Infant Barlow's Disease in Association with Atrial Septal Defect.

CLINICAL DATA: Female, seven years old, referred to our service complaining about congestive heart failure symptoms due to mitral valve regurgitation and atrial septal defect. Technical description: Echocardiographic findings compatible with Barlow's disease and atrial septal defect, ostium secundum type. OPERATION: She was submitted to mitral valvuloplasty with chordal shortening and prosthetic posterior ring (Gregori-Braile®) along with patch atrioseptoplasty. COMMENTS: Mitral valve regurgitation is a rare congenital heart disease and Barlow's disease is probably rarer. Mitral valve repair is the treatment of choice.

Mitral valve prolapse: arrhythmic risk during pregnancy and postpartum.

BACKGROUND AND AIMS: Arrhythmic mitral valve prolapse (AMVP) is linked to life-threatening ventricular arrhythmias (VAs), and young women are considered at high risk. Cases of AMVP in women with malignant VA during pregnancy have emerged, but the arrhythmic risk during pregnancy is unknown. The authors aimed to describe features of women with high-risk AMVP who developed malignant VA during the perinatal period and to assess if pregnancy and the postpartum period were associated with a higher risk of malignant VA. METHODS: This retrospective international multi-centre case series included high-risk women with AMVP who experienced malignant VA and at least one pregnancy. Malignant VA included ventricular fibrillation, sustained ventricular tachycardia, or appropriate shock from an implantable cardioverter defibrillator. The authors compared the incidence of malignant VA in non-pregnant periods and perinatal period; the latter defined as occurring during pregnancy and within 6 months after delivery. RESULTS: The authors included 18 women with AMVP from 11 centres. During 7.5 (interquartile range 5.8-16.6) years of follow-up, 37 malignant VAs occurred, of which 18 were pregnancy related occurring in 13 (72%) unique patients. Pregnancy and 6 months after delivery showed increased incidence rate of malignant VA compared to the non-pregnancy period (univariate incidence rate ratio 2.66, 95% confidence interval 1.23-5.76). CONCLUSIONS: The perinatal period could impose increased risk of malignant VA in women with high-risk AMVP. The data may provide general guidance for pre-conception counselling and for nuanced shared decision-making between patients and clinicians.

Mitral annular disjunction and mitral valve prolapse extrapolating adult data to an adolescent cohort?

PURPOSE OF REVIEW: The aim of this study is to provide an update on mitral valve prolapse (MVP) and mitral annular disjunction (MAD) and who may be at risk for ventricular arrhythmias and sudden cardiac death. RECENT FINDINGS: MVP is generally considered a benign condition. However, a small subset of patients may be at risk for life-threatening ventricular arrhythmias. Among the risk factors identified in adults include patients with bileaflet mitral valves, myxomatous changes, myocardial fibrosis, and the presence of MAD. Advances in multimodal imaging have allowed for improved identification of fibrosis, anatomical valve derangements, and the amount of MAD. Recent guidelines have suggested that patients with MVP with or without MAD may be at risk for life-threatening arrhythmias if they have had prior ventricular arrhythmias, ventricular dysfunction, or unexplained syncope. Yet, extrapolation of adult data to a pediatric cohort with similar MVP and MAD at this juncture is challenging. There is, however, early evidence that some pediatric patients with significant myocardial fibrosis or abnormal tissue Doppler may be at risk for ventricular tachycardia. SUMMARY: Mitral valve prolapse and mitral annular disjunction at times coexist and at other times can be seen as isolated entities. While the incidence of arrhythmic MVP is quite rare, there is increasing evidence that certain select adults with MVP may be at risk for ventricular tachycardia and sudden cardiac death. Future multicenter studies are needed to better understand the natural history of arrhythmic mitral valve disease and how early disease manifestation in children may impact findings now being reported in young adults.

Evaluation of left ventricular function in patients with mitral annular disjunction using speckle tracking echocardiography.

BACKGROUND: Mitral annular disjunction (MAD) is a structural abnormality characterized by the systolic detachment of the posterior mitral annulus and the ventricular myocardium. It is usually observed coexistent with mitral valve prolapse (MVP) and associated with a mechanical dysfunction despite preserved electrical isolation function of the mitral annulus. This study aimed to evaluate left ventricular (LV) function using speckle tracking echocardiography in MVP patients with MAD. METHODS: This study was designed as a prospective, single-center study including 103 patients with MVP and 40 age- and sex-matched control subjects. Transthoracic echocardiography and cardiac magnetic resonance imaging were performed to assess LV function and MAD presence. RESULTS: MAD (+) MVP (n = 34), MAD (-) MVP (n = 69), and control (n = 40) groups were enrolled in the study. Among the MVP patients, 34 (33%) had MAD. T-negativity in the inferior leads on electrocardiography was more frequent in the MAD (+) group than in the MAD (-) patients (4.3% vs. 20.6%, p = .014). Mitral regurgitation degree, Pickelhaube sign (17.6% vs. 1.4%, p = .005), and late gadolinium enhancement frequency (35.3% vs. 10.6%, p = .002) were significantly higher in MAD (+) patients. MAD (+) patients had significantly impaired global longitudinal strain (-23.1 ±  2.1 vs. -23.5 ± 2.3, p < .001), basal longitudinal strain (BLS) (-19.6 ±  1.5 vs. -20.5 ± 1.9, p < .001), Mid-Ventricular Longitudinal Strain (-22.2 ± 1.7 vs. -23.2 ± 2.2, p < .001) and LA strain (-24.5 ± 3.9 vs. -27.2 ± 3.6, p < .001) when compared to MAD (-) MVP patients, despite similar LV ejection fraction. All these values of MVP patients were also significantly lower than the control group. The mean MAD distance was 7.8 ± 3.2 mm in MAD (+) patients. Patients with two or more symptoms were higher in the MAD (+) group than in the MAD (-) group (4.3% vs. 44.1%, p < .001). CONCLUSION: This study demonstrated a significant decrease in longitudinal strain in MVP patients with MAD, indicating myocardial dysfunction. These findings suggest that MAD may contribute to LV dysfunction and highlight the importance of early detection in younger patients. Further research is needed to explore the functional implications and long-term outcomes of MAD.

What Do We Know So Far About Ventricular Arrhythmias and Sudden Cardiac Death Prediction in the Mitral Valve Prolapse Population? Could Biomarkers Help Us Predict Their Occurrence?

PURPOSE OF THE REVIEW: To summarize currently available data on the topic of mitral valve prolapse (MVP) and its correlation to the occurrence of atrial and ventricular arrhythmias. To assess the prognostic value of several diagnostic methods such as transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance, cardiac computed tomography, electrocardiography, and electrophysiology concerning arrhythmic episodes. To explore intra and extracellular biochemistry of the cardiovascular system and its biomarkers as diagnostic tools to predict rhythm disturbances in the MVP population. RECENT FINDINGS: MVP is a common and mainly benign valvular disorder. It affects 2-3% of the general population. MVP is a heterogeneous and highly variable phenomenon with three structural phenotypes: myxomatous degeneration, fibroelastic deficiency, and forme fruste. Exercise intolerance, supraventricular tachycardia, and chest discomfort are the symptoms that are often paired with psychosomatic components. Though MVP is thought to be benign, the association between isolated MVP without mitral regurgitation (MR) or left ventricle dysfunction, with ventricular arrhythmia (VA) and sudden cardiac death (SCD) has been observed. The incidence of SCD in the MVP population is around 0.6% per year, which is 6 times higher than the occurrence of SCD in the general population. Often asymptomatic MVP population poses a challenge to screen for VA and prevent SCD. Therefore, it is crucial to carefully assess the risk of VA and SCD in patients with MVP with the use of various tools such as diagnostic imaging and biochemical and genetic screening.

Quantification of Mitral Regurgitation in Mitral Valve Prolapse by Three-Dimensional Vena Contracta Area: Derived Cutoff Values and Comparison With Two-Dimensional Multiparametric Approach.

BACKGROUND: Echocardiographic grading of mitral regurgitation (MR) in mitral valve prolapse (MVP) is challenging. Three-dimensional (3D) vena contracta area (VCA) has been proposed as a valuable method. However, data defining the cutoff values of severity and validation in the subset of patients with MVP are scarce. The aim of this study was to validate the 3D VCA by 3D color-Doppler transesophageal echocardiography (TEE) in patients with MVP and to define the cutoff values of severity grading. The secondary aim was to compare 3D VCA to the effective regurgitant orifice area estimation by proximal isovelocity surface area (EROA-PISA) method. METHODS: A total of 1,138 patients with at least moderate MR who underwent TEE were included. Three-dimensional VCA was measured, and the cutoff value and area under the curve (AUC) for the prediction of severe MR were estimated by receiver operating characteristic curve using a guideline-suggested multiparametric approach as the reference standard. In a subgroup of patients, 3D regurgitant volume (RV) and 3D fraction were calculated from mitral and left ventricular outflow tract stroke volumes to further validate 3D VCA against a 3D volumetric reference standard. RESULTS: The optimal 3D VCA cutoff value for predicting severe MR was 0.45 cm2 (specificity, 0.87; sensitivity, 0.90) with an AUC of 0.95 using a multiparametric approach as reference. Three-dimensional VCA had a good linear correlation with EROA-PISA (r = 0.62, P < .05) with larger values compared to EROA-PISA (0.63 cm2 vs 0.44 cm2, P < .05). A cutoff of 0.50 cm2 (AUC of 0.84; sensitivity, 0.78; specificity, 0.78) predicts an EROA-PISA of 0.40 cm2. Three-dimensional VCA had a good linear correlation with 3D RV (r = 0.56, P < .01), with an AUC of 0.86 to predict a 3D fraction >50%. CONCLUSIONS: The present study suggests 0.45 cm2 as the best cutoff value of 3D VCA to define severe MR in patients with MVP, showing an optimal agreement with the reference standard multiparametric approach and 3D RV.

Determinants of Ventricular Arrhythmias in Mitral Valve Prolapse.

BACKGROUND: Mitral valve prolapse (MVP) may be associated with ventricular arrhythmias (VA) even in the absence of significant valvular regurgitation. Curling, mitral annulus disjunction (MAD) and myocardial fibrosis (late gadolinium enhancement [LGE]) may account for arrhythmogenesis. OBJECTIVES: This study investigated the determinants of VA in patients with MVP without significant regurgitation. METHODS: This study included 108 patients with MVP (66 female; median age: 48 years) without valve regurgitation. All patients underwent 12-lead electrocardiography, 12-lead 24-hour electrocardiographic Holter monitoring, exercise stress test, and cardiac magnetic resonance. Patients were divided into 2 groups (arrhythmic and no-arrhythmic MVP), according to the presence of VA with a right bundle branch block pattern. RESULTS: The 62 patients (57%) with arrhythmic MVP showed: 1) higher MAD (median length: 6.0 vs 3.2 mm; P = 0.017); 2) higher prevalence of curling (79% vs 52%; P = 0.012); and 3) higher prevalence of left ventricular LGE (79% vs 52%; P = 0.012). Mediation analysis showed that curling had both a direct (P = 0.03) and indirect effect mediated by LGE (P = 0.04) on VA, whereas the association between MAD and VA was completely mediated by LGE. Patients with severe VA showed more pronounced morphofunctional alterations, in terms of MAD (7.0 vs 4.6 mm; P = 0.004) and presence and severity of curling (respectively, 91% vs 64%; P = 0.010; and 4 vs 3 mm; P = 0.004), compared to those without severe VA. CONCLUSIONS: In patients with MVP the occurrence of VA with right bundle branch block morphology is the expression of more severe morphologic, mechanical, and tissue alterations. Curling has both a direct and an indirect effect on VA.

Mitral annular disjunction in idiopathic ventricular fibrillation patients: just a bystander or a potential cause?

AIMS: Previously, we demonstrated that inferolateral mitral annular disjunction (MAD) is more prevalent in patients with idiopathic ventricular fibrillation (IVF) than in healthy controls. In the present study, we advanced the insights into the prevalence and ventricular arrhythmogenicity by inferolateral MAD in an even larger IVF cohort. METHODS AND RESULTS: This retrospective multi-centre study included 185 IVF patients [median age 39 (27, 52) years, 40% female]. Cardiac magnetic resonance images were analyzed for mitral valve and annular abnormalities and late gadolinium enhancement. Clinical characteristics were compared between patients with and without MAD. MAD in any of the 4 locations was present in 112 (61%) IVF patients and inferolateral MAD was identified in 24 (13%) IVF patients. Mitral valve prolapse (MVP) was found in 13 (7%) IVF patients. MVP was more prevalent in patients with inferolateral MAD compared with patients without inferolateral MAD (42 vs. 2%, P < 0.001). Pro-arrhythmic characteristics in terms of a high burden of premature ventricular complexes (PVCs) and non-sustained ventricular tachycardia (VT) were more prevalent in patients with inferolateral MAD compared to patients without inferolateral MAD (67 vs. 23%, P < 0.001 and 63 vs. 41%, P = 0.046, respectively). Appropriate implantable cardioverter defibrillator therapy during follow-up was comparable for IVF patients with or without inferolateral MAD (13 vs. 18%, P = 0.579). CONCLUSION: A high prevalence of inferolateral MAD and MVP is a consistent finding in this large IVF cohort. The presence of inferolateral MAD is associated with a higher PVC burden and non-sustained VTs. Further research is needed to explain this potential interplay.

Insights into malignant mitral valve degenerative disease from a sudden cardiac death cohort highlighting significant measurement differences from normal.

AIMS: Mitral valve prolapse (MVP) is an accepted cause of sudden cardiac death (SCD) in most autopsy series. Diagnosis at autopsy relies upon subjective assessment with no established objective pathological criteria. This study set out to establish objective measurements to help pathologists dealing with SCD. METHODS: We diagnosed 120 (1.5%) cases of MVP in 8108 cases of SCD. We measured the mitral annulus, anterior and posterior leaflets, rough zone and mitral annular disjunction (MAD) in 27 MVP cases and compared them to 54 age- and sex-matched normal mitral valves. RESULTS: Age of death was 39 ± 16 years, with 59 females and 61 males. History of mild MV disease was present in 19 (16%). Eleven (9%) died associated with exertion. Left ventricular hypertrophy was present in nine (15%) females and 10 (16%) males. Both MV leaflets showed thickening and ballooning in all individuals. MVP showed highly significantly increased annular circumference, elongation and thickening of both leaflets as well as increased MAD (all P < 0.001). Left ventricular fibrosis was present in 108 (90%), with interstitial fibrosis in the posterolateral wall and papillary muscle in 88 (81%) and coexisting replacement fibrosis in 40 (37%). CONCLUSION: This is the largest MVP associated with SCD series highlighting a young cohort with equal representation of males and females. There is involvement of both leaflets with significant annular dilatation, elongation and thickening of both leaflets with MAD. Left ventricular fibrosis explains arrhythmia. Our quantitative measurements should serve as a reference for pathologists assessing post-mortem hearts for MVP.

Feasibility of concomitant exclusion of left atrial appendage during novel transapical off-pump beating heart mitral valve repair.

The AtriClip device enables the safe and reproducible epicardial clipping of the left atrial appendage. Transapical off-pump beating heart mitral valve repair using NeoChord DS100 Artificial Chordae Delivery System has matured and become more standardized. We aim to evaluate the feasibility of combining NeoChord repair and left atrial appendage exclusion in a single procedure through the same minithoracotomy in patients with mitral valve prolapse and atrial fibrillation. From 2018 to 2019, seven patients with severe mitral regurgitation and atrial fibrillation underwent transesophageal echocardiography-guided transapical off-pump mitral valve repair with the novel NeoChord DS 1000 system and concomitant left atrial appendage exclusion using the AtriClip Pro II device. Both procedures were performed via left mini-thoracotomy. The AtriClip device was applied after the NeoChord repair was done. All seven patients had less than moderate mitral regurgitation after the NeoChord repair and successful left atrial appendage occlusion. There were no device or procedure-related complications. Clinical follow-up revealed significant symptomatic improvement, and no cardiovascular complications were reported. Transesophageal echocardiography at 6-12 months post-procedure showed stable left atrial appendage occlusion with no residual flow between the left atrium and the left atrial appendage and a stump of less than 5 mm. Beating heart epicardial clipping of the left atrial appendage using AtriClip concomitant with transapical mitral valve repair using Neochord DS 1000 system is a feasible and safe treatment option in mitral valve prolapse and atrial fibrillation in patients with limited indications. However, its safety needs to be confirmed in a larger series of 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.

Left ventricular fibrosis in arrhythmic mitral valve prolapse: quantification and comparison of semi-automated techniques assessed by cardiac magnetic resonance.

PURPOSE: Left ventricular (LV) fibrosis has a key role in arrhythmogenesis in patients with mitral valve prolapse (MVP). Cardiac magnetic resonance identifies LV fibrosis by using late gadolinium enhancement (LGE) technique. LGE assessment and quantification in patients with MVP lacks of standardization protocols. METHODS: 66 MVP patients with normal systolic function and without significant regurgitation were enrolled. Semi-automated gray-scale thresholding techniques using full width at half maximum (FWHM) and 2, 3 and 5 standard deviation (SD) above the remote myocardium were used and compared with the visual assessment, considered as the gold standard. RESULTS: LGE was identified in 41 MVP patients (62%) and quantified. The mean quantity of LGE visually assessed was 2.40 ± 1.07% or 1.40 ± 0.82 g. With FWHM, LGE resulted 3.56 ± 1.23% or 1.99 ± 1.13 g. Using thresholding, the mean LGE quantity was 9.2 ± 3.1% or 4.82 ± 2.28 g for 2-SD, 5.72 ± 1.75% or 3.06 ± 1.47 g for 3-SD and 2.36 ± 0.99% or 1.29 ± 0.79 g for 5-SD. The 5-SD measurement in percentage demonstrated a good correlation with LGE quantification visually assessed (2.40 ± 1.07 vs. 2.363 ± 0.9909, p = 0.543). When compared with the gold standard, the 5-SD threshold quantification, both in percentage and in grams, revealed the least intra-observer (respectively, ICC: 0.976 and 0.966) and inter-observer variability (respectively ICC: 0.948 and 0.935). CONCLUSION: The 5-SD gray-scale threshold technique in percentage revealed the best correlation with the visual assessment and an optimal reproducibility in MVP patient.

Effects of Mitral Valve Surgery on Ventricular Arrhythmia in Mitral Valve Prolapse Patients: Five-Year Eollow-up.

Aim      To evaluate the effect of mitral valve (MV) repair and replacement on the incidence of ventricular arrhythmias (VA) and to identify risk factors for the persistence of VA in patients with MV prolapse and severe mitral regurgitation (MR) during a mid-term follow-up.Material and methods  A single-site observational, prospective study successively enrolled 30 patients (mean age, 55.2±9.9 years, 60% men) who underwent MV repair or replacement for severe MR due to MV prolapse or chordal avulsion. Transthoracic echocardiography and Holter monitoring were performed in all patients before and annually after surgery. A pathomorphological study of MV fragments excised during surgery was performed.Results During the five-year follow-up period (144 person-years), one case of sudden cardiac death outside a health care facility was recorded. MR severity progressed in three patients after MV repair. The total number of all VAs decreased during the follow-up period, with a significant decrease in the number of paroxysms of unstable ventricular tachycardia during the first two years after surgery. The presence of VA in the postoperative period was correlated with the severity of postoperative left ventricular (LV) remodeling: end-diastolic volume (EDV) (rs=0.69; p=0.005), LV ejection fraction (EF) (rs = -0.55; p=0.004) and severity of MV myxomatous alterations according to histological study data (rτ=0.58; p=0.045). The beta-blocker treatment did not influence the VA frequency and severity (rs= -0.18; p=0.69). According to a univariate regression analysis only EDV (p = 0.001), LVEF <50% (p = 0.003), and myxomatous MV degeneration (p = 0.02) were risk factors for persistent ventricular tachycardia in the postoperative period.Conclusion      Surgical intervention on MV in patients with MV prolapse and severe MR decreased the number of cases of malignant VAs and was correlated with the postoperative changes in LV volume and function, as well as the severity of MV myxomatous alterations.

Long-term outcomes of patients with ventricular arrhythmias and negative programmed ventricular stimulation followed with implantable loop recorders: Impact of delayed-enhancement cardiac magnetic resonance imaging.

BACKGROUND: Programed ventricular stimulation (PVS) is a risk stratification tool in patients at risk for adverse arrhythmia outcomes. Patients with negative PVS may yet be at risk for adverse arrhythmia-related events, particularly in the presence of symptomatic ventricular arrhythmias (VA). OBJECTIVE: To investigate the long-term outcomes of real-world patients with symptomatic VA without indication for device therapy and negative PVS, and to examine the role of cardiac scaring on arrhythmia recurrence. METHODS: Patients with symptomatic VA, and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR), and negative PVS testing were included. All patients underwent placement of implantable cardiac monitors (ICM). Survival analysis was performed to investigate the impact of LGE-CMR findings on survival free from adverse arrhythmic events. RESULTS: Seventy-eight patients were included (age 60 ± 14 years, women n = 36 (46%), ejection fraction 57 ± 9%, cardiomyopathy n = 26 (33%), mitral valve prolapse [MVP] n = 9 (12%), positive LGE-CMR scar n = 49 (62%), history of syncope n = 23 (29%)) including patients with primarily premature ventricular contractions (n = 21) or nonsustained VA (n = 57). Patients were followed for 1.6 ± 1.5 years during which 14 patients (18%) experienced VA requiring treatment (n = 14) or syncope due to bradycardia (n = 2). Four/9 patients (44%) with MVP experienced VA (n = 3) or syncope (n = 1). Baseline characteristics between those with and without adverse events were similar (p > 0.05); however, the presence of cardiac scar on LGE-CMR was independently associated with an increased risk of adverse events (hazard ratio: 5.6 95% confidence interval: [1.2-27], p = 0.03, log-rank p = 0.03). CONCLUSIONS: In a real-world cohort with long-term follow-up, adverse arrhythmic outcomes occurred in 18% of patients with symptomatic VA despite negative PVS, and this risk was significantly greater in patients with positive DE-CMR scar. Long term-monitoring, including the use of ICM, may be appropriate in these patients.

The Prevalence and Characteristics of Arrhythmic Mitral Valve Prolapse in Patients With Unexplained Cardiac Arrest.

BACKGROUND: There is growing evidence that mitral valve prolapse (MVP) is associated with otherwise unexplained cardiac arrest (UCA). However, reports are hindered by the absence of a systematic ascertainment of alternative diagnoses. OBJECTIVES: This study reports the prevalence and characteristics of MVP in a large cohort of patients with UCA. METHODS: Patients were enrolled following an UCA, defined as cardiac arrest with no coronary artery disease, preserved left ventricular ejection fraction, and no apparent explanation on electrocardiogram. A comprehensive evaluation was performed, and patients were diagnosed with idiopathic ventricular fibrillation (IVF) if no cause was found. Echocardiography reports were reviewed for MVP. Patients with MVP were divided into 2 groups: those with IVF (AMVP) and those with an alternative diagnosis (nonarrhythmic MVP). Patient characteristics were then compared. The long-term outcomes of AMVP were reported. RESULTS: Among 571 with an initially UCA, 34 patients had MVP (6%). The prevalence of definite MVP was significantly higher in patients with IVF than those with an alternative diagnosis (24 of 366 [6.6%] vs 5 of 205 [2.4%]; P = 0.03). Bileaflet prolapse was significantly associated with AMVP (18 of 23 [78%] vs 1 of 8 [12.5%]; P = 0.001; OR: 25.2). The proportion of patients with AMVP who received appropriate implantable cardioverter-defibrillator therapies over a median follow-up of 42 months was 21.1% (4 of 19). CONCLUSIONS: MVP is associated with otherwise UCA (IVF), with a prevalence of 6.6%. Bileaflet prolapse appears to be a feature of AMVP, although future studies need to ascertain its independent association. A significant proportion of patients with AMVP received appropriate implantable cardioverter-defibrillator therapies during follow-up.