In Vivo Dynamic Strains of the Mitral Valve Annulus

2007 ◽  
Author(s):  
Brett Zubiate ◽  
Michael Sacks ◽  
Robert C. Gorman ◽  
Joseph H. Gorman
Keyword(s):  
Mitral Valve ◽  
Cardiac Cycle ◽  
Dimensional Space ◽  
Complex Structure ◽  
Three Dimensional ◽  
Mitral Annulus ◽  
Mitral Valve Leaflet ◽  
Valve Function ◽  
Integrated Operation

The mitral valve apparatus is a complex structure with multiple components that require seamless, integrated operation for normal valve function. One of these components is the annulus, a fibrous ring of tissue that defines the boundary between the mitral valve leaflets and the surrounding superstructure of the heart. During the cardiac cycle the annulus undergoes large deformations and dramatic shape changes. Moreover, the annulus motion represents a key boundary condition for mitral valve leaflet deformation. Yet, to date our knowledge of the subtle deformations this structure undergoes during the cardiac cycle remains very limited. In the present study, an array of 1 mm diameter piezoelectric sonocrystals was implanted in 5 sheep to quantify annular deformation over the complete cardiac cycle. These crystals act as fiducial markers for the mitral annulus with a temporal resolution of ∼1ms and a special resolution of .01mm in a calibrated three dimensional space. A quintic order generalized 3D spline was developed to reconstruct the annular geometry.

scholarly journals Acute Effect of Mitral Valve Repair on Mitral Valve Geometry

2018 ◽  
Vol 67 (07) ◽  
pp. 516-523 ◽  
Author(s):  
Thilo Noack ◽  
Kathleen Wittgen ◽  
Philipp Kiefer ◽  
Fabian Emrich ◽  
Matthias Raschpichler ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Cardiac Cycle ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Mitral Annulus ◽  
Acute Effect ◽  
Dynamic Changes ◽  
4D Imaging ◽  
Ring Annuloplasty ◽  
Before And After

Background The aim of this study was to quantify acute mitral valve (MV) geometry dynamic changes throughout the cardiac cycle using three-dimensional transesophageal echocardiography (3D TEE) in patients undergoing surgical MV repair (MVR) with ring annuloplasty and optional neochord implantation. Methods Twenty-nine patients (63 ± 10 years) with severe primary mitral regurgitation underwent surgical MVR using ring annuloplasty with or without neochord implantation. We recorded 3D TEE data throughout the cardiac cycle before and after MVR. Dynamic changes (4D) in the MV annulus geometry and anatomical MV orifice area (AMVOA) were measured using a novel semiautomated software (Auto Valve, Siemens Healthcare). Results MVR significantly reduces the anteroposterior diameter by up to 38% at end-systole (36.8–22.7 mm; p < 0.001) and the lateromedial diameter by up to 31% (42.7–30.3 mm; p < 0.001). Moreover, the annular circumference was reduced by up to 31% at end-systole (129.6–87.6 mm, p < 0.001), and the annular area was significantly decreased by up to 52% (12.8–5.7 cm2; p < 0.001). Finally, the AMVOA experienced the largest change, decreasing from 1.1 to 0.2 cm2 during systole (at midsystole; p < 0.001) and from 4.1 to 3.2 cm2 (p < 0.001) during diastole. Conclusions MVR reduces the annular dimension and the AMVOA, contributing to mitral competency, but the use of annuloplasty rings reduces annular contractility after the procedure. Surgeons can use 4D imaging technology to assess MV function dynamically, detecting the acute morphological changes of the mitral annulus and leaflets before and after the procedure.

In-Vivo Dynamic Strains of the Ovine Anterior Mitral Valve Leaflet

2011 ◽  
Author(s):  
Manuel Rausch ◽  
Wolfgang Bothe ◽  
John-Peder Escobar-Kvitting ◽  
Serdar Goktepe ◽  
Craig Miller ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Surgical Repair ◽  
High Morbidity ◽  
Valve Leaflet ◽  
Mitral Valve Leaflet ◽  
Excellent Research ◽  
Valve Function ◽  
Repair Techniques

Throughout the cardiac cycle the Mitral Valve (MV) experiences complex mechanical and hemodynamic loading [1]. Dysfunction of the MV may have devastating consequences and has been associated with high morbidity and mortality. Surgical repair techniques are available to treat malfunctioning MVs [2]. However, it is likely that interventions such as surgical repair may cause alterations in the loading conditions and associated deformations of the MV. In consequence such alterations could result in detrimental remodeling and disturb normal valve function. It is therefore essential to characterize the MV under in-vivo conditions as accurately as possible and thereby establish a baseline of the normal valve. Even though excellent research has been conducted in-vivo [3], in-vitro [4], as well as in-silico [5], the Anterior Mitral Valve Leaflet (AMVL) has never been characterized from a mechanical perspective across its entire surface. The goal of this study is, hence, to provide a more complete picture of the deformations across the entire AMVL in the beating heart.

Coordinate-Free Analysis of Mitral Valve Dynamics in Normal and Ischemic Hearts

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Paul Dagum ◽  
Tomasz A. Timek ◽  
G. Randall Green ◽  
David Lai ◽  
George T. Daughters ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Color Doppler ◽  
Mitral Annulus ◽  
Left Ventricular ◽  
Free System ◽  
Ring Annuloplasty ◽  
3D Geometry ◽  
Valve Function ◽  
Valve Dynamics ◽  
Radiopaque Markers

Background —The purpose of this investigation was to study mitral valve 3D geometry and dynamics by using a coordinate-free system in normal and ischemic hearts to gain mechanistic insight into normal valve function, valve dysfunction during ischemic mitral regurgitation (IMR), and the treatment effects of ring annuloplasty. Methods and Results —Radiopaque markers were implanted in sheep: 9 in the ventricle, 1 on each papillary tip, 8 around the mitral annulus, and 1 on each leaflet edge midpoint. One group served as a control (n=7); all others underwent flexible Tailor partial (n=5) or Duran complete (n=6) ring annuloplasty. After an 8±2-day recovery, 3D marker coordinates were measured with biplane videofluoroscopy before and during posterolateral left ventricular ischemia, and MR was assessed by color Doppler echocardiography. Papillary to annular distances remained constant throughout the cardiac cycle in normal hearts, during ischemia, and after ring annuloplasty with either type of ring. Papillary to leaflet edge distances similarly remained constant throughout ejection. During ischemia, however, the absolute distances from the papillary tips to the annulus changed in a manner consistent with leaflet tethering, and IMR was observed. In contrast, during ischemia in either ring group, those distances did not change from preischemia, and no IMR was observed. Conclusions —This analysis uncovered a simple pattern of relatively constant intracardiac distances that describes the 3D geometry and dynamics of the papillary tips and leaflet edges from the dynamic mitral annulus. Ischemia perturbed the papillary-annular distances, and IMR occurred. Either type of ring annuloplasty prevented such changes, preserved papillary-annular distances, and prevented IMR.

scholarly journals Mitral valve opening in the ovine heart

1998 ◽  
Vol 274 (2) ◽  
pp. H552-H563 ◽  
Author(s):  
Matts O. Karlsson ◽  
Julie R. Glasson ◽  
Ann F. Bolger ◽  
George T. Daughters ◽  
Masashi Komeda ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Three Dimensional ◽  
Mitral Annulus ◽  
Posterior Leaflet ◽  
Anterior Leaflet ◽  
Rapid Fall ◽  
Valve Opening ◽  
Radiopaque Markers ◽  
Edge Separation ◽  
Central Cusp

To study the three-dimensional size, shape, and motion of the mitral leaflets and annulus, we surgically attached radiopaque markers to sites on the mitral annulus and leaflets in seven sheep. After 8 days of recovery, the animals were sedated, and three-dimensional marker positions were measured by computer analysis of biplane videofluorograms (60/s). We found that the oval mitral annulus became most elliptical in middiastole. Both leaflets began to descend into the left ventricle (LV) during the rapid fall of LV pressure (LVP), before leaflet edge separation. The anterior leaflet exhibited a compound curvature in systole and maintained this shape during opening. The central cusp of the posterior leaflet was curved slightly concave to the LV during opening. Markers at the border of the “rough zone” were separated by 10 mm during systole. We conclude that coaptation occurs very near the leaflet edges, that the annulus and leaflets move toward their open positions during the rapid fall of LVP, and that leaflet edge separation, the last event in the opening sequence, occurs near the time of minimum LVP.

Comparison of the sustainability of mitral annular dynamics between two semi-rigid annuloplasty devices

2019 ◽  
Vol 56 (2) ◽  
pp. 360-368 ◽  
Author(s):  
Stefaan Bouchez ◽  
Frank Timmermans ◽  
Tine Philipsen ◽  
Katrien François ◽  
Thierry Bové
Keyword(s):  
Mitral Valve ◽  
Mitral Valve Repair ◽  
Cardiac Cycle ◽  
3D Structure ◽  
Mitral Annulus ◽  
Width Ratio ◽  
Valve Repair ◽  
Postoperative Changes ◽  
Folding Dynamics ◽  
Saddle Shape

Abstract OBJECTIVES The choice of annuloplasty device is fundamental at the time of mitral valve repair, the goal being to optimally restore the physiological 3-dimensional (3D) structure and dynamics of the mitral annulus (MA). This study evaluated MA dynamics after annuloplasty with 2 different semi-rigid devices. METHODS Thirty-three patients eligible for mitral valve repair were selected for annuloplasty with the Physio II ring (Edwards Lifesciences, Irving, CA, USA) (n = 17) or the Memo 3D ring (LivaNova, Saluggia, Italy) (n = 16). MA dynamics were assessed with transoesophageal 3D echocardiography intraoperatively and 1 year after repair. RESULTS The postoperative changes in the anteroposterior diameter {3.7% [standard deviation (SD) 2.7] vs 1.9% [SD 1.3]; P = 0.013} and in the annular height [27.7% (SD 8.7) vs 18.0% (SD 13.9); P = 0.003] were significantly larger with the Memo 3D ring during the cardiac cycle. The restoration of the saddle shape at baseline was superior with the Physio II ring, defined by a larger systolic annular height-to-commissural width ratio [15.1% (SD 2.3) vs 7.1% (SD 2.4); P < 0.001]. These observations of MA dynamics were sustained after 1 year, shown by a greater anteroposterior extension [5.1% (SD 1.0) vs 1.7% (SD 1.6); P = 0.002] and change in annular height-to-commissural width ratio [15.7% (SD 12.7) vs 3.1% (SD 3.0); P = 0.020] for the Memo 3D ring. There were no significant differences in mitral valve function between the 2 devices. CONCLUSIONS The MA dynamics after annuloplasty with the Physio II and Memo 3D rings demonstrated a better systolic 3D restoration of the saddle shape with the Physio II ring, whereas the saddle-shaped geometry improved significantly with the Memo 3D ring, as a dynamic phenomenon. The Memo 3D ring also showed increased anteroposterior annular mobility and folding dynamics throughout the cardiac cycle. Moreover, the observed differences in MA dynamics between both devices appeared to be sustainable 1 year after ring implantation.

scholarly journals An Implantable Sensorized Lead for Continuous Monitoring of Cardiac Apex Rotation

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4195
Author(s):  
Emanuela Marcelli ◽  
Laura Cercenelli
Keyword(s):  
Continuous Monitoring ◽  
Dimensional Space ◽  
Animal Experiments ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Cardiac Monitoring ◽  
Cardiac Apex ◽  
Angular Velocities

Changes in the pattern or amplitude of cardiac rotation have been associated with important cardiovascular diseases, including Heart Failure (HF) which is one of the major health problems worldwide. Recent advances in echocardiographic techniques have allowed for non-invasive quantification of cardiac rotation; however, these examinations do not address the continuous monitoring of patient status. We have presented a newly developed implantable, transvenous lead with a tri-axis (3D) MEMS gyroscope incorporated near its tip to measure cardiac apex rotation in the three-dimensional space. We have named it CardioMon for its intended use for cardiac monitoring. If compared with currently proposed implantable systems for HF monitoring based on the use of pressure sensors that can have reliability issues, an implantable motion sensor like a gyroscope holds the premise for more reliable long term monitoring. The first prototypal assembly of the CardioMon lead has been tested to assess the reliability of the 3D gyroscope readings. In vitro results showed that the novel sensorized CardioMon lead was accurate and reliable in detecting angular velocities within the range of cardiac twisting velocities. Animal experiments will be planned to further evaluate the CardioMon lead in in vivo environments and to investigate possible endocardial implantation sites.

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