Mid-term outcomes of right ventricular papillary muscle approximation for severe functional tricuspid regurgitation.

OBJECTIVES: Recurrence of tricuspid regurgitation (TR) after tricuspid annuloplasty can occur in cases where a dilated right ventricle exists and subsequent leaflet tethering follows. We previously reported a new technique of the right ventricular papillary muscle approximation (RV-PMA) for functional TR associated with leaflet tethering. The objective of this study is to elucidate the mid-term outcomes and evaluate the durability of RV-PMA. METHODS: Between January 2014 and March 2023, we applied RV-PMA in 20 patients of advanced functional TR with severe leaflet tethering. The indication of the technique was severe TR with leaflet tethering height >8 mm, and/or a right ventricular end-diastolic diameter >45 mm. The patients were followed up with echocardiography before discharge and at annual interval thereafter. RESULTS: There was no perioperative mortality. In the echocardiography performed before discharge, TR was decreased to mild or less in 85%, and a significant improvement in right ventricular end-diastolic diameter and tethering height were achieved (53-45 mm and 11.1-4.4 mm, respectively). Furthermore, during the median 3-year follow-up period, TR was kept controlled mild or less in 80% of the cases. CONCLUSIONS: RV-PMA is considered to be a safe, effective and durable technique as an additional approach for tricuspid annuloplasty.

Current management of tricuspid regurgitation: a focus on the spiral suspension approach.

The indication for surgery for tricuspid regurgitation (TR) has reached a major turning point. It has become clear that the presence of moderate or severe TR alone worsens the prognosis of life, and the previous guidelines of Japanese Circulation Society, in which the indication for surgery was recommended at the timing of "right heart failure difficult to treat medically," now recommends surgery with a trigger of "repeated right heart failure" in the 2020 edition. In addition, a new repair technique targeting at subvalvular structure has been developed for end-stage TR to overcome a high TR recurrence rate that is associated with severe right ventricular enlargement and leaflet tethering. This review focuses on the spiral suspension technique, in which the papillary muscles are spirally suspended towards the septal leaflet annulus to correct tethering and enhances the understanding of its application in the context of TR management.

Interpapillary muscle distance independently predicts recurrent mitral regurgitation.

OBJECTIVE: Ischaemic secondary mitral regurgitation (ISMR) after surgery is due to the displacement of papillary muscles resulting from progressive enlargement of the left ventricle end-diastolic diameter (LVEDD). Our aim was to prove that if the interpapillary muscle distance (IPMD) is surgically stabilized, an increase in LVEDD will not lead to a recurrence of ischaemic mitral regurgitation (MR). METHODS: Ninety-six patients with ISMR, who underwent surgical revascularisation and annuloplasty, were randomly assigned in a 1:1 ratio to undergo papillary muscle approximation (PMA). At the 5-year follow-up, we assessed the correlation between PMA and echocardiographic improvements, the effect size of PMA on echocardiographic improvements, and a prediction model for recurrent MR using inferential tree analysis. RESULTS: There was a significant correlation between PMA and enhancements in both the α and ß angles (Spearman's rho > 0.7, p < 0.01). The α angle represents the angle between the annular plane and either the A2 annular-coaptation line or the P2 annular-coaptation line. The ß angle indicates the angle between the annular plane and either the A2 annular-leaflet tip line or the P2 annular-leaflet tip line. PMA led to substantial improvements in LVEDD, tenting area, α and ß angles, with a large effect size (Hedge's g ≥ 8, 95% CI ORs ≠ 1). The most reliable predictor of recurrent MR grade was the interpapillary distance, as only patients with an interpapillary distance greater than 40 mm developed ≥ 3 + grade MR. For patients with an IPMD of 40 mm or less, the best predictor of recurrent MR grade was LVEDD. Among the patients, only those with LVEDD greater than 62 mm showed moderate (2+) MR, while only those with LVEDD less than or equal to 62 mm had absent to mild (1+) MR. CONCLUSION: Prediction of recurrent ischaemic MR is not independent of progressive LVEDD increase. PMA-based surgical procedure stabilises IPMD.

Resection of hypertrophic papillary muscles and mitral valve replacement in a patient with midventricular hypertrophic obstructive cardiomyopathy - a new approach.

Midventricular hypertrophic obstructive cardiomyopathy (HOCM) is characterized by hypertrophy of the interventricular septum (IVS) and - in rare cases - of the papillary muscles (PM), which subsequently can cause dynamic left ventricular outflow tract obstruction (LVOTO) and severe heart failure symptoms. We report on a rare case of a 44-year-old patient suffering from midventricular HOCM with hypertrophic anterolateral PM and an additional chorda between the PM and the IVS.We describe a new surgical approach via right anterolateral thoracotomy in 3-dimensional (3D) video-assisted minimal-invasive technique with resection of hypertrophic PMs as well as the entire mitral valve-apparatus and valve replacement avoiding septal myectomy and potentially associated complications. After an uneventful procedure clinical symptoms improved from NYHA III-IV at baseline to NYHA 0-I postoperatively and remained stable over a follow-up period of 24 months. Therefore, the presented technique may be considered as a new and alternative approach in patients with hypertrophic PMs and hypertrophic IVS as subtype of midventricular HOCM.

Posterior Papillary Muscle Suspension for Treating Systolic Anterior Motion in Hypertrophic Obstructive Cardiomyopathy.

Systolic anterior motion of the anterior mitral leaflet can persist after ventricular septal myectomy for obstructive hypertrophic cardiomyopathy, resulting in residual pressure gradients and mitral regurgitation. However, additional procedures for systolic anterior motion involving mitral valve leaflet suturing and resection may lead to future valve disease. Therefore, we adopted posterior papillary muscle suspension, a subvalvular procedure for functional mitral regurgitation, to treat systolic anterior motion without directly intervening in the mitral valve leaflets. Papillary muscle suspension toward the posterior mitral annulus moved the papillary muscles away from the interventricular septum and successfully eliminated the systolic anterior motion and midventricular pressure gradient. In terms of avoiding direct mitral interventions, this procedure is a viable option for systolic anterior motion, especially in cases of very mild mitral regurgitation.

Neochordal Goldilocks: Analyzing the biomechanics of neochord length on papillary muscle forces suggests higher tolerance to shorter neochordae.

OBJECTIVE: Estimating neochord lengths during mitral valve repair is challenging, because approximation must be performed largely based on intuition and surgical experience. Little data exist on quantifying the effects of neochord length misestimation. We aimed to evaluate the impact of neochord length on papillary muscle forces and mitral valve hemodynamics, which is especially pertinent because increased forces have been linked to aberrant mitral valve biomechanics. METHODS: Porcine mitral valves (n = 8) were mounted in an ex vivo heart simulator, and papillary muscles were fixed to high-resolution strain gauges while hemodynamic data were recorded. We used an adjustable system to modulate neochord lengths. Optimal length was qualitatively verified by a single experienced operator, and neochordae were randomly lengthened or shortened in 1-mm increments up to ±5 mm from the optimal length. RESULTS: Optimal length neochordae resulted in the lowest peak composite papillary muscle forces (6.94 ± 0.29 N), significantly different from all lengths greater than ±1 mm. Both longer and shorter neochordae increased forces linearly according to difference from optimal length. Both peak papillary muscle forces and mitral regurgitation scaled more aggressively for longer versus shorter neochordae by factors of 1.6 and 6.9, respectively. CONCLUSIONS: Leveraging precision ex vivo heart simulation, we found that millimeter-level neochord length differences can result in significant differences in papillary muscle forces and mitral regurgitation, thereby altering valvular biomechanics. Differences in lengthened versus shortened neochordae scaling of forces and mitral regurgitation may indicate different levels of biomechanical tolerance toward longer and shorter neochordae. Our findings highlight the need for more thorough biomechanical understanding of neochordal mitral valve repair.

Right ventricular papillary muscle approximation to the septum as an adjunct technique during tricuspid valve repair in congenital heart surgery.

OBJECTIVE: Tricuspid regurgitation is often caused by leaflet splaying from displaced papillary muscles or ventricular dilatation. Traditional annuloplasty may not address this mechanism. The present study describes a single institution's experience using right ventricular papillary muscle approximation for tricuspid valve repair. METHODS: Right ventricular papillary muscle approximation consists of suturing the anterior papillary muscle to a point of the septum (septum or septal papillary muscle) that optimizes leaflet coaptation. We describe our technique and analyze clinical data of patients undergoing tricuspid valve repair with right ventricular papillary muscle approximation during congenital heart surgery between 2012 and 2021. RESULTS: Right ventricular papillary muscle approximation was performed as an adjunct procedure in 207 of 825 tricuspid valve repairs (25.1%). Discharge tricuspid regurgitation grade was mild tricuspid regurgitation or less in 153 patients (73.9%), and 140 patients (67.6%) had mild tricuspid regurgitation or less at a median latest follow-up of 3.2 years (interquartile range, 0.7-6.8). Thirty patients (14.5%) underwent 11 early tricuspid valve reinterventions (3 due to right ventricular papillary muscle approximation dehiscence) and 21 late tricuspid valve reinterventions. Estimated 5-year freedom from tricuspid valve reintervention was 84% (95% CI, 77.0-89.2). Systemic right ventricle physiology (odds ratio, 2.88, P = .048) and multiple mechanisms of tricuspid regurgitation (odds ratio, 7.35, P = .038) were significant predictors of tricuspid valve reintervention on multivariable analysis. CONCLUSIONS: Tricuspid valve repair with right ventricular papillary muscle approximation demonstrates acceptable short-term durability, but similar to other tricuspid valve repair strategies is less durable in patients with systemic right ventricle pressure and multiple mechanisms of tricuspid regurgitation. Right ventricular papillary muscle approximation is a safe and effective adjunct technique that should be considered in patients with tricuspid regurgitation caused by leaflet splaying from displaced papillary muscles or right ventricle dilatation.

Rough-zone suspension with mitral valve replacement for ventricular functional mitral regurgitation.

Chordal preservation is recommended in mitral valve replacement for functional mitral regurgitation to preserve left ventricular function. In contrast, papillary muscle suspension toward the anterior mitral annulus can induce left ventricular reverse remodeling after mitral valve replacement for functional mitral regurgitation. However, the extent of suspension depends on the surgeon's experience. Therefore, we developed a new concept of chordal preservation, called rough-zone suspension, which not only spares the subvalvular structure but also suspends the papillary muscles toward the annulus. This procedure is simple and reproducible for determining the extent of suspension, and can increase the probability of left ventricular reverse remodeling after mitral valve replacement for functional mitral regurgitation.

[Traumatic Right Atrial Rupture and Right Ventricular Papillary Muscle Rupture].

A 18-year-old man was driving at 100 km/h on a motorbike and collided with a utility pole. He was taken to our hospital in a state of shock due to an unstable pelvic fracture and cardiac tamponade. Pericardial drainage was carried out, but intrapericardial hemorrhage persisted and the patient underwent emergency thoracotomy and suture of right atrial injury. After hemodynamic condition improved, the patient was transferred to a tertiary care facility. For the pelvic fracture, open reduction and fixation was performed on the 6th day after injury. During recovery, moderate mitral valve regurgitation and severe tricuspid valve regurgitation due to rupture of the right ventricular papillary muscle were diagnosed. The patient's exercise tolerance was too reduced to continue rehabilitation. Thirty-seven days after the injury, mitral and tricuspid valve repair was performed. Four months after the injury, he was discharged without sequelae.

Echocardiographic diagnosis of rupture of mitral valve papillary muscle.

OBJECTIVE: To explore the value of echocardiography in diagnosing papillary muscle rupture (PMR) of the mitral valve, and summarize the characteristic echocardiographic features of different types. METHODS: Echocardiograms of 13 PMR patients confirmed by surgery in Wuhan Union Hospital between January 2009 and December 2022 were retrospectively analyzed and their preoperative transthoracic echocardiography (TTE) was compared with surgical findings. RESULTS: A total of 9020 patients underwent mitral valve repair or replacement surgery during the study period including 13 (0.14%) for PMR. Of the 13 PMRs, 8 cases were partial PMR(P-PMR), 5 cases were complete PMR(C-PMR); 3 cases were anterolateral PMR, and 10 were posteromedial PMR. The diagnostic accuracy, sensitivity, and specificity of the preoperative TTE were 99.9%, 53.8% and 99.9% respectively. Echocardiographic features of 10 patients (5-C-PMR and 5 P-PMR) with detailed TTE and intraoperative transesophageal echocardiography (TEE) data included: both anterior and posterior leaflets prolapse (C-PMR 60% vs P-PMR 60%); flail leaflet (C-PMR100% vs P-PMR 40%); All C-PMRs and P-PMRs have severe, eccentric and lateral regurgitation; flail attachment (chordae tendinae and ruptured PM) at the tip of prolapsed leaflet (C-PMR100% vs P-PMR 60%); high-echo masses resembled "champagne glasses" in 100% of the C-PMR; high-echo masses resembled "lotus-seedpod" in 60% and "dumbbell-shaped" torn PM in remaining 40% of the P-PMR. CONCLUSIONS: Different PMR subtypes have different echocardiographic characteristics. Combining TTE and TEE can accurately identify the typical features of PMR such as ipsilateral hemipetal leaflet prolapse, high-echoic mass at the tip of the leaflet, massive eccentricity and lateral regurgitation.

Use of a QDOT MICRO catheter to identify a premature ventricular contraction origin in the right ventricular anterior papillary muscle in a repaired truncus arteriosus.

The ventricular papillary muscles (VPMs) can be a source of premature ventricular contractions (PVCs). Catheter ablation of VPM PVCs is challenging because of the anatomical complexity, such as the apical structures in proximity to the ventricular walls. The QDOT MICRO catheter (Biosense Webster, Diamond Bar, CA, USA) has microelectrodes embedded along the circumference of its distal tip and can provide information on which side of its tip myocardial activation is earlier. This repaired truncus arteriosus case demonstrates the usefulness of the microelectrode recording in identifying a PVC origin in a right VPM apex close to the right ventricular anterior wall.

Implications of the anatomy of papillary muscle connections for mapping and ablation of focal ventricular arrhythmias.

BACKGROUND: Ventricular arrhythmias (VAs) originating from papillary muscles (PAPs) can be challenging when targeted with catheter ablation. Reasons may include premature ventricular complex pleomorphism, structurally abnormal PAPs, or unusual origins of VAs from PAP-myocardial connections (PAP-MYCs). OBJECTIVE: The purpose of this study was to correlate PAP anatomy with mapping and ablation of PAP VAs. METHODS: In a series of 43 consecutive patients with frequent PAP arrhythmias referred for ablation, the anatomy and structure of PAPs and VA origins were analyzed using multimodality imaging. Successful ablation sites were analyzed for location on the PAP body or a PAP-MYC. RESULTS: In a total of 17 of 43 patients (40%), VAs originated from a PAP-MYC (in 5 of 17 patients, the PAP inserted into the mitral valve anulus); and in 41 patients, VAs originated from a PAP body. VAs from a PAP-MYC more often had delayed R-wave transition than did other PAP VAs (69% vs 28%; P < .001). Patients with failed procedures had more PAP-MYCs (24.8 ± 8 PAP-MYCs per patient vs 16 ± 7 PAP-MYCs per patient; P < .001). CONCLUSION: Multimodality imaging identifies anatomic details of PAPs that facilitate mapping and ablation of VAs. In more than a third of patients with PAP VAs, VAs originate from connections between PAPs and the surrounding myocardium or between other PAPs. VA electrocardiographic morphologies are different when VAs originate from PAP-connection sites as compared with VAs originating from the PAP body.

Papillary muscle approximation in chronic ovine functional tricuspid regurgitation.

OBJECTIVE: Isolated tricuspid ring annuloplasty remains the surgical standard for functional tricuspid regurgitation repair but offers suboptimal results when right ventricular dilation and remodeling along with papillary muscle displacement is present. Addressing subvalvular remodeling with papillary muscle approximation may improve clinical outcomes. METHODS: Functional tricuspid regurgitation and biventricular dysfunction were induced in 8 healthy sheep by rapid ventricular pacing (200-240 bpm) for 27 ± 6 days. Subsequently, animals underwent cardiopulmonary bypass for implantation of sonomicrometry crystals on the tricuspid annulus, right ventricle, and papillary muscle tips. Papillary approximation sutures were anchored between anterior-posterior and anterior-septal papillary muscles and externalized through right ventricular free wall to epicardial tourniquets. After weaning from cardiopulmonary bypass, sequential papillary muscle approximations were performed. Simultaneous hemodynamic, sonomicrometry, and echocardiographic data were collected at baseline and after each papillary muscle approximation. RESULTS: With rapid pacing, right ventricular fractional area change decreased from 59 ± 6% to 38 ± 8% (P < .001), whereas tricuspid annulus diameter increased from 2.4 ± 0.3 cm to 3.3 ± 0.6 cm (P = .003). Tricuspid regurgitation (0-4+) increased from +0 ± 0 to +3.3 ± 0.7 (P < .001). Both anterior-posterior and anterior-septal papillary muscle approximation significantly reduced functional tricuspid regurgitation from +3.3 ± 0.7 to +2 ± 0.5 and +1.9 ± 0.6, respectively (P < .001). Reduction of tricuspid insufficiency with both subvalvular interventions was associated with decreased distance of the anterior papillary muscle to the annular centroid. CONCLUSIONS: Papillary muscle approximations were effective in reducing severe ovine functional tricuspid regurgitation associated with right ventricular dilation and papillary muscle displacement. Further studies are needed to evaluate efficacy of this adjunct to ring annuloplasty in repair of severe functional tricuspid regurgitation.

Acute inferior myocardial infarction combined with papillary muscle rupture: A case report. / 急性下壁心肌梗死合并乳头肌断裂1例.

The incidence of acute myocardial infarction (AMI) is increasing. Acute papillary muscle rupture is one of the serious and rare mechanical complications of AMI, which occurs mostly in inferior and posterior myocardial infarction. A patient with acute inferior myocardial infarction developed pulmonary edema and refractory shock, followed by cardiac arrest. After cardiopulmonary resuscitation (CPR), revascularization of criminal vessels was carried out by emergency percutaneous transluminal coronary angioplasty (PTCA) under the support of intra-aortic balloon pump (IABP) and extra corporeal membrane oxygenation (ECMO). Although the patient was given a chance for surgery, his family gave up treatment due to unsuccessful brain resuscitation. It reminds that mechanical complications such as acute papillary muscle rupture, valvular dysfunction and rupture of the heart should be highly suspected when cardiogenic pulmonary edema and cardiogenic shock are difficult to correct in acute inferior myocardial infarction. Echocardiogram and surgery should be put forward when revascularization of criminal vessels is available.

Transcatheter edge-to-edge mitral valve repair for post-myocardial infarction papillary muscle rupture and acute heart failure: A systematic review.

Papillary muscle rupture (PMR) is a rare complication of acute myocardial infarction (AMI) associated with high mortality and morbidity. Surgery is the gold-standard treatment for these patients, but it is burdened by a high perioperative risk due to hemodynamic instability. Mitral transcatheter edge-to-edge repair (M-TEER) was reported to be safe and effective in unstable patients with significant mitral regurgitation. However, data in patients with post-AMI PMR are limited to a few case reports. In this review, we summarized all data available regarding percutaneous treatment of post-AMI PMR. These results show that M-TEER is safe and effective in this setting with low in-hospital mortality and complications and high rate of significant mitral regurgitation reduction.

Extracorporeal life support in mitral papillary muscle rupture: Outcome of multicenter study.

BACKGROUND: Post-acute myocardial infarction papillary muscle rupture (post-AMI PMR) may present variable clinical scenarios and degree of emergency due to result of cardiogenic shock. Veno-arterial extracorporeal life support (V-A ECLS) has been proposed to improve extremely poor pre- or postoperative conditions. Information in this respect is scarce. METHODS: From the CAUTION (meChanical complicAtion of acUte myocardial infarcTion: an InternatiOnal multiceNter cohort study) database (16 different Centers, data from 2001 to 2018), we extracted adult patients who were surgically treated for post-AMI PMR and underwent pre- or/and postoperative V-A ECLS support. The end-points of this study were in-hospital survival and ECLS complications. RESULTS: From a total of 214 post-AMI PMR patients submitted to surgery, V-A ECLS was instituted in 23 (11%) patients. The median age was 61.7 years (range 46-81 years). Preoperatively, ECLS was commenced in 10 patients (43.5%), whereas intra/postoperative in the remaining 13. The most common V-A ECLS indication was post-cardiotomy shock, followed by preoperative cardiogenic shock and cardiac arrest. The median duration of V-A ECLS was 4 days. V-A ECLS complications occurred in more than half of the patients. Overall, in-hospital mortality was 39.2% (9/23), compared to 22% (42/219) for the non-ECLS group. CONCLUSIONS: In post-AMI PMR patients, V-A ECLS was used in almost 10% of the patients either to promote bridge to surgery or as postoperative support. Further investigations are required to better evaluate a potential for increased use and its effects of V-A ECLS in such a context based on the still high perioperative mortality.

Papillary muscle ventricular ectopy ablation in a malignant mitral valve prolapse: Ablation in Malignant Mitral Valve Prolapse: Ablation in Malignant Mitral Valve Prolapse.

Patients with mitral valve prolapse (MVP) have a heterogeneous clinical spectrum, ranging from benign to severe clinical presentations such as sudden cardiac death (SCD). Some of the markers of "arrhythmic MVP" include inverted/biphasic T-waves, QT prolongation, and polymorphic premature ventricular contractions (PVCs) originating from the left ventricular outflow tract and papillary muscles (PMs). The genesis of arrhythmias in MVP recognizes the combination of the substrate (fibrosis) and the trigger (mechanical stretch). Therefore, ablation of ventricular arrhythmias originating from PMs in a patient with MVP can be considered an adjunctive strategy to lower the arrhythmic burden and reduce the risk of ICD shocks.