Mitral annulus after mitral repair: geometry and dynamics.

To evaluate the narrowing of the left ventricular outflow tract (LVOT) during systole caused by a rigid mitral prosthesis, the geometric relationship between the prosthesis (or the mitral annulus) and the left ventricular base (LVB) was studied in five patients with mechanical mitral valve prostheses and eight normal subjects. The images of the mitral valve annulus (MVA) and the LVOT orifice reconstructed in three dimensions were projected on the plane of the LV base. Calculating the areas of these projected images (i.e., those for MVA [Sm], LVOT orifice [So], the LVB [Sb; Sb = Sm + So]), the MVA-LVB ratio (Sm/Sb) was determined. In the normal subject, the MVA-LVB ratio was nearly constant during systole (59 +/- 5% at 0 msec and 62 +/- 7% at 300 msec, respectively), whereas in the patients with prostheses, the ratio increased from 61 +/- 4% (0 msec) to 69 +/- 4% (300 msec). The increase in MVA-LVB ratio reduces the proportionate share of LVOT orifice in relation to the total LVB. The ideal mitral valve prosthesis should be flexible at the annulus to attain good performance in LVB dynamics.

During the last few decades, the use of intraoperative echocardiography has become increasingly evident as anesthesiologists, cardiologists, and surgeons continue to appreciate its potential application as an invaluable tool for monitoring cardiac performance and diagnosing pathology in patients undergoing cardiac surgery (1,2). The essential information provided by intraoperative echocardiography regarding hemodynamic management, cardiac valve function, congenital heart lesions, and great vessel pathology has contributed to its widespread popularity. In fact, perioperative echocardiography has been shown to influence cardiac anesthetic and surgical management in as many as 50% of cases (3). The publication of guidelines describing the indications for performing intraoperative echocardiography based on reviews of the literature and expert opinion of task force members from the Society of Cardiovascular Anesthesiologists (SCA), American Society of Anesthesiologists, and American Society of Echocardiography (ASE) has also facilitated the growth of this important diagnostic tool (4,5). Despite its overwhelming popularity and favorable influence on perioperative clinical decision-making and outcomes (1,2,6), the transesophageal echocardiographic (TEE) approach to a comprehensive echocardiographic examination has some limitations. For example, TEE imaging of the distal ascending aorta and aortic arch may be impaired by the interposition of the trachea and main bronchi (7–9). In addition, a TEE probe may occasionally be difficult or impossible to advance into the esophagus or, in patients with significant gastroesophageal pathology, TEE probe placement may even be contraindicated (10). Furthermore, TEE may be rarely associated with perioperative morbidity from oropharyngeal and gastroesophageal injury (e.g., dysphagia, gastrointestinal hemorrhage, gastroesophageal rupture) (10,11). Thus, an experienced echocardiographer must be familiar with other imaging approaches to conduct a comprehensive perioperative echocardiographic examination. More than a decade before the introduction of TEE, epicardial echocardiography was already in use as a diagnostic imaging modality to assist cardiac surgeons, anesthesiologists, and cardiologists with clinical decision-making (12). A comprehensive epicardial echocardiographic examination can be performed efficiently and safely (13), and may be the most practical intraoperative imaging technique when a TEE probe cannot be inserted or when probe placement is contraindicated. Epicardial echocardiography may be superior to TEE because it can provide more optimal image resolution when using higher frequency probes (14). In addition, epicardial echocardiography may offer better windows for imaging anterior cardiac structures including the aorta, aortic valve (AV), pulmonic valve, and pulmonary arteries, and, therefore, may have a favorable influence on perioperative surgical decision-making (15,16). However, epicardial imaging requires direct access to the anterior surface of the heart, and consequently cannot be performed without a sternotomy. Furthermore, the epicardial approach does not permit continuous monitoring, and requires interruption of the surgical procedure for imaging. The most recent recommendations by the ASE and SCA Task Force Guidelines for Training in Perioperative Echocardiography include epicardial and epiaortic imaging as core components of advanced training (5). Thus, the following guidelines for performing a comprehensive epicardial echocardiographic examination have been developed by the ASE Council for Intraoperative Echocardiography to establish requirements for training, and to standardize a comprehensive epicardial examination using a set of 7 reliably obtained views. TRAINING GUIDELINES The epicardial approach is unique among the readily used echocardiographic imaging windows in that it requires a collaborative effort with the cardiac surgeon to either allow the echocardiographer to guide them in obtaining images, or alternatively permit the echocardiographer to have direct access to the epicardial surface within the operative field. Experience in epicardial echocardiography is an important component of advanced, rather than basic perioperative echocardiographic training as defined by the ASE and SCA Task Force Guidelines for Training in Perioperative Echocardiography (5). Epicardial echocardiographic training should include the study of 25 epicardial examinations of which five are personally directed under the supervision of an advanced echocardiographer, before a trainee should pursue independent interpretation and application of the information to perioperative clinical decision-making. EPICARDIAL PROBE PREPARATION Epicardial echocardiography is performed by placing the ultrasound transducer on the epicardial surface of the heart to acquire 2-dimensional, color flow, and spectral Doppler images in multiple planes. Because of the proximity of the probe to the heart, epicardial echocardiography typically uses higher frequency probes (5–12 MHz). The probe is placed in a sterile sheath along with sterile acoustic gel or saline to optimize acoustic transmission. Two sheaths may also be used in an attempt to increase sterility. Warm sterile saline can be poured into the mediastinal cavity to further enhance acoustic transmission from the probe to the epicardial surface. The depth setting and the depth of transmit focus is then adjusted to visualize the near field. If a multifrequency probe is used, the frequency is increased to obtain the highest resolution image possible. Epicardial images may only be obtained by an operator who is wearing a sterile gown and gloves, and uses sterile technique within the operative field as described in these guidelines. This task may be performed either by a diagnosing physician with advanced perioperative echocardiography training or, alternatively and perhaps more practically, by a cardiac surgeon under the direct guidance of an advanced echocardiographer. Interpretation of epicardial echocardiographic images for the purpose of directing intraoperative surgical and anesthesia decision-making should only be performed by a physician with advanced perioperative echocardiography training. IMAGING PLANES The following proposed guidelines describe 7 epicardial echocardiographic imaging planes consistent with the ASE recommendations for transthoracic echocardiograph (TTE) nomenclature (17). We recognize that placement of the transducer directly on the heart provides views that can be slightly different than those obtained by TTE. These views will be identified as "modified" views. Individual patient characteristics, anatomic variations, or time constraints may limit the ability to obtain every component of the recommended comprehensive epicardial echocardiographic examination. Furthermore, there may be certain clinical situations where additional views may be necessary to address specific anatomic or pathologic questions. However, the 7 recommended views should permit the completion of a comprehensive 2-dimensional and Doppler echocardiographic evaluation in the vast majority of cardiac surgical cases, and should be obtainable in 5–10 min (13). Epicardial AV Short-Axis View (TTE Parasternal AV Short-Axis Equivalent) The ultrasound transducer is placed on the aortic root above the AV annulus, with the ultrasound beam directed toward the AV in a short-axis (SAX) orientation to obtain the epicardial AV SAX view (Fig. 1A). Appropriate transducer alignment and orientation is critical and requires the orientation marker (indentation) on the transducer to face toward the patient's left. The transducer typically has to be rotated approximately 30 degrees clockwise to develop this view. The right coronary cusp will be at the top of the monitor screen, the left coronary cusp will be on the right, and the noncoronary cusp will be on the left side of the screen adjacent to the interatrial septum (Fig. 1B). By slowly moving the transducer, the coronary ostia can be visualized. The area of the AV can also be measured in this view using planimetry.Figure 1.: Epicardial aortic valve (AV) short-axis (SAX) view (transthoracic echocardiographic parasternal AV SAX equivalent). A, Porcine anatomic specimen demonstrating ultrasound transducer oriented above AV annulus so that ultrasound beam can be aligned in SAX plane to AV. B, When orientation marker (indentation) on transducer is pointed toward patient's left, right coronary cusp (R) will be at top of monitor screen, left coronary cusp (L) will be on right, and noncoronary cusp (N) will be on left side of screen adjacent to interatrial septum. PA, Pulmonary artery.Epicardial AV Long-Axis View (TTE Suprasternal AV Long-Axis Equivalent) The epicardial AV long-axis (LAX) view is obtained from the epicardial AV SAX view by positioning the probe upward along the right-sided surface of the aortic root with the orientation marker slightly rotated clockwise and directed to the patient's left. The ultrasound beam is directed posteriorly to visualize the left ventricular (LV) outflow tract (LVOT) and AV (Fig. 2). This view can be used to determine LVOT, aortic annulus, and sinotubular junction diameters. Furthermore, the LAX orientation provided by this view permits optimal alignment of a continuous wave and pulse wave Doppler ultrasound beam, to measure pressure gradients across the AV and LVOT. Similarly, color flow Doppler interrogation of the AV can be used to grade the degree of aortic insufficiency.Figure 2.: Epicardial aortic (AO) valve (AV) long-axis (LAX) view (transthoracic echocardiographic suprasternal AV LAX equivalent). A, Porcine anatomic specimen demonstrating ultrasound transducer oriented along AO root, and directing ultrasound beam posteriorly to visualize left ventricular outflow tract (LVOT) and AV. B, AV and LVOT are well visualized. PA, Pulmonary artery.Epicardial LV Basal SAX View (TTE Modified Parasternal Mitral Valve Basal SAX Equivalent) The epicardial LV basal SAX view is obtained from the epicardial AV SAX position by moving the probe toward the apex along the right ventricle (RV) with the transducer orientation marker again directed toward the patient's left (Fig. 3A). This view will approximate what will be achieved with a right parasternal TTE imaging plane, and shows more of the RV and tricuspid valve than the standard left parasternal TTE orientation (Fig. 3B). The RV will be on top in the near field and the LV below it in the far field of the ultrasound beam sector. The mitral valve (MV) annulus is well visualized in this view with its typical "fish mouth" appearance. The MV anterolateral commissure will be on the right and the posteromedial commissure will be on the left of the screen. The anterior leaflet will appear on the top of the screen and the posterior leaflet will be underneath. The epicardial LV basal SAX view can be used to evaluate the anterior and posterior leaflets of the MV in 2-dimensional imaging. Color flow Doppler can also be used to determine the origin of mitral regurgitation jets and obtain an estimate of the regurgitant orifice area. Finally, basal LV regional wall motion can be assessed using the same LV wall orientation as seen in the epicardial LV mid-SAX view discussed below.Figure 3.: Epicardial left ventricle (LV) basal short-axis (SAX) view (transthoracic echocardiographic modified parasternal mitral valve [MV] basal SAX equivalent). A, Porcine anatomic specimen demonstrating proper probe positioning for developing epicardial LV basal SAX view. B, MV annulus is well visualized with its typical "fish mouth" appearance. MV anterior leaflet (AL) appears on top of screen and posterior leaflet (PL) is underneath. When transducer orientation marker is directed toward patient's left, MV anterolateral commissure will be on right and posteromedial commissure will be on left of screen. RV, Right ventricle.Epicardial LV Mid-SAX View (TTE Parasternal LV Mid-SAX Equivalent) Repositioning or angulating the probe inferiorly and to the left from the epicardial LV basal SAX view in an apical direction along the RV myocardial surface allows visualization of the RV and LV in SAX at the level of the papillary muscles and the LV apex (Fig. 4A). When the transducer orientation marker faces the patient's left, the anterolateral papillary muscle will be on the right side of the display and the posteromedial papillary muscle will be on the left side. The septal wall of the LV will be displayed on the left followed by the anterior, lateral, and inferior walls, respectively, in a clockwise rotation (Fig. 4B). The RV can be evaluated similarly by moving the transducer further toward the patient's right. LV and RV areas, global LV function, and LV regional wall motion can all be evaluated with this view.Figure 4.: Epicardial left ventricle (LV) mid short-axis (SAX) view (transthoracic echocardiographic parasternal LV mid-SAX equivalent). A, Porcine anatomic specimen demonstrating proper epicardial probe positioning toward right ventricle apex for developing epicardial LV mid-SAX view. B, With transducer orientation marker directed toward patient's left, LV anterolateral papillary muscle will be on right and posteriomedial papillary muscle will be on left of ultrasound sector displayed on monitor. Septal (S) wall of LV is displayed on left followed by anterior (A), lateral (L), and inferior (I) walls, respectively, in clockwise rotation.Epicardial LV LAX View (TTE Parasternal LAX Equivalent) From the epicardial LV mid-SAX view, the ultrasound beam can be angled superiorly and rotated toward the patient's right shoulder to generate the epicardial LV LAX view as depicted in Figure 5A. This view allows visualization of the inferolateral and anteroseptal walls of the LV and the RV, left atrium (LA), LVOT, AV, and MV (Figs. 5B and C). Color Doppler interrogation of the AV and MV is possible in this view. A rightward orientation of the beam allows evaluation of the right atrium and tricuspid valve (not shown). Further probe manipulation also permits spectral Doppler of the tricuspid valve. Hence, this view is useful for diagnosing and quantifying aortic, mitral, and tricuspid regurgitation. The interventricular septum can also be evaluated for ventricular septal defects, LVOT obstruction, or systolic anterior motion of the MV.Figure 5.: Epicardial left ventricle (LV) long-axis (LAX) view (transthoracic echocardiographic parasternal LAX equivalent). A, Porcine anatomic specimen demonstrating proper probe positioning with ultrasound beam angled superiorly and toward patients left shoulder to obtain epicardial LV LAX view. B, Porcine anatomic specimen with resected anterior ventricular wall demonstrating visualization of LV and right ventricle (RV), left atrium (LA), LV outflow tract (LVOT), interventricular septum (IVS), aortic valve (AV), and mitral valve (MV). C, Corresponding epicardial LV LAX echocardiographic view.Epicardial 2-Chamber View (TTE Modified Parasternal LAX Equivalent) From the epicardial LV LAX view, movement of the probe toward the anterior surface of the LV and further rotation of the transducer clockwise from the parasternal LAX view as described above will develop the epicardial 2-chamber view, permitting evaluation of the LA, LA appendage, MV, and LV (Fig. 6). Pathology that can be assessed in this view includes LA masses, and abnormalities in LA size, MV anatomy, and MV leaflet motion. Finally, regional wall motion of the basal and mid segments of the anterior and inferior LV walls can also be obtained. This view is the most difficult to consistently obtain unless the LV is dilated.Figure 6.: Epicardial 2-chamber view (transthoracic echocardiographic modified parasternal long-axis [LAX] equivalent). A, Porcine anatomic specimen demonstrating proper probe positioning with ultrasound transducer rotated 90 degrees from epicardial left ventricle (LV) LAX view to obtain epicardial 2-chamber view. B, Porcine anatomic specimen with resected anterior ventricular wall demonstrating left atrium (LA), mitral valve (MV), and LV. To completely eliminate right ventricle, transducer must be place directly on LV, which is possible only in patients with severe LV dilation (not shown). C, Corresponding epicardial 2-chamber echocardiographic image in patient with LV dilation.Epicardial RV Outflow Tract View (TTE Parasternal SAX Equivalent) The epicardial RV outflow tract view is developed by moving the transducer over the RV outflow tract and directing the ultrasound beam toward the patients left shoulder (Fig. 7). The RV outflow tract, pulmonic valve, and proximal main pulmonary artery can be visualized. Orienting a spectral Doppler beam parallel to blood flow permits the evaluation of chamber pressures and quantification of pulmonic stenosis. Color flow Doppler can also be used to evaluate pulmonic regurgitation or stenosis. Finally, this view is also useful for diagnosing a proximal pulmonary embolism or assisting with positioning a pulmonary artery catheter.Figure 7.: Epicardial right ventricular (RV) outflow tract (RVOT) view (transthoracic echocardiographic parasternal short-axis equivalent). A, Porcine anatomic specimen with resected anterior ventricular wall demonstrating proper probe positioning for developing epicardial RV inflow tract/RVOT view. B, RVOT, pulmonic valve (PV), proximal main pulmonary artery, and aortic valve (AV) can be visualized.CONCLUSION As the population of patients with complex cardiac surgical conditions and increasing comorbidity becomes more prevalent, there will be a greater and perhaps more important role for experienced perioperative echocardiographers, who should assume the responsibility of acquiring advanced echocardiographic cognitive and technical skills. The most recent recommendations by the ASE and SCA Task Force Guidelines for Training in Perioperative Echocardiography state that advanced training includes the "ability to acquire or direct the acquisition of all necessary echocardiographic data including epicardial and epiaortic imaging" (5). Although intraoperative epicardial echocardiography was introduced into clinical practice in the early 1970s for the evaluation of open MV commissurotomy, its use has declined during the last decade because of the increasing availability and improved technologic design of TEE probes. The epicardial approach to a comprehensive echocardiographic examination does present certain potential limitations and disadvantages compared with TEE. Nonetheless, a fundamental understanding of the skills required to obtain and interpret images as suggested in these guidelines for performing a comprehensive epicardial examination may be an advantageous adjunct or even a substitute when TEE probe insertion is contraindicated or cannot be performed. Epicardial echocardiography may also provide the best balance between safety and the efficient acquisition of vital information necessary to optimize the perioperative treatment of patients who are critically ill.

Hypertrophic cardiomyopathy (HCM) is a common monogenetic cardiac disease with a prevalence of 0.2%1 that usually is inherited as an autosomal dominant trait with variable penetrance and expression. Clinically, HCM is defined by the presence of left ventricular (LV) hypertrophy (LVH) unexplained by abnormal loading conditions.1 The natural history varies from an asymptomatic course to drug-refractory angina/dyspnea, sudden cardiac death (SCD), and end-stage heart failure. The incidence of HCM-related SCD is approximately 1% to 2% in children and adolescents and 0.5% to 1% in adults.2,3 In this review, we examine the impact of advanced diagnostic imaging technologies on HCM, with particular emphasis on the detection of particular genetic subtypes. In ≈60% of cases, HCM is inherited as an autosomal dominant trait caused by mutations in genes coding for cardiac sarcomere proteins (Figure 1).4–7 Mutations in genes encoding Z-disc proteins and proteins involved in calcium regulation account for <5% of cases. The absence of sarcomeric gene mutations can be explained by limitations of current mutation detection techniques or mutations in as yet unidentified genes, but in some cases, hypertrophy is caused by other diseases that mimic the phenotype of sarcomeric protein disease. Table 1 lists genetic disorders associated with HCM. Figure 1. A schematic illustration of a cardiac sarcomere. View this table: Table 1. Currently Known Genes Implicated in HCM More than 600 different sarcomeric gene mutations are reported in patients with HCM.8–16 The majority are missense mutations, but nonsense, frameshift, and in-frame insertion/deletion mutations also occur. Most mutations are characterized by incomplete penetrance and variable clinical expression likely due to locus heterogeneity and the effect of mutations at different locations within the same gene. Most mutations probably have a dominant negative effect on sarcomere function, but in some cases, haploinsufficiency (ie, only a single functional …

Sizing for Mitral Annuloplasty: Where Does Science Stop and Voodoo Begin?

Septal myectomy is a well-established surgical intervention for patients with hypertrophic obstructive cardiomyopathy (HOCM). However, mitral annulus dynamics in HOCM patients and the procedure's impact on them are not fully understood. This study aimed to evaluate the mitral valve annulus's dynamics and the effect of septal myectomy on its geometry and function using three-dimensional transesophageal echocardiography (3D TEE) in HOCM patients. A single-site, prospective observational study was conducted at a tertiary-level hospital; 26 patients with HOCM who underwent septal myectomy were included. Intraoperative 3D TEE was performed before and after surgery to assess mitral annular dimensions, area, and motion. Clinical outcomes, including New York Heart Association (NYHA) functional class and left ventricular outflow tract (LVOT) gradient, were also evaluated. Preoperative and postoperative transesophageal images were analyzed offline to measure mitral annular dynamics across the cardiac cycle using dedicated software and Doppler-derived pressure gradients. Throughout the four phases of the cardiac cycle (late diastole, early systole, mid-systole, and late systole), there were no significant dynamic changes in mitral annulus dimensions, specifically, the anteroposterior (AP) diameter (p = 0.286), anterolateral-posteromedial (AL-PM) diameter (p = 0.922), sphericity index (p = 0.311), inter-trigonal diameter (p = 0.982), intercommissural diameter (p = 0.999), 3D saddle-shaped annulus area (p = 0.714), 3D saddle-shaped annulus perimeter (p = 0.754), annulus height (p = 0.981), nonplanar angle (p = 0.902), aorto-mitral angle (p = 0.949), and saddling (p = 0.231). Immediately after septal myectomy, despite significant LVOT gradient reduction (88.4±45.6mmHg preoperative vs. 9.3±4.7mmHg postoperative; p<0.001), no significant improvements were detected in mitral annular parameters (p>0.05 for all parameters). 3D TEE offers critical insights into the dynamics of the mitral valve annulus across various phases of the cardiac cycle. In patients with HOCM, the mitral valve annulus exhibits reduced dynamic motion, with a notable loss of normal systolic AP contraction and saddling. Immediate postoperative assessments did not demonstrate significant improvements in mitral annulus dynamics. Therefore, further longitudinal studies are necessary to assess long-term changes in mitral annulus dynamics due to LV remodeling following septal myectomy procedures.

A simplified method for determining regurgitant fraction by Doppler echocardiography in patients with aortic regurtitation

Introduction According to the literature, in approximately 60% of cases, aortic valve annulus (AVA) is greater in end-systole, equal with end-diastolic value in 8% and larger in end-diastole in 32% of healthy subjects. However, it is unclear whether any left ventricular (LV) functional differences may be behind this phenomenon. Therefore, the aim of the present study was to investigate the potential LV volumetric and functional differences observed in healthy individuals based on whether the end-diastolic or end-systolic AVA area is larger. Methods The present study comprised 112 healthy adults who underwent two-dimensional (2D) Doppler echocardiography together with 3D speckle-tracking echocardiography (3DSTE). Three subgroups were created, in which end-systolic AVA area was greater (n=70), end-systolic and end-diastolic AVA areas were equal (n=8) and end-diastolc AVA area was greater (n=34). Results No differences in routine 2D echocardiographic data and 3DSTE-derived LV volumetric parameters could be detected between the groups examined. Global and mean segmental LV strain did not differ between the groups examined. However, basal LV radial (29.1 ± 9.2% vs. 34.3 ± 13.3%, p&amp;lt;0.05) and longitudinal (-19.2 ± 3.9% vs. -20.9 ± 4.4%, p&amp;lt;0.05) strains proved to be significantly reduced in subjects with a greater end-diastolic AVA area as compared to cases with a greater end-systolic AVA area. Subjects with equal end-diastolic and end-systolic AVA areas showed significantly reduced basal LV longitudinal strain as compared to those with greater end-systolic AVA area (-17.7 ± 3.5% vs. -20.9 ± 4.4%, p&amp;lt;0.05). Additionally, basal LV rotation proved to be significantly lower in subjects with greater end-diastolic AVA area as compared to those with a greater end-systolic AVA area as well (-3.43 ± 1.49 degrees vs. -4.50 ± 2.33 degrees, p&amp;lt;0.05). Conclusions Although most of healthy adults have greater end-systolic than end-diastolic AVA area, 30% of cases show greater end-diastolic AVA area. Healthy subjects with a greater end-diastolic AVA area have reduced basal radial and longitudinal LV strains, as well as lower basal LV rotation as compared to those with a greater end-systolic AVA area.

BackgroundMitral annular disjunction (MAD) is characterised by a separation of the mitral valve hinge point and the left ventricular (LV) myocardium and significantly increases the risk of ventricular arrhythmias and sudden cardiac death. Potential underlying mechanisms of arrhythmias include the combination of LV fibrosis serving as the arrhythmic substrate and mechanical stretch acting as a triggering factor.PurposeTo investigated functional and morphological predictors of left ventricular (LV) fibrosis in patients with MAD.MethodsCardiac magnetic resonance (CMR) reports and images of 111 patients with inferolateral MAD were reviewed; MAD distance, presence and size of mitral valve prolapse (MVP), midmyocardial replacement fibrosis of the basal inferolateral LV wall as well as the movement pattern of the basal inferolateral LV segment were analysed. Longitudinal and radial systolic displacement of the basal inferolateral LV segment was judged as homogeneous or accelerated by visual impression by two independent investigators. Differences between patients with and without LV fibrosis was calculated using Pearson's chi-squared test for categorical variables and ANOVA or Wilcoxon rank-sum as appropriate for continuous variables. Univariable and multivariable logistic regression models were used to identify patient characteristics independently associated with fibrosis of the basal inferolateral LV wall.ResultsMedian age was 52 years (interquartile range [IQR] 36-69) and 47% were female. Midmyocardial replacement fibrosis of the basal inferolateral LV wall was present in 27 (24%) patients. Patients with fibrosis were older (63.0 years [IQR 53.0-70.0] vs. 47.5 years [IQR 34.0-67.5], p=0.011), more likely to have MVP (24 [89%] vs. 58 [69%], p=0.041), had larger anterior (3.0 mm [IQR 0.0-4.0] vs. 0.0 mm [IQR 0.0-3.0], p=0.010), larger posterior prolapse size (4.0 mm [IQR 2.0-7.0] vs. 2.5 mm [IQR 0.0-4.5], p=0.016), larger median MAD distance (6.0mm [IQR 5.0-9.0] vs. 5.0mm [IQR3.0-8.0], p=0.018) and were more likely to exhibit an accelerated longitudinal motion of the basal inferolateral LV wall (20 [74%] vs. 26 [31%], p<0.001) (Table 1). Multivariable logistic regression revealed that age (odds ratio [OR] 1.06, confidence interval [CI] 1.03-1.10, p=0.001) and accelerated longitudinal motion of the basal inferolateral LV wall (OR 10.59, CI 2.84-39.49, p<0.001) were the only significant predictors of replacement fibrosis (Table 2). Finally, posterior MVP distance (OR 1.29, CI 1.02-1.62, p=0.032) and MAD size (OR 1.28, CI 1.05-1.56, p=0.017) were associated with an accelerated motion of the basal inferolateral LV segment.ConclusionAge and accelerated longitudinal motion of the basal inferolateral LV segment predict replacement fibrosis of the basal inferolateral wall in patients with MAD. MAD size and posterior MVP size are significantly associated with this accelerated movement pattern.

Funding AcknowledgementsType of funding sources: Foundation. Main funding source(s): British Heart FoundationBackgroundElectrogram morphology is used to identify the atrio-ventricular annuli during catheter ablation procedures with a "balanced" signal considered to represent the annuli. However, anatomical studies highlight a significantly greater mass of ventricular myocardium compared to atrial myocardium at the valve plane suggesting the correct electrical signature of the anatomical annulus may not be a balanced signal.PurposeTo identify the relationship between atrial and ventricular electrogram components at the anatomically defined mitral valve annulus.MethodsMapping of the mitral annulus was performed in patients undergoing ablation for paroxysmal atrial fibrillation. Following femoral venous access and trans-septal puncture, left atrial anatomy was defined using rotational angiography performed using a 100ml contrast injection 4 seconds prior to X-ray acquisition, during rapid pacing and apnoea while covering 200 degrees at 40 degrees/s. A SmartTouch SF ablation catheter (Biosense Webster) was advanced into the left atrium and used to record intracardiac electrograms at four positions around the mitral annulus and at five predetermined levels ranging from ventricular to atrial (Figure, panel A). Data analysis was performed using OpenEP (https://openep.io). For each electrogram, the distance to the mitral valve plane and the amplitudes of atrial and ventricular electrogram components were calculated (Figure, panel B and C). Mean electrogram component amplitudes were calculated including all points recorded within ±2.5mm of the mitral valve plane. For each patient, a linear regression model was fitted and used to identify the atrial/ventricular ratio at the anatomically defined mitral valve annulus (Figure, panel D).ResultsThe protocol was completed in 9 patients, including analysis of 240 atrial or ventricular electrogram components. Within ±2.5mm of the anatomically defined mitral valve annulus, the mean recorded amplitudes of atrial and ventricular electrogram components was 0.15±0.17mV and 1.35±1.27mV, respectively (A/V ratio 1:9). Using the linear regression model, the ventricular electrogram component was calculated to be 16.5±11.6 times greater in amplitude than the atrial electrogram component at the mitral valve plane (A/V ratio 1:16). The use of a balanced signal to identify the mitral valve annulus resulted in a positional error of -7.9±9.5mm (i.e. identifying a level which is approximately ~8mm too "atrial" compared to the anatomically defined annulus).ConclusionThe conventional use of a "balanced" electrogram signal does not identify the anatomical mitral valve annulus. An atrial/ventricular electrogram ratio between 1:9 and 1:16 best approximates the mitral valve annular plane determined by left atrial rotational angiography. These findings have relevance in target site selection for an accessory pathway and the ventricular extent of linear ablation at the mitral isthmus.Figure

Background and Aims End-systolic elastance (Ees) derived from sequential pressure-volume (PV) loops acquired during inferior vena cava occlusion (IVCO) is the reference for quantification of in vivo left ventricular (LV) contractile performance. Given the challenges associated with midline laparotomy surgeries in animal models and the barriers of performing such measures in clinical practice, a number of single-beat estimations of LV contractile function have been proposed. Here, we examined the agreement between two single-beat estimates of Ees obtained from basal LV and arterial hemodynamics in rats and pigs and the Ees obtained from IVCO (Ees(IVC)). We also tested whether a novel approach of leveraging the respiratory-induced oscillations in cardiac PV (i.e., changes in intrathoracic pressure) during mechanical ventilation enables a “naturally” occurring change in cardiac preload and the subsequent estimation of Ees (Ees(RES)). Methods 38 Wistar rats (300-350g; aged 10 wks) and 22 Yucatan mini-pigs (20-25 kg, aged 8-12 wks) were used. Once anesthetized and ventilated, animals were instrumented with 1) a LV PV catheter for assessments of LV Ees(IVC) during IVCO and LV hemodynamics, and 2) a femoral arterial catheter to record basal systemic hemodynamics. Basal LV and arterial indices, including end-systolic volume (ESV), end-systolic pressure (ESP), and arterial systolic blood pressure (SBP), were averaged over a 30s (rats) or 60s period (pigs). Ees(IVC) was measured as the slope of end-systolic PV relationship (ESPVR). From the basal LV and arterial data we then calculated single-beat estimation of Ees(IVC), including the ESP and ESV ratio (EesSB1), and the ESP (SBP × 0.9) and EDV ratio (EesSB2). Estimation of Ees(RES) was analogous to Ees(IVC) however, respiratory-induced oscillations in cardiac preload, rather than an IVCO, was used to calculate the slope of the ESPVR. Absolute agreement between metrics was examined using intra-class correlation coefficients (ICC). Results In rats, while we found a moderate agreement between Ees(SB1) (ICC = 0.685, P < 0.001), Ees(SB2) (ICC = 0.685, P < 0.001) and Ees(IVC), there was excellent agreement between Ees(RES) and Ees(IVC) (ICC = 0.934 P < 0.001). In pigs, although a moderate agreement was observed between Ees(RES) and Ees(IVC) (ICC = 0.572, P = 0.033), no agreements were noted between Ees(SB1) (ICC = 0.352, P = 0.101), Ees(SB2) (ICC = 0.320, P = 0.0741) and Ees(IVC). Conclusion Thesefindings demonstrate that the single-beat estimates of Ees show moderate agreement with Ees(IVC) in rats. Utilizing the respiratory-induced changes in cardiac preload during mechanical ventilation, however, may provide a better less-invasive approach for estimation of cardiac contractile performance, especially in a small animal model.

Although the influence of respiration on ventricular filling, as evaluated by Doppler technique, and the evaluation of diastolic velocities of mitral valve annulus (MVA), as measured by Doppler tissue imaging (DTI), can provide valuable information for the study of left ventricular (LV) diastolic function, the concomitant effects of aging, tidal volume (TV), and respiratory rate (RR) on these velocities have not been quantitatively investigated. We evaluated 12 normal male volunteers (Group I) aged 20-26 years (mean: 22.8) and 8 normal subjects aged 41 to 54 years old (mean: 45.9) (Group II). Using DTI we measured peak early (E(a)) and late (A(a)) velocities of longitudinal axis expansion at lateral and medial MVA. Doppler mitral and tricuspid flow velocities were measured: peak early (E) and late (A) inflow velocity, early (E(i)) and late (A(i)) flow integral, and deceleration time of peak early mitral flow velocity (DT). Respiratory cycles were simultaneously recorded at RR of 9, 12, 15, and 18 cycles/min and TV of 600 and 900 mL during respiration (RESP). (1) E, A, and A(i) in MV had negligible change during respiration, but E(i) was significantly reduced during inspiration; (2) DT reduced slightly with inspiration, but the change was significant only with TV of 900 mL; (3) an important increase of E in right ventricular flow was observed during inspiration; (4) variations of RR and TV did not significantly influence right and left ventricular inflow in normal subjects, in the conditions of this investigation; (5) a significant increase of E(a) at medial MVA was documented during inspiration only in young subjects; (6) a significant decrease of A(a) at medial MVA was observed during inspiration in both groups of volunteers; (7) RR and TV did not influence MVA velocities in young and adult subjects; (8) a consistent reduction in E(a) and a significant increase in A(a) were observed with increasing age; (9) these changes were more conspicuous and consistent than those documented in ventricular filling when young and middle-age men are compared, suggesting that the DTI is more sensitive to detect changes in diastolic function; and (10) in addition, these data suggest that, for evaluation of diastolic function, in clinical context, it is not necessary to control rigorously RR or TV.

Mitral measurement: All or nothing?

Noninvasive assessment of diastolic dysfunction relies on multiple echocardiographic indicators, including measurements from both standard B-mode images and Doppler, obtained at various cardiac locations such as the mitral annulus, tricuspid annulus, left ventricle, and left atrium. The diagnostic process is complex and subject to interobserver variability, making accurate and rapid evaluation challenging. Automated semantic segmentation of key cardiac structures, such as the left atrium, left ventricle, and mitral valve annulus, offers a potential solution by capturing temporal changes throughout the cardiac cycle. This study aims to improve the accuracy of segmenting the left atrium, left ventricle, and mitral valve annulus in echocardiographic images and to leverage the resulting temporal segmentation features for more reliable identification of diastolic dysfunction. This study presents Diff-TransUNet, a novel segmentation model incorporating a noise-robust Differential Transformer module. Evaluations on private (1137 training images, 135 validation images, and 88 test images), CAMUS (1400 training images, 200 validation images, and 200 test images), and EchoNet-Dynamic (5000 training images, 2546 validation images, and 2528 test images) datasets demonstrate improved performance over state-of-the-art methods, assessed by Dice coefficient (Dice), Intersection-over-Union (IoU), and 95th percentile Hausdorff Distance (HD95) metrics. Statistical analysis was performed to compare Diff-TransUNet with baseline methods across evaluation metrics. To control for errors arising from multiple comparisons, p-values were adjusted using the Benjamini-Hochberg false discovery rate (FDR) correction. Statistical significance was assessed at a 95% confidence level. In addition to p-values, Cohen's d effect size was computed to quantify the practical significance of performance differences. The proposed Diff-TransUNet achieved a Dice of 87.49%, IoU of 79.07%, and HD95 of 1.48 on the private dataset. Compared with state-of-the-art models, Dice improved by 1.35%-4.30% (p<0.05, Cohen's d=0.32-0.90), IoU by 1.97%-5.67% (p<0.05, Cohen's d=0.37-1.03), and HD95 by 0.16-0.83 (p<0.05, Cohen's d=0.21-0.90). On the CAMUS dataset, the model achieved a Dice of 88.74%, IoU of 80.58%, and HD95 of 2.83, showing improvements of 1.07%-4.96% (p<0.05, Cohen's d=0.18-0.63) in Dice, 1.55%-6.89% (p<0.05, Cohen's d=0.19-0.71) in IoU, and 0.41-2.85 (p<0.05, Cohen's d=0.12-0.46) in HD95 compared to advanced models. On the EchoNet-Dynamic dataset, the model obtained a Dice of 92.25%, IoU of 85.87%, and HD95 of 1.65, outperforming other methods by 0.42%-2.00% (p<0.05, Cohen's d=0.10-0.40) in Dice, 0.69%-3.21% (p<0.05, Cohen's d=0.10-0.43) in IoU, and 0.21-1.12 (p<0.05, Cohen's d=0.09-0.34) in HD95. Furthermore, by extracting volumetric segmentation features, the proposed method achieved an accuracy of 88.95% (95 % CI 87.15% to 90.08%) in identifying diastolic dysfunction. The proposed Diff-TransUNet model achieves significant improvements in ultrasound segmentation. Features extracted from the left ventricle, left atrium, and mitral annulus segmented by Diff-TransUNet can be effectively used for the identification of diastolic dysfunction.

Mitral valve–sparing operation in subaortic stenosis caused by anomalous papillary muscle and discrete subaortic stenosis

Cardiac resynchronization therapy (CRT) has been reported to improve cardiac performance. However, CRT in patients with advanced heart failure is not always accompanied by an improvement in survival rates. We investigated the association between hemodynamic studies and long-term prognosis after CRT. A total of 68 consecutive patients receiving CRT devices due to advanced heart failure were assessed by hemodynamic study and long-term outcome after implantation of the device. Hemodynamic parameters were measured both with the CRT on and off. Patients demonstrated significant improvement in the maximum first derivative of left ventricular (LV) pressure (LV dP/dt(max) ) and QRS duration after periods with the CRT on. During the follow-up period of 34.9 ± 17.6 months, basal LV dP/dt(max) and isovolemic LV pressure half-time (T½), but not percent change in LV dP/dt(max) , were independent predictors of cardiac mortality or hospitalization due to heart failure after multivariate Cox regression analysis. The Kaplan-Meier survival analysis revealed that patients in the lowest basal LV dP/dt(max) tertile or the longest basal T½ tertile exhibited a significantly higher cardiac-caused mortality or heart failure hospitalization. Lower LV dP/dt(max) or longer T½ independently predicts cardiac mortality or heart failure hospitalization in patients receiving CRT. The assessment of the basal LV dP/dt(max) and T½ could provide useful information in long-term prognosis after CRT.