Third sternotomy with modified Bentall/Konno procedure for recurrent multilevel left ventricular outflow tract obstruction in a 15-year-old.

This is a 15-year-old, 73.5 kg male who was born with congenital aortic valve stenosis. He underwent a transcatheter balloon aortic valvuloplasty in the neonatal period, followed by an open aortic valvotomy at 2 months of age. When he was 3 years old, he underwent aortic root replacement with a 15 mm aortic homograft. Recently, he presented with recurrent left ventricular outflow tract obstruction that appeared valvular and subvalvular in nature. We present our technique of repeat aortic root replacement and left ventricular outflow tract enlargement using modified Bentall combined with Konno-Rastan aortoventriculoplasty.

Left ventricular stent-graft implantation for severe left ventricular outflow tract obstruction after transcatheter mitral valve implantation.

Left ventricular outflow tract obstruction is a rare complication following transcatheter mitral valve implantation. Diagnosing the underlying cause is mandatory to select from different treatment options. We report a case of stent-graft implantation into the left ventricular outflow tract for dynamic left ventricular outflow tract obstruction caused by systolic anterior motion of the anterior mitral valve leaflet (SAM).

Exercise Testing to Unmask Latent LVOT Obstruction in a Highly Symptomatic Patient With Hypertrophic Cardiomyopathy.

Rest imaging in hypertrophic cardiomyopathy may underestimate or miss left ventricular outflow tract obstruction, leading to suboptimal management decisions that negatively affect symptomatic patients. The 2024 hypertrophic cardiomyopathy guidelines describe exercise stress testing as an important tool to determine overall exercise tolerance and latent, exercise-provoked left ventricular outflow tract obstruction.

Mitral Geometry on the Mechanism of Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy.

OBJECTIVE: The mechanism of left ventricular outflow tract obstruction (LVOTO) is complex in hypertrophic cardiomyopathy (HCM). We aimed to evaluate the impact of mitral valve geometry on LVOTO by echocardiography. MATERIALS AND METHODS: The study population comprised 177 consecutive patients with HCM. Morphological findings of left ventricular hypertrophy and LVOTO-related abnormalities were assessed by comprehensive transthoracic echocardiography. Aortomitral angle, mitral leaflet length, and coaptation height were measured and analyzed at rest. Multivariable stepwise forward logistic regression analysis was performed to identify geometric predictors of LVOTO. RESULTS: One hundred thirty-seven patients had an LVOT gradient ≥30 mm Hg. Multivariable logistic regression showed that aortomitral angle (odds ratio [OR], 0.89; 95% CI, 0.83-0.95, P < .001), coaptation height (OR, 1.96; 95% CI, 1.41-2.72, P < .001), and accessory mitral valve chordae tendineae (OR, 13.1; 95% CI, 4.32-39.95; P < .001) were independently associated with LVOTO. Receiver operating characteristic analysis showed that the area under the curve of mitral coaptation height was higher (area under the curve = 0.815) than the other 2 indicators (P < .05). CONCLUSION: Mitral coaptation height, aortomitral angle, and accessory mitral valve chordae tendineae were important predictors of SAM and LVOTO in HCM independent of septal hypertrophy.

Left ventricular outflow tract obstruction/hypertrophic cardiomyopathy/takotsubo syndrome: A new hypothesis of takotsubo syndrome pathophysiology.

The pathophysiology of TTS is still elusive. This viewpoint proposes that TTS is an acute coronary syndrome, engendered by an ASNS/catecholamine-induced LVOTO, which results in an enhanced wall stress and afterload-based supply/demand mismatch, culminating in a segmental myocardial ischemic injury state, in susceptible individuals. Such individuals are felt to be particularly women with chronic hypertension, known or latent HCM, or non-HCM segmental myocardial hypertrophy, and certain structural abnormalities involving the LV and the MV apparatus. Recommendations are provided to explore further this hypothesis, while maintaining our focus on all other advanced TTS pathophysiology hypotheses for all patients, or those who do not experience LVOTO, men, the young, and patients with reverse, mid-ventricular, or right ventricular TTS, in whom more prolonged hyperadrenergic stimulation and/or larger amounts of blood-ridden catecholamines, segmental particularities of cardiac innervation and/or density of α-, and ß-adrenergic receptors, pheochromocytoma, neurological chronic or acute comorbidities/catastrophies, coronary epicardial/microvascular vasospasm, and CMD.

Half-turned truncal switch operation for dextro-transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction and an abnormal coronary pattern.

We describe a surgical technique for a half-turned truncal switch operation in a 5-year-old child with dextro-transposition of the great arteries (D-TGA), a ventricular septal defect, a left ventricular outflow tract obstruction and a complex coronary pattern. The benefit of the half-turned truncal switch is the creation of haemodynamically superior biventricular outflow tracts and the maximal use of an autologous pulmonary valve in the right ventricular outflow tract, thereby avoiding the right ventricular-pulmonary artery conduit.

Repair of complex transposition of great arteries: What is the best technique to avoid outflow tract obstructions?

OBJECTIVES: This study aimed to evaluate the short-/mid-term outcome of patients with complex dextro (d)-/levo (l)-transposition of the great arteries (TGA), ventricular septal defect and left ventricular outflow tract obstructions. METHODS: A single-centre, retrospective review of all complex dextro-TGA (n = 85) and levo-TGA (n = 22) patients undergoing different surgeries [Arterial switch operation + left ventricular outflow tract obstruction-resection (ASO-R), half-turned truncal switch/Mair (HTTS), Nikaidoh and Rastelli] between May 1990 and September 2022 was performed. Groups were analysed using Kruskal-Wallis test with post hoc pairwise comparison and Kaplan-Meier time-to-event models. RESULTS: A total of 107 patients [ASO-R (n = 20), HTTS (n = 23), Nikaidoh (n = 21), Rastelli (n = 43)] were included, with a median age of 1.0 year (0.5-2.5) and surgical repair median follow-up was 3.8 years (0.3-10.5). Groups did not differ in respect to early postoperative complications/early mortality. Five-year overall survival curves were comparable: ASO-R 78.9% (53.2-91.5), HTTS 75.3% (46.8-89.9), Nikaidoh 85% (60.4-94.9) and Rastelli 83.9% (67.5-92.5), P = 0.9. Highest rates of right ventricular outflow tract (RVOT) reinterventions [33.3% and 32.6% (P = 0.04)] and reoperations [28.6% and 32.6% (P = 0.02)] occurred after Nikaidoh and Rastelli procedures. However, overall freedom from RVOT reinterventions and RVOT reoperations at 5 years did not differ statistically significantly between the groups (ASO-R, HTTS, Nikaidoh and Rastelli): 94.4% (66.6-99.2), 69.1% (25.4-90.5), 67.8% (34-86.9), 64.4% (44.6-78.7), P = 0.2, and 90.0% (65.6-97.4), 91% (50.8-98.7), 65.3% (32.0-85.3) and 67.0% (47.4-80.6), P = 0.3. CONCLUSIONS: Surgical repair of complex dextro-/levo-TGA can be performed with satisfying early/mid-term survival. RVOT reinterventions/reoperations were frequent, with highest rates after Nikaidoh and Rastelli procedures. Left ventricular outflow tract obstruction reoperations were rare with zero events after Nikaidoh and HTTS procedures.

Alternância entre bloqueio focal do ventrículo esquerdo e bloqueio de ramo mascarado durante cintilografia com estresse farmacológico: relato de caso / Alternation between focal left ventricular block and masked bundle branch block during pharmacological stress scintigraphy: case report

INTRODUÇÃO: O bloqueio de ramo mascarado é caracterizado no eletrocardiograma por um bloqueio de ramo direito (BRD) evidente no plano horizontal, associado ao bloqueio divisional anterossuperior (BDAS) e ondas S mínimas ou ausentes na derivação DI, o que dá ao plano frontal um padrão semelhante ao bloqueio de ramo esquerdo (BRE) com eixo de QRS desviado para esquerda. Por outro lado, o eletrocardiograma no bloqueio focal ou periférico do ventrículo esquerdo (VE) evidencia um QRS com retardo final e duração ≥ 120 ms, porém sem critérios de BRE ou BRD. RELATO DE CASO: Paciente masculino, 76 anos, com histórico de hipertensão, diabetes mellitus do tipo 2, dislipidemia, ex-tabagista, portador de insuficiência cardíaca com fração de ejeção reduzida realizou cateterismo cardíaco em dezembro de 2023, por doença arterial coronariana (DAC) estável, relevando: oclusão no terço médio da coronária direita, recebendo circulação colateral, 2º ramo diagonal com lesão de 80% no terço proximal e 1º ramo marginal com lesão de 70% no óstio de seu sub-ramo inferior, além de diversas lesões <50%. Devido a doença difusa e vasos de fino calibre foi optado por otimização do tratamento clínico. Paciente interna após 2 meses por dor torácica sendo solicitado cintilografia miocárdica com prova farmacológica (dipiridamol). O paciente apresentava o seguinte eletrocardiograma em repouso: Ritmo sinusal, bloqueio focal do VE + BDAS, presença de onda R alta em V2 - sugestivo de área inativa lateral. (Figura 1) Durante infusão de dipiridamol, paciente apresentou alteração do eletrocardiograma evoluindo para padrão de bloqueio de ramo mascado. (figura 2) E retornando ao seu eletrocardiograma de base após o término da infusão. A cintilografia evidenciou queda da fração de ejeção de 27% basal para 21% no estresse, ausência de sinais de isquemia do miocárdio e hipocaptação persiste de grande extensão nas paredes inferior, inferosseptal e inferolateral do ventrículo esquerdo. CONCLUSÃO: O bloqueio focal do VE e o bloqueio mascarado estão relacionados a fibrose ou disfunção miocárdica. A presença desses bloqueios se traduz em prognóstico desfavorável, estando associada a um maior risco de morte por doença cardiovascular e a um aumento substancial do risco de arritmias. Nesse caso podemos caracterizar um paciente com DAC estabelecida e grande área de fibrose, e a alteração no eletrocardiograma encontrada reforça a gravidade do quadro e implica pior prognóstico clínico.

Transcatheter Myotomy to Reduce Left Ventricular Outflow Obstruction.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction is a source of morbidity in hypertrophic cardiomyopathy (HCM) and a life-threatening complication of transcatheter mitral valve replacement (TMVR) and transcatheter aortic valve replacement (TAVR). Available surgical and transcatheter approaches are limited by high surgical risk, unsuitable septal perforators, and heart block requiring permanent pacemakers. OBJECTIVES: The authors report the initial experience of a novel transcatheter electrosurgical procedure developed to mimic surgical myotomy. METHODS: We used septal scoring along midline endocardium (SESAME) to treat patients, on a compassionate basis, with symptomatic LVOT obstruction or to create space to facilitate TMVR or TAVR. RESULTS: In this single-center retrospective study between 2021 and 2023, 76 patients underwent SESAME. In total, 11 (14%) had classic HCM, and the remainder underwent SESAME to facilitate TMVR or TAVR. All had technically successful SESAME myocardial laceration. Measures to predict post-TMVR LVOT significantly improved (neo-LVOT 42 mm2 [Q1-Q3: 7-117 mm2] to 170 mm2 [Q1-Q3: 95-265 mm2]; P < 0.001; skirt-neo-LVOT 169 mm2 [Q1-Q3: 153-193 mm2] to 214 mm2 [Q1-Q3: 180-262 mm2]; P < 0.001). Among patients with HCM, SESAME significantly decreased invasive LVOT gradients (resting: 54 mm Hg [Q1-Q3: 40-70 mm Hg] to 29 mm Hg [Q1-Q3: 12-36 mm Hg]; P = 0.023; provoked 146 mm Hg [Q1-Q3: 100-180 mm Hg] to 85 mm Hg [Q1-Q3: 40-120 mm Hg]; P = 0.076). A total of 74 (97.4%) survived the procedure. Five experienced 3 of 76 (3.9%) iatrogenic ventricular septal defects that did not require repair and 3 of 76 (3.9%) ventricular free wall perforations. Neither occurred in patients treated for HCM. Permanent pacemakers were required in 4 of 76 (5.3%), including 2 after concomitant TAVR. Lacerations were stable and did not propagate after SESAME (remaining septum: 5.9 ± 3.3 mm to 6.1 ± 3.2 mm; P = 0.8). CONCLUSIONS: With further experience, SESAME may benefit patients requiring septal reduction therapy for obstructive hypertrophic cardiomyopathy as well as those with LVOT obstruction after heart valve replacement, and/or can help facilitate transcatheter valve implantation.

Simultaneous surgical repair of a cardiac myxoma causing left ventricular outflow tract obstruction and a ventricular septal defect in a small dog.

Background: Cardiac myxomas are benign tumours that can occur in any heart chamber or valve. They are extremely rare in dogs. We present a novel case involving a cardiac myxoma in the left ventricular outflow tract (LVOT) and a ventricular septal defect (VSD) in a small dog. Case Description: A female miniature dachshund (age, 7 months; weight, 2.88 kg) presented with growth insufficiency, lethargy, and a cardiac murmur. Echocardiography revealed a small polypoid mass in the LVOT and a membranous VSD. Simultaneous surgeries were performed to resect the mass (aortotomy) and close the VSD (right atriotomy) using low-flow cardiopulmonary bypass with surface-cooling hypothermia and retrograde cardioplegia. The tumour was histopathologically identified as a myxoma. The dog survived with no cardiac complications for 11 years after surgery. Conclusion: To our knowledge, this is the first report of ante-mortem diagnosis and simultaneous surgical repair of a cardiac myxoma obstructing the LVOT and a VSD in a small-breed dog. In addition to describing this complicated case, this report presents what we believe is the first reported use of retrograde cardioplegia during open-heart surgery in a small-breed dog.

Combined transaortic/transapical left ventricular septal myectomy for subaortic and midventricular obstruction in a paediatric patient.

The patient is a 15-year-old girl who was diagnosed with hypertrophic cardiomyopathy and has been symptomatic due to severe left ventricular outflow tract obstruction. Combined transaortic and transapical left ventricular septal myectomy was performed to relieve the left ventricular outflow tract obstruction and address both subaortic and midventricular gradients.

[Left Ventricular Outflow Tract Obstruction After Transcatheter Aortic Valve Replacement due to Pannus Formation].

We experienced a case of surgical aortic valve re-replacement due to structural valve deterioration caused by pannus formation 4 years after transcatheter aortic valve replacement( TAVR). The patient underwent surgery because the mean transvalvular pressure gradient increased to 48 mmHg on echocardiography. Contrast-enhanced computed tomography (CT) was useful for predicting the site of adhesion to surrounding tissue preoperatively and exploring the presence of the pannus. Intraoperative findings showed the TAVR valve was covered with neointima except around the origins of the left and right coronary arteries and was firmly adhered to the surrounding tissues. As residual pannus was present in the subvalvular tissues, it was carefully removed. The explanted TAVR valve functioned well with good opening and closure. The postoperative course was uneventful. Pannus formation can result from mechanical stress. TAVR valves put significantly greater stress on the left ventricular outflow tract than surgical valves and may be more likely to cause pannus formation.

Left Ventricular Outflow Tract Obstruction in Congenital Heart Disease: The Role of Cardiovascular Computed Tomography in Surgical Decision Making.

Patients with many forms of congenital heart disease (CHD) and hypertrophic cardiomyopathy undergo surgical intervention to relieve left ventricular outflow tract obstruction (LVOTO). Cardiovascular Computed Tomography (CCT) defines the complex pathway from the ventricle to the outflow tract and can be visualized in 2D, 3D, and 4D (3D in motion) to help define the mechanism and physiologic significance of obstruction. Advanced cardiac visualization may aid in surgical planning to relieve obstruction in the left ventricular outflow tract, aortic or neo-aortic valve and the supravalvular space. CCT scanner technology has advanced to achieve submillimeter, isotropic spatial resolution, temporal resolution as low as 66 msec allowing high-resolution imaging even at the fast heart rates and small cardiac structures of pediatric patients ECG gating techniques allow radiation exposure to be targeted to a minimal portion of the cardiac cycle for anatomic imaging, and pulse modulation allows cine imaging with a fraction of radiation given during most of the cardiac cycle, thus reducing radiation dose. Scanning is performed in a single heartbeat or breath hold, minimizing the need for anesthesia or sedation, for which CHD patents are highest risk for an adverse event. Examples of visualization of complex left ventricular outflow tract obstruction in the subaortic, valvar and supravalvular space will be highlighted, illustrating the novel applications of CCT in this patient subset.

Results of a hybrid approach for high risk term newborn patients with interrupted aortic arch (IAA) with left ventricular outflow tract obstruction.

This study aims to share the results of critically ill newborn cases with interrupted aortic arch (IAA) and Left ventricular outflow tract (LVOT) obstruction (LVOTO) who underwent the hybrid approach, which consists of bilateral pulmonary artery banding and/or patent ductus arteriosus stenting, as first-line treatment. This retrospective study includes the results of high-risk term newborns whom we applied a hybrid approach due to IAA and LVOTO in our clinic between January 1, 2021 and December 31, 2021. The demographic characteristics, hybrid approach methods and results of the cases were evaluated. Nine cases underwent hybrid approach during the study period. The mean age and weight at interventions were 7 days (3-16 days) and 3280 g (2700-4300 g). Six of the patients were diagnosed with type B IAA, 2 with type A, and one with type C. LVOTO was present in 7 patients. The success rate for the procedures was 100%. No patients died during the procedure or within the first 5 days after the procedure or from reasons related to the procedure. The median length of the hospital stay after stent placement was 28 days (22-35 days) for discharged patients. Three patients died in interstage period, and 6 patients underwent total corrective surgery after a median of 7 months (4-10 months). The average LVOT diameter was increased from 3.1 mm to 4.8 mm before total repair surgery. The hybrid approach should be kept in mind for treating high risk newborns with IAA with LVOTO and high-risk newborns who are not suitable for single stage total corrective surgery.