Overview of mitral valve replacement versus mitral valve repair due to ischemic papillary muscle rupture: A meta-analysis inspired by a case report.

BACKGROUND: Papillary muscle rupture (PMR) is an infrequent but catastrophic complication after myocardial infarction (MI). Surgical procedure is considered the optimal treatment, despite high risk. However, the gold standard technique is still a major dilemma. Therefore, a meta-analysis was carried out to assess and provide an overview comparing mitral valve replacement (MVR) and mitral valve repair (MVr) for PMR post-MI. METHODS: A systematic literature search was performed. Data were extracted and verified using a standardized data extraction form. Meta-analysis was realized mainly using RevMan 5.4 software. RESULTS: From four observational studies 1640 patients were identified; 81% underwent MVR and 19% MVr. Operative mortality results were significantly higher in MVR group than the MVr group. MVR was performed under emergency conditions and patients admitted in cardiogenic shock or who required the use of mechanical cardiac support underwent MVR. MVr had shorter time of hospitalization and similar incidence of postoperative complications than MVR. No significant differences existed between the two procedures regarding cardiopulmonary bypass time. CONCLUSIONS: Mitral valve repair appears to be a viable alternative to MVR for post-MI PMR, given that it has lower operative mortality, shorter time of hospitalization and similar incidence of short-term postoperative complications than MVR. However, it needs to be pointed out that MVR was associated with the most critical clinical condition following PMR. There is uncertainty regarding the overall survival and improvement of the quality of life between the procedures. Nevertheless, further completed investigation is required.

Comparison of robotic magnetic navigation-guided and manual catheter ablation of ventricular arrhythmias arising from the papillary muscles.

Aims: Due to the complex anatomy of the left ventricular (LV) and right ventricular (RV) papillary muscles (PMs), PM ventricular arrhythmias (VAs) can be challenging to target with ablation. We sought to compare the outcomes of robotic magnetic navigation-guided (RMN) ablation and manual ablation of VAs arising from the LV and RV PMs. Methods and results: We evaluated 35 consecutive patients (mean age 65 ± 12 years, 69% male) who underwent catheter ablation of 38 VAs originating from the LV and RV PMs as confirmed by intracardiac echocardiography. Catheter ablation was initially performed using RMN-guidance in 24 (69%) patients and manual guidance in 11 (31%) patients. Demographic and procedural data were recorded and compared between the two groups. The VA sites of origin were mapped to 20 (53%) anterolateral LV PMs, 14 (37%) posteromedial LV PMs, and 4 (11%) RV PMs Acute successful ablation was achieved for 20 (74%) VAs using RMN-guided ablation and 8 (73%) VAs using manual ablation (P = 1.000). Fluoroscopy times were significantly lower among patients undergoing RMN ablation compared to patients undergoing manual ablation [median 7.3, interquartile range (IQR) 3.9-18 vs. 24 (16-44) min; P = 0.005]. Retrograde transaortic approach was used in 1 (4%) RMN patients and 5 (46%) manual patients (P = 0.005). No procedural complications were seen in study patients. Conclusion: Use of an RMN-guided approach to target PM VAs results in comparable success rates seen with manual ablation but with lower fluoroscopy times and decreased use of transaortic retrograde access.

The tip of the muscle is a dominant location of ventricular ectopy originating from papillary muscles in the left ventricle.

INTRODUCTION: Frequent ventricular premature complexes (VPCs) may cause symptoms and/or lead to deterioration of LV systolic function. Although frequent VPCs may be abolished by catheter ablation, it may be challenging in case of their origin from the LV papillary muscles (PMs). Our collaborative study aimed to analyze in detail the site of origin and the outcome of ablation. METHODS: Consecutive 34 patients (males: 68%; aged 62 ± 12 years; LV ejection fraction: 50 ± 9%) undergoing catheter ablation of VPCs originating from PMs were included. All procedures were guided by intracardiac echocardiography. RESULTS: The size and shape of PMs were highly variable. The length of anterolateral and posteromedial PM was 23 ± 4 mm and 28 ± 7 mm, respectively. In about one-third of patients, the PM was formed by two distinctly separate heads. The ectopic foci were located on anterolateral, posteromedial or both PM in 35%, 56% and 9% of cases, respectively. Their location was found within the distal, mid, or proximal (basal) third of PM in the 67%, 19%, and 14%, respectively. A total of 86% of PM foci were acutely abolished and long-term success was achieved in 65% of patients. Absence of VPCs of other morphologies and a high burden of ectopic activity before ablation were associated with favorable clinical outcome. CONCLUSION: VPCs originate predominantly from the distal portion of the PM. This knowledge may facilitate the mapping in patients with infrequent ectopic beats. Intracardiac echocardiography is of crucial importance for navigation of the ablation catheter and for assessment of its stability at PM target sites.

Imaging characteristics of papillary muscle site of origin of ventricular arrhythmias in patients with mitral valve prolapse.

BACKGROUND: Mitral valve prolapse has been associated with increased risk of ventricular arrhythmias. We aimed to examine whether certain cardiac imaging characteristics are associated with papillary muscle origin of ventricular arrhythmias in these patients. METHODS AND RESULTS: We screened electronic medical records of all patients documented to have mitral valve prolapse on either transthoracic echocardiogram (TTE) or cardiac magnetic resonance imaging (CMR) in our center, who also underwent an electrophysiologic study (EPS) between 2007 and 2016. Anterior and posterior mitral leaflet thickness and prolapsed distance were measured on TTE and late gadolinium enhancement (LGE) was assessed on CMR. Patients were categorized as papillary muscle positive (pap (+)) or negative (pap (-)) using EPS. Eighteen patients were included in this study. Of the 15 patients who underwent TTE, a significantly higher proportion of patients in the pap (+) group had an anterior to posterior leaflet prolapse ratio of >0.45 indicating more symmetric leaflet prolapse. There were no differences in anterior or posterior leaflet thickness or prolapse distance between the groups. Patients in the pap (+) group were more likely to be women. Of the 7 patients who underwent CMR, those who were pap (+) were more likely to have LGE in the region of the papillary muscles than those who were pap (-). CONCLUSION: Female gender, more symmetric bileaflet prolapse on TTE, and the presence of papillary muscle LGE on CMR may be associated with papillary muscle origin of ventricular arrhythmias in patients with mitral valve prolapse.

Intracardiac echo-facilitated 3D electroanatomical mapping of ventricular arrhythmias from the papillary muscles: assessing the 'fourth dimension' during ablation.

AIMS: Ventricular arrhythmias (VA) originating from a papillary muscle (PM) have recently been described as a distinct clinical entity with peculiar features that make its treatment with catheter ablation challenging. Here, we report our experience using an intracardiac echo-facilitated 3D electroanatomical mapping approach in a case series of patients undergoing ablation for PM VA. METHODS AND RESULTS: Sixteen patients who underwent catheter ablation for ventricular tachycardia (VT) or symptomatic premature ventricular contractions originating from left ventricular PMs were included in the study. A total of 24 procedures (mean 1.5 per patient) were performed: 15 using a retrograde aortic approach and 9 using a transseptal approach. Integrated intracardiac ultrasound for 3D electroanatomical mapping was used in 15 of the 24 procedures. The posteromedial PM was the most frequent culprit for the clinical arrhythmia, and the body was the part of the PM most likely to be the successful site for ablation. The site of ablation was identified based on the best pace map matching the clinical arrhythmia and the site of earliest the activation. At a mean follow-up of 10.5 ± 7 months, only two patients had recurrent arrhythmias following a repeat ablation procedure. CONCLUSION: An echo-facilitated 3D electroanatomical mapping allows for real-time creation of precise geometries of cardiac chambers and endocavitary structures. This is useful during procedures such as catheter ablation of VAs originating from PMs, which require detailed representation of anatomical landmarks. Routine adoption of this technique should be considered to improve outcomes of PM VA ablation.

[Recurrent transient ischemic stroke in a young patient with papillary fibroelastoma of the mitral valve and hyperhomocysteinemia. A case report]. / Accidents vasculaires cérébraux ischémiques transitoires récurrents chez une jeune patiente secondaire à un fibroélastome papillaire de la valve mitrale et une hyperhomocystéïnémie. A propos d'une observation.

We describe a case of a young patient admitted for recurrent ischemic stroke caused by a papillary fibroelastoma of the mitral valve and a hyperhomocysteinemia. A papillary fibroelastoma is a benign cardiac tumor which can be associated with serious embolic complications. A moderate plasma level of hyperhomocysteinemia is considered as a risk factor of ischemic stroke. The authors suggest that this association increases the risk of ischemic stroke in their patient. The tumor was surgically removed to avoid new embolic events associated with a vitamin B supplementation. After surgery and acid folic supplementation, no recurrence was observed.

Intrapericardial echocardiography: a novel catheter-based approach to cardiac imaging.

BACKGROUND: Transvascular catheter-based intracardiac echocardiography has been successfully used to help guide catheter ablation and electrophysiologic procedures. It has recently been demonstrated that catheters can be safely placed into the pericardial space to allow for epicardial cardiac mapping and ablation. We evaluated the feasibility of catheter-based intrapericardial echocardiography (IPE) during such procedures to identify cardiac structures and visualize intracardiac catheters. METHODS: IPE was performed in 7 goats by placing a phased-array ultrasound transducer contained within a 10F steerable catheter into the pericardial space using the same transthoracic subxyphoid approach as used to map and ablate epicardial ventricular tachycardia. Images were obtained of cardiac structures and of intracardiac ablation catheters. After the procedure, the hearts were harvested to assess for possible IPE-related lesions. RESULTS: The IPE catheter could be easily placed inside the pericardial space in all animals. In 7 of 7 cases, longitudinal and short-axis views of right- and left-sided chambers and valves were obtained, similar in orientation to transesophageal echocardiography. Visualization of atrial appendages (6/7), pulmonary veins (6/7), coronary arteries (6/7), and coronary sinus (3/6) was also feasible. Assessment of intracardiac transvalvar and venous blood flow was achieved by spectral and color Doppler. The ablation catheter could be clearly visualized inside cardiac chambers. No arrhythmias were induced with IPE catheter manipulation. After harvesting the hearts, no lesions resulting from the procedure were observed. CONCLUSION: In this experimental setting, IPE was able to provide detailed images of cardiac structures and establish the relative position of the ablation catheter.

Ventricular remodeling induced by retinoic acid supplementation in adult rats.

Retinoic acid (RA) plays a role in regulating cardiac geometry and function throughout life. The aim of this study was to analyze the cardiac effects of RA in adult rats. Wistar rats were randomly allocated to a control group (n = 18) receiving standard rat chow and a group treated with RA (n = 14) receiving standard rat chow supplemented with RA for 90 days. All animals were evaluated by echocardiography, isolated papillary muscle function, and morphological studies. Whereas the RA-treated group developed an increase in both left ventricular (LV) mass and LV end-diastolic diameter, the ratio of LV wall thickness to LV end-diastolic diameter remained unchanged when compared with the control group. In the isolated papillary muscle preparation, RA treatment decreased the time to peak developed tension and increased the maximum velocity of isometric relengthening, indicating that systolic and diastolic function was improved. Although RA treatment produced an increase in myocyte cross-sectional area, the myocardial collagen volume fraction was similar to controls. Thus our study demonstrates that small physiological doses of RA induce ventricular remodeling resembling compensated volume-overload hypertrophy in rats.

Transient mitral regurgitation following vagal stimulation-induced ventricular arrhythmia in rabbits: a color Doppler echocardiographic study.

BACKGROUND AND AIM OF THE STUDY: Cervical vagal stimulation in rabbits frequently causes systolic murmur with bigeminy due to premature ventricular contractions. The bigeminy disappears in a few minutes, but the systolic murmur persists for a few days. Peculiar lesions of the mitral valves, mitral annulus and papillary muscles, and an increase in left atrial weight, frequently develop in a week. In this study, color Doppler echocardiography was used to examine whether the systolic murmur was due to mitral regurgitation. METHODS: Echocardiographic monitoring was carried out in anesthetized rabbits restrained in the supine position. RESULTS: Doppler echocardiography and phonocardiography showed systolic murmur at 6 h, three days, and at one, two, three and four weeks after vagal stimulation. At 6 h after stimulation, phonocardiography showed systolic click and late systolic murmur; Doppler echocardiography showed marked mitral regurgitation. The systolic murmur and mitral regurgitation were attenuated and the papillary muscle was swollen three days after vagal stimulation. Following stimulation, mitral regurgitation disappeared within one week, and papillary muscle swelling improved after three weeks. CONCLUSION: Doppler echocardiography confirmed that systolic murmur caused by vagal stimulation in rabbits was due to mitral regurgitation.