A surgical experience of symptomatic sigmoid septum: drastic exacerbation of mitral regurgitation after sufficient ventricular septal myectomy

A case of syncope after exertion due to sigmoid septum evaluated by exercise stress echocardiography

A sigmoid septum is associated with sharp angulation and aging of the aortic root; however, it does not affect the pressure gradient in the left ventricular outflow tract and is generally asymptomatic. This report describes a 73-year-old woman who presented with syncope after exertion. Echocardiography revealed that the cause was left ventricular outflow tract stenosis associated with a sigmoid septum; her symptoms improved with beta-blocker therapy. Exercise stress echocardiography was performed to determine treatment efficacy. Sigmoid septum causes syncope on exertion; however, drug therapy is effective. Exercise stress echocardiography is effective in determining treatment efficacy. If syncope is present, a sigmoid septum should be considered as a cause.

Learning objectives

1.A sigmoid septum is part of or resembles hypertrophic cardiomyopathy, resulting in left ventricular outflow tract (LVOT) stenosis that is exacerbated by exertion and may cause syncope.2.A sigmoid septum is a differential diagnosis for the cause of syncope and is diagnosed using cardiac echocardiography.3.LVOT stenosis due to a sigmoid septum can be improved with drug therapy such as beta-blockers.4.The effects of beta-blocker therapy can be determined by exercise stress echocardiography.

Surgical Therapy for Patients with Severe Aortic Stenosis in the Era of Transcatheter Aortic Valve Replacement

Aortic stenosis (AS) is the most common valvular heart disease and is most frequently recognized among elderly people. Surgical aortic valve replacement (SAVR) is the most effective therapy, but its indication is sometimes difficult, and is impossible for high operative risk patients. Transcatheter aortic valve replacement (TAVR) was recently approved in Japan for high risk and inoperable patients with severe AS. TAVR is a less invasive method because it does not require a cardiopulmonary bypass and is associated with excellent surgical outcomes. In Western countries, the indication of TAVR has already been extended to moderate operative risk patients with severe AS, and is going to be further extended to low risk patients. The number of patients undergoing TAVR is increasing progressively, and there are effective alternative therapies for patients with severe AS. Selection of these surgical methods will be important in the near future. In regard to low operative risk patients especially, not only operative mortality, but also long-tern mortality and morbidity and quality of life should be taken into consideration. It is considered that some comorbidities in AS patients will be revealed to have an impact on surgical outcomes at the time when these surgical methods are selected. In this review, we examine end-stage renal disease on hemodialysis, functional tricuspid regurgitation, and sigmoid septum, and give an outline of what influence SAVR and TAVR have on the surgical outcomes of severe AS patients.

Total Clinical Course and Autopsy Findings of Left Ventricular Outflow Tract Obstruction Due to Sigmoid Septum: Histologically Proven Isolated Basal Septal Hypertrophy

We herein report the total course and autopsy findings of a woman who complained of chest discomfort and had plasma B-type natriuretic peptide 43 pg/mL and left ventricular outflow tract obstruction (with a resting pressure gradient of 181 mmHg) due to sigmoid septum at 73 years of age. Betaxolol and verapamil decreased her pressure gradient to 14 mmHg, but the pressure gradient (101 mmHg) again worsened. The betaxolol dose was increased and cibenzoline was added, resulting in a pressure gradient ≤21 mmHg. An autopsy was performed after death from a urinary tract infection at 80 years of age. The absence of any disarray of cardiac myocytes was confirmed.

The evolution of basal septal hypertrophy: From benign and age-related normal variant to potentially obstructive and symptomatic cardiomyopathy

Localized thickening of the basal portion of the ventricular septum or basal septal hypertrophy (BSH) has been identified both at autopsy and by imaging studies for decades; despite numerous investigations, there is no consensus on the significance of this finding and a remarkable lack of consistency in terminology. This paper summarizes the scientific literature on the topic, focusing on recent echocardiographic findings. A case description illustrating some of the complex issues involved in measurement and diagnosis and differentiation from sigmoidal hypertrophic cardiomyopathy (HCM) is presented. Criteria are proposed for diagnosing pathologic BSH which include the following: (1) Exertional symptoms compatible with left ventricular outflow tract obstruction (LVOTO) such as dyspnea, near-syncope, and chest discomfort; (2) Documented LVOTO gradient demonstrated at peak bicycle or post-treadmill exercise >30 mm Hg; and (3) Symptomatic improvement with β-blocker (or other negative inotropic) therapy (preferably accompanied by documentation of reduction of exercise-induced LVOT).