A percutaneous approach to create tricuspid regurgitation in swine: a model for transcatheter tricuspid valve therapy assessment.

PURPOSE: The purpose of this study was to develop a simple and effective percutaneous approach to create tricuspid regurgitation in swine. METHODS: Eleven pigs (71.68 ± 7.70 kg, 3 male) were involved in this study. A grasping forceps was introduced into the right ventricle through a steerable sheath under fluoroscopic guidance and used to disrupt the tricuspid valve apparatus by avulsing leaflet or chordae tendineae repeatedly. Transthoracic echocardiography and right ventricular angiography were used to evaluate the degree of tricuspid regurgitation created. RESULTS: Ten of the 11 pigs (90.91%) achieved severe tricuspid regurgitation and 1 (9.09%) obtained moderate tricuspid regurgitation immediately after the procedure. Heart rate of the pigs significantly increased immediately after tricuspid regurgitation creation compared to baseline (88.64 ± 23.24 vs. 76.00 ± 15.30 bpm, P = 0.02), but recovered to normal level at one month follow-up (77.09 ± 11.97 bpm, P = 0.85). The right atrium, tricuspid valve annulus, and right ventricle dilated obviously one month after tricuspid regurgitation creation (dimension changes: 3.01 ± 0.35 vs. 3.56 ± 0.40 cm, P = 0.02; 2.92 ± 0.36 vs. 3.37 ± 0.39 cm, P = 0.01; 3.06 ± 0.42 vs. 3.60 ± 0.47 cm, P = 0.03 respectively). Autopsy findings showed that rupture of leaflet and/or chordae tendineae finally led to the tricuspid regurgitation. CONCLUSIONS: Severe tricuspid regurgitation can be created by a simple and effective percutaneous approach with a grasping forceps in swine model and right heart dilation can be observed consistently at one-month follow-up. This model will be valuable in pre-clinical studies for developing new tricuspid valve repair or replacement technique to treat severe tricuspid regurgitation.

Transcatheter Valve Replacement for Right-sided Valve Disease in Congenital Heart Patients.

Pulmonary and/or tricuspid valve dysfunction is common among individuals with congenital heart disease, and surgical intervention often carries prohibitive risks. Transcatheter valve replacement (TVR) of the right-sided cardiac valves has become a viable treatment option over the past two decades, while continued technological development aims to broaden its applicability to an even larger portion of those with repaired congenital heart disease. To date, two transcatheter valves have been approved for use in patients with dysfunctional right ventricular to pulmonary artery conduits as well as those with failing pulmonic bioprosthetic valves, and are also used off-label in the "native" RVOT and within surgically repaired/replaced but failing tricuspid valves. TVR has demonstrated comparable safety and short-term outcomes to that of surgical valve replacement. This article aims to review current available devices, focusing on their safety, efficacy and on and off label usage, while briefly describing some of the emerging devices and novel procedural techniques that will likely lead to significant expansion of transcatheter treatment of right sided valve disease in the future.

Three-dimensional dynamic assessment of tricuspid and mitral annuli using cardiovascular magnetic resonance.

AIMS: To explore the potentiality of cardiovascular magnetic resonance (CMR) in the quantitative evaluation of mitral valve annulus (MVA) and tricuspid valve annulus (TVA) morphology and dynamics. METHODS AND RESULTS: CMR was performed in 13 normal subjects and 9 patients with mitral (n = 7) or tricuspid regurgitation (n = 2), acquiring cine-images in 18 radial long-axis planes passing through the middle of MVA or TVA. A novel algorithm was used to obtain dynamic three-dimensional (3D) reconstruction of MVA and TVA. Analysis was feasible in all cases, allowing accurate 3D annular reconstruction and tracking. The 3D area increased from systole [MVA, median = 10.0 cm(2) (first quartile = 8.6, third quartile = 11.4); TVA, 11.2 cm(2) (8.8-13.2)] to diastole [MVA, 10.6 cm(2) (9.4, 11.7); TVA, 11.9 cm(2) (9.2-13.5)], with TVA larger than MVA. While the longest diameter showed similar systolic and diastolic values, the shortest diameter elongated from systole [MVA, 30 mm (29-33); TVA, 33 mm (31-36)] to diastole [MVA, 31 mm (29-32); TVA, 36 mm (33-39)]. Also, TVA became more circular than MVA. TVA showed lower peak systolic excursion in the septal [15.9 mm (13.0-18.5)] and anterior regions [17.9 mm (12.2-20.7)] compared with the posterior [21.9 mm (18.6-24.0)] segment. Values in MVA were smaller than in TVA, slightly higher in anterior [11.2 mm (9.5-13.0)] than in posterior [12.4 mm (10.2-14.6)] segments. Valvular regurgitation was associated with enlarged, flattened, and more circular annuli. CONCLUSION: The applied method was feasible and accurate in normal and regurgitant valves, and may potentially have an impact on diagnosis, improvement of surgical techniques and design of annular prostheses.

In vitro assessment of available coaptation area as a novel metric for the quantification of tricuspid valve coaptation.

Tricuspid regurgitation (TR) is associated with increased mortality in patients undergoing mitral valve repair. In recent decades, TR has been addressed using annuloplasty concomitantly with mitral valve repair by some surgeons. However, repair efficacy and durability are often suboptimal. Increased understanding of tricuspid valve coaptation and the effects of pathological and repair conditions may be useful to inform future repair design. In the present study, we propose a two-dimensional in vitro technique, available coaptation area (ACA), to quantify the area of each tricuspid leaflet available for coaptation. Preliminary results showed that annular dilatation caused a significant (p<0.05) decrease in anterior leaflet ACA (0.92±0.18cm(2)), and combined annular dilatation and papillary muscle (PM) displacement resulted in a significant decrease in posterior leaflet ACA (0.87±0.15cm(2)). Isolated PM displacement did not have a significant effect on ACA, and the septal leaflet showed no changed in ACA under the conditions tested. In addition to quantifying ACA, our technique allows for the detailed mapping of leaflet coaptation, which may be used to reveal specific sites of malcoaptation on each leaflet. Application of the ACA method in future studies may lead to the development of specialized tricuspid repair strategies and annuloplasty ring designs that target specific regions of the tricuspid valve based on underlying pathological conditions.

Quantitative assessment of asymmetric aortic dilation with valve-related aortic disease.

RATIONALE AND OBJECTIVES: Previous work suggests that ascending aortic (AsAo) dilation can be asymmetric and is potentially related to valve-related blood flow abnormalities. The aim of this study was to investigate the relationship between the aortic valve and AsAo dilation using a quantitative, three-dimensional assessment of aortic shapes. MATERIALS AND METHODS: Computed tomographic and magnetic resonance images of the thorax were retrospectively reviewed. Four groups with aortic dilation were studied: those with tricuspid aortic valves (TAVs) with and without stenosis and those with bicuspid aortic valves (BAVs) with and without stenosis. Controls had either TAVs or BAVs but no aortic stenosis or dilation. In additional to standard orthogonal diameters, a unique measurement of AsAo asymmetry was used: the ratio of the greater to lesser curvatures measured using three-dimensional reformats in a "candy-cane" orientation. RESULTS: A total of 105 patients were identified. Ratios of greater to lesser curvature in patients with aortic dilation and nonstenotic TAVs were not significantly different from those in controls (1.69 vs 1.55, P > .20), but the asymmetry reflected by this ratio was markedly increased in patients with aortic dilation and stenotic TAVs (1.94, P < .001). Patients with aortic dilation and BAVs had significantly elevated ratios regardless of the status of the aortic valve (1.96 for nonstenotic and 2.05 for stenotic vs 1.53 for controls, P < .001). CONCLUSIONS: Asymmetric AsAo dilation with relative bulging of the greater curvature is linked to aortic stenosis, but it is also seen with nonstenotic BAVs. This suggests that the hemodynamic forces that contribute to aortic dilation are not fully revealed by conventional assessment of the aortic valve.

A novel low-fidelity simulator for both mitral valve and tricuspid valve surgery: the surgical skills trainer for classic open and minimally invasive techniques.

OBJECTIVES: Simulators have been proven to equip trainee surgeons with better skills than the traditional, standard approach to skill development. The purpose of this study was to develop a low-fidelity, low-cost, reusable and portable simulation device, which could provide training in nearly the full range of mitral valve surgery techniques, in both the classic, open approach as well as the minimally invasive approach. METHODS: This novel simulator is made up of commonly available components. The basic elements are a classic baby bottle, with the associated feeding teat and screw ring, in combination with a sheet of dental dam. The detailed process for making this simulator is outlined in this article. Maximum suture tensile strength on the different components was tested with a digital force gauge. Reusability and the rate of wear as a result of suturing were documented. Total cost was calculated in euros (€). RESULTS: This study resulted in a simulation model very similar in size to the actual anatomical dimensions of the mitral valve. Various pathological conditions, according to Carpentier's Functional Classification, could be simulated. This led to the possibility of providing training in several mitral valve surgical techniques. As the model developed, it became clear that it could also be used to practice tricuspid valve surgery techniques. Maximum mean suture tensions on the silicone teat and dental dam were 42.11 and 11.15 N/m(2), respectively. The feeding teat started wearing after approximately 45 suture placements. Total cost of the study model was €5.14. CONCLUSIONS: This relatively simple, low-cost, low-fidelity model can provide simulation training in nearly the full range of mitral valve and tricuspid valve surgical techniques, in both the classic open approach and the minimally invasive approach-and do so almost anywhere. Especially when used by young cardiothoracic surgeons in training, this model may contribute to the development of technical skills and procedural knowledge required for adequate performance in the operating room.

Assessment of right ventricular function using echocardiographic speckle tracking of the tricuspid annular motion: comparison with cardiac magnetic resonance.

BACKGROUND: Assessment of right ventricular (RV) function is difficult due to the complex shape of this chamber. Tricuspid annular plane systolic excursion (TAPSE) measured with M-mode echocardiography is frequently used as an index of RV function. However, its accuracy may be limited by ultrasound beam misalignment. We hypothesized that two-dimensional (2D) speckle tracking echocardiography (STE) could provide more accurate estimates of RV function. Accordingly, STE was used to quantify tricuspid annular displacement (TAD), from which RV longitudinal shortening fraction (LSF) was calculated. These STE derived indices were compared side-by-side with M-mode TAPSE measurements against cardiac magnetic resonance (CMR) derived RV ejection fraction (EF). METHODS: Echocardiography (Philips iE33, four-chamber view) and CMR (Siemens, 1.5 T) were performed on the same day in 63 patients with a wide range of RV EF (23-70% by CMR). TAPSE was measured using M-mode echocardiography. TAD and RV LSF were obtained using STE analysis (QLAB CMQ, Philips). TAPSE, TAD and RV LSF values were compared with RV EF obtained from CMR short axis stacks. RESULTS: STE analysis required <15 seconds and was able to track tricuspid annular motion in all patients as verified visually. Correlation between RV EF and TAD (0.61 free-wall, 0.65 septal) was similar to that with M-mode TAPSE (0.63). However, STE-derived RV LSF showed a higher correlation with CMR EF (r = 0.78). CONCLUSION: RV LSF measurement by STE is fast and easy to obtain and provides more accurate evaluation of RV EF than the traditional M-mode TAPSE technique, when compared to CMR reference. (Echocardiography 2012;29:19-24).

Assessment of right ventricular systolic function: comparison between cardiac magnetic resonance derived ejection fraction and pulsed-wave tissue Doppler imaging of the tricuspid annulus.

BACKGROUND: Systolic right ventricular (RV) function is an important predictor in the course of various congenital and acquired heart diseases. Its practical determination by echocardiography remains challenging. We compared routine assessment of lateral tricuspid annular systolic motion velocity (TV(lat), cm/s) using pulsed-wave tissue Doppler imaging from the apical 4-chamber view with cardiac magnetic resonance (CMR) as reference method. METHODS AND RESULTS: 254 individuals (43 ± 18 years) underwent both CMR (contiguous short axis slices; retrogated cine steady state free precession technique; manual contour tracing) and echocardiography within 2 ± 2 months. Seventy-five had coronary artery disease, 87 congenital heart disease, 17 dilated cardiomyopathy, 15 pulmonary artery hypertension, and 47 normal findings. RV ejection fraction (EF) by CMR was 51 ± 12% (range 17-78%). There was a linear correlation between RVEF and TV(lat) (r=0.60; p<0.0001). A TV(lat) cut-off of 12 cm/s identified patients with normal EF (≥50%) with 81% sensitivity and 68% specificity, and a threshold of TV(lat) <9 cm/s identified patients with severely reduced RVEF (<30%) with 82% sensitivity and 86% specificity. CONCLUSIONS: Systolic long-axis velocity measurements of the lateral tricuspid annulus allow a reliable assessment of RVEF in clinical routine. A threshold of TV(lat)<9 cm/s identifies patients with severely reduced RVEF (<30%) with high sensitivity and specificity.

Utility of 3D transoesophageal echocardiography for the assessment of tricuspid and pulmonary valves in carcinoid heart disease.

We report on the case of a 45-year-old lady with metastatic carcinoid tumour and carcinoid syndrome who develops severe valvulopathy involving the tricuspid and pulmonary valve. The use of three-dimensional transoesophageal echocardiography allowed more detailed morphological assessment of tricuspid and pulmonary valve pathology, sub-valvular apparatus and improved delineation of the relationship between these structures and surrounding cardiac chambers.

Assessment of atrial electromechanical coupling and influential factors in nonrheumatic paroxysmal atrial fibrillation.

BACKGROUND: Sequential analysis of atrial electromechanical coupling (P-A) by Doppler tissue imaging (DTI) might provide important insight into the mechanisms of paroxysmal atrial fibrillation (PAF). HYPOTHESIS: The purpose of this study was to evaluate P-A and the dispersion of P-A, and to analyze the influential factors of P-A. METHODS: One hundred and ten patients with PAF and 87 normal controls were enrolled. Using DTI, the time intervals from the beginning of P-wave to the onset of atrioventricular ring motion related to atrial contraction were measured. RESULTS: Atrial electromechanical coupling at the interventricular septum atrioventricular annulus (P-A1), left lateral mitral annulus (P-A2) and right lateral tricuspid annulus (P-A3) in PAF group were significantly longer than those in control (p < 0.001). The difference between P-A2 and P-A1 (T1), P-A2 and P-A3 (T3) in PAF group were greater than those in control before age correction (p < 0.05). The linear regression analysis showed that the duration of PAF episodes and age were the greatest influential factors of P-A1 (r = 0.564). Left atrial anterior-posterior dimension (LAD) and age were the greatest influential factors of P-A2 (r = 0.459). The LAD was the greatest influential factors of T1 and T3 (r = 0.408, 0.542). CONCLUSIONS: The atrial electromechanical coupling was significantly longer and the dispersion of P-A at left lateral mitral annulus was greater in PAF patients. The prolongation of P-A may be related to left atrial enlargement, long episodes of PAF and aging and the dispersion of P-A at left lateral mitral annulus to LAD.

Assessment of the maximum voltage-guided technique for cavotricuspid isthmus ablation during ongoing atrial flutter.

OBJECTIVES: We aimed to test the maximum voltage-guided cavotricuspid isthmus (CTI) ablation technique during ongoing atrial flutter. BACKGROUND: Former pathological and electrophysiological studies clarified that the cavotricuspid isthmus is composed of distinct muscular bundles, which are responsible for the conduction of electrical activation. Based on this observation, a maximum voltage-guided ablation technique (MVGT) was developed. This technique was assessed during pacing from the coronary sinus and was reported to be a feasible method to reach bidirectional isthmus block without the need for a complete anatomic ablation line. METHODS: This was a prospective, randomized single center study. Twenty patients underwent CTI ablation during atrial flutter. In group I (10 pts) CTI ablation was performed with complete anatomical ablation line. In group II (10 pts) ablation was guided by the highest amplitude potentials on the CTI sequentially until bidirectional isthmus block was reached. The following parameters were compared: acute success rate, procedure time, fluoroscopy time, number of radiofrequency (RF) applications and total RF duration. RESULTS: In all patients, atrial flutter terminated during ablation. Bidirectional isthmus block could be achieved in all pts. Procedure time was shorter in group II (107 +/- 40 vs 68 +/- 19 min, p < 0.01). Significantly less fluoroscopy was used in group II (22.6 +/- 10.6 vs 12.1 +/- 3.8 min, p < 0.01). There were less RF applications in group II (27.1 +/- 21.5 vs 5.9 +/- 2.4, p < 0.001). CONCLUSIONS: (1) The major finding of this study is that MVGT is a feasible method even during ongoing atrial flutter. (2) Our data confirm that MVGT is an effective technique for CTI ablation with considerable decrease in procedure and fluoroscopy times.

Transthoracic three-dimensional echocardiography for the assessment of straddling tricuspid or mitral valves.

BACKGROUND: The advent of 3D echocardiography has provided a technique which, potentially, could afford significant additional information over conventional cross-sectional echocardiography in the assessment of patients with straddling atrioventricular valves prior to surgical correction. METHODS: Eight patients, aged from 1 month to 9.2 years, were examined with 3D echocardiography. All but three had discordant ventriculoarterial connections or double outlet right ventricle. Data suitable for reconstruction was acquired with transthoracic scanning. Right and left ventricular volumes were calculated in the 3D dataset. RESULTS: 3D echocardiography proved capable of defining the exact degree of straddling by imaging the proportion of tension apparatus attached to either side of the ventricular septum. It was able also to display the atrioventricular junction "en face", thus permitting identification of the precise site of insertion of the muscular ventricular septum relative to the atrioventricular junction. This made it possible first, to calculate the degree of valvar override, and second, to predict the location of the penetrating atrioventricular bundle. End-diastolic volume of the right ventricle in those with straddling tricuspid valves was 73 (61-83)% of normal, and, of the left ventricle in those with mitral valvar straddling 71 (40-97)% of normal. CONCLUSIONS: 3D echocardiography can aid in planning the optimal surgical procedure in patients with straddling or overrriding atrioventricular valves, as it provides diagnostic information superior to standard cross-sectional techniques. It also allows for exact measurement of the volumes of the respective ventricles.

[Quantitative assessment of pulmonary regurgitation by two-dimensional Doppler color flow imaging: postoperative evaluation of patients with tetralogy of Fallot].

Pulmonary regurgitation (PR) is a serious event following surgical repair for tetralogy of Fallot. For quantitative assessments of PR using noninvasive methods, we performed Doppler color flow imaging in 38 children, whose ages ranged from three to 15 years. All images were obtained from one to 10 years after surgery. The right ventricle and pulmonary valve were demonstrated in the parasternal short-axis view. The images of PR flow were in red and were frozen when the area of a signal was maximum (early to mid diastole). The PR distance index (PRDI), which is the maximum PR flow distance divided by square root of the body surface area, was measured. The PR area index (the maximum PR flow area/body surface area) (PRAI) was also calculated using a track ball. Cardiac catheterization was performed for 12 patients without residual L-R shunts or any apparent tricuspid regurgitation. PR was graded (0 = absent, 1 = trivial, 2 = mild, 3 = moderate, 4 = severe) according to the projection of contrast medium in the right ventricle as seen on the main pulmonary arteriogram. The size of the right ventricle was expressed as the right ventricular end-diastolic volume (RVEDV; % of normal), as determined from the cineangiogram, and the tricuspid valve annulus diameter (TVD; % of normal) from a four-chamber view of the two-dimensional echocardiogram. There were significant differences between the PRDI and the PRAI of five patients with PR of grades 1-2 and those of seven patients with PR of grade 3-4 (p less than 0.01, p less than 0.01, respectively). There was significant correlation between the % RVEDV and the % TVD observed (r = 0.82, p less than 0.01). Significant negative correlations were observed between the PRDI and right ventricular ejection fraction (RVEF), and the PRAI and RVEF (r = -0.68, p less than 0.02; r = -0.82, p less than 0.01, respectively). RVEF was below normal in all seven patients (100%) with PR of grade 3 or more and in one of five patients (20%) with PR of grade 2 or less. The PRDI of 2.5 or more, or the PRAI of 4.0 or more was equivalent to a PR of grade 3 or more and was a reliable index of significant PR.(ABSTRACT TRUNCATED AT 400 WORDS)

[Intraoperative assessment of the reconstruction of atrioventricular valves using transesophageal echocardiography]. / Intraoperative Beurteilung der Rekonstruktion von Atrioventrikularklappen mittels transösophagealer Echokardiographie.

To obtain good results in cardiac valve reconstruction surgery it is necessary to assess intraoperatively the efficiency of mitral or tricuspid valve repair. In 15 patients (three with mitral stenosis, 12 with mitral insufficiency) the mitral valve, in eight patients the tricuspid valve and in two patients both av-valves were reconstructed individually by commissurotomy and/or annulorrhaphy. During cardiac arrest, the valves were tested by filling the left or right ventricle with saline solution. After weaning from the extra-corporeal-circulation (ECC) I-2 cm3 of agitated Gelifundol were injected into the ventricle and the amount of regurgitation of micro-bubbles into the atrium was assessed by intraoperative two-dimensional transesophageal echocardiography. In 20 patients, testing during cardiac arrest and contrast echocardiography showed identical and good results. In two patients, the efficiency of mitral or tricuspid reconstruction could be finally verified by transoesophageal echocardiography. In another patient who was operated because of HOCM and a severe mitral insufficiency, the Bigelow procedure was combined with mitral valve reconstruction. Intraoperative open testing showed a good functional result, but a remaining severe mitral insufficiency was detected by transesophageal contrast echocardiography. An intraoperative decision for valve replacement was made. Our results show that transesophageal contrast echocardiography is a simple and accurate method of assessing the efficiency of valve reconstruction procedures. In some cases it gives more information than testing during cardiac arrest.