Inverse Relationship Between Membranous Septal Length and the Risk of Atrioventricular Block in Patients Undergoing Transcatheter Aortic Valve Implantation

Abstract

Short MS, insufficient difference between MS length and implantation depth, and the presence of calcification in the basal septum, factors that may all facilitate mechanical compression of the conduction tissue by the implanted valve, predict conduction abnormalities after TAVI with self-expandable valves. CT assessment of membranous septal anatomy provides unique pre-procedural information about the patient-specific propensity for the risk of AV block.

Anatomical risk models for paravalvular leak and landing zone complications for balloon‐expandable transcatheter aortic valve replacement

“…A shorter membranous septum length increases the risk of conduction disturbances post‐TAVR because the conduction system emerges below the membranous septum. Hamdan et al have previously reported this finding in patients undergoing self‐expandable TAVR . This is the first study to show such an association in patients that underwent TAVR with a balloon‐expandable THV.…”

“…Midsystolic images were used to measure (Fig. ) aortic annulus angulation and membranous septum length from coronal views ; shortest and longest diameter, area, and perimeter at the sinotubular junction (STJ), annulus, and LVOT (4 mm below de annulus); area of each valve leaflet measured at the sinus of valsalva level (NC, noncoronary; LC, left coronary; RC, right coronary leaflet); and distance from the annulus to left (LCA) and right coronary artery (RCA). Calcification was quantitatively measured as described by Khalique et al using the cutoff of 550 Hounsfield units (HU), which was increased or decreased in those patients with MDCTs with high or low luminal attenuation, respectively.…”

Relationship between the membranous septum and the virtual basal ring of the aortic root in candidates for transcatheter implantation of the aortic valve

“…The so-called height of the membranous septum has been proposed as a potential independent predictor for periprocedural disturbances in conduction (Hamdan et al 2015;Maeno et al 2017). This hypothesis is almost certainly valid, since the shorter the membranous septum, the greater is the likelihood that the atrioventricular conduction axis will be at risk of damage during the procedures (Massing and James, 1976;Anderson et al 2000;Kawashima and Sato, 2014;Stephenson et al 2017).…”

Permanent pacemaker insertion in patients with conduction abnormalities post transcatheter aortic valve replacement: a review and proposed guidelines

“…An implantation depth of less than 6 mm and newer designs that allow implantation higher in the LVOT also show a lower trend in conduction abnormalities and PPM implants (6,8,29). A short membranous septum is believed to be an additional risk for heart block, and this risk can be determined by a pre-TAVR implant risk stratification (36).…”