Ventricular Obstruction Research Articles

Trans catheter edge to edge repair for mitral regurgitation and left ventricular outflow obstruction in hypertrophic cardiomyopathy

Abstract Background Based on previous reports, mitral valve transcatheter edge to edge repair (TEER) may be considered in patients with severe mitral regurgitation (MR) and left ventricular obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) that are high risk for surgery. Objective We aimed to evaluate the feasibility, and immediate and short-term outcomes of mitral TEER in symptomatic patients with severe MR and HOCM. Methods Five patients (age 75±6, 3 men) with severe MR and HOCM with high surgical risk, and anatomy not suitable for septal ethanol ablation, who remained symptomatic despite maximally tolerated drug therapy were selected for TEER using the MitrClip system. Result The procedure was performed successfully on all 5 patients. Devices were deployed at the A2-P2 scallops of the mitral valve. MR severity declined from severe to mild in all patients, left ventricular outflow (LVOT) maximal gradient decreased from 140±46 to 8±5 mmHg after TEER, and was 41±32 mmHg at 4±2 month follow- up, Clinically, all patients reported improvement of their symptoms to Class I-II NYHA functional Class. Conclusion TEER may be a beneficial procedure for severely symptomatic patients with severe MR and obstructive HOCM on maximal tolerated medical therapy, who are not amenable to surgery because of excessive risk, old age, and frailty.Pre and Post procedure EchoPre and Post Cath

Novel Frameshift Variant of the MYBPC3 Gene Associated with Hypertrophic Cardiomyopathy Significantly Decreases the Level of This Gene’s Transcript in the Myocardium

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease with a prevalence of 1 : 200–1 : 500 in the general population. The majority of HCM-linked pathogenic (or likely pathogenic) variants is located in eight genes encoding proteins of sarcomere, the main contractile unit of cardiomyocytes; one of these genes, MYBPC3, is the most commonly affected and usually associated with the more benign clinical course of the disease compared to other HCM-related genes. Here, we describe a novel frame shift variant NM_000256.3:c.2781_2782insCACA of the MYBPC3 gene that causes familial HCM in the heterozygous state. The proband had a progressive heart failure despite the surgical removal of left ventricular tract obstruction. Evaluation of levels of transcripts produced from the mutant allele and wild-type allele of the MYBPC3 gene in proband myocardial tissue and comparison of their total levels with ones in the control samples from patients without HCM showed a significant allele-specific reduction of mutant transcript levels. Our results expand the spectrum of known genetic variants with a proven role in the development of HCM.

Septal Myectomy for Isolated Midventricular Obstruction After Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy

BackgroundAlcohol septal ablation is an alternative to surgical myectomy for septal reduction in obstructive hypertrophic cardiomyopathy, particularly in high-risk surgical patients. However, alcohol septal ablation can sometimes result in residual left ventricular obstruction, typically in the subaortic area and, much more rarely, in the midventricular region. MethodsThis report presents 3 unique cases of isolated midventricular obstruction without systolic anterior motion that required surgical myectomy after alcohol septal ablation. ResultsThree patients presented with persistent or recurrent symptoms of left ventricular outflow obstruction after alcohol septal ablation. Surgical myectomy, performed through a transapical approach alone or in combination with a transaortic approach, successfully reduced intracavitary gradients and septal thickness in all 3 patients. One patient underwent cardiac transplantation 2 years after septal myectomy due to diastolic heart failure without obstruction. ConclusionsThis case series highlights concerns about the use of alcohol septal ablation for patients with long-segment subaortic obstruction and midventricular involvement, suggesting that surgical myectomy may be a more suitable treatment option for this anatomic subtype.

Safety and Effectiveness of Mavacamten Use in Hypertrophic Obstructive Cardiomyopathy: A Systematic Review and Meta-Analysis.

Hypertrophic obstructive cardiomyopathy (HOCM) is a complex genetic cardiac disease that causes left ventricular hypertrophy and obstruction of the outflow tract. Mavacamten, a novel cardiac myosin inhibitor, has emerged as a potentially beneficial therapeutic option. This meta-analysis aimed to determine whether mavacamten is effective and safe for use in patients with HOCM. A systematic literature search was performed in PubMed and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials (RCTs) that compared mavacamten to placebo in patients with HOCM. The primary objectives were changes in the gradients associated with the Valsalva maneuver and resting left ventricular outflow tract (LVOT). Alterations in the left atrial volume index (LAVI), left ventricular mass index (LVMI), and NT-proBNP level were secondary outcomes. Safety outcomes were also evaluated. Random effects models were used in the meta-analysis. Two RCTs comprising 332 patients were included. Mavacamten significantly reduced the Valsalva LVOT gradient (mean difference (MD) = -54.94 mmHg; 95% CI: -70.32, -39.56; P = 0.13) and resting LVOT gradient (MD= -42.44 mmHg; 95% CI: -67.52, -17.36; P<0.001) compared to placebo. Significant improvements were also observed in LAVI (MD = -7.18 mL/m²; 95% CI: -11.00, -3.37; P = 0.24) and NT-proBNP levels (RR = 0.58; 95% CI: 0.39, 0.84; P<0.001). LVMI showed a trend toward reduction (MD = -19.15 g/m²; 95% CI: -41.98, 3.69; P<0.001). Mavacamten demonstrated a favorable safety profile with few reported adverse events. This meta-analysis aimed to demonstrate the efficacy and short-term safety of mavacamten in patients with HOCM. Considerable improvement was observed in the LVOT gradients, cardiac remodeling measures, and indicators of cardiac stress when mavacamten was administered. Based on this data, mavacamten appears to offer the potential for a paradigm shift in the management of HOCM. However, studies conducted over an extended period are required to validate its long-term effectiveness and safety profile.

Neuronavigational assisted ventriculo-peritoneal shunt surgery in the idiopathic intracranial hypertension (IIH) patients

Object. Lumboperitoneal shunt are commonly used for idiopathic intracranial hypertension (IIH) because of the difficulty of insertion of Ventriculoperitoneal (VP) shunt into normal or small-sized ventricles. The authors showed their experience with VP shunts for IIH with the help of a Neuronavigation system. Methods. This is a retrospective study of 16 patients of IIH in whom Neuronavigation was used to guide the insertion of a shunt in the ventricle for IIH at our institution. A trial of either acetazolamide or steroid therapy had failed in all patients. Results. Shunt placement was successful and uncomplicated in each case except for one patient in which shunt failure occurred (6.25%) post-operatively. Outcomes were assessed at 12 months which were favourable regarding symptoms 13 cases (81.25%) got relief in headaches and 4 patients (25%) showed improvement in vision. Misplacement of the shunt occurred in one case postoperatively and Shunt failure occurred in 2 cases (12.50%) during the follow-up period due to ventricular end obstruction. These three patients required shunt revision. Progression of the visual deficit did not occur. Conclusion. Our results suggest that the Neuronavigation-guided ventriculoperitoneal shunt is a good alternative to Lumboperitoneal shunt in IIH patients.

Case Series of Double Chamber Right Ventricle in Ventricular Septal Defect: Should It Be Missed Out?

Double chamber right ventricle is a rare disorder caused by an abnormal muscular bundle that separates the right ventricle into high- and low-pressure chambers. In this case series, we highlighted two cases with various clinical features while having a double chamber right ventricle. The initial case involves an infant who presented with significant symptoms at the age of two. He was diagnosed with a double chamber right ventricle and an outlet ventricular septal defect. Case two is asymptomatic, with the discovery of a double chamber right ventricle at the age of nine during echo follow-up for the underlying ventricular septal defect. This case series demonstrates the importance of monitoring right ventricular obstruction in patients who have an underlying ventricular septal defect, given the tendency to overlook the presence of a double chamber right ventricle.

From dyspnea to diagnosis, unmasking undifferentiated cardiac sarcoma: a case report

BackgroundSarcomas are the most common type of cardiac malignancy, but they are extremely rare. Within this group, angiosarcomas have the highest frequency, followed by undifferentiated sarcomas. This type of tumor has a poor prognosis and a high recurrence rate. Information about these tumors is limited, relying mainly on case reports and autopsy series. The purpose of this case report is to detail the multifaceted approach to diagnosing and managing an undifferentiated cardiac sarcoma and contribute to the literature.Case presentationA 28-year-old man presented with dyspnea and chest pain, which had developed progressively over several weeks. Physical examination revealed low blood pressure, elevated heart rate, and diminished heart sounds. Imaging, including a CT scan, identified a hypodense mass in the right ventricle. Further evaluation through echocardiograms and contrast angiotomography confirmed a mass causing right ventricular obstruction. Part of the tumor was surgically removed and diagnosed as cardiac sarcoma. Histopathological analysis of the mass showed an undifferentiated cardiac sarcoma.ConclusionThis case underscores the significance of including cardiac tumors as a potential cause when diagnosing cardiac masses. It also demonstrates the poor prognosis and tendency for recurrence, while revealing the absence of established management guidelines.

Comparing clinical and echocardiographic outcomes following valve-sparing versus transannular patch repair of tetralogy of Fallot: a systematic review and meta-analysis.

Transannular patch (TAP) repair of tetralogy of Fallot (ToF)relieves right ventricular tract obstruction but may lead to pulmonary regurgitation. Valve-sparing (VS) procedures can avoid this situation, but there is a potential for residual pulmonary stenosis. Our goal was to evaluate clinical and echocardiographic outcomes of TAP and VS repair for ToF. A systematic search of the PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials and Web of Science databases was carried out to identify articles comparing conventional TAP repair and VS repair for ToF. Random-effects models were used to perform meta-analyses of the clinical and echocardiographic outcomes. Forty studies were included in this meta-analysis with data on 11723 participants (TAP: 6171; VS: 5045). Participants who underwent a VS procedure experienced a significantly lower cardiopulmonary bypass time [mean difference (MD): -14.97; 95% confidence interval (CI): -22.54, -7.41], shorter ventilation duration (MD: -15.33; 95% CI: -30.20, -0.46) and shorter lengths of both intensive care unit (ICU) (MD: -0.67; 95% CI: -1.29, -0.06) and hospital stays (MD: -2.30; 95% CI: [-4.08, -0.52). There was also a lower risk of mortality [risk ratio: 0.40; 95% CI: (0.27, 0.60) and pulmonary regurgitation [risk ratio: 0.35; 95% CI: (0.26, 0.46)] associated with the VS group. Most other clinical and echocardiographic outcomes were comparable in the 2 groups. This meta-analysis confirms the well-established increased risk of pulmonary insufficiency following TAP repair while also demonstrating that VS repairs are associated with several improved clinical outcomes. Continued research can identify the criteria for adopting a VS approach as opposed to a traditional TAP repair.

Predicting the presence of 4th ventricular outlet obstruction in Chiari I Malformation

IntroductionA subset of children with Chiari 1 malformation (CM-1) have a 4th ventricle arachnoid veil—a thin membrane covering the outlet of the 4th ventricle. Studies suggest that failure to disrupt this veil during posterior fossa decompression can reduce the likelihood of syringomyelia resolution. However, there is no reliable method for predicting the presence of the veil without direct surgical exploration. This study aims to evaluate the association between pre-operative symptoms, radiographic measurements, and the arachnoid veil.MethodsA retrospective review of an institutional database of children evaluated for CM-I was conducted. For patients treated with surgery, operative notes were reviewed to determine if an arachnoid veil was present. Logistic regression was used to test for relationship of clinical variables and radiographic measurements with the presence of an arachnoid veil.ResultsOut of 997 children with CM-1, 226 surgical patients were included in the analysis after excluding those with inadequate documentation. An arachnoid veil was found in 23 patients (10.2%). Larger syrinx, spinal canal, and thecal sac diameters were significantly associated with the presence of a veil, with odds ratios of 1.23 (95% CI 1.2–1.48; p = 0.03), 1.27 (95% CI 1.02–1.59; p = 0.03), and 1.35 (95% CI 1.03–1.77; p = 0.03), respectively. No significant associations were found with any signs or symptoms.ConclusionsArachnoid veil was present in 10% of cases. Radiographic measurements indicating larger syrinx size were the only variables found to be significantly associated with an arachnoid veil. Exploration of the 4th ventricular outlet is recommended for CM-I decompression in the setting of expansile syringomyelia.

New echocardiographic screening tool for left ventricular tract obstruction risk assessment in TMVR

BackgroundTranscatheter mitral valve replacement (TMVR) is an alternative to conventional surgery to treat severe mitral disease but its use is limited by the risk of left ventricular outflow tract obstruction (LVOTO). Screening depends on ECG-gated computed tomography (CT) that is not widely available and requires contrast. We developed and validated a transthoracic echocardiographic (TTE) method to assess the risk of LVOTO after TMVR with the Tendyne System. MethodsWe measured the LVOT longitudinal area on preoperative TTE dataset of patients screened for TMVR. The LVOT was measured as the box-area included by the aortic valve annulus, the anterior mitral leaflet (AML), the c-septum distance line, and the respective length of the AML on the interventricular septum. We analyzed the correlation between the TTE LVOT-box and the CT-measured neoLVOT area. Prediction performance for eligible patients was tested with ROC curves. ResultsThirty-nine patients were screened, out of 14 patients (36%) not eligible for TMVR, 8 had risk of LVOTO. We found a linear correlation between the TTE LVOT-box and the CT-measured Neo-LVOT (r = 0.6, p = 0.002). ROC curve showed that the method is specific and sensitive and the cut-off value of the measure LVOT-box is 350 mm2. ConclusionsThe proposed method is reliable to evaluate the risk of LVOTO after TMR with the Tendyne System. It is quick and easy and can be used as a first-line assessment in the outpatient clinic. Patients with LVOT-box <350 mm2 should not be further screened with ECG-gated cardiac CT.

Ventricular catheter tissue obstruction and shunt malfunction in 9 hydrocephalus etiologies.

Hydrocephalus is a neurological disorder with an incidence of 80-125 per 100,000 births in the United States. The most common treatment, ventricular shunting, has a failure rate of up to 85% within 10 years of placement. The authors aimed to analyze the association between ventricular catheter (VC) tissue obstructions and shunt malfunction for each hydrocephalus etiology. Patient information was collected from 5 hospitals and entered into a REDCap (Research Electronic Data Capture) database by hydrocephalus etiology. The hardware samples were fixed, and each VC tip drainage hole was classified by tissue obstruction after macroscopic analysis. Shunt malfunction data, including shunt revision rate, time to failure, and age at surgery, were correlated with the degree of tissue obstruction in VCs for each etiology. Posthemorrhagic hydrocephalus was the most common etiology (48.9% of total cases). Proximal catheter obstruction was the most frequent cause of hardware removal (90.4%). Myelomeningocele (44% ± 29%), other congenital etiologies (48% ± 40%), hydrocephalus with brain tumors (45% ± 35%), and posthemorrhagic hydrocephalus (41% ± 35%) showed tissue aggregates in more than 40% of the VC holes. A total of 76.8% of samples removed because of symptoms of obstruction showed cellular or tissue aggregates. No conclusive etiological associations were detected when correlating the percentage of holes with tissue for each VC and age at surgery, shunt revision rates, or time between shunt implantation and removal. The proximal VC obstruction was accompanied by tissue aggregates in 76.8% of cases. However, the presence of tissue in the VC did not seem to be associated with hydrocephalus etiology.

Left Ventricular Assist Device Pump Obstruction Reduces Native Heart Efficiency.

Obstruction of the LVAD flow path can occur when blood clots or tissue overgrowth form within the inflow cannula, pump body, or outflow graft, and it can lead to thrombus, embolism, and stroke. The goal of this study was to measure the impact of progressive pump inflow obstruction on the pressure and flow dynamics of the LVAD-supported heart using a mock circulatory loop. Pump obstruction (PO) was produced by progressively blocking a fraction of the LVAD inlet area. Pressures, flows, and the midplane velocity field of the LV were measured for three LVAD speeds and six PO levels. Pressure and flow decreased with PO, shifting more of the flow through the aortic valve such that the total flow decreased by 6-11% and decreased the efficiency of the work of the native heart up to 60%. PO restricts diastolic flow through the LVAD, which reduces mitral inflow and decreases the strength and energy of the intraventricular vortices. The changes in flow architecture produced by PO include flow stasis and increased shear, which predispose the system to thromboembolic risk. Analysis of the contributions to external work may enable early detection, which allows time for therapeutic intervention, reducing the likelihood of pump replacement and the risk of complications.

Founder effect of a pathogenic TNNT2 variant in the northwest of Spain responsible for a non-severe phenotype of hypertrophic cardiomyopathy

Abstract Background Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disorder, with a prevalence between 1/250-500 individuals. The yield of genetic testing for this condition stands at 40%. The most prevalent genes are MYBPC3 and MYH7, with small contributions of other genes, such as TNNT2, TNNI3, TPM1, MYL2 or FHOD3. At our center, we have identified a recurrent variant in TNNT2, p.Asn271Ile, associated with HCM. Most probands came from the northwest of Spain (Galicia), which suggested that they may share a common origin. Purpose We aimed to determine whether carriers of the p.Asn271Ile variant in TNNT2 share a common haplotype, in order to estimate the age of the mutation and describe the associated phenotype. Methods We analyzed probands who had TNNT2 sequenced by NGS at our center. Enrichment of the variant was observed in the HCM cohort. Eight highly polymorphic microsatellite markers flanking the variant in 18 Galician HCM probands were also analyzed, compromising a region of approximately 7,300 kb. Custom PCR assays were designed, and fragment length analysis was performed by capillary electrophoresis. Results TNNT2 p.Asn271Ile was identified in 49/28,802 probands (0.17%). The variant was significantly enriched in HCM probands (47/11,870; 0.39%) compared to internal non-HCM controls (2/14,804; 0.02%), with an OR=29.3 (IC95%=7.1-120.7). The analysis revealed that the 18 HCM Galician probands shared a common haplotype of 500 kb, estimating that p.Asn271Ile has arisen approximately 26.5 generations ago (650 years). Regarding genotype-phenotype correlation, our data (more than 180 carriers from 64 families) shows a relatively benign behavior, with an advance mean age at diagnosis [(49.8 (±17.7)], non-severe left ventricular hypertrophy [15.3 (±5.3)], and a lower rate of major events among carriers of p.Asn271Ile in TNNT2, compared to both other genetic variants in TNNT2 and the main genetic cause of HCM (i.e., null variants in MYBPC3) (p=0.0001 for both comparisons). The prevalence of left ventricular systolic dysfunction and left ventricular tract obstruction was also smaller than that described for other sarcomeric genes (3.54% and 12%, respectively). Conclusions A founder effect of the pathogenic variant p.Asn271Ile has been demonstrated, with the variant arising approximately 650 years ago. The clinical behavior in carriers of this cohort showed to be relatively benign compared to the behavior of other genetic variants in this gene and null variants in MYBPC3.

Analysis of conventional echocardiographic features in apical hypertrophic cardiomyopathy patients complicated with left ventricular apical aneurysm

Objective: To explore the basic characteristics of conventional echocardiography of apical hypertrophic cardiomyopathy (ApHCM) patients complicating with left ventricular apical aneurysm (LVAA). Methods: This is a retrospective study. Patients who underwent echocardiography and cardiac magnetic resonance (CMR) and were diagnosed with ApHCM complicated with LVAA by CMR at Fuwai Hospital, Chinese Academy of Medical Sciences from August 2012 to July 2017 were enrolled. According to whether LVAA was detected by echocardiography, the enrolled patients were divided into two groups: LVAA detected by echocardiography group and LVAA not detected by echocardiography group. Clinical data of the two groups were compared to analyze the causes of missed diagnosis by echocardiography. Results: A total of 21 patients were included, of whom 67.0% (14/21) were males, aged (56.1±16.5) years. Patients with chest discomfort accounted for 81.0% (17/21), palpitation 38.1% (8/21), syncope 14.3% (3/21). ECG showed that 21 (100%) patients had ST-T changes and 18 (85.7%) had deep T-wave invertion. Echocardiography revealed ApHCM in 17 cases (81.0%) and LVAA in 7 cases (33.3%). The mean left ventricular apical aneurysm diameter was 33.0 (18.0, 37.0) mm, and left ventricular ejection fraction was (66.5±6.6) %, and left ventricular apex thickness was (21.0±6.3) mm. Left ventricular outflow tract obstruction was presented in 4 cases and middle left ventricular obstruction in 10 cases. The mean left ventricular apical aneurysm diameter of LVAA detected by echocardiography was greater than that of LVAA not detected by echocardiography (25.0 (18.0, 28.0) mm vs. 16.0 (12.3, 21.0) mm, P=0.006). Conclusions: Conventional echocardiography examination has certain limitations in the diagnosis of ApHCM. Smaller LVAA complicated with ApHCM is likely to be unrecognized by echocardiography. Clinicians should improve their understanding of this disease.

Surgical Considerations in Shone Complex.

Shone complex is defined by 4 anomalies: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and coarctation of the aorta. Establishing a clear definition is one of the principal challenges in the study of Shone complex as not all patients have all lesions. The essential feature of Shone complex is multilevel left-sided obstruction involving both the left ventricular inflow and outflow. This anatomic variability is reflected in the clinical presentation as signs of left ventricular inflow obstruction are often masked by outflow obstruction and the multilevel nature of the condition is thus underappreciated. Surgical treatment is often stepwise addressing the outflow obstruction first. In this review, geared to the pediatric cardiac anesthesiologist, we review the pathophysiology, diagnosis, treatment, and outcomes of Shone complex.

Predicting endoscopic third ventriculostomy success in pediatric shunt dysfunction: a monocentric retrospective case series of 70 consecutive children, systematic review, and meta-analysis.

The outcome of endoscopic third ventriculostomy (ETV) in children who had previously received shunts and who were experiencing shunt dysfunction is still discussed in terms of efficacy (success rate from 40% to 80%) and safety (0%-32.5% of complications). Reported predictive factors of secondary ETV failure are age, early onset of hydrocephalus, and prematurity. The best surgical strategy in the different subgroups of patients with shunt dysfunction is still debated. Therefore, the authors aimed to identify subgroups of patients in whom shunt treatment was associated with favorable outcome of ETV, to define the role of ETV in patients with global rostral midbrain dysfunction syndrome. This study was a monocentric retrospective case series and a meta-analysis of children who had previously received shunts and who underwent secondary ETV for shunt dysfunction between 2012 and 2022. Clinical and MRI features were examined, along with surgical outcome, etiology of hydrocephalus, and preoperative ETV Success Score. Univariate and multivariate analyses were performed to find predictors of outcome of secondary ETV. Youden's J index was calculated on age distribution to find an optimal age cutoff. Systematic review of the literature and a meta-analysis were performed according to the PRISMA statement. Seventy consecutive patients were included. The overall success rate of secondary ETV was 63%. Primary obstructive hydrocephalus, age ≥ 36 months, and the presence of aqueductal obstruction were predictors of ETV success. Multivariate analysis found that age < 36 months, primary inflammatory hydrocephalus, and presence of fourth ventricular obstruction were associated with ETV failure. All patients with global rostral midbrain dysfunction syndrome experienced clinical and radiological improvement after ETV. The meta-analysis showed that postinflammatory etiology and age < 36 months were predictors of ETV failure. ETV is safe and effective for children with obstructive hydrocephalus experiencing shunt dysfunction, notably in cases of primary obstructive hydrocephalus with aqueductal stenosis, and among children whose age was ≥ 36 months who had postinflammatory hydrocephalus.

Mid-ventricular Obstructive Cardiomyopathy after Takotsubo Cardiomyopathy: A Case Report.

A 93-year-old woman was transferred to our hospital for lightheadedness. She had had Takotsubo cardiomyopathy for seven years. Transthoracic apical four-chamber echocardiography showed a large apical aneurysm. Pulsed-wave Doppler echocardiography at the left ventricular (LV) basal obstruction showed flow directed from the apex to the base during systole and isovolumic relaxation time. The patient was therefore diagnosed with mid-ventricular obstructive cardiomyopathy with a large apical aneurysm and paradoxical flow. The present case suggests that Takotsubo cardiomyopathy may become mid-ventricular obstructive hypertrophic cardiomyopathy without change in its structure.

Decreased left heart flow in fetal lambs causes left heart hypoplasia and pro-fibrotic tissue remodeling

Low blood flow through the fetal left heart is often conjectured as an etiology for hypoplastic left heart syndrome (HLHS). To investigate if a decrease in left heart flow results in growth failure, we generate left ventricular inflow obstruction (LVIO) in mid-gestation fetal lambs by implanting coils in their left atrium using an ultrasound-guided percutaneous technique. Significant LVIO recapitulates important clinical features of HLHS: decreased antegrade aortic valve flow, compensatory retrograde perfusion of the brain and ascending aorta (AAo) from the arterial duct, severe left heart hypoplasia, a non-apex forming LV, and a thickened endocardial layer. The hypoplastic AAo have miRNA-gene pairs annotating to cell proliferation that are inversely differentially expressed by bulk RNA-seq. Single-nucleus RNA-seq of the hypoplastic LV myocardium shows an increase in fibroblasts with a reciprocal decrease in cardiomyocyte nuclei proportions. Fibroblasts, cardiomyocytes and endothelial cells from hypoplastic myocardium have increased expression of extracellular matrix component or fibrosis genes with dysregulated fibroblast growth factor signaling. Hence, a severe sustained ( ~ 1/3 gestation) reduction in fetal left heart flow is sufficient to cause left heart hypoplasia. This is accompanied by changes in cellular composition and gene expression consistent with a pro-fibrotic environment and aberrant induction of mesenchymal programs.

P358 FATAL CONSPIRACY: MIDVENTRICULAR OBSTRUCTIVE HYPERTROPHIC CARDIOMYOPATHY COMPLICATED BY GIANT APICAL ANEURYSM AND SEVERE MITRAL REGURGITATION

Abstract This case refers to a 69–year–old woman with a history of hypertrophic cardiomyopathy (HCM) with severe mid–ventricular obstruction complicated by apical aneurysm and restrictive phenotype. This patient had no left ventricular outflow tract obstruction and previous examinations showed moderate mitral regurgitation (MR) with suboptimal echocardiographic follow–up. ICD was previously implanted for primary prevention. Disease progression was complicated by episodes of acute heart failure (HF) caused by atrial fibrillation/tachycardia (AF or AT) with rapid ventricular response despite pharmacological therapy and a transcatheter ablation attempt. The patient was admitted to our Cardiac Intensive Care Unit with acute pulmonary oedema and extreme general frailty. EKG showed normal sinus rhythm alternating with AT with high ventricular rate. Transthoracic (TTE) and transesophageal (TEE) echocardiograms gave evidence of severe hypertrophy of left ventricular (LV) mid–cavity segments (mid IVS = 26 mm) with mid–ventricular systolic obliteration (with no more evidence of significant gradient) and a large apical aneurysm (37x35 mm) resulting in an “hourglass” shaped LV cavity (Figure 1). In addition the examinations highlighted systolic dysfunction with severe stroke volume reduction and severe MR caused by annulus dilatation with anterior jet direction due to leaflets abnormal coaptation (Figure 2). HF was multifactorial, caused not only by MR and atrial tachyarrhythmias but also due to the abnormal large apical aneurysm and the small left ventricular chamber with low compliance. The anatomical features obtained from TEE and cardiac CT (Figure 3) were analyzed by the Heart Team. Surgery with aneurysmectomy and mitral valve repair or replacement was excluded due to patient‘s frailty. Despite the suboptimal valve and LV chamber anatomy, percutaneous mitral valve repair with MitraClip was considered but also deferred owing to the unstable hemodynamic conditions. Further hemodynamic deterioration led to the patient’s exitus. Discussion HCM with mid–ventricular obstruction may be complicated by apical aneurysm. Large apical aneurysms can reduce LV contractile efficiency and the combination with severe MR can cause further loss of anterograde cardiac output leading to a progressive and fatal deterioration. A better outcome can only be achieved through careful follow–up and early detection and management of disease complications.

P14 CT SCAN DERIVED PARAMETERS PREDICT LEFT VENTRICLE OBSTRUCTION AFTER TAVI

Abstract Introduction Mid Ventricular (MVO) and Left Ventricular Outflow Tract Obstruction (LVOTO) after Trans–catheter Aortic Valve Implantation (TAVI) have been previously described and are associated with adverse outcome. Pre–procedural identification of patient at risk of MVO and LVOTO after TAVI may help pre–operative risk stratification and patient selection and facilitate intra–operative management, finally improving clinical outcomes. This study aims to identify CT–scan and Echocardiographic predictors of Left Ventricular Obstruction (LVO), defined as the composite of MVO and LVOTO. Methods We retrospectively reviewed pre–operative CT scans and Trans–Thoracic Echocardiography of 349 patients treated with TAVI at our Centre between January 2019 and December 2021. Correlations between post–operative development of MVO and LVOTO and pre–operative Echocardiographic and CT scan measurements were tested. Results LVO occurred in 16.3% of patients after TAVI. At univariate analysis clinical factors associated to LVO were female gender (OR=2.2, p=0.006) and body surface area (OR=0.19, p=0.006); pre–procedural echocardiographic parameters identified were end–diastolic–diameter (OR=0.89, p&amp;lt;0.001) and left ventricular ejections fraction (OR=1.09, p&amp;lt;0.001), whereas pre–procedural CT scan measurements associated to LVO were intraventricular septum to leaflet coaptation length (SLCL; OR=0.87, p&amp;lt;0.001) and left ventricular systolic area (OR=0.9, p&amp;lt;0.001). After multivariate analysis, only left ventricular ejection fraction (OR=1.1, p&amp;lt;0.001) and the CT scan derived parameters SLCL (OR=0.9, p&amp;lt;0.001) and left ventricular area (OR=0.9; p&amp;lt;0.001) were able to predict LVO after TAVI. Conclusions Left ventricle obstruction (LVOTO + MVO) after TAVI can be predicted by CT scan derived parameters. Pre–procedural identification of patients at risk may help intraprocedural and postprocedural management, thus improving clinical outcomes.