loop CircAdapt model of the human heart and circulation using echocardiographic deformation imaging. Based on patient-specific estimated parameters we aim to reveal the mechanical substrate underlying deformation abnormalities in patients with arrhythmogenic cardiomyopathy (AC). Methods: We used adaptive multiple importance sampling to estimate the posterior distribution of regional myocardial tissue properties. This methodology is implemented in the CircAdapt cardiovascular modeling platform and applied to estimate active and passive tissue properties underlying regional deformation patterns, left ventricular volumes, and right ventricular diameter. First, we tested the accuracy of this method and its inter- and intraobserver variability using nine datasets obtained in AC patients. Second, we tested the trueness of the estimation using nine in silico generated virtual patient datasets representative for various stages of AC. Finally, we applied this method to two longitudinal series of echocardiograms of two pathogenic mutation carriers without established myocardial disease at baseline. Results: Tissue characteristics of virtual patients were accurately estimated with a highest density interval containing the true parameter value of 9% (95% CI [0-79]). Variances of estimated posterior distributions in patient data and virtual data were comparable, supporting the reliability of the patient estimations. Estimations were highly reproducible with an overlap in posterior distributions of 89.9% (95% CI [60.1-95.9]). Clinically measured deformation, ejection fraction, and end-diastolic volume were accurately simulated. In presence of worsening of deformation over time, estimated tissue properties also revealed functional deterioration. Conclusion: This method facilitates patient-specific simulation-based estimation of regional ventricular tissue properties from non-invasive imaging data, taking into account both measurement and model uncertainties. Two proof-of-principle case studies suggested that this cardiac digital twin technology enables quantitative monitoring of AC disease progression in early stages of disease.

A head-to-head comparison of speckle tracking echocardiography and feature tracking cardiovascular magnetic resonance imaging in right ventricular deformation

AIMS

Speckle tracking echocardiography (STE) and feature tracking cardiovascular magnetic resonance imaging (FT-CMR) are advanced imaging techniques which are both used for quantification of global and regional myocardial strain. Direct comparisons of STE and FT-CMR regarding right ventricular (RV) strain analysis are limited. We aimed to study clinical performance, correlation and agreement of RV strain by these techniques, using arrhythmogenic right ventricular cardiomyopathy (ARVC) as a model for RV disease.

METHODS AND RESULTS

We enrolled 110 subjects, including 34 patients with definite ARVC, 30 preclinical relatives of ARVC patients, and 46 healthy control subjects. Global and regional RV longitudinal peak strain (PS) were measured by STE and FT-CMR. Both modalities showed reduced strain values in ARVC patients compared to ARVC relatives (STE global PS: P < 0.001; FT-CMR global PS: P < 0.001) and reduced strain values in ARVC relatives compared to healthy control subjects (STE global PS: P = 0.042; FT-CMR global PS: P = 0.084). There was a moderate, albeit significant correlation between RV strain values obtained by STE and FT-CMR [global PS r = 0.578 (95% confidence interval 0.427-0.697), P < 0.001]. Agreement between the techniques was weak (limits of agreement for global PS: ±11.8%). Correlation and agreement both deteriorated when regional strain was studied.

CONCLUSION

RV STE and FT-CMR show a similar trend within the spectrum of ARVC and have significant correlation, but inter-modality agreement is weak. STE and FT-CMR may therefore both individually have added value for assessment of RV function, but RV PS values obtained by these techniques currently cannot be used interchangeably in clinical practice.

Right ventricular strain rate during exercise accurately identifies male athletes with right ventricular arrhythmias

AIMS

Athletes with right ventricular (RV) arrhythmias, even in the absence of desmosomal mutations, may have subtle RV abnormalities which can be unmasked by deformation imaging. As exercise places a disproportionate stress on the right ventricle, evaluation of cardiac function and deformation during exercise might improve diagnostic performance.

METHODS AND RESULTS

We performed bicycle stress echocardiography in 17 apparently healthy endurance athletes (EAs), 12 non-athletic controls (NAs), and 17 athletes with RV arrhythmias without desmosomal mutations (EI-ARVCs) and compared biventricular function at rest and during low (25% of upright peak power) and moderate intensity (60%). At rest, we observed no differences in left ventricular (LV) or RV function between groups. During exercise, however, the increase in RV fractional area change (RVFAC), RV free wall strain (RVFWSL), and strain rate (RVFWSRL) were significantly attenuated in EI-ARVCs as compared to EAs and NAs. At moderate exercise intensity, EI-ARVCs had a lower RVFAC, RVFWSL, and RVFWSRL (all P < 0.01) compared to the control groups. Exercise-related increases in LV ejection fraction, strain, and strain rate were also attenuated in EI-ARVCs (P < 0.05 for interaction). Exercise but not resting parameters identified EI-ARVCs and RVFWSRL with a cut-off value of >-2.35 at moderate exercise intensity had the greatest accuracy to detect EI-ARVCs (area under the curve 0.95).

CONCLUSION

Exercise deformation imaging holds promise as a non-invasive diagnostic tool to identify intrinsic RV dysfunction concealed at rest. Strain rate appears to be the most accurate parameter and should be incorporated in future, prospective studies to identify subclinical disease in an early stage.

Echocardiographic deformation imaging unmasks global and regional mechanical dysfunction in patients with idiopathic ventricular fibrillation: A multicenter case-control study

BACKGROUND

Idiopathic ventricular fibrillation (IVF) is diagnosed in patients with sudden onset of ventricular fibrillation of unidentified origin. New diagnostic tools that can detect subtle abnormalities are needed to diagnose and treat patients with an underlying substrate.

OBJECTIVE

The purpose of this study was to explore echocardiographic deformation characteristics in IVF patients.

METHODS

Echocardiograms were analyzed with deformation imaging by 2-dimensional speckle tracking. Global and regional measurements of the left ventricle (LV) and right ventricle (RV) were performed. Regional LV deformation patterns were evaluated for the presence of postsystolic shortening. Regional RV deformation patterns were classified as type I (normal) or type II/III (abnormal).

RESULTS

In total, 47 IVF patients (mean age 45 years; left ventricular ejection fraction [LVEF] 56%) and 47 healthy controls (mean age 41 years; LVEF 60%) were included. IVF patients showed more global deformation abnormalities as indicated by lower LV global longitudinal strain (18.5% ± 2.6% vs 21.6% ± 1.8%; P <.001) and higher LV mechanical dispersion (41 ± 12 ms vs 26 ± 6 ms; P <.001). In addition, IVF patients showed more regional LV postsystolic shortening compared to healthy controls (50% vs 11%; P <.001). Abnormal RV deformation patterns were observed in 16% of IVF patients and in none of the control subjects (P <.001).

CONCLUSION

We were able to show both regional and global echocardiographic deformation abnormalities in IVF patients. This study provides evidence that localized myocardial disease is present in a subset of IVF patients.

The Prognostic Importance of Right Ventricular Longitudinal Strain in Patients with Cardiomyopathies, Connective Tissue Diseases, Coronary Artery Disease, and Congenital Heart Diseases

Right ventricular (RV) systolic function represents an important independent predictor of adverse outcomes in many cardiovascular (CV) diseases. However, conventional parameters of RV systolic function (tricuspid annular plane excursion (TAPSE), RV myocardial performance index (MPI), and fractional area change (FAC)) are not always able to detect subtle changes in RV function. New evidence indicates a significantly higher predictive value of RV longitudinal strain (LS) over conventional parameters. RVLS showed higher sensitivity and specificity in the detection of RV dysfunction in the absence of RV dilatation, apparent wall motion abnormalities, and reduced global RV systolic function. Additionally, RVLS represents a significant and independent predictor of adverse outcomes in patients with dilated cardiomyopathy (CMP), hypertrophic CMP, arrhythmogenic RV CMP, and amyloidosis, but also in patients with connective tissue diseases and patients with coronary artery disease. Due to its availability, echocardiography remains the main imaging tool for RVLS assessment, but cardiac magnetic resonance (CMR) also represents an important additional imaging tool in RVLG assessment. The findings from the large studies support the routine evaluation of RVLS in the majority of CV patients, but this has still not been adopted in daily clinical practice. This clinical review aims to summarize the significance and predictive value of RVLS in patients with different types of cardiomyopathies, tissue connective diseases, and coronary artery disease.

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.

The Role of Cardiac Magnetic Resonance in Evaluation of Idiopathic Ventricular Arrhythmia in Children

The aim of the study was to assess the role of cardiovascular magnetic resonance (CMR) in the diagnosis of idiopathic VA in children. This retrospective single-centre study included a total of 80 patients with idiopathic ventricular arrhythmia that underwent routine CMR imaging between 2016 and 2020 at our institution. All patients underwent a 3.0 T scan involving balanced steady-state free precession cine images as well as dark-blood T2W images and assessment of late gadolinium enhancement (LGE). In 26% of patients (n = 21) CMR revealed cardiac abnormalities, in 20% (n = 16) not suspected on prior echocardiography. The main findings included: non-ischemic ventricular scars (n = 8), arrhythmogenic right ventricular cardiomyopathy (n = 6), left ventricular clefts (n = 4) and active myocarditis (n = 3). LGE was present in 57% of patients with abnormal findings. Univariate predictors of abnormal CMR result included abnormalities in echocardiography and severe VA (combination of >10% of 24 h VA burden and/or presence of ventricular tachycardia and/or polymorphic VA). CMR provides valuable clinical information in many cases of idiopathic ventricular arrhythmia in children, mainly due to its advanced tissue characterization capabilities and potential to assess the right ventricle.

Right ventricular function and dyssynchrony in Brugada syndrome: Highlighting the importance of the mechanical substrate in the right ventricular outflow tract

BACKGROUND

Current evidence suggests that Brugada syndrome (BrS), far from being a purely electrical condition, is associated with subtle mechanical abnormalities primarily affecting the right ventricle (RV). We aimed to characterize RV function in BrS and investigate the echocardiographic profile of patients with arrhythmic events, with a special focus on parameters of RV dyssynchrony using speckle-tracking echocardiography (STE).

METHODS

An echocardiogram was performed in 71 BrS patients and 25 healthy controls. STE was performed to assess regional and global RV mechanics, including RV outflow tract shortening (RVOTS). RVOT contraction time was considered to calculate the modified RV mechanical dispersion (RVMD_m). Arrhythmic events were prospectively evaluated in the BrS cohort.

RESULTS

Compared to controls, BrS patients showed subtle contractile abnormalities, including impaired RV longitudinal strain, higher RV index of myocardial performance (RIMP) and lower RVOTS. BrS patients also exhibited a greater contraction delay between the lateral and the septal aspect of the RV. After a median follow-up of 7.3 year (IQR 5.2-10.8), 6 patients presented malignant arrhythmic events. RIMP >0.50, RVOTS <16.2% and RVMD_m > 42 ms showed high sensitivity for the identification of BrS patients with arrhythmic events during follow-up.

CONCLUSIONS

Subtle RV mechanical abnormalities were present in BrS patients. RIMP and RVOTS, a novel STE-derived parameter, were found to be sensitive markers of arrhythmic events. Adding the RVOT contraction time to the analysis of RVMD may help identify patients at higher risk, reflecting the importance of the RVOT mechanical substrate in the assessment of the arrhythmic risk in BrS.

Electromechanical substrate characterization in arrhythmogenic cardiomyopathy using imaging-based patient-specific computer simulations

AIMS

Arrhythmogenic cardiomyopathy (AC) is an inherited cardiac disease, characterized by life-threatening ventricular arrhythmias and progressive cardiac dysfunction. The aim of this study is to use computer simulations to non-invasively estimate the individual patient's myocardial tissue substrates underlying regional right ventricular (RV) deformation abnormalities in a cohort of AC mutation carriers.

METHODS AND RESULTS

In 68 AC mutation carriers and 20 control subjects, regional longitudinal deformation patterns of the RV free wall (RVfw), interventricular septum (IVS), and left ventricular free wall (LVfw) were obtained using speckle-tracking echocardiography. We developed and used a patient-specific parameter estimation protocol based on the multi-scale CircAdapt cardiovascular system model to create virtual AC subjects. Using the individual's deformation data as model input, this protocol automatically estimated regional RVfw and global IVS and LVfw tissue properties. The computational model was able to reproduce clinically measured regional deformation patterns for all subjects, with highly reproducible parameter estimations. Simulations revealed that regional RVfw heterogeneity of both contractile function and compliance were increased in subjects with clinically advanced disease compared to mutation carriers without clinically established disease (17 ± 13% vs. 8 ± 4%, P = 0.01 and 18 ± 11% vs. 10 ± 7%, P < 0.01, respectively). No significant difference in activation delay was found.

CONCLUSION

Regional RV deformation abnormalities in AC mutation carriers were related to reduced regional contractile function and tissue compliance. In clinically advanced disease stages, a characteristic apex-to-base heterogeneity of tissue abnormalities was present in the majority of the subjects, with most pronounced disease in the basal region of the RVfw.

Assessment of right atrial dyssynchrony by 2D speckle-tracking in healthy young men following high altitude exposure at 4100 m

Background

High altitude exposure induces overload of right-sided heart and may further predispose to supraventricular arrhythmia. It has been reported that atrial mechanical dyssynchrony is associated with atrial arrhythmia. Whether high altitude exposure causes higher right atrial (RA) dyssynchrony is still unknown. The aim of study was to investigate the effect of high altitude exposure on right atrial mechanical synchrony.

Methods

In this study, 98 healthy young men underwent clinical examination and echocardiography at sea level (400 m) and high altitude (4100 m) after an ascent within 7 days. RA dyssynchrony was defined as inhomogeneous timing to peak strain and strain rate using 2D speckle-tracking echocardiography.

Results

Following high altitude exposure, standard deviation of the time to peak strain (SD-TPS) [36.2 (24.5, 48.6) ms vs. 21.7 (12.9, 32.1) ms, p<0.001] and SD-TPS as percentage of R–R’ interval (4.6 ± 2.1% vs. 2.5 ± 1.8%, p<0.001) significantly increased. Additionally, subjects with higher SD-TPS (%) at high altitude presented decreased right ventricular global longitudinal strain and RA active emptying fraction, but increased RA minimal volume index, which were not observed in lower group. Multivariable analysis showed that mean pulmonary arterial pressure and tricuspid E/A were independently associated with SD-TPS (%) at high altitude.

Conclusion

Our data for the first time demonstrated that high altitude exposure causes RA dyssynchrony in healthy young men, which may be secondary to increased pulmonary arterial pressure. In addition, subjects with higher RA dyssynchrony presented worse RA contractile function and right ventricular performance.

Right Ventricular Functional Abnormalities in Arrhythmogenic Cardiomyopathy: Association With Life-Threatening Ventricular Arrhythmias

OBJECTIVES

This study aimed to perform an external validation of the value of right ventricular (RV) deformation patterns and RV mechanical dispersion in patients with arrhythmogenic cardiomyopathy (AC). Secondly, this study assessed the association of these parameters with life-threatening ventricular arrhythmia (VA).

BACKGROUND

Subtle RV dysfunction assessed by echocardiographic deformation imaging is valuable in AC diagnosis and risk prediction. Two different methods have emerged, the RV deformation pattern recognition and RV mechanical dispersion, but these have neither been externally validated nor compared.

METHODS

We analyzed AC probands and mutation-positive family members, matched from 2 large European referral centers. We performed speckle tracking echocardiography, whereby we classified the subtricuspid deformation patterns from normal to abnormal and assessed RV mechanical dispersion from 6 segments. We defined VA as sustained ventricular tachycardia, appropriate implantable cardioverter-defibrillator therapy, or aborted cardiac arrest.

RESULTS

We included 160 subjects, 80 from each center (43% proband, 55% women, age 41 ± 17 years). VA had occurred in 47 (29%) subjects. In both cohorts, patients with a history of VA showed abnormal deformation patterns (96% and 100%) and had greater RV mechanical dispersion (53 ± 30 ms vs. 30 ± 21 ms; p < 0.001 for the total cohort). Both parameters were independently associated to VA (adjusted odds ratio: 2.71 [95% confidence interval: 1.47 to 5.00] per class step-up, and 1.26 [95% confidence interval: 1.07 to 1.49]/10 ms, respectively). The association with VA significantly improved when adding RV mechanical dispersion to pattern recognition (net reclassification improvement 0.42; p = 0.02 and integrated diagnostic improvement 0.06; p = 0.01).

CONCLUSIONS

We externally validated 2 RV dysfunction parameters in AC. Adding RV mechanical dispersion to RV deformation patterns significantly improved the association with life-threatening VA, indicating incremental value.

Impact of pregnancy and risk factors for ventricular arrhythmias in women with tetralogy of Fallot

Objective

Patients with tetralogy of Fallot (TOF) have high survival rates 30 years after surgical repair. Many patients experience pregnancy; however, the effects of pregnancy on the long-term cardiovascular outcome are not well known. We investigated the association of pregnancy and cardiac function with occurrence of ventricular arrhythmia (VA) in women with TOF.

Methods

We recruited 80 women with repaired TOF from the national database. Holter monitoring or implanted devices detected VA, defined as non-sustained or sustained ventricular tachycardia or aborted cardiac arrest. All patients underwent echocardiography. Blood tests included NT-proBNP (N-terminal pro-brain natriuretic peptide).

Results

55 (69%) women had experienced pregnancy. Mean age was lower in nulliparous compared with those with children (30±9 vs 40±9, p<0.01).

VA had occurred in 17 (21%) women. Prevalence of VA was higher in women who had experienced pregnancy (n=16, 94%) compared with nulliparous (n=1, 6%) (p=0.02), also when adjusted for age (OR 12.9 (95% CI 1.5 to 113.2), p=0.02).

Right ventricular mechanical dispersion was more pronounced in patients with VA (50±8 ms vs 39±14 ms, p=0.01, age-adjusted OR 2.1 (95% CI 1.3 to 7.5), p=0.01). NT-proBNP was also a marker of VA (211 ng/L (127 to 836) vs 139 ng/L (30 to 465), p=0.007). NT-proBNP >321 ng/L (normal values <170 ng/L) detected women with VA (p=0.019), also independent of age (OR 7.2 (95% CI 1.7 to 30.1), p=0.007).

Conclusion

Pregnancy was associated with higher prevalence of VA among women with TOF. Right ventricular mechanical dispersion and NT-proBNP were age-independent markers of VA. These may have importance for pregnancy counselling and risk stratification.

Determinants and prognostic implications of left ventricular mechanical dispersion in aortic stenosis

AIMS

The present study aimed at investigating the association between left ventricular (LV) mechanical dispersion measured with speckle tracking echocardiography and severity of aortic stenosis (AS) and its impact on prognosis.

METHODS AND RESULTS

This retrospective study included 630 patients [age 72 (62-78) years, 61.4% men] with various grades of AS (mild AS, 19.8%; moderate AS, 37.0%; severe AS, 43.2%). LV mechanical dispersion (defined as standard deviation of time from Q/R on electrocardiogram to peak longitudinal strain in 17 LV segments) was assessed by speckle tracking echocardiography. Clinical, electrocardiographic, and echocardiographic determinants of increased LV mechanical dispersion were evaluated. During a follow-up of 107 (43-133) months, the independent association between LV mechanical dispersion and all-cause mortality (n = 302, 48%) was evaluated including aortic valve replacement as time-dependent co-variate. LV mechanical dispersion increased significantly with increasing severity of AS (mild AS, 54.5 ± 17.2 ms; moderate AS, 56.7 ± 19.3 ms; severe AS, 70.9 ± 24.3 ms; P < 0.001). Independent determinants of increased mechanical dispersion included older age (β = 0.28; P = 0.003), lower LV ejection fraction (β = -0.24; P = 0.020), smaller aortic valve area (β = -8.55; P = 0.001), larger LV mass index (β = 0.20; P < 0.001), and longer QRS duration (β = 1.12 per each 10 ms increase; P = 0.012). LV mechanical dispersion showed incremental prognostic value for all-cause mortality (hazard ratio 1.10 per each 10 ms increase, 95% confidence interval 1.04-1.15; P < 0.001).

CONCLUSION

LV mechanical dispersion assessed by speckle tracking echocardiography increases significantly with severity of AS and is significantly associated with all-cause mortality.

Combined right and left ventricular mechanical dispersion enhance the arrhythmic risk stratification in hypertrophic cardiomyopathy

BACKGROUND

Ventricular arrhythmias are the most frequent cause of sudden cardiac death in individuals with hypertrophic cardiomyopathy (HCM). In the present study we investigated if combined left ventricular (LV) and right ventricular (RV) mechanical dispersion (MD) are correlated with ventricular arrhythmias. We aimed also to analyze if MD enhances the arrhythmic risk stratification in HCM.

METHODS

The cohort included 47 subjects with HCM and 36 healthy individuals. All the studied population underwent clinical, 24-h electrocardiographic (ECG) monitoring for detection and description of non-sustained ventricular tachycardia (NSVT) in terms of number of events, maximal rate and length and comprehensive transthoracic echocardiography, including strain rate imaging. MD was calculated as standard deviation of time from the peak of R wave on ECG to maximum LV or RV shortening in 17 LV and 3 RV segments.

RESULTS

HCM subjects with NSVT on ECG monitoring had increased LVMD (81±18ms vs 42±8ms) and RVMD (52±26 vs 25±23ms) compared with the HCM group without NSVT or compared with the healthy controls. On receiver operating characteristic curves the cut-off values associated with optimal specificity and sensitivity were 62ms for LVMD and 39ms for RVMD. LVMD (OR=1.86, 95% CI 1-1.06, p=0.01) and RVMD (OR=1.04, 95% CI 1.01-1.07, p=0.003) were the only independent variables that correlated with longer and faster NSVT and furthermore improved the risk stratification of NSVTs.

CONCLUSIONS

In a cohort of subjects with HCM, LVMD and RVMD correlates with the presence of NSVT on ECG monitoring. Combined LVMD and RVMD may improve the risk stratification of HCM with NSVT.

Absence of ECG Task Force Criteria does not rule out structural changes in genotype positive ARVC patients

AIMS

In Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), electrophysiological pathology has been claimed to precede morphological and functional pathology. Accordingly, an ECG without ARVC markers should be rare in ARVC patients with pathology identified by cardiac imaging. We quantified the prevalence of ARVC patients with evidence of structural disease, yet without ECG Task Force Criteria (TFC).

METHODS AND RESULTS

We included 182 probands and family members with ARVC-associated mutations (40 ± 17 years, 50% women, 73% PKP2 mutations) from the Nordic ARVC Registry in a cross-sectional analysis. For echocardiography and cardiac MR (CMR), we differentiated between "abnormalities" and TFC. "Abnormalities" were defined as RV functional or structural measures outside TFC reference values, without combinations required to fulfill TFC. ECG TFC were used as defined, as these are not composite parameters. We found that only 4% of patients with ARVC fulfilled echocardiographic TFC without any ECG TFC. However, importantly, 38% of patients had imaging abnormalities without any ECG TFC. These results were supported by CMR data from a subset of 51 patients: 16% fulfilled CMR TFC without fulfilling ECG TFC, while 24% had CMR abnormalities without any ECG TFC. In a multivariate analysis, echocardiographic TFC were associated with arrhythmic events.

CONCLUSION

More than one third of ARVC genotype positive patients had subtle imaging abnormalities without fulfilling ECG TFC. Although most patients will have both imaging and ECG abnormalities, structural abnormalities in ARVC genotype positive patients cannot be ruled out by the absence of ECG TFC.

Effect of kidney transplantation on right ventricular function, assessment by 2- dimensional speckle tracking echocardiography

Background

Advanced chronic kidney disease often results in adverse cardiovascular outcomes and is the leading cause of mortality in patients with end stage renal diseases (ESRD). There is much information about the effect of chronic kidney diseases (CKD) on the left ventricle (LV) chamber, but the right ventricle (RV) as a neglected chamber had not been evaluated precisely, in spite of its importance.

Objectives

The aim of this study was to evaluate the impact of successful kidney transplants on the RV systolic and diastolic function using the advanced method of 2D speckle tracking echocardiography and comparison with the conventional methods.

Method

The study included 48 patients with CKD who were eligible for kidney transplantation and underwent successful kidney transplantations. Right ventricular indices were evaluated, while RV function was focused by conventional methods and 2D speckle tracking echocardiography before the successful kidney transplant and 1 week, 1 month, and 3 months after the successful kidney transplant.

Results

The results of the study showed that RV global longitudinal strain and RV free wall longitudinal strain improved over the time (P = 0.024, P < 0.001 respectively). It also represented that kidney transplantation did not have significant effect on the RV mid cavity diameter, tissue velocity, Myocardial performance index, RV longitudinal diameter, and Tricuspid annular plane systolic excursion indices, but for other indices this effect was significant. On the differences between the mean slope of regression line of the GLS variable in hypertensive subjects (1.0 ± 0.2) and non-hypertensive subjects (0.36 ± 0.32), an independent t-test showed that between the two groups in terms of the improvement of RVGLS, there was a significant statistical difference (P = 0.0067).

Conclusion

Most of the ESRD patients had subtle RV dysfunction which could be better detected by recent echocardiography methods than conventional methods. Moreover, kidney transplantation led to considerable improvements in RV function in this population.