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To briefly review the pathophysiology and natural history of hypertrophic cardiomyopathy (HCM) and to describe the diagnosis, assessment, and contemporary management strategies. HCM-related mortality remains low; however, symptoms due in large part to LVOT obstruction remain a clinical dilemma. Several medical therapies have been shown to reduce symptoms and improve functional capacity, including several recent phase 2 clinical trials involving the novel myosin modulator mavacamten. In patients with refractory symptoms, septal reduction therapy or advanced therapies remain viable options in many cases. HCM is a complex and heterogeneous disease with diverse presentations and variable anatomy and clinical outcomes. The majority of patients will remain asymptomatic or with minimal symptoms and long-term survival remains high. For symptomatic patients, a variety of medical therapies, along with septal reduction therapies, have been shown to reduce symptoms and improve functional capacity.

A 23-year-old female of Taussig-Bing heart with antero-posterior relation of the great arteries was underwent Patrick-McGoon's intraventricular rerouting at 6 years old of age. The left ventricular outflow obstruction (peak pressure gradient of 100 mmHg) developed, and severe aortic valve regurgitation following bacterial endocarditis was noted. The conversion to Rastelli's type operation and aortic valve replacement were performed successfully at 23 years old of age. She is doing well without any significant left or right ventricular outflow obstruction at 7 years postoperatively.

To evaluate the long-term outcome of percutaneous septal ablation (PTSMA) after a previous myectomy.Myectomy usually results in symptomatic improvement and reduction of dynamic obstruction in hypertrophic obstructive cardiomyopathy patients (HOCM-pts.). However, a few pts. remain with severe symptoms and obstruction, and need additional interventions.We reviewed our database of 450 pts. who underwent PTSMA in our institution, and identified 11 (7 women, 4 men, mean age: 50 +/- 14 years) with residual or recurrent NYHA class symptomsor =III and significant left ventricular outflow obstruction (LVOTO) despite a previous myectomy 4 +/- 5 years ago. In-hospital and follow-up data covering 6 +/- 4 years, focusing on mortality and morbidity, symptoms, exercise capacity, and echocardiographic measures were collected.PTSMA was performed by injection of 3.6 +/- 2.9 ml of alcohol. There was no peri-procedural or late death in this cohort. CK peaked at 614 +/- 434 U/l. In addition to two pts. who already had a pacemaker implanted, two more (18%) who both had pre-existing left bundle branch block were pacemaker-dependent after PTSMA. During follow-up, 9 pts. (81%) reported significant and stable improvement. Two pts. (18%) developed progressive class III symptoms until their last follow-up, one of these together with persistent AF and a non-fatal stroke, the other received an ICD for primary prophylaxis and entered our pre-transplant program. Echo-Doppler showed sustained LVOTO elimination without global LV dilatation in all cases.PTSMA is an effective non-surgical option for treating symptoms and residual or recurrent LVOTO after a previous surgical myectomy. The high rate of conduction disturbances in this post-surgical cohort translated into a higher rate of pacemaker dependency after PTSMA.

Congenital supravalvular aortic stenosis (SVAS) is a rare cause of congenital left ventricular outflow obstruction and pressure overload, with a diffuse form that often extends into the aortic arch, and can be associated with stenoses in other vascular territories. Knowledge of the extent of disease involvement can be complementary to medical management or critically important prior to surgical intervention. We report a case of diffuse SVAS and demonstrate the utility of ECG-gated multidetector computed tomography (CT) as a comprehensive diagnostic tool in evaluating such patients.

Accessory mitral valve tissue is one of the rare anomalies of embryonic development of the endocardial cushion. We describe here a case of a 9 year old male who presented with dyspnoea on exertion. Transthoracic and transesophageal echocardiography revealed aneurysm of membranous part of the interventricular septum producing left ventricular outflow obstruction. Left ventriculography showed a filling defect in the area of mitral aortic interventricular fibrosa probably a localized subaortic membrane. But intraopertive findings showed an accessory mitral valve tissue attached to the annulus of anterior leaflet with its chordal attachment to the papillary muscles of normal mitral valve and to the interventricular septum. The anomalous tissue was excised with its attachment through the aortotomy and left atriotomy. We emphasize, that fixed type of left ventricular outflow tract obstruction produced by an accessory mitral tissue can mimic an aneurysm of the interventricular septum on echocardiography and surgical excision through bicameral approach is recommended.

Three patients with patent ductus arteriosus and moderate aortic stenosis had a marked reduction in aortic valve gradient following transcatheter ductal occlusion. The hemodynamic effects of an aortopulmonary shunt on the severity of left ventricular outflow obstruction and the implications on intervention are discussed.

The detection and characterization of subpulmonary obstruction by echocardiography would be useful in the preoperative evaluation of patients with transposition of the great arteries (TGA). Twenty-two unselected patients with cath proven TGA were studied by standard echocardiographic techniques utilizing a Hoffrel 101B ultrasonescope interfaced with a Cambridge fiberoptic recorder. At catheterization, 7/22 patients had evidence of significant left ventricular outflow tract (LVOT) obstruction as evidenced by the presence of a systolic pressure gradient greater than 30 mmHg or angiographic evidence for severe narrowing of the LVOT. Of these 7 patients, 6 demonstrated anterior displacement of the mitral valve ring (MVR). The remaining patient with LVOT obstruction showed a discrete posterior displacement of the anterior border of the LVOT which was responsible for narrowing of the subpulmonary area. Of the 15/22 patients with a gradient of less than 30 mmHg across the LVOT, only one had anterior displacement of the MVR which was greater than 1 cm. That patient also showed subpulmonary narrowing by angiography. These data suggest that anterior displacement of the MVR or posterior deviation of the anterior border of the LVOT indicates the presence of sub-pulmonary obstruction in TGA.

Transient hypertrophic subaortic stenosis due to interventricular septal hypertrophy is an important cause of morbidity in the infant of the diabetic mother (IDM). The purpose of this study was to quantitate left ventricular outflow obstruction through estimation of cardiac output (CO) by pulsed Doppler ultrasound. We evaluated 42 IDMs (White class B, C, D) and compared them to 2 control groups, one comparable in BW and the other similar in GA. Septal hypertrophy was found in 18/42 (43%) of the IDMs. Morbidity increased with advancing septal thickness. Hyaline membrane disease was not present in any of the patients.