Salvage Extracorporeal Membrane Oxygenation Prior to "Bridge" Transcatheter Aortic Valve Replacement.

We describe a patient who presented in profound cardiogenic shock due to bioprosthetic aortic valve stenosis requiring salvage Extracorporeal Membrane Oxygenation followed by a "bridge" valve-in-valve transcatheter aortic valve replacement. doi: 10.1111/jocs.12750 (J Card Surg 2016;31:403-405).

Septal-lateral annnular cinching perturbs basal left ventricular transmural strains.

OBJECTIVE: Septal-lateral annular cinching ('SLAC') corrects both acute and chronic ischemic mitral regurgitation in animal experiments, which has led to the development of therapeutic surgical and interventional strategies incorporating this concept (e.g., Edwards GeoForm ring, Myocor Coapsys, Ample Medical PS3). Changes in left ventricular (LV) transmural cardiac and fiber-sheet strains after SLAC, however, remain unknown. METHODS: Eight normal sheep hearts had two triads of transmural radiopaque bead columns inserted adjacent to (anterobasal) and remote from (midlateral equatorial) the mitral annulus. Under acute, open chest conditions, 4D bead coordinates were obtained using videofluoroscopy before and after SLAC. Transmural systolic strains were calculated from bead displacements relative to local circumferential, longitudinal, and radial cardiac axes. Transmural cardiac strains were transformed into fiber-sheet coordinates (X(f), X(s), X(n)) oriented along the fiber (f), sheet (s), and sheet-normal (n) axes using fiber (alpha) and sheet (beta) angle measurements. RESULTS: SLAC markedly reduced (approximately 60%) septal-lateral annular diameter at both end-diastole (ED) (2.5+/-0.3 to 1.0+/-0.3 cm, p=0.001) and end-systole (ES) (2.4+/-0.4 to 1.0+/-0.3 cm, p=0.001). In the LV wall remote from the mitral annulus, transmural systolic strains did not change. In the anterobasal region adjacent to the mitral annulus, ED wall thickness increased (p=0.01) and systolic wall thickening was less in the epicardial (0.28+/-0.12 vs 0.20+/-0.06, p=0.05) and midwall (0.36+/-0.24 vs 0.19+/-0.11, p=0.04) LV layers. This impaired wall thickening was due to decreased systolic sheet thickening (0.20+/-0.8 to 0.12+/-0.07, p=0.01) and sheet shear (-0.15+/-0.07 to -0.11+/-0.04, p=0.02) in the epicardium and sheet extension (0.21+/-0.11 to 0.10+/-0.04, p=0.03) in the midwall. Transmural systolic and remodeling strains in the lateral midwall (remote from the annulus) were unaffected. CONCLUSIONS: Although SLAC is an alluring concept to correct ischemic mitral regurgitation, these data suggest that extreme SLAC adversely effects systolic wall thickening adjacent to the mitral annulus by inhibiting systolic sheet thickening, sheet shear, and sheet extension. Such alterations in LV strains could result in unanticipated deleterious remodeling and warrant further investigation.

Comparison of aortic root diameter to left ventricular outflow diameter versus body surface area in patients with marfan syndrome.

Aortic root dilation is important in the diagnosis of familial aortic syndromes, such as Marfan syndrome, and an important risk factor for aortic complications, such as dissection or rupture. Transthoracic echocardiography reliably measures the absolute aortic root size; however, the degree of abnormality of the measurement requires correction for the expected normal aortic root size for each patient. The expected normal size is currently predicted according to the body surface area (BSA) and age. However, the correlation between root size and BSA is imperfect, particularly for older patients. A potential exists to improve the diagnosis and treatment of patients with aortic disease, with an improved estimation of normal aortic root size. A reference size derived from within the cardiovascular system has been hypothesized to provide a more direct correlation with the aortic root size. Images from the Stanford echocardiography database were reviewed, and measurements of the aortic root and internal dimensions were performed in a control cohort (n = 150). The measurements were repeated in adult patients with Marfan syndrome (n = 70) on serial echocardiograms (145 total studies reviewed). Of the 150 control patients, excellent correlation was found between the aortic root and left ventricular outflow tract diameters, r(2) = 0.67, and r(2) = 0.34 with BSA (p <0.0001, for both). More importantly, using the left ventricular outflow tract to predict the normal aortic root size, instead of the BSA and age, improved the diagnostic accuracy of aortic root measurements for diagnosing Marfan syndrome. In conclusion, an internal cardiovascular reference, the left ventricular outflow tract diameter, can improve the diagnosis of aortic disease and might provide a better reference for the degree of abnormality.

"Peninsula-style" transverse aortic arch replacement in patients with bicuspid aortic valve.

Although the optimal surgical treatment of the dilated aortic arch is controversial in patients with a bicuspid aortic valve, such exists in more than 70% of bicuspid aortic valve patients. Aortic wall histologic abnormalities are present from the aortic root to the distal arch regardless of aortic size. We describe a simple "peninsula-style" technique of transverse arch replacement used in conjunction with valve-sparing aortic root replacement for patients with a bicuspid aortic valve. This provides resection of the entire dilated thoracic aorta, preserving the arch branches in continuity with the proximal descending aorta.

Presystolic mitral annular septal-lateral shortening is independent from left atrial and left ventricular contraction during acute volume depletion.

BACKGROUND: The mitral annulus (MA) is a dynamic structure that joins the left atrium (LA) and left ventricle (LV), but it is unknown whether MA motion is coupled to the LA or the LV or neither of the two. Since a well orchestrated coordination of LA, MA and LV septal-lateral (S-L) dynamics is essential for efficient valve closure, we assessed their functional coupling in an experimental ovine model. To assess the coupling under a wide range of physiological conditions, data were acquired in normal and acutely volume depleted hearts. METHODS: In 10 sheep, radiopaque markers were placed in LA, MA and LV base (LVbase). Twelve weeks postoperatively, 4-D marker coordinates were obtained by stereo videofluoroscopy (60 frames/s) before (CTRL) and during acute inferior vena caval occlusion (VCO). Septal-lateral dimensions were calculated as distances between corresponding marker pairs in the LA, MA and LVbase 5 frames before end-diastole (ED-84 ms) and at end-diastole. Dynamics during late diastole are described as changes from ED-84 ms versus end-diastole. To study the functional coupling between LA, MA and LVbase we calculated slopes during late diastole from simple linear regressions on an animal-by-animal basis. RESULTS: During late diastole in CTRL, the LA and MA both shortened along the S-L dimension (32.9 +/- 6.6 mm vs 31.0 +/- 5.5 mm, p = 0.026 and 27.3 +/- 3.7 mm vs 24.6 +/- 4.1 mm, p = 0.005, respectively) whereas the LVbase lengthened (56.2 +/- 9.3 mm vs 57.3 +/- 9.3 mm, p = 0.012). VCO abolished septal-lateral dynamics of LA and LVbase during late diastole (27.8 +/- 4.3 mm vs 27.4 +/- 3.9 mm, p = 0.155 and 49.4 +/- 7.7 mm vs 49.5 +/- 7.5 mm, p = 0.752, respectively) while the MA still shortened (19.0 +/- 2.9 vs 18.0 +/- 2.8, p = 0.042). Under CTRL conditions LA dynamics were linearly dependent from MA dynamics (average coefficient 0.57, p = 0.001), suggesting that LA and MA are functionally coupled. With acute volume depletion, MA dynamics were linearly independent from both, LA and LV (average coefficient 0.28, p = 0.159 and 0.58, p = 0.192, respectively). CONCLUSION: Whereas MA and LA dynamics are coupled during late diastole in hearts with normal LV volumes, presystolic mitral annular septal-lateral shortening is independent from LA and LV dynamics with acute volume depletion. A better understanding of mitral annular dynamics and their functional coupling may help improve mitral valve repair strategies.

Releasable annuloplasty ring insertion--a novel experimental implantation model.

OBJECTIVE: Experimental testing of annuloplasty ring (AR) effects requires a control group if the AR is implanted conventionally. Our goal was to develop a reversible AR insertion method that allows for beating heart assessment with and without an AR, providing the ability to evaluate the effects of an AR in the same animal (internal control). We tested the feasibility of this technique in an in vivo ovine model using four-dimensional (4-D) radiopaque marker tracking. METHODS: Before the operation, a rigid AR (Edwards Geoform, Edwards Lifesciences, Irvine, CA, USA) was prepared by stitching the middle parts of eight double-armed sutures evenly spaced through the ring fabric using a Spring Eye needle. The resulting loops were 'locked' with polypropylene sutures. In addition, two drawstring sutures were attached to the AR. Using cardiopulmonary bypass and cardioplegic arrest, 12 adult sheep had 16 radiopaque markers sewn to the mitral annulus. The AR was implanted by stitching the eight sutures equidistantly in a perpendicular direction through the mitral annulus. The sheep were transferred to the catheterisation laboratory and 4-D marker coordinates were obtained using biplane videofluoroscopy (60 Hz) with the AR inserted (Geo-AR). The locking sutures were then released, the AR was pulled up to the atrial roof using the drawstring sutures and another dataset was acquired (control). Maximum and minimum mitral annular areas (MAA(max), MAA(min)) during the cardiac cycle were derived from implanted markers. Data are provided from one representative animal. RESULTS: AR insertion and release were uneventful in all animals. Whereas the mitral annulus was dynamic in the control state (MAA(max): 9.0 cm(2), MAA(min): 7.8 cm(2)), mitral annular dynamics were abolished in the Geo-AR case (MAA(max): 6.2 cm(2), MAA(min): 6.0 cm(2)). CONCLUSIONS: This novel releasable AR implantation method is feasible and permits in vivo assessment of AR effects in the same heart. The new technique should facilitate experimental AR testing and promote the development of ARs based on physical criteria.