Surgical Repair of Secondary Subaortic Stenosis in Congenital Heart Disease Without Initial Subaortic Obstruction.

BACKGROUND: Secondary subaortic stenosis (SSS) is a rare heart disease of the left ventricular outflow tract (LVOT). It usually occurs after cardiovascular correction with or without initial left ventricular outflow tract obstruction (LVOTO). Because most patients with SSS are asymptomatic, many do not realize the need for reoperation until the obstruction worsens. Few studies suggest the characteristics and reasons of SSS without initial SAS. We conducted a retrospective study to describe the characteristics and surgical outcomes of these patients. METHODS: In this study, we examined a single-center retrospective cohort of SSS patients without initial SAS undergoing resection from 2010 to 2019. Patients are defined as secondary subaortic obstruction requiring surgery after cardiovascular correction. Demographics, perioperative findings, and clinical data were analyzed. RESULTS: Twenty-three patients had undergone secondary cardiac surgery for SSS without initial SAS during 10 years in our center. The median age at operation was 7.3 (4.0-13.5) years. In this study, the most commonly associated cardiac lesions were ventricular septal defect (VSD), atrioventricular septal defect (AVSD), patent ductus arteriosus (PDA), and coarctation arch hypoplasia (COA). The surgical techniques included membranous resection of five patients, fibromuscular resection of 17 patients, and reconstruction of the intraventricular baffle of one patient. The results of surgery in these patients are satisfied. The average LVOT gradient at the last follow up was 14.9 (7.8-26.2) mmHg. There was no operative mortality. Two patients had postoperative complications. The median follow-up period was 2.9 (1.1-4.3) years with one late death. Two patients (8.7%) had recurrence of stenosis. CONCLUSIONS: Secondary subaortic stenosis is an uncommon heart disease. The reason is related to several causes, including missed diagnosis, unnoticed abnormalities of LVOT, and further changes of geometric morphology by intracardiac surgery. The results of surgery in these patients are satisfied. However, the recurrence of stenosis is still frequent.

An Unusual Case of Left Ventricular Outflow Tract Obstruction after Aortic Valve Replacement.

Surgical valve replacement improves the symptoms and prognosis of patients with valvular heart diseases. Aortic regurgitation elicits volume overload that causes enlargement of the left ventricle (LV), while the LV size often shrinks to near normal after aortic valve replacement (AVR), which is referred to as "reverse remodeling". We experienced a case in which LV outflow tract (LVOT) obstruction became apparent after AVR, resulting in worsening of heart failure. A 65-year-old man who had undergone surgical AVR for aortic valve regurgitation 15 months previously exhibited dyspnea on effort accompanied with severe LVOT obstruction. With double pressure catheters, we directly recorded an augmented pressure gradient in the LVOT and rapid relief of the obstruction by intravenous administration of the anti-arrhythmic drug cibenzoline. Since the considerable LV hypertrophy had been indicated by an electrocardiogram and echocardiography before AVR, we suspected that dilation of the LV chamber due to aortic valve regurgitation could have masked the subclinical LVOT obstruction, which became clinically evident after LV size reduction due to reverse remodeling after AVR.

Plasma metabolomic profiling of hypertrophic cardiomyopathy patients before and after surgical myectomy suggests postoperative improvement in metabolic function.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a common inherited heart disorder complicated by left ventricle outflow tract (LVOT) obstruction, which can be treated with surgical myectomy. To date, no reliable biomarkers for LVOT obstruction exist. We hypothesized that metabolomic biomarkers for LVOT obstruction may be detectable in plasma from HCM patients. METHODS: We conducted metabolomic profiling on plasma samples of 18 HCM patients before and after surgical myectomy, using a commercially available metabolomics platform. RESULTS: We found that 215 metabolites were altered in the postoperative state (p-value < 0.05). 12 of these metabolites were notably significant after adjusting for multiple comparisons (q-value < 0.05), including bilirubin, PFOS, PFOA, 3,5-dichloro-2,6-dihydroxybenzoic acid, 2-hydroxylaurate, trigonelline and 6 unidentified compounds, which support improved organ metabolic function and increased lean soft tissue mass. CONCLUSIONS: These findings suggest improved organ metabolic function after surgical relief of LVOT obstruction in HCM and further underscore the beneficial systemic effects of surgical myectomy.

External compression due to seroma of ventricular assist device outflow graft.

A 45-year-old woman with repaired complex congenital heart disease, who underwent placement of Jarvik 2000, a ventricular assist device (VAD) for 4 years, experienced abdominal pain due to outflow graft compression caused by seroma formation between the outflow graft and ringed Gore-Tex graft. We exchanged the pump of Jarvik 2000 and punched several small holes in the new ringed Gore-Tex graft. Seroma formation between the two grafts should be considered as a cause of outflow graft obstruction in patients with the long-term support of VAD, and additional surgical interventions to the ringed Gore-Tex graft may prevent this complication.

Giant Right Ventricular Outflow Tract Myxoma Mimics Pulmonary Embolism: A Case Report.

Right ventricular myxoma is very rare, especially its originating from the right ventricular outflow tract (RVOT) and extending to the main pulmonary artery. Here, we report a case of a giant RVOT myxoma, indistinguishable from pulmonary embolism (PE). Although the myxoma is a candidate for urgent surgery, this case satisfied diagnostic criteria for PE and had no indication for intervention, according to the guideline. The strategy for this mass can be completely different, depending on the diagnosis. Surgical extraction was selected because of atypical clinical course, findings, and nagging debut for neoplasm. Then it made hemodynamic status stable by releasing RVOT obstruction and allowed to reveal the diagnosis as myxoma histopathologically.

Membranous septal aneurysm causing severe right ventricular outflow obstruction in an adult with trisomy 18.

Membranous ventricular septal aneurysm is a known entity but rarely causes severe right ventricular outflow obstruction. We report a 40-year-old female with trisomy 18 who developed severe right ventricular outflow obstruction caused by an enormous membranous septal aneurysm associated with unrepaired inlet ventricular septal defect with perimembranous extension.

An unusual case of a solitary cardiac myofibroma causing severe right ventricular outflow tract obstruction in an infant.

Cardiac tumours are relatively uncommon, particularly in children. Myofibroma is an extremely rare variety of cardiac tumour, which nearly always arises in the context of infantile myofibromatosis. Herein, we present a case of a solitary cardiac myofibroma causing right ventricular outflow tract obstruction in a 2-month-old male infant.

Surgical Septal Myectomy for the Treatment of Residual Left Ventricular Outflow Tract Obstruction Following Failed Alcohol Septal Ablation.

The reasons of residual left ventricular outflow tract (LVOT) obstruction following alcohol septal ablation (ASA) remain unclear, and outcomes of myectomy following failed ASA remain underreported.Thirteen symptomatic patients (10 women, a median age of 60.0 years) who underwent septal myectomy following failed ASA were reviewed. The patients were followed up for a median of 6 months. The clinical characteristics and outcomes of these patients were analyzed and were compared with those of 178 patients who underwent isolated myectomy without previous ASA at our institution during the same period.In the first ASA procedure, the median number of septal perforator arteries injected was 1.0 with the median value of peak creatine kinase following ablation of 978.5 U/L.Uncontrollable extent and location of infarcted myocardium caused by ablation and mitral subvalvular anomalies were found in four (30.8%) and seven (53.8%) patients, respectively. No operative or follow-up deaths occurred. The median maximum LVOT gradients fell from preoperative 112.0 to 8.5 mmHg at follow-up (P < 0.001). Compared with controls, patients with failed ASA had a higher proportion of mitral subvalvular anomalies (53.8% versus 13.5%, P = 0.001) and developed a higher incidence of complete atrioventricular block following myectomy (15.4% versus 1.7%, P = 0.038).Low institutional or operator experience with ablation, uncontrollable extent and location of infarcted myocardium caused by ablation, and mitral subvalvular anomalies may be reasons for failed ASA. Surgical myectomy for the treatment of residual LVOT obstruction after unsuccessful ASA may be associated with favorable results.

Gradient variability in hypertrophic cardiomyopathy: New insights from computer-assisted, high fidelity, rest and exercise hemodynamic analysis.

OBJECTIVES: This study examines the intrapatient variability in peak instantaneous left ventricular outflow tract (LVOT) gradients and aortic pulse pressures during rest, exercise, and after ventricular ectopy. BACKGROUND: Although the variability in LVOT gradients in patients with hypertrophic cardiomyopathy (HCM) is well known, the predictors of such variation are not. We hypothesized that quantitative invasive analysis of gradient variation could identify useful predictors of maximal gradients. METHODS: Variability in continuously recorded, high-fidelity left ventricular and aortic pressure waveforms were evaluated by computer-assisted analysis in the resting state (N = 659 beats) and during supine exercise (N = 379 beats) in a symptomatic patient with a resting LVOT gradient >30 mmHg and frequent ventricular ectopy. RESULTS: At rest, the peak left ventricular and aortic pressures at the time of the peak instantaneous LVOT gradient for all sinus and postectopic beats followed consistent regression slopes characterizing the potential energy loss between the LV cavity and aorta. During exercise, similar regression slopes were identified, and these converged with the resting slopes at the point of the maximal measured LVOT gradient. Component analysis of the LVOT gradient suggests that resting beat-to-beat variability provides information similar to post-ectopic pressures for predicting maximal gradients in obstructive-variant HCM. CONCLUSIONS: Our study suggests that computer-assisted analysis of hemodynamic variability in HCM may prove useful in characterizing the severity of obstruction. Further study is warranted to confirm the reproducibility and utility of this finding in a population with clinically significant exercise-induced gradients.

Incidence and Risk Factors for Right Ventricular Outflow Tract Obstruction after the Arterial Switch Operation.

BACKGROUND: The aim of this study was to evaluate the incidence and risk factors for the development of right ventricular outflow tract obstruction (RVOTO) after the arterial switch operation (ASO). METHODS: Between 1983 and 2014, a total of 688 patients underwent ASO. RVOTO was defined as any obstruction of the right ventricular outflow tract (RVOT) requiring reintervention. RESULTS: RVOTO developed in 79 patients (11%) at a median time of 3.8 years (range, 1 day-23.6 years) after ASO. Freedom from RVOT reintervention was 96 ± 1, 89 ± 1, and 83 ± 2% at 1, 10, and 25 years, respectively. Independent risk factors for the development of RVOTO in a Cox's regression model were side-by-side great arteries (p < 0.001), aortic arch anomalies (p < 0.001), use of a pericardial patch for augmentation of the coronary buttons (p < 0.001), and a peak gradient more than 20 mm Hg over the RVOT at discharge (p < 0.001). CONCLUSION: The incidence of RVOTO after ASO is not negligible. Complex morphology, such as side-by-side great arteries and aortic arch anomalies influences the development of RVOTO.

Near Total Occlusion of Right Ventricle by Cardiac Mass.

The incidence of primary cardiac tumors is very rare (0.02%) with the majority being benign. Angiosarcoma is the most common malignant cardiac tumor. However, regardless of the histological nature of cardiac tumors, they can cause life-threatening mechanical obstruction. We present a case of urgent surgical removal of a right ventricular (RV) mass. Echocardiography was instrumental for confirmation of the diagnosis, delineation of the anatomical extent of the tumor, evaluation for associated structural involvement and assessment of repair along with constant hemodynamic monitoring.

Dec1 Deficiency Suppresses Cardiac Perivascular Fibrosis Induced by Transverse Aortic Constriction.

Cardiac fibrosis is a major cause of cardiac dysfunction in hypertrophic hearts. Differentiated embryonic chondrocyte gene 1 (Dec1), a basic helix-loop-helix transcription factor, has circadian expression in the heart; however, its role in cardiac diseases remains unknown. Therefore, using Dec1 knock-out (Dec1KO) and wild-type (WT) mice, we evaluated cardiac function and morphology at one and four weeks after transverse aortic constriction (TAC) or sham surgery. We found that Dec1KO mice retained cardiac function until four weeks after TAC. Dec1KO mice also revealed more severely hypertrophic hearts than WT mice at four weeks after TAC, whereas no significant change was observed at one week. An increase in Dec1 expression was found in myocardial and stromal cells of TAC-treated WT mice. In addition, Dec1 circadian expression was disrupted in the heart of TAC-treated WT mice. Cardiac perivascular fibrosis was suppressed in TAC-treated Dec1KO mice, with positive immunostaining of S100 calcium binding protein A4 (S100A4), alpha smooth muscle actin (αSMA), transforming growth factor beta 1 (TGFß1), phosphorylation of Smad family member 3 (pSmad3), tumor necrosis factor alpha (TNFα), and cyclin-interacting protein 1 (p21). Furthermore, Dec1 expression was increased in myocardial hypertrophy and myocardial infarction of autopsy cases. Taken together, our results indicate that Dec1 deficiency suppresses cardiac fibrosis, preserving cardiac function in hypertrophic hearts. We suggest that Dec1 could be a new therapeutic target in cardiac fibrosis.

Permanent Pacing in a Patient with Left Ventricular Mid-Cavity Obstruction and Apical Aneurysm.

Hypertrophic cardiomyopathy with left ventricular (LV) mid-cavity obstruction and LV apical aneurysm is associated with high morbidity and mortality rates. However, consensus is lacking on the treatment modality for LV mid-cavity obstruction and LV apical aneurysm. Here, we report a case of reduced LV mid-cavity pressure gradient and symptoms, treated using permanent pacing. The effect of permanent pacing on pressure gradient and symptoms lasted for 4 years. As pacing is relatively non-invasive compared to surgical therapy, permanent pacing is a good option, especially in the elderly patients with LV mid-cavity obstruction and apical aneurysm.

Associations Between Multiple Circulating Biomarkers and the Presence of Atrial Fibrillation in Hypertrophic Cardiomyopathy with or Without Left Ventricular Outflow Tract Obstruction.

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Data regarding the correlations of biomarkers and AF in HCM patients are rather limited. We sought to explore the associations between the presence of AF and circulating biomarkers reflecting cardiovascular function (N-terminal pro-brain natriuretic peptide, NT-pro BNP), endothelial function (big endothelin-1, big ET-1), inflammation (high-sensitivity C-reactive protein), and myocardial damage (cardiac troponin I, cTnI) in HCM patients with and without left ventricular outflow tract obstruction (LVOTO).In all, 375 consecutive HCM in-hospital patients were divided into an AF group (n = 90) and a sinus rhythm (SR) group (n = 285) according to their medical history and electrocardiogram results.In comparison with the SR group, peripheral concentrations of big ET-1, NT-pro BNP, and cTnI were significantly higher in patients with AF. Only the biomarker of big ET-1, together with palpitation and left atrial diameter (LAD), was independently associated with AF in HCM patients. Ln big ET-1 was positively related to Ln NT-pro BNP, LAD, and heart rate, but negatively related to left ventricular ejection fraction. Combined measurements of big ET-1 ≥ 0.285 pmol/L and LAD ≥ 44.5 mm indicated good predictive values in the presence of AF, with a specificity of 94% and a sensitivity of 85% in HCM patients.Big ET-1 has been identified as an independent determinant of AF, regardless of LVOTO, and is significantly related to parameters representing cardiac function and remodeling in HCM. Big ET-1 might be a valuable index to evaluate the clinical status of AF in HCM patients.

Ruptured Sinus of Valsalva Aneurysm with Subaortic Membrane causing Severe Left Ventricular Outflow Tract Obstruction.

ABSTRACT: Rupture sinus of Valsalva aneurysm (SVA) is an uncommonly encountered condition. It can present with wide range of manifestations from an asymptomatic murmur to cardiogenic shock. The case discussed in this report had a rare combination of ruptured SVA with subaortic membrane. Corrective cardiac surgery was advised, but due to financial constraints, the patient was not willing for surgery.

Usefulness of Cibenzoline Stress Echocardiography to Determine Severity of Aortic Stenosis in a Patient with Combined Left Ventricular Outflow Tract Obstruction and Aortic Stenosis.

Left ventricular outflow tract obstruction (LVOTO) is sometimes accompanied by aortic stenosis (AS). Reliable estimation of the true severity of AS is often difficult because it cannot be discriminated from dual stenosis. A 75-year-old woman was referred to our hospital due to traumatic hemopneumothorax with exertional dyspnea. Echocardiography revealed AS and LVOTO by chance. A continuous Doppler echocardiography revealed a late-systolic peaking dagger-shaped profile with a 6.0 m/s of peak jet velocity across the LVOT and aortic valve, but it was difficult to discriminate between the coexisting peak flows. For an accurate evaluation of AS, we performed landiolol (short acting beta-blocker) and cibenzoline (Na+ channel-blocking agent) stress echocardiography with simultaneous recordings of both left ventricular and aortic pressure by catheter examination. Cibenzoline successfully eliminated the LVOTO, but landiolol did not. Cibenzoline stress echocardiography enabled us to evaluate the AS severity as less than moderate, resulting in proper decision-making. The findings in this case clearly showed that cibenzoline stress echocardiography has a potential utility for determining AS severity in a patient with coexistent dynamic LVOTO.

Prediction of ventricular tachyarrhythmia in Brugada syndrome by right ventricular outflow tract conduction delay signs.

BACKGROUND: Brugada syndrome (BrS) is an autosomal dominant disease responsible for sudden cardiac death in young individuals without structural anomalies. The most critical part in the management of this channelopathy is identification of high-risk patients, especially asymptomatic subjects. Prior studies have shown that conduction delay in the right ventricular outflow tract (RVOT) is the main mechanism for developing ventricular tachyarrhythmia (VTA) in BrS patients. The aim of this study was to investigate the significance of electrocardiographic RVOT conduction delay parameters as predictors for development of VTA in patients with BrS. METHODS AND RESULTS: We retrospectively analyzed electrocardiograms obtained from 147 BrS patients (43 ± 15 years, 65% men) and assessed the following electrocardiographic parameters: (1) Tzou criteria (V1R > 0.15 mV, V6S > 0.15 mV, and V6S:R > 0.2), (2) prominent S wave in lead I, lead II, and lead III, (3) SII > SIII, and (4) prominent Q wave in lead III as possible predictors of VTA occurrences during follow-up. Prominent SI, SII, SIII, SII > SIII, QIII, and +ve Tzou criteria occurred more frequently in patients who either presented with VTA or developed VTA during the follow-up of 56 (IQR: 40-76) months. SII > SIII has the highest area under the curve for prediction of VTA (AUC: 0.84, sensitivity: 80%, specificity: 89%). Multivariable regression analysis showed that prominent S waves in lead I, SII > SIII and +ve Tzou criteria are independent predictors for VTA in BrS patients. CONCLUSION: Prominent S in lead I, SII > SIII and +ve Tzou criteria can be used as effective signs for predicting VTA in patients with BrS.

Percutaneous pulmonary valve implantation in grown-up congenital heart disease patients: Insights from the Zurich experience.

OBJECTIVES: The aim of the study was to assess indications, procedural success, complications, echocardiographic, and clinical outcomes of percutaneous pulmonary valve implantation (PPVI) in adult patients with congenital heart disease (CHD). BACKGROUND: PPVI offers a non-surgical treatment option for failing prosthetic conduits in pulmonary position. However, efficacy and clinical outcomes after PPVI are still underreported. METHODS: From January 2008 to March 2016, 25 adult CHD patients with right ventricular outflow tract (RVOT) stenosis and/or pulmonary regurgitation underwent PPVI in our institution. Clinical and echocardiographic data was collected at baseline, at 12 months of follow-up and yearly afterwards. RESULTS: Tetralogy of Fallot and repaired pulmonary atresia were among the most prevalent underlying congenital defects. Twenty-one (84%) received a Medtronic Melody® and four (16%) patients an Edwards Sapien valve prosthesis. The PPVI procedure was successful in all 25 patients. Pre-stenting was performed in all but two (8%) patients. PPVI reduced peak-to-peak pulmonary valve gradient from 43 (IQR 28-60) mmHg to 16 (IQR 14-22) mmHg (P < 0.001). Periprocedural complications occurred in two (8%) patients (tricuspid valve damage, pulmonary artery perforation). Over a median follow-up of 43 (IQR 18-58) months all patients were alive. Only two (8%) required re-operation and two (8%) developed stent fractures (one of them had not undergone pre-stenting). NYHA functional class improved significantly, with 20 (80%) patients in NYHA class I on follow-up. CONCLUSIONS: PPVI with Medtronic Melody or Edwards Sapien valve conduits is safe and provides effective relief from right ventricular outflow tract obstruction or pulmonary regurgitation.

Pacing for hypertrophic obstructive cardiomyopathy: an update and future directions.

In hypertrophic cardiomyopathy (HCM) patients with symptoms caused by left ventricular outflow tract obstruction (LVOTO), treatment options include negative inotropic drugs, myectomy, septal alcohol ablation and AV sequential pacing with or without an implantable cardioverter defibrillator (ICD). Pacing is rarely used in spite of its relative simplicity and promising results. In this review the current evidence of AV sequential pacing from observational, randomised studies and long and very long-term follow-up studies is given and put in the context of present guidelines recommendations. These studies indicate that AV sequential pacing improves symptoms and quality of life through decreases in LVOTO, systolic anterior movement and mitral regurgitation. Effects on morbidity and mortality are lacking. We describe the mechanisms of action, the prerequisites for successful pacing and provide practical advice on how to optimise therapy. Moreover, the role of the ICD for primary and secondary prevention is discussed with reference to the ESC HCM guidelines. In summary, AV sequential pacing for HOCM is underused in clinical practise despite evidence from two randomised controlled studies. This concept is currently the focus of two randomised studies: a planned randomised controlled study that will compare AV sequential pacing to TASH and an ongoing study that compares CRT to AAI pacing in HOCM patients. In this review we highlight the current evidence and the new interest for this therapy.

S-R difference in V1-V2 is a novel criterion for differentiating the left from right ventricular outflow tract arrhythmias.

AIM: The correct estimation of the VA origin as RVOT or LVOT results in reduced ablation duration reduced radiation exposure and decreased number of vascular access. In our study, we aimed to detect the predictive value of S-R difference in V1-V2 for differentiating the left from right ventricular outflow tract arrhythmias. METHODS: We included 123 patients with symptomatic frequent premature ventricular outflow tract contractions who underwent successful catheter ablation (70 male, 53 female; mean age 46.2 ± 13.9 years, 61 RVOT, 62 LVOT origins). S-R difference in V1-V2 was calculated with this formula on the 12-lead surface ECG: (V1S + V2S) - (V1R + V2R). Conventional ablation was performed in 101 (82.1%) patients, CARTO electroanatomic mapping system was used in 22 (17.9%) patients. RESULTS: V1-2 SRd was found to be significantly lower for LVOT origins than RVOT origins (p < .001). The cutoff value of V1-2 SRd obtained by ROC curve analysis was 1.625 mV for prediction of RVOT origin (sensitivity: 95.1%, specificity: 85.5%, positive predictive value: 86.5%, negative predictive value: 94.5%). The area under the curve (AUC) was 0.929 (p < .001). CONCLUSION: S-R difference in V1-V2 is a novel and simple electrocardiographic criterion for accurately differentiating RVOT from LVOT sites of ventricular arrhythmia origins. The use of this simple ECG measurement could improve the accuracy of OTVA localization, could be beneficial for decreasing ablation duration and radiation exposure. Further studies with larger patient population are needed to verify the results of this study.