Severe Left Ventricular Outflow Tract Research Articles

Predictors of an optimal clinical outcome with alcohol septal ablation for obstructive hypertrophic cardiomyopathy

Alcohol septal ablation has emerged as a therapy for patients with obstructive hypertrophic cardiomyopathy (HCM). However, there are limited data on the predictors of success with the procedure. We examined patient characteristics and cardiac morphology as well as procedural data on 166 HCM patients (mean age, 63 years; 43% men), who underwent ablation at Mayo Clinic. Patients were contacted to determine vital status and symptoms to assess the primary endpoint of survival free of death and severe symptoms (New York Heart Association, class III or IV dyspnea). The strongest patient characteristics that predicted clinical success were older age, less severe left ventricular outflow tract gradient, lesser ventricular septal hypertrophy, and a smaller left anterior descending (LAD) diameter. Mitral valve geometry or ventricular septal morphology did not predict outcome. Patients with ≥3 characteristics (age ≥65 years, gradient <100 mmHg, septal hypertrophy ≤18 mm, LAD diameter <4.0 mm) had superior 4-year survival free of death and severe symptoms (90.4%) in comparison to those with two characteristics (81.6%) and ≤1 characteristic (57.5%). Case volume with >50 patients was an independent predictor of survival free of severe symptoms. The volume of alcohol injected, number of arteries injected, or size of septal perforator artery were not predictive of clinical success. Greater case volume and selection for key patient and anatomic characteristics are associated with superior outcomes with alcohol septal ablation.

Modern management of systolic anterior motion of the mitral valve

Systolic anterior motion (SAM) of the mitral valve (MV) can be a life-threatening condition. The SAM can result in severe left ventricular outflow tract obstruction and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)). The mechanisms of SAM are complex and depend on the functional status of the ventricle. The SAM can occur in the normal population, but is typically observed in patients with HCM or following MV repair. Echocardiography (2D, 3D and stress) has a central diagnostic role as the application of echocardiographic SAM predictors allows the incorporation of prevention techniques during surgery and post-operative SAM assessment. Cardiac magnetic resonance imaging has a special role in understanding the dynamic nature of SAM, especially in anatomically atypical hearts (including HCM). This article describes what the clinician needs to know about SAM ranging from pathophysiological mechanisms and imaging modalities to conservative (medical) and surgical approaches and their respective outcomes. A stepwise approach is advocated consisting of medical therapy, followed by aggressive volume loading and beta-adrenoceptor blockade. Surgery is the final option. The correct choice of surgical technique requires an understanding of the anatomical substrate of SAM.

Expanding the indications for septal myectomy in patients with hypertrophic cardiomyopathy: Results of operation in patients with latent obstruction

Many patients with symptomatic hypertrophic cardiomyopathy have minimal left ventricular outflow tract gradients, and there is uncertainty whether their limitation is due to diastolic dysfunction or labile outflow tract obstruction. The purpose of this study was to characterize the clinical presentation and outcome of septal myectomy in patients with hypertrophic cardiomyopathy and latent obstruction. Among 749 patients who underwent septal myectomy, 249 had latent obstruction with minimal (0-30 mm Hg) resting gradients preoperatively. All were symptomatic and had more severe left ventricular outflow tract obstruction provoked by Valsalva maneuver or amyl nitrite inhalation during Doppler echocardiography or by stimulation with isoproterenol during catheterization. Clinical characteristics, survival, and functional outcome of these patients were compared with those of 500 patients with more severe resting left ventricular outflow tract obstruction who underwent myectomy during the same period. Compared with those with severe obstruction, more patients with latent obstruction were male (63% vs 52%, P < .003), but ages were similar (53 ± 14 years vs 52 ± 15 years). Preoperative symptoms and functional limitation were similar in the 2 groups with 86% and 85%, respectively, having New York Heart Association class III or IV disability. Among patients with latent obstruction, mixed venous oxygen saturation was 61.6% ± 19.0% of predicted compared with 56.8% ± 17.3% for those with severe resting obstruction (P < .008). Septal thickness was less in patients with latent obstruction (20 ± 9 mm vs 22 ± 15 mm, P < .001). Early mortality was 1% in each group, and survival at 5 and 10 years was 93% and 87%, respectively, for patients with latent obstruction compared with 93% and 74%, respectively, for patients with severe resting obstruction preoperatively (P = .34). Self-reported late functional status was similar; 3 to 5 years postoperatively, 81% of patients with latent obstruction preoperatively were in New York Heart Association class I or II compared with 77% of patients with severe resting obstruction. Patients with obstructive hypertrophic cardiomyopathy who have low resting gradients and latent obstruction may have limiting symptoms comparable to those of patients with more severe resting gradients. Septal myectomy should be offered to these patients because survival and symptom relief are excellent, suggesting that dynamic obstruction is the major hemodynamic problem rather than diastolic dysfunction.

Severe left ventricular outflow tract obstruction as a complication of mitral valve repair: Case report

Systolic anterior motion (SAM) is a postoperative complication of mitral valve repair, with an incidence of 5–10%. Early recognition of the signs and symptoms of SAM is essential for the management of these patients. This article focuses on the pathophysiology and dynamics of SAM and the treatment strategies described in the literature. The authors present a case study and echocardiographic images illustrating the clinical relevance of the mechanism involved, in order to clarify whether surgical reintervention is necessary.

The Use of Terlipressin for Management of Dynamic Left Ventricular Outflow Tract Obstruction Complicating Othotropic Liver Transplantation: A Case Report

We describe a patient with structurally normal heart who developed hemodynamic instability during orthotropic liver transplantation caused by severe dynamic left ventricular outflow tract obstruction. Successful management of this adverse event was facilitated by the use of intravenous terlipressin. The case highlights a role for terlipressin as a selective vasopressin receptor agonist with subsequent effects on systemic vascular resistance.

Accessory Mitral Valve Tissue Causing Severe Left Ventricular Outflow Tract Obstruction in a Post-Senning Patient with Transposition of the Great Arteries

Accessory mitral valve tissue is a rare congenital anomaly associated with congenital cardiac defects and is usually detected in the first decade of life. We describe the case of an 18-year old post-Senning asymptomatic patient who was found to have accessory mitral valve tissue on transthoracic echocardiography producing severe left ventricular outflow tract obstruction.

Postnatal Left Ventricular Outflow Tract Obstruction Caused by Multiple Rhabdomyoma Tumors

Rhabdomyoma is the most common benign cardiac neoplasm in neonates. Most patients with rhabdomyoma experienced spontaneous regression. Yet some of them need surgical therapy because of hemodynamic problems of the heart such as arrhythmia, outflow tract obstruction and valvular dysfunction. We found multiple masses in both ventricles on the patient’s fetal echocardiogram. Heart failure caused by severe left ventricular outflow tract obstruction quickly presented after birth. The mass interfering with the outflow tract was resected via the transaortic approach at the first day of birth. Postoperative echocardiography showed complete release of the outflow tract obstruction. He was discharged on the postoperative day 8. During the 3 years of follow up, we found that the sizes of the remnant masses had gradually decreased.

Six-month results of a repositionable and retrievable pericardial valve for transcatheter aortic valve replacement: The Direct Flow Medical aortic valve

Transcatheter aortic valve implantation is considered an alternative for patients at high risk for conventional surgery. The Direct Flow Medical aortic valve (Direct Flow Medical, Inc, Santa Rosa, Calif) is a nonmetallic tissue valve prosthesis intended to treat patients with severe aortic stenosis at high risk for surgery. Thirty-one patients at high surgical risk were enrolled in the trial (logistic EuroSCORE 28% ± 7%, Society of Thoracic Surgeons score 23% ± 9%). Twenty-two patients underwent successful retrograde transcatheter aortic valve implantation, and 9 patients did not undergo implantation owing to excessive calcifications or access issues. Mean preinterventional gradient and effective orifice area were 49 ± 14 mm Hg and 0.54 ± 0.16 cm(2), respectively, and 71% of patients were in New York Heart Association functional class III. Mean postprocedural gradient was 14.9 ± 5.5 mm Hg with an effective orifice area of 1.4 ± 0.31 cm(2). Two patients were converted to surgery and 2 patients died after implantation: 1 of myocardial infarction and 1 of congestive heart failure. One patient had a stroke 2 days after the procedure and 3 patients required a pacemaker. At 6 months the mean aortic valve gradient and effective orifice area were 19.8 mm Hg and 1.30 cm(2), respectively. The majority of patients had no paravalvular leak (58%) and 42% had grade 1/4 paravalvular leak; 69% were in New York Heart Association functional class I and 25% were in class II. The 3- and 6-month survivals were 87.1% and 80.6%, respectively (4/6 deaths in 31 patients). Transcatheter aortic valve implantation using the study valve appears safe and results are promising at 6 months. Severe leaflet and left ventricular outflow tract calcification affects procedural outcome; therefore, careful patient selection is crucial.

Intermediate results following complex biventricular repair of left ventricular outflow tract obstruction in neonates and infants☆

Although the majority of infants with severe left ventricular outflow tract obstruction (LVOTO) can be managed with balloon or surgical aortic valvotomy, a more complex biventricular repair may be required in a subset of infants with multi-level obstruction, failure of or complication to prior intervention. In the presence of normal left ventricle size and inflow, the Ross procedure is applied in patients with/without ventricular septal defect (VSD), while the Yasui procedure is applied only in those with VSD. We report mid-term outcomes in a single institution. Thirty-five consecutive infants with severe LVOTO underwent complex biventricular repair using the Ross (n=21) or Yasui (n=14) procedure. Outcomes were studied using univariate and multivariable parametric models. The Ross procedure was done at a median age of 88 days (8-353 days), in 8/21 (38%) neonates. As many as 12/21 (57%) had prior catheter and/or surgical intervention. Concomitant procedures included arch reconstruction (n=4/21, 19%) and mitral valve repair (n=6/21, 29%). In addition, 14/21 (67%) had annular enlargement (modified Ross-Konno). Haemodynamic manifestation was isolated obstruction (n=10/21, 48%) or mixed obstruction/regurgitation (n=11/21, 52%). Survival was 81% at 1 month, 70% at 1 year and 63% at 5 years. In multivariable regression models, factors associated with increased risk of mortality included neonatal surgery (p=0.007), mitral valve repair (p=0.02), longer cross-clamp time (p=0.003), and postoperative extracorporeal membrane oxygenator (ECMO) (p=0.004). Freedom from any cardiac re-operation was 86% at 5 years. The Yasui procedure was done at a median age of 36 days (7-207 days), 6/14 (43%) in neonates. As many as 13/14 procedures (93%) were primary and one procedure followed a prior single-stage Norwood palliation. A total of 10/14 (71%) had critical aortic stenosis and 4/14 (29%) had atresia. All patients had VSD, and 11/14 (79%) required concomitant arch reconstruction. Survival was 79% at 1 month and 5 years while 5-year freedom from re-operation was 57%. Complex biventricular repair can be performed in neonates and infants with severe LVOTO with mid-term survival that is equivalent to that published following balloon or surgical aortic valvotomy. Associated lesions are significant factors that influence outcome and proper patient selection may further improve survival. In neonates with concomitant arch obstruction and VSD, the Yasui operation may be associated with lower early mortality risk. Neonates with concomitant mitral valve pathology may be better served with single ventricle palliation strategy.

Transaortic Correction of Systolic Anterior Motion of the Mitral Leaflet After Aortic and Mitral Valve Replacement

Left ventricular outflow tract obstruction is a rare and critical complication after mitral valve replacement. We report a patient who presented with severe left ventricular outflow tract obstruction caused by systolic anterior motion of the native mitral leaflet after aortic and mitral valve replacement. The patient was successfully treated by resection of the anterior mitral leaflet through the 19-mm bioprosthetic valve in the aortic position. This approach is quite simple and effective, even through the small aortic bioprosthesis, and does not require a second mitral valve replacement.

Left Ventricular Outflow Tract Bypass Operation for Biventricular Correction in a Newborn with Severe Left Ventricular Outflow Tract Obstruction and Interrupted Aortic Arch

Left Ventricular Outflow Tract Bypass Operation for Biventricular Correction in a Newborn with Severe Left Ventricular Outflow Tract Obstruction and Interrupted Aortic Arch

Restrictive ventricular septal defect and critical subaortic stenosis in tetralogy of Fallot

Tetralogy of Fallot is characterized by a non-restrictive malalignment ventricular septal defect (VSD), an overriding aorta and right ventricular outflow tract obstruction resulting from anterior deviation of the infundibular septum. Due to the large VSD, systolic pressures are equal in both ventricles. In rare cases, redundant tricuspid valve tissue may prolapse into the VSD resulting in restriction of the defect size and causing suprasystemic pressure in the right ventricle. Subaortic obstruction by prolapse of the redundant tricuspid tissue into the left ventricular outflow tract, although theoretically possible in this situation, has not been described yet in the literature. We report on a newborn with tetralogy of Fallot presenting with cyanosis and severe arterial hypotension a few hours after birth. Echocardiography revealed redundant hammock-like accessory tricuspid valve tissue almost completely occluding the originally large VSD. Suprasystemic pressure in the right ventricle resulted in protrusion of tricuspid valve tissue across the VSD and thereby caused severe left ventricular outflow tract obstruction. Emergency pulmonary balloon valvuloplasty performed for decompression of the right ventricle, reduced prolapse of tricuspid tissue into the left ventricular outflow tract and resulted in significant improvement of pulmonary and systemic blood flow. In tetralogy of Fallot, accessory tricuspid valve tissue may obstruct the VSD as well as the left ventricular outflow tract resulting in a life threatening condition in newborns shortly after birth.

Pulmonary Atresia with Intact Ventricular Septum Causing Severe Left Ventricular Outflow Tract Obstruction

We describe an infant with pulmonary atresia with intact ventricular septum (PAIVS) and severe left ventricular outflow tract (LVOT) obstruction secondary to a suprasystemic right ventricle causing leftward displacement of the interventricular septum. Imaging demonstrated an aneurysmal dilation at the base of the proximal main pulmonary artery (MPA) with no forward flow from the right ventricle. During transannular patch and central shunt placement, the communication between the pulmonary artery and the right ventricle was enlarged to ensure adequate decompression. We report this successful palliation and resulting complete elimination of the LVOT obstruction in a very unique presentation of PAIVS in a newborn.

Acute Mitral Regurgitation due to Spontaneous Chordal Rupture in a Patient With Obstructive Hypertrophic Cardiomyopathy

A 69-year-old male presented with obstructive hypertrophic cardiomyopathy, mitral valve regurgitation, and myxomatous mitral valve prolapse. A spontaneous chordal rupture and acute severe mitral regurgitation resulted in abrupt clinical deterioration despite complete relief of severe left ventricular outflow tract obstruction and systolic anterior motion of the anterior mitral leaflet. The patient underwent extensive cardiac surgery due to intractable heart failure. Surgical procedures included a mitral valve replacement, a septal myectomy, and the Maze procedure.

Surgical Treatment of Subaortic Stenosis and Noncompaction of the Left Ventricle

Late presentation of noncompaction of the left ventricle is rare, especially in the adult congenital population. We describe successful surgical management of severe pulmonary hypertension related to severe left ventricular outflow tract narrowing in the context of noncompaction of the ventricle in a 46-year-old female.

Assessment of left ventricular size and function in neonates with critical aortic stenosis or severe left ventricular outflow tract obstruction

Assessment of left ventricular size and function in neonates with critical aortic stenosis or severe left ventricular outflow tract obstruction

The Ross Procedure in Infants and Young Children

This study reviews our experience with the Ross procedure in infants and young children. From September 1993 to September 2004, 52 children less than 15 years of age underwent a Ross procedure. The patients ranged in age from 4 days to 15 years old (median, 5 years). Fifteen patients (29%) were less than 2 years of age. The predominant indication for the Ross procedure was aortic stenosis. Sixteen patients underwent a Ross-Konno procedure for severe left ventricular outflow tract obstruction. Thirty-four patients had 48 previous interventions. Preoperatively, 6 patients showed severe left ventricular dysfunction, and 2 of the patients required ventilation and inotropic support. Concomitant procedures were performed in 8 patients. Three patients had a mitral valve replacement, 2 patients had a ventricular septal defect closure and an aortic arch reconstruction, 2 patients had aortic arch reconstructions, and 1 patient had resection of a coarctation and a ventricular septal defect closure. Patients were followed up for a median of 43 months (range, 1 to 130). Overall survival was 85% +/- 5% at 1 and 82% +/- 5% at 2, 5, and 10 years. Hospital mortality was 5 of 52 patients (9.6%). All deaths occurred in neonates or infants less than 2 months of age, who needed urgent surgery. Three patients died late of noncardiac causes. At last follow-up, all patients were classified in New York Heart Association functional class I or II. No patient had endocarditis of the autograft or the right ventricular outflow tract replacement. During the follow-up, no event of thrombembolism was observed. No patient required the insertion of a permanent pacemaker. Overall freedom from reoperation is 57% +/- 15% at 10 years. One patient required the replacement of the autograft at 6 months postoperatively. The development of mild aortic insufficiency was observed in 24 patients, and moderate aortic insufficiency in 1 patient during follow-up. Freedom from reoperation for the right ventricular outflow tract replacement is 60% +/- 15% at 10 years. The Ross procedure represents an attractive approach to aortic valve disease in young children. However, a high early mortality rate has to be considered when performing this procedure in neonates or infants who present in critical preoperative condition.

Aortic Atresia or Severe Left Ventricular Outflow Tract Obstruction with Ventricular Septal Defect: Results of Primary Biventricular Repair in Neonates

Aortic Atresia or Severe Left Ventricular Outflow Tract Obstruction with Ventricular Septal Defect: Results of Primary Biventricular Repair in Neonates

Impact of Symptom to Reperfusion Time on Left Ventricular Diastolic Properties after Primary Angioplasty for Acute Myocardial Infarction

and has been followed up for presumed hypertrophic cardiomyopathy. Results: 2D transthoracic echocardiographic images confirmed severe left ventricular outflow tract obstruction. In addition, there was a right ventricular outflow tract gradient, which appeared to be subvalvular. The origin of the obstruction could not be defined by 2D echo. A 3D echocardiogram was able to localise the right ventricular gradient tomuscle bundles in the right ventricular outflow tract, below the level of the pulmonary valve. Invasive haemodynamic testing confirmed dynamic obstructions in the right and left ventricular outflow tracts. Left ventricular and right ventricular angiograms confirmed these findings. Coronary angiography revealed normal coronary arteries. Cardiac MRI showed displacement of both ventricles into the left hemithorax with subpulmonary obstruction contributed to, both by muscle bundles and apparent compression of the right ventricle by a severe pectus abnormality. Conclusions: Multimodality imaging was required to identify the multiple causes of biventricular outflow tract obstruction in this unusual case, thus allowing the patient to proceed to definitive surgical treatment with septal myomectomy, plication of the anterior mitral valve leaflet, right ventricular outflow tractmuscle resection andpectus excavatum repair.

Apical ballooning syndrome during treatment with a vascular endothelial growth factor receptor antagonist

Apical ballooning syndrome (ABS) describes acute regional myocardial dysfunction and has a strong association with emotional stress and female sex. Whilst catecholamine excess has been described in this condition, the precise etiology remains elusive. We report the atypical case of a 61 year old male who developed ABS in the absence of a clear precipitant. His concurrent treatment with a vascular endothelial growth factor (VEGF) receptor antagonist may provide an insight into the pathogenesis of this enigmatic condition. We present a biologically plausible explanation as to why VEGF antagonism may have an important role through its modulation of nitric oxide and catecholamine effects. This hypothesis may also provide an important insight into the cardiovascular toxicities associated with this class of drug. In addition, we report the success of treatment with a beta blocker in ABS complicated by a severe left ventricular outflow tract obstruction.