Bileaflet Mitral Valve Prolapse Research Articles

A COMPLEX CASE OF EARLY ONSET ATRIAL FIBRILLATION IN AN ENDURANCE ATHLETE: THE IMPORTANCE OF FAMILY HISTORY

Abstract Introduction Early onset atrial fibrillation (AF) in an endurance athlete represents a challenge for the cardiologist, especially in apparent absence of an overt structural heart disease. Different genetic variants have been associated with early onset AF but indications to genetic testing are still under definition. Case A 54–year–old man (BMI 19 kg/sqm), previous competitive athlete (Nordic running and walking) presented to the Emergency Department with sudden onset palpitations and dyspnea due to high penetrance AF (145 bpm). Family history (FH) was positive for cerebrovascular accidents in both parents and for early onset (<60 years) AF in the father. The man had a recent history of borderline hypertension, of effort related syncope of and of infundibular, isolated, premature ventricular complexes during a maximal exercise stress test (otherwise negative for ischemia) which ultimately led to the denial of competitive sport eligibility. Sinus rhythm (SR) was acutely restored with flecainide and the patient was discharged with low dose nadolol. Cardiac US showed normal left ventricular (LV) dimensions and thicknesses (10 mm), with regular LVEF (60%) and global longitudinal strain (–18%), mildly dilated left atrium (LAVI 36 ml/sqm) and bi–leaflet mitral valve prolapse without significant mitral regurgitation, mitro–anular disjunction nor Pickelhaube sign; 24h Holter ECG showed SR with rare supraventricular (SV) ectopic beats and a 4 beats SV run. Due to the recurrence of short episodes of palpitations, rhythm control with flecainide and antithrombotic prophylaxis were started and AF ablation was planned. Genetic testing for early onset AF identified a nonsense variant (c.84665delG; p.Gly28222fs*2) in TTN gene, classified as likely pathogenic (C4), so far not reported in scientific literature. Also, despite a moderate–low cardiovascular risk as assessed by SCORE2, mostly due to the FH and the desire to engage in high intensity exercise, coronary CT was prescribed, which showed a critical coronary disease leading to stenting on left anterior descending artery and intermediate branch. Cardiac MRI was planned. Conclusions Early onset AF in endurance athletes should not be underrated and a thorough examination including a detailed family history should be performed. TTN is the single gene most frequently associated with early onset AF in absence of an overt structural heart disease, but the subsequent clinical evolution is still largely unknown.

Myocardial work indices in bileaflet mitral valve prolapse patients.

Mechanisms underlying left ventricular dysfunction and arrhythmogenesis in bileaflet mitral valve prolapse (BMVP) patients are not well defined. Myocardial work index (MWI) is a non-invasive assessment that correlates with myocardial oxygen consumption. We aimed to compare global and regional MWI in BMVP patients with normal controls. In this retrospective study, we calculated MWI in BMVP patients and controls using GE EchoPAC (GE Healthcare, Chicago, IL, USA) software. Of 147 BMVP patients (59% women, mean age 54 ± 15 years), 16 had a flail mitral leaflet. There was regional heterogeneity in MWIs, with increased posterolateral trident myocardial work (2099 ± 271 vs. 1895 ± 321 mm Hg%, P = 0.039), constructive work (2831 ± 366 vs. 2257 ± 338 mm Hg%, P < 0.001), wasted work [87 (52-194) vs. 71 (42-103) mm Hg%, P = 0.015], peak systolic strain (-23.0 ± 2.4 vs. -19 ± 3%, P < 0.001), and reduction in myocardial work efficiency [95.00 (93.50-97.75) vs. 96.75 (95.00-97.75) %, P = 0.020] in 100 BMVP patients compared with age- and sex-matched controls. BMVP patients' basal septal wall MWIs were lower than those of controls. The higher work indices in patients with BMVP were reduced in those who developed flail leaflets. No significant differences in work indices were seen between ventricular arrhythmia and non-arrhythmia BMVP patients. Regional differences in MWIs were noted in the BMVP patients compared with controls, with overall reduced myocardial efficiency in the posterolateral trident and basal septal regions. In cross-sectional analysis, MWIs were not different in patients with ventricular tachyarrhythmias. Impact of MWI on long-term prognosis needs to be determined.

Mitral annular disjunction; how accurate are we? A cardiovascular MRI study defining risk

AimsMitral Annular Disjunction (MAD) refers to embryologic fibrous separation between mitral annular ring and basal left ventricular myocardium. Since its original description, the role of MAD in arrhythmic mitral valve prolapse (MVP) has been the subject of active research. In this study we sought to assess prognostic and imaging characteristics of MVP patients with and without underlying MAD. Methods and resultsPatients with posterior or bi-leaflet MVP were retrospectively identified via a review of all patients referred to our cardiac magnetic resonance (CMR) imaging laboratory from January 2015 to May 2022. MVP patients were further stratified by underlying MAD status. A total of 100 MVP patients undergoing CMR imaging (52 MVP patients with posterior MAD) were retrospectively identified with female comprising 55 % of the cohort. MVP patients with MAD were more likely to have an abnormal basal inferolateral/ papillary muscles LGE (51 % vs 21 %, p < 0.01). Posterior MAD longitudinal disjunction gap in ‘mm’ was a predictor of ventricular tachycardia (VT) [1.29, p = 0.01)]. Using ROC curve analysis, a disjunction gap of ≥ 4 mm was predictive of VT (AUC-0.71, p < 0.01), and incorporation of LGE in ROC model further improved AUC to 0.78 confirmed via Akaike information criterion (p < 0.01). ConclusionAbnormal LGE involving basal inferolateral myocardium and papillary muscles may provide etiologic substrate for arrythmia in MVP patients.

Abstract 16239: Left Atrial Function by Speckle-Tracking Echocardiography in Mitral Valve Prolapse: Evidence of a Primary Atriopathy and Clinical Implications

Background: Prior studies support the prognostic role of left atrial (LA) volume in predicting overall mortality in mitral valve prolapse (MVP). However, the prognostic impact of LA function on cardiac outcome as quantified by speckle tracking echocardiography (STE) is unknown. Moreover, whether the mitral leaflet “atrialization” observed in bileaflet MVP with mitral annular disjunction (MAD) affects LA function irrespective of mitral regurgitation (MR) severity remains unclear. We sought to investigate the prognostic role of LA global longitudinal strain (LAGLS) and MVP subtype in a large registry of MVP patients with various degrees of MR. Methods: We identified 411 consecutive patients (59±17 years, 52% women) with MVP and clinical, echocardiographic and outcome data. LAGLS was measured offline using STE. Survival analysis was performed to assess the composite risk of cardiac death, heart failure hospitalization, or new onset of atrial fibrillation. Results: Compared to other MVP subtypes, bileaftlet MVP had lower LAGLS regardless of MR severity ( Fig 1A&amp;1B ). Of note, in the subgroup with no or mild MR, LAGLS was significantly lower in bileaflet compared to posterior MVP (p=0.003). There was a trend toward lower LAGLS according to MVP with vs without MAD (p=0.08) ( Fig 1C ). In multivariable linear regression adjusted for several risk factors, including MR grade, bileaflet MVP remained significantly associated with lower LAGLS (p=0.003). A total of 79 cardiovascular events occurred during a mean follow-up of 4.6±2.9 years. There was a significant increase in the risk of events as LAGLS decreased (log-rank: p&lt;0.001) ( Fig 1D ). Conclusion: Bileaflet MVP is associated with lower LAGLS regardless of MR severity, suggesting a primary atriopathy in this MVP subtype. Abnormal LAGLS is linked to higher risk of cardiovascular events. Hence, assessment of LA function using STE may help improve risk stratification in MVP and could represent a useful tool in clinical practice.

Abstract 18674: Deep Phenotyping Arrhythmogenic MVP With Imaging and Genotyping Reveals Important Shared Genetic Etiology With Arrhythmia and Cardiomyopathy Genes

Introduction: Mitral valve prolapse (MVP) has a high population prevalence 2-4% with an arrhythmogenic subtype presenting with premature ventricular complexes (PVC) ventricular tachycardia (VT) and sudden death. There is a continued search for markers of MVP to help risk stratify patients. Hypothesis: Arrhythmogenic MVP shares genetic etiology with Mendelian causes of arrhythmia and cardiomyopathy Methods: Consecutive adult patients with arrhythmogenic MVP patients prospectively evaluated Results: A total of 33 cases (age 55±15 years, female 51.5%) presented with history of hypertension (33%), diabetes (3%), coronary disease (12%), atrial fibrillation (45%), bileaflet MVP (58%) and syncope (18%). ECG findings include inverted T-waves in inferior leads in 6%, pleomorphic PVC in 6%, Ventricular couplets in 51.5%, non-sustained VT in 73% and sustained VT in 33%; High PVC burden was seen in 55% of cases with burden 15±14%. Echocardiography noted LV ejection fraction of 55±8%, mitral regurgitations in 70% (severe 18%, moderate 27%, mild 24%), mitral annular disjunction in 39%, and Pickelhaube sign in 9% of cases. Cardiac magnetic resonance showed LVESV 113±119mm, LVEDV 117±70mm, and late Gadolinium enhancement in 48% with highest prevalence in basal inferolateral segment. PET-CT performed in 17 cases and showed fluorodeoxyglucose uptake in 24% cases, mostly in basal inferolateral segment as well. Genetic testing was performed in 23 cases and reported a putative pathogenic variant in 21.7%: FLNC (Exemplar case, Figure 1 ) cause of dilated cardiomyopathy, TBX5 cause of Holt-Oram syndrome, DSP cause of arrhythmogenic cardiomyopathy , TTN causes of dilated cardiomyopathy, MTO1 cause of mitochondrial hypertrophic cardiomyopathy. Conclusion: Full evaluation of arrhythmogenic MVP with multimodality imaging and genetic testing reveals high burden of fibrosis, inflammation, and candidate pathogenic variants.

Abstract 16003: A Case of Ventricular Fibrillation Arrest in a Healthy Young Female With Newly Discovered Mitral Annular Disjunction

Introduction: Mitral annular disjunction (MAD) is an under-recognized cause of ventricular arrhythmias. Case Presentation: A previously healthy, athletic 43-year-old female suddenly collapsed during a staff meeting at a medical center. Cardiopulmonary resuscitation was initiated and she was found to be in ventricular fibrillation, requiring three defibrillation shocks to achieve ROSC. EKG was notable for prolonged QTc without signs of pre-excitation or Brugada syndrome. Patient denied any personal or family cardiac history but endorsed frequent palpitations in the past. No electrolyte derangements were identified. Coronary angiography revealed normal origins of the coronary arteries and no evidence of obstructive disease. Transthoracic echocardiogram demonstrated normal left ventricular systolic function, normal wall thickness, and no regional wall motion abnormalities. There was mild bileaflet mitral valve prolapse with mild mitral regurgitation and mitral annular disjunction measuring 0.7 cm. Cardiac MRI was obtained and demonstrated biventricular dilation (consistent with athlete’s heart) with evidence of MAD. The myocardium was normal with no evidence of late enhancement. She underwent dual-chamber cardioverter-defibrillator implantation for secondary prevention. Discussion: Mitral annular disjunction is a structural abnormality involving atrial displacement of the mitral annulus, leading to an abnormal separation between the posterior mitral valve leaflet and basal ventricular myocardium during systole. Etiology of MAD remains unclear. It is estimated to be present in 8.7% of the general population and in over 30% of individuals with mitral valve prolapse. This case presents an example of a previously healthy patient with sudden cardiac arrest. After extensive workup, MAD was identified as the most likely trigger for her new onset arrhythmia. This case highlights the severe, and potentially fatal, arrhythmias that can arise from MAD. It is important to recognize MAD seen on echocardiograms and counsel patients on potential complications. Patients with MAD and increased risk factors should undergo further evaluation with cardiac MRI and/or electrophysiology studies.

Mitral valve prolapse—arrhythmic faces of the valve disease

Mitral valve prolapse (MVP) is a relatively common mitral valvulopathy and the most common cause of isolated primary mitral regurgitation (MR) requiring surgical repair. It affects about 1–3% of the general population. Although MVP is viewed as a benign condition, the association between MVP and sudden cardiac death (SCD) has been proven. Patients with MVP have a three times higher risk of SCD than the general population. The underlying mechanisms and predictors of arrhythmias, which occur in patients with MVP, are still poorly understood. However, some echocardiographic features such as mitral annulus disjunction (MAD), bileaflet MVP (biMVP), and papillary muscle (PM) fibrosis were frequently linked with increased number of arrhythmic events and are referred to as “arrhythmogenic” or “malignant”. Arrhythmogenic MVP (AMVP) has also been associated with other factors such as female sex, polymorphic premature ventricular contraction (PVC), abnormalities of T-waves, and Pickelhaube sign on tissue Doppler tracing of the lateral part of the mitral annulus. Cardiac magnetic resonance (CMR) imaging and speckle tracking echocardiography are new tools showing significant potential for detection of malignant features of AMVP. This paper presents various data coming from electrocardiography (ECG) analysis, echocardiography, and other imaging techniques as well as compilation of the recent studies on the subject of MVP.

Alfieri versus conventional repair for bileaflet mitral valve prolapse

ObjectiveMitral valve repair for bileaflet prolapse can be complex, involving multiple chords or resection. The Alfieri technique for bileaflet disease is simple but may be associated with mitral stenosis or recurrent mitral regurgitation. Outcomes of patients with bileaflet prolapse undergoing mitral valve repair using the Alfieri versus conventional chord/resection techniques were compared. MethodsAdults undergoing mitral valve repair for bileaflet prolapse for degenerative disease from 2017 to 2023 were stratified by repair technique. Outcomes including operative mortality and echocardiogram data were compared. Time to event analysis was used to characterize freedom from recurrent mitral regurgitation (moderate or greater mitral regurgitation). ResultsAmong 188 patients with bileaflet prolapse, 37% (70) were repaired with the Alfieri and the remaining patients were repaired with chords/resection. Compared with chords/resection, patients undergoing the Alfieri had shorter cardiopulmonary bypass and crossclamp times. Operative mortality (0% [0/70] vs 2% [2/118], P = .27) was similar between both techniques. The mean mitral gradient was low and similar for the Alfieri versus chords/resection (3 vs 3, P = .34). Development of recurrent mitral regurgitation at 2 years, incorporating the competing risk of death and mitral reintervention, was 4.3% (95% CI, 1.5%-9.3%) for the Alfieri technique and 5.8% (95% CI, 2.2%-11.8%) for chord/resection (P = .83). ConclusionsBoth the Alfieri and chord/resection techniques had low rates of recurrent mitral regurgitation at 2 years. The mitral valve gradient was low and similar regardless of technique; thus, those who received the Alfieri technique did not have an increased rate of mitral stenosis. The Alfieri may be an underused technique for bileaflet prolapse.

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

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

PE-454609-2 MARFAN SYNDROME AND VENTRICULAR ARRHYTHMIAS IN PEDIATRICS: MITRAL ANNULAR DISJUNCTION, MITRAL VALVE PROLAPSE OR BOTH – WHICH IS THE REAL CULPRIT?

Mitral Annular Disjunction (MAD) and Mitral Valve Prolapse (MVP) have been associated with sudden death and ventricular arrhythmias (VA) in adults with connective tissue disease (CTD). While rare, there has been a case report of sudden cardiac death due to VA in a pediatric Marfan patient. However, risk factors have not been well described in this population. Our aim is to assess the association of MAD and MVP with VA in pediatric patients with Marfan syndrome. A retrospective single center cohort study was conducted and included all patients (≤ 21yrs) with clinical (based on Ghent’s criteria) and/or genetic diagnosis of Marfan syndrome. Clinical data including ambulatory cardiac monitoring and echocardiograms were reviewed prior to any mitral valve intervention, if applicable. 32 patients (38% female) with Marfan syndrome (66% with fibrillin 1 mutation) were included. The mean age was 13.5 ± 4.5 yrs. The results revealed MAD in 8 pts (25%), isolated MVP in 5 pts (16%) and bileaflet MVP in 14 pts (44%). Anterior MVP was seen in 16 pts (50%) and posterior MVP in 17 pts (53%). The mean MAD distance was 6.7 ± 2.3 mm. There was normal LV systolic function in 31 pts (97%). The median duration of cardiac monitoring was 58 hrs (IQR: 33-191). 26 pts (81%) had isolated ventricular ectopy (VE), 27 pts (84%) had complex VE (defined as couplets, triplets or NSVT), 4 pts (12.5%) had NSVT and none had sustained VT. The median VE per hour was 0.2 (IQR: 0-1). There was no R on T seen but short coupled VE (<350ms) was seen in 46% of isolated, 46% of couplets and 67% of triplets. Monomorphic ectopy was seen in 28% of isolated and 100% of couplets, triplets and NSVT. There were 5 total episodes of NSVT (Figure 1) with a mean HR of 159 ± 29 bpm, an absolute minimum HR of 94 bpm and maximum HR of 222 bpm. MAD was not associated with the presence of, or complexity in, ventricular arrhythmias. Anterior MVP was only associated with complexity in VE (p= 0.043), but posterior MVP and bileaflet MVP were not. MAD was associated with MVP (anterior, posterior and bileaflet; p= 0.026). There was a high incidence of complex VE and NSVT in this cohort of pediatric Marfan patients despite low overall ectopy burden. Anterior MVP but not MAD was associated with complexity in VE. However, MAD was associated with MVP. Larger studies are needed to better characterize MAD, including distance and circumferential extent, and MVP and their association with VA in pediatric patients with CTD.

PO-04-194 PROGNOSTIC SIGNIFICANCE OF ELECTROPHYSIOLOGIC TESTING FOR VENTRICULAR ARRHYTHMIAS IN PATIENTS WITH MITRAL ANNULAR DISJUNCTION

Mitral annular disjunction (MAD), with or without mitral valve prolapse (MVP), is associated with a higher risk of ventricular arrhythmias (VA) and sudden cardiac death. The prognostic significance of VA inducibility during electrophysiological studies (EPS) in patients with MAD is unclear. To assess the prognostic significance of VA inducibility in patients with MAD undergoing EPS. We included 21 patients with MAD and no history of sustained VAs who underwent EPS for risk stratification. Patients who underwent ablation of any VA during the same procedure were excluded. EPS protocol included programmed ventricular stimulation with up to triple extrastimuli and with burst pacing from 2 ventricular sites. Post-EPS events including sustained VAs, appropriate implantable-cardioverter defibrillator (ICD) shocks, and sudden death, were assessed according to the EPS results. Mean age at the time of EPS was 46±16 years, and 15 (71.4%) patients were female. Mean MAD length was 10±4 mm. 18 (85.7%) patients had MVP (bileaflet MVP in 15 patients and posterior MVP in 3 patients). Non-sustained ventricular tachycardia (NSVT) was induced in 2 (9.5%) patients, sustained monomorphic ventricular tachycardia (VT) in 4 (19%) patients, and ventricular fibrillation (VF) in 9 (42.9%) patients, while six (28.6%) patients had no inducible VAs. 10 (47.6%) patients underwent ICD implantation due to inducible sustained VT (n=4) or VF (n=6), while 5 (23.8%) patients received an implantable loop recorder (ILR). After a median follow-up of 18.9 months, 4 (19%) patients had incident sustained VT or VF, all among patients with an ICD. These events occurred in 2 of the 4 patients with inducible VT and 2 of the 9 with inducible VF, while no events occurred in those with inducible NSVT or no inducible VAs. Inducible sustained VT or VF at EPS did not demonstrate a statistically significant association with incident sustained VAs (p=0.13). No deaths occurred in any patients in this series. More than half of patients with MAD referred for risk stratification EPS had inducible sustained VT or VF. Inducibility of VT/VF was not statistically associated with incident sustained VAs though this analysis is limited by the small sample size. Larger prospective studies are needed to clarify the role of EPS with standardized protocols in the risk stratification of patients with MAD, including investigation of the value of right and left ventricular stimulation.

SCN5A variants as genetic arrhythmias triggers for familial bileaflet mitral valve prolapse

Mitral valve prolapse (MVP) is a common valvulopathy with variable outcomes. Several studies reported MVP as an underestimated cause of life-threatening arrhythmias and sudden cardiac death (SCD), mostly in young adult women. The association of MVP with ventricular arrhythmias as a substrate of SCD has been documented in patients with MVP. Genetic variations in DCHS1, DZIP1, FLNA and PLD1 genes have been associated with MVP. The index case, a 42-year-old woman, was diagnosed with a bileaflet myxomatous MVP after a resuscitated SCD at the age of 27 years. MVP was the only abnormality found to explain the occurrence of life-threatening ventricular arrhythmia. Structural cardiac diseases and Brugada syndrome were excluded. Family screening revealed one symptomatic daughter with a history of two syncopes at 11 years old during physical effort. Her echocardiography showed a bileaflet MVP and a mildly dilated left ventricle. The MVP is complicated by moderate mitral regurgitation (MR). The oldest sister, 23 years old is currently asymptomatic. Her echocardiography revealed a prodromal MVP with a mild holosystolic MR. The father had normal echocardiography. The aim of this study was to identify the likely causative genetic etiology of the familial MVP and particularly the arrhythmias substrate linked to this phenotype. Whole exome sequencing (WES) was performed for the family. WES data were analyzed with a primary focus on genes related to MVP but also on genes implicated in valvular and aortic defects. Using family-based exome sequencing, no variants were found in known MVP genes. However, we identified two missense variants in the SCN5A gene. A rare variant SCN5A: p.Ala572Asp and the functional modifying SCN5A:p.His558Arg polymorphism. Both variants are shared between the mother and her daughter with a history of resuscitated SCD and syncopes, respectively. The second daughter with prodromal MVP as well as her healthy father carried only the SCN5A:p.His558Arg polymorphism. Our study is highly suggestive of the contribution of SCN5A mutations as a potential genetic cause of the electric instability leading to ventricular arrhythmias in familial MVP cases with syncope and/or SCD history.

Mitral Annular Substrate and Ventricular Arrhythmias in Arrhythmogenic Mitral Valve Prolapse With Mitral Annular Disjunction

BackgroundIn patients with bileaflet mitral valve prolapse (MVP), mitral annular disjunction (MAD) is associated with increased risk of sudden cardiac death via incompletely understood mechanisms. ObjectivesThis study assessed the substrate for ventricular arrhythmias in patients with bileaflet MVP and MAD as well as outcomes of catheter ablation with an emphasis on sustained, monomorphic ventricular tachycardia (VT). MethodsA total of 18 consecutive patients (11 women, mean age 54 ± 15 years) with bileaflet MVP and MAD underwent catheter ablation for VT, and/or premature ventricular complexes (PVCs). Eight patients had a prior cardiac arrest. ResultsPVCs were targeted for ablation in all 18 patients (symptomatic PVCs n = 15, PVC-induced ventricular fibrillation n = 3). Sustained monomorphic VT was targeted in 7 of 18 patients. Electroanatomic mapping showed low voltage in the area of the mitral annulus corresponding to VT target sites in 6 of 7 patients with sustained VT. Four of 7 patients had low voltage in the areas of MAD. Six of 7 patients with VT were rendered noninducible post-ablation. The PVC burden was reduced from 11.0% ± 10.4% to 4.0% ± 5.5% (P = 0.004). Over a mean follow-up of 33.9 ± 43.4 months, no VTs recurred. There were no major complications. No repeat ablations for VT occurred. Five of 18 patients required repeat ablation for PVCs. ConclusionsIn patients with bileaflet MVP and MAD undergoing catheter ablation, the mitral valve annulus often contains low-voltage areas harboring the substrate for monomorphic VT and PVCs. Ablation in these patients was safe and improved arrhythmia control.

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

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

The Importance of Mitral Valve Prolapse Doming Volume in the Assessment of Left Ventricular Stroke Volume with Cardiac MRI.

There remains a debate whether the ventricular volume within prolapsing mitral valve (MV) leaflets should be included in the left ventricular (LV) end-systolic volume, and therefore factored in LV stroke volume (SV), in cardiac magnetic resonance (CMR) assessments. This study aims to compare LV volumes during end-systolic phases, with and without the inclusion of the volume of blood on the left atrial aspect of the atrioventricular groove but still within the MV prolapsing leaflets, against the reference LV SV by four-dimensional flow (4DF). A total of 15 patients with MV prolapse (MVP) were retrospectively enrolled in this study. We compared LV SV with (LV SVMVP) and without (LV SVstandard) MVP left ventricular doming volume, using 4D flow (LV SV4DF) as the reference value. Significant differences were observed when comparing LV SVstandard and LV SVMVP (p < 0.001), and between LV SVstandard and LV SV4DF (p = 0.02). The Intraclass Correlation Coefficient (ICC) test demonstrated good repeatability between LV SVMVP and LV SV4DF (ICC = 0.86, p < 0.001) but only moderate repeatability between LV SVstandard and LV SV4DF (ICC = 0.75, p < 0.01). Calculating LV SV by including the MVP left ventricular doming volume has a higher consistency with LV SV derived from the 4DF assessment. In conclusion, LV SV short-axis cine assessment incorporating MVP dooming volume can significantly improve the precision of LV SV assessment compared to the reference 4DF method. Hence, in cases with bi-leaflet MVP, we recommend factoring in MVP dooming into the left ventricular end-systolic volume to improve the accuracy and precision of quantifying mitral regurgitation.

Mitral Annulus Disjunction, Annuloaortic Ectasia, and Pseudoaneurysm of Aortomitral Interannular Fibrosa in a 2-Year-Old Child

Genetically determined deficiency of connective tissue predisposes to the prolapsed mitral valve and an abnormal fibrous annulus including mitral annulus disjunction and dehiscence of aortomitral annular fibrosa. In a more severe phenotype, there may be abnormal aortic tissue, leading to annuloaortic ectasia. This report describes a 2-year-old male child who presented with failure to thrive and was found to have Barlow's syndrome with bileaflet mitral valve prolapse and mitral annulus disjunction, annuloaortic ectasia, and a pseudoaneurysm of interannular fibrosa. The case is reported for its interesting unifying linkage among various defects.

317 IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IN ARRHYTMIC MITRAL VALVE PROLAPSE: YOU'LL BE CONSIDER IT FOR PRIMARY PREVENTION OF SUDDEN CARDIAC DEATH?

Abstract A 50-year-old female with a history of bileaflet mitral valve prolapse (MVP) was admitted to our Department for persistent palpitation. Physical examination revealed a mid-systolic click, followed by a mid-to-late apical systolic murmur. The electrocardiogram showed sinus rhythm with negative T-waves in inferior leads and repetitive polymorphic premature ventricular contractions (PVCs) with a right bundle branch block pattern and superior axis morphology suggestive of a possible origin from the posterior papillary muscle. The echocardiography confirmed normal ventricular ejection fraction, bileaflet MVP with moderate regurgitation, systolic curling and mitral annulus disjunction. Exercise stress testing demonstrated an increase of polymorphic PVCs during maximum effort. The cardiac magnetic resonance showed an underlying late gadolinium enhancement at the level of the papillary muscles and in the inferobasal region. After a multidisciplinary evaluation, a transvenous implatable cardioverter defibrillator (ICD) was implanted for primary prevention without clear indications deriving from current guidelines. After eleven years, the patients experienced two appropriate shocks due to polymorfic ventricular tachycardia while she was sleeping. Furthermore, the patient underwent successful mechanical transvenous lead extraction and ICD re-implantation for lead failure. During this hospitalization a subsequent echocardiography detected severe ventricular dilatation with moderate systolic disfunction. Conclusion Our report demonstrated that MVP represents potentially cause of life-threatening ventricular arrhythmias and tachycardia induced cardiomyopathy. Beta-blockers are often inadequate in order to reduce PVCs burden. We need more arrhytmic predictors to assestment of sudden cardiac death risk and evaluate ICD for primary prevention. Obtain left ventricular function recovery is difficult and it requires a multidisciplinary approach. It will be important in the future to better define the role will play cathether ablation and mitral valve repair or replacement to prevent malignant arrhytmias.

SCN5A Variants as Genetic Arrhythmias Triggers for Familial Bileaflet Mitral Valve Prolapse.

Mitral valve prolapse (MVP) is a common valvular heart defect with variable outcomes. Several studies reported MVP as an underestimated cause of life-threatening arrhythmias and sudden cardiac death (SCD), mostly in young adult women. Herein, we report a clinical and genetic investigation of a family with bileaflet MVP and a history of syncopes and resuscitated sudden cardiac death. Using family based whole exome sequencing, we identified two missense variants in the SCN5A gene. A rare variant SCN5A:p.Ala572Asp and the well-known functional SCN5A:p.His558Arg polymorphism. Both variants are shared between the mother and her daughter with a history of resuscitated SCD and syncopes, respectively. The second daughter with prodromal MVP as well as her healthy father and sister carried only the SCN5A:p.His558Arg polymorphism. Our study is highly suggestive of the contribution of SCN5A mutations as the potential genetic cause of the electric instability leading to ventricular arrhythmias in familial MVP cases with syncope and/or SCD history.

Abstract 12600: Mitral Annular Disjunction: How Accurate Are We? A Cardiovascular MRI Study Defining Risk

Background: Mitral Annular Disjunction (MAD) refers to embryologic fibrous separation between mitral annular ring and basal left ventricular myocardium. Since its original description, the role of MAD in arrhythmic mitral valve prolapse (MVP) has been subject of active research. In this study we sought to assess prognostic and imaging characteristics of MVP patients with and without underlying MAD. Methods: Patients with posterior or bi-leaflet MVP were retrospectively identified via a review of all patients referred to our cardiac magnetic resonance (CMR) imaging laboratory from January 2015 to May 2022. MVP patients were further stratified by underlying MAD status. CMR characteristics including late gadolinium enhancement (LGE) distribution, clinical characteristics, and data on mitral valve intervention were determined. Results: A total of 100 MVP patients undergoing CMR imaging (52 MVP patients with posterior MAD) were retrospectively identified with female comprising 55% of the cohort. MVP patients with MAD were more likely to have an abnormal basal inferolateral/ papillary muscles LGE (51% vs 21%, p&lt;0.01). Posterior MAD longitudinal disjunction gap in ‘mm’ was a predictor of ventricular tachycardia (VT) [1.23, p=0.03)]. Similarly, posterior MAD as a binary variable was predictor of VT (11, p&lt;0.01), ventricular arrhythmia (composite of VT, and non-sustained VT) (2.4, p=0.03), and major adverse cardiac events (MACE) (composite of VT, syncope, and mitral valve intervention) (2.5, p=0.03). Using ROC curve analysis, a disjunction gap of &gt; 4 mm was predictive of VT (AUC-0.71, p&lt;0.01), and incorporation of LGE in ROC model further improved AUC to 0.78 confirmed via Akaike information criterion (p&lt;0.05), see Figure. Conclusion: Abnormal LGE involving basal inferolateral myocardium and papillary muscles may provide substrate for arrythmia in MVP patients. Further, for the first time, a MAD threshold of &gt; 4 mm is demonstrated to stratify the VT risk.

Abstract 11981: Neutrophil-To-Lymphocyte Ratio and Ventricular Arrhythmia in Mitral Valve Prolapse

Introduction: Inflammation may mediate the association of mitral valve prolapse (MVP) with ventricular scarring and arrhythmia. The purpose of this study is to investigate the association of neutrophil- and platelet-to-lymphocyte ratios (NLR, PLR) with ventricular arrhythmia in MVP. Hypothesis: We hypothesized that hematological markers of inflammation predict ventricular arrhythmia in MVP. Methods: Clinical and demographic data were extracted from electronic medical records for all patients aged 18-90 years with MVP on echocardiography between 2016-19 at our institution. We studied 65 patients who had a differential blood count within six months prior to an ambulatory ECG (A- ECG) monitor (median age [IQR] 69.6 [60.5-77.1] years; 61.5% female; 12.3% African American). Patients with surgery or infection within six months prior to CBC were excluded. PVC burden and complex ventricular ectopy (cVE) on A-ECG were compared with NLR and PLR. Logistic and bivariate regression was used to analyze clinical, ECG, and echocardiographic factors associated with NLR and PLR. Results: Factors associated with NLR were congestive heart failure (p=0.005), male sex (p=0.015), age (p=0.033), and bileaflet MVP (p=0.036). NLR was associated with absolute PVC burden (R2 0.08, p=0.023) and cVE (median [IQR] 3.1 [1.6 - 5.8]), versus without cVE (1.7 [1.6-3.1], p=0.044). An NLR of 5.6 yielded 50% sensitivity and 90% specificity for PVC burden &gt;1% (AUC 0.69). No significant association was found between PLR and PVC burden or cVE. Conclusions: NLR is associated with PVC burden and complex ventricular ectopy in MVP, suggesting that inflammation is a significant factor in the pathogenesis of ventricular arrhythmia in this condition.