Rheologic genesis of discrete subvalvular aortic stenosis: A Doppler echocardiographic study

Abstract

To determine whether morphologic structures or abnormal flow patterns predispose to pathologic proliferation of subvalvular tissue, 26 patients (mean age 19.8 +/- 10.3 years) were studied greater than or equal to 6 months after operation for isolated discrete subvalvular aortic stenosis. The aortic root diameter and the mitral-aortic separation were measured with sector echocardiography. Flow patterns in the left ventricular outflow tract of these patients and control subjects were evaluated with a color flow mapping system optimized for the detection of turbulence. All control subjects had laminar flow throughout systole in the left ventricular outflow tract. By contrast, turbulence originating well below the site where the shelf had previously been resected was observed in 20 (77%) of the 26 patients. In 16 of these 20 patients turbulence was caused by a ridge, which in 13 patients could be identified as the offshoot of a ventricular band. In four patients the turbulence was caused by malalignment of the muscular and membranous septum, resulting in protrusion of the muscular septum into the outflow tract. Except for the latter four patients, the aortic root diameter was 84 +/- 10% of values predicted by body surface area, with values in six patients falling below the third percentile (p less than 0.01). The mitral-aortic separation was 9.7 +/- 3.5 mm, values in 21 patients falling above the 97th percentile (p less than 0.001). These data support the theory that discrete subvalvular aortic stenosis may be caused by a chronic flow disturbance, preferably in a small and long outflow tract. Left ventricular bands, if reaching the outflow tract, may be a factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Extended septoplasty for subaortic stenosis developed 19 years after double-outlet right ventricle repair

“…Cicini et al' concluded that subaortic stenosis is an uncommon late complication of VSD closure and is an acquired condition that grows progressively severe. Gewillig et al 6 supported the theory that subaortic stenosis may be due to a chronic flow disturbance caused by a somewhat narrowed and elongated LVOT. In our case, the aortic valve was displaced anteriorly and distally.…”

Secondary subaortic stenosis in heart defects without any initial subaortic obstruction: a multifactorial postoperative event☆

“…The pathophysiological theories for the development of subaortic stenosis without a previous heart operation (turbulence theory and geometric theory) [2,4] can be extrapolated to SSS. Anatomical elements causing turbulent abnormal flow patterns in the subaortic region were present in 93% of our patients and thus may have contributed to the development of SSS through stimulation of the endothelium.…”

“…Subaortic stenosis usually occurs without a previous heart operation, but it can also occur after initial heart surgery (secondary subaortic stenosis or SSS). The pathophysiology of subaortic stenosis without a previous heart operation is now closer to being understood [2]: it is an acquired heart lesion and proposed aetiologies range from polygenic inheritance [3] and biochemical stress to abnormal flow and geometric patterns within the left ventricular vestibule [2,4]. After initial resection, the rate of recurrence requiring reoperation varies in the literature between 4% and 35% [5].…”

Subaortic Membrane; Surgical Results of Resection. A Single Centre Experience.

“…2 Turbulence of blood flow at this angel results in endocardial injury that initiates fibrosis and ultimately membrane formation. 3,4 Most of the times it is associated with a VSD, PDA, a bicuspid aortic valve, AVSD or coarctation of aorta. It usually presents in the first decade of life with features of progressive Left Ventricle obstruction and Left Ventricle hypertrophy.…”