Anomalous papillary muscle insertion into mitral valve leaflet: Autopsy study and implications.

Anomalous papillary muscle (APM) insertion into the anterior mitral valve leaflet is often associated with hypertrophic cardiomyopathy (HCM) but is reported in other cases as a rare finding. Mere presence does not strictly imply hemodynamic disturbance, and several types exist, with various impacts on left ventricular outflow tract (LVOT) obstruction. The interpretation of isolated anomaly is challenging at autopsy because significant LVOT obstruction is dynamic. We analyzed autopsy cases with APM regarding the site of PM insertion and origin, number of PM bellies, anomalous insertions, heart weight, left ventricle (LV) thickness, LV endocardial fibrosis, subjects' age, sex, cause, and manner of death. A total of 20 cases were identified. Fourteen were identified incidentally, while in 670 systematically examined hearts, the APM was identified in six cases, indicating a prevalence of 0.9%. In eight cases, the manner of death was natural (one case with HCM), and in 12 non-natural. Type II anomaly of PM was most frequent (n = 8), followed by Type III (n = 7) and Type I (n = 5). Subjects who died of natural causes were significantly older and had heavier hearts (median 455 g vs. 330 g; p < 0.05) without difference in LV thickness (median 16 mm vs. 15 mm; p > 0.05). Histology performed in four cases showed a pattern of direct insertion of cardiomyocytes into the leaflet's thick fibrous tissue with a narrow overlapping zone. The APM is rare, can be easily overlooked, and does not imply significant pathology per se. We discussed proper assessment of the significance of this anomaly at autopsy.

Anomalous papillary muscles-Implications in the surgical treatment of hypertrophic obstructive cardiomyopathy.

OBJECTIVES: To categorize and assess the functional significance of anomalous papillary muscles in patients undergoing surgical management of obstructive hypertrophic cardiomyopathy. METHODS: We reviewed the records of operations for obstructive hypertrophic cardiomyopathy and identified 73 patients with an anomalous papillary muscle. Anomalous papillary muscles inserting directly into the body of the anterior mitral valve leaflet were classified as type I, those with both direct insertion into the body of the leaflet and attachment to the free edge of the anterior leaflet were categorized as type II, and anomalous papillary muscles inserting into the free edge of the anterior leaflet were grouped as type III. Additionally, we investigated detection rates by preoperative transthoracic echocardiography, intraoperative transesophageal echocardiography, and cardiac magnetic resonance imaging. RESULTS: The mean age of patients was 51.9 ± 12.3 years, and 49.3% were male. The anomalous papillary muscle was classified as type I in 31.5% of patients, type II in 35.6%, and type III in 32.9%. Only type I and type II anomalous papillary muscles contributed to left ventricular outflow tract obstruction. The anomalous papillary muscle was detected on preoperative transthoracic echocardiography in 11% of patients and by intraoperative transesophageal echocardiography in 27.4% of patients. No anomalous papillary muscles were identified on cardiac magnetic resonance imaging. All patients underwent septal myectomy with or without (n = 34) associated excision of the anomalous papillary muscle. Excision of the papillary muscles was more common in patients with type I and II (76.4% and 80.8%, respectively) when compared with type III (4.2%). Ten patients underwent mitral valve repair, and 1 patient had mitral valve replacement. CONCLUSIONS: Papillary muscle abnormalities are important findings in patients with obstructive hypertrophic cardiomyopathy but are not identified preoperatively in the majority of patients. Recognition of anomalous papillary muscles intraoperatively and understanding of the morphologic subtypes are critical to adequate gradient relief and preservation of mitral valve function. The optimum approach involves a transaortic extended septal myectomy associated with the resection of the anomalous papillary muscles in patients with type I and II anatomy.

Parachute mitral valve associated with reticular chordae tendineae in an adult: case report.

BACKGROUND: Parachute mitral valve with reticular chordae tendineae is an extremely rare anomaly. CASE PRESENTATION: We present a case of parachute mitral valve associated with distinctive reticular chordae tendineae in an adult. It was diagnosed from the echocardiogram. The patient was referred for surgery. Valve analysis showed thickened mitral valve leaflets and commissures. The chordae tendinae were lengthy and thick. All the chordae tendinae merged into a solitary papillary muscle. A distinctive reticular fibrous tissue was found on mitral valve apparatus as the chordae tendinae intermixed each other. The only functional communication between the left atrium and the left ventricle was through the reticular spaces. This anomaly was considered to be unrepairable and was replaced with a mechanical valve. CONCLUSIONS: An extremely rare and unique case of parachute mitral valve associated with reticular chordae tendineae was reported. Mitral valve replacement is a reasonable choice in patients with parachute mitral valve with reticular chordae tendineae.

Surgery for Anomalous Papillary Muscle Directly Into the Anterior Mitral Leaflet.

BACKGROUND: The anomalous insertion of papillary muscle directly into the anterior mitral leaflet is a rare congenital anomaly concomitant with hypertrophic cardiomyopathy. We herein report our surgical technique, which is designed to relieve left ventricular obstruction and preserve the mitral valve and subvalvular apparatus. METHODS: Among 38 patients who underwent septal myectomy from 2007 to 2020, 4 had an anomalous mitral subvalvular apparatus with papillary muscle with direct insertion into the anterior mitral leaflets. In all cases, mitral valve repair was accomplished with excision and reconstruction of all anomalous papillary muscles, concomitant with septal myectomy. In another 34 patients, 20 cases needed mitral valve repair with regard to systolic anterior motion by hypertrophic cardiomyopathy. The comparison study was conducted between the anomalous papillary muscle group (group A) and the others (group B). RESULTS: There was no early or late death in group A, and there were 3 early deaths and 2 late deaths in group B. The mean peak gradient in the left ventricle was significantly decreased in both groups. Mitral valve regurgitation grade was also significantly decreased from 3 to 0.5 without valve replacement in group A, and from 2 to 0.6 in group B. Six patients needed mitral valve replacement because of the thickness of anterior mitral leaflet in group B. CONCLUSIONS: Hypertrophic obstructive cardiomyopathy associated with the anomalous insertion of papillary muscle can be successfully treated without mitral valve replacement. Excision and reconstruction with the anomalous papillary muscle seems to be a feasible operation to reduce mitral regurgitation and relieve outflow tract obstruction.

Intraventricular muscle bundle as a novel cause of left ventricular aneurysm.

BACKGROUND: There are a variety of causes of left ventricular aneurysm, but it is rarely due to a disturbance in intraventricular hemodynamics. To the best of our knowledge, there have been no reports of ventricular aneurysm at the left ventricular apex caused by an abnormal left ventricular muscle bundle. CASE PRESENTATION: We report two cases of patients with congenital abnormal left ventricular muscle bundles which caused disturbances in intraventricular hemodynamics. This process eventually led to a left ventricular aneurysm at the apex of the heart. In both cases, transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) indicated ventricular aneurysm formation at the apex of the left ventricle. There were also abnormal muscular bundles connecting the ventricular septum and the posterior wall of the left ventricle. The only differences between these two cases were the comorbidities and severity of symptoms. CONCLUSION: Ventricular aneurysm at the apex of the left ventricle is common. However, it is rare for a ventricular aneurysm to form due to intraventricular hemodynamic disturbances caused by an abnormal muscle bundle as opposed to that due to original ventricular wall damage, which is more common. There is currently a lack of relevant studies on the treatment and prognosis of such patients. Whether surgical resection of a ventricular aneurysm leads to a better prognosis remains uncertain.

Direct insertion of papillary muscle into mitral valve leaflets in a healthy patient without hypertrophic cardiomyopathy.

We present the case of a healthy young woman that was evaluated before participation in amateur sports. A systolic and diastolic murmur was heard during the physical examination. Two-dimensional echocardiography was performed, and a direct insertion of the posteromedial papillary muscle into the mitral valve leaflets was found. Mild mitral stenosis and moderate regurgitation were also found. Because she was asymptomatic, a follow-up in 6 months was planned to control the evaluation of her valve disease.

Subdivision of the left ventricle by a discrete ridge and anomalous papillary muscle causing mid-ventricular obstruction: A case report.

A 16-year-old healthy boy visited our department because of a heart murmur. A 12-lead electrocardiogram showed left QRS axis deviation and repolarization abnormalities. Transthoracic echocardiography and a computed tomographic scan revealed a hypertrophied papillary muscle and a discrete ridge arising from the septal wall, causing mid-ventricular obstruction. Doppler echocardiography revealed that the pressure gradient at the obstruction was mild. The patient will be followed up annually, without medication or physical restriction.

Correction of left ventricular outflow tract obstruction caused by anomalous papillary muscle and subaortic membrane

Abstract This paper presents a case study of a 30-year-old male patient with dyspnea on exertion had echocardiographic diagnosis of aortic subvalvar stenosis. Discrete mitral regurgitation and aortic valve dysplasia with mild to moderate insufficiency and hypertrophic cardiomyopathy were also noted. During surgery, a rare condition was identified: presence of papillary muscle anomaly associated with the subaortic membrane as a cause of obstruction of the left ventricular outflow tract. With the resection of these structures and a mitral valve annuloplasty, the patient evolved with a significant improvement of clinical condition and heart failure, with no residual mitral insufficiency.

Starfish in the heart: Congenital anomaly of the papillary muscles.

Most common congenital anatomical abnormalities of the subvalvular apparatus (papillary muscles and chordae tendineae) are parachute or parachute like mitral valve. This is more commonly reported among the pediatric population as they develop heart failure symptoms shortly after birth. Reports of adult cases are rare and incidental. Multimodality imaging has an important role in evaluating such anatomical abnormalities, and identification of possible related complications. We are describing a rare atypical variant of parachute like mitral valve.

Left Ventricular Dilatation and Posterior Papillary Muscle Displacement in an Ex Vivo Pulsatile Model of Functional Mitral Regurgitation.

BACKGROUND: Surgical method of choice for functional mitral regurgitation (FMR) is debatable, since recurrence of FMR post-annuloplasty has been reported in a significant number of cases. Developing a pulsatile FMR heart model by left ventricular dilatation can be a favorable option for usage in the primary stages of developing new surgical techniques that adjunctively targets the posterior papillary muscle (PPM) geometry. METHODS: PPM of ex vivo ovine hearts (N = 22) was displaced by three different sizes of patches to induce left ventricular dilatation and FMR. Mitral regurgitation (MR) flow, left ventricular and annular geometry were measured from the dynamic pulsatile flow system before and after patch placement. RESULTS: Outward displacement of PPM was significantly increased in all patch sizes compared to baseline (P = .016, P = .031, and P = .008 from small to large patch, respectively). Left ventricular volume (LVV) significantly increased from 18.53 (15.01-26.03) mL at baseline to 27.5 (19.45-42.46) mL after large patch placement (P = .031). However, the small and medium patch groups did not show significant changes in the LVV after patch placement. MR significantly increased 554 (185-1,919.3) mL/min after applying the large patch compared to baseline (P = .016). There were no significant changes from baseline in MR flow after applying the small and medium patch. Application of the large patch produced the highest proportion of FMR heart models (87.5%, P = .031). CONCLUSION: The large patch ex vivo pulsatile heart model demonstrated outward displacement of the PPM and significantly produced MR flow. This ex vivo pulsatile heart model can be used to facilitate surgical techniques that targets the PPM displacement in FMR patients.

Partial Hammock Valve: Surgical Repair and Long-Term Follow-Up in 23 Patients.

BACKGROUND: In 2006, we reported a "forme frustrée" of hammock valve involving the posterior mitral leaflet resulting in restricted leaflet motion and mitral regurgitation. The purpose of this retrospective report is to describe the surgical techniques and long-term outcome of 23 patients with partial hammock valve who underwent successful repaired over a 22-year period (1995 to 2017). METHODS: Partial hammock valve is defined as anomalous papillary muscles that have hypertrophied and fused together. There are three or four papillary muscles implanted high on the posterior wall, forming a palisade under the posterior leaflet. Twenty-three patients were operated on, 19 adults and 4 children. In all but 3 patients, repair consisted of posterior leaflet enlargement of the P2 and P3 segments with a semilunar patch of bovine pericardium. The fused papillary muscles were split longitudinally, and some secondary chordae were cut. All adult patients received a prosthetic ring. RESULTS: A satisfactory repair was achieved in all patients. Mean age at the time of operation was 62 ± 11 years (range, 6 days to 79 years). Hospital mortality occurred in 1 patient (1 of 23; 4.3%). Mean follow-up was 7 years (range, 1 to 22). Actuarial survival rate at 7 years was 70%. At last echocardiogram, all survivors were free from mitral regurgitation grade II or higher. There was no reoperation. CONCLUSIONS: Partial hammock valve is a rare congenital anomaly resulting in mitral regurgitation. Patch enlargement of the posterior leaflet achieves long-term repair. It is safe and reliable.

Right Atrial Anomalous Muscle Bundle Presenting with Acute Superior Vena Cava Syndrome and Pulmonary Embolism: Surgical Management.

BACKGROUND: An anomalous muscle bundle (AMB) crossing the right atrial cavity represents a pathologic finding with unproved clinical significance. This congenital anomaly may be difficult to recognize via echocardiography and could be confused with other intracavitary lesions. METHODS: We report the case of a 53-year-old woman presented to the cardiovascular service with acute superior vena cava (SVC) syndrome and submassive pulmonary embolism. RESULTS: The patient underwent venography, confirming SVC stenosis. A ventilation/perfusion lung scan showed 2 sizable perfusion defects because of pulmonary embolism. Magnetic resonance imaging and echocardiography imaging demonstrated a right atrium (RA) mass. Surgery was then carried out using standard cardiopulmonary bypass; the right atrial muscle bundle was excised, and SVC reconstruction was performed. The patient was discharged uneventfully and remains symptom-free at 2-year follow-up. CONCLUSIONS: In cases of nonmalignant pathology of SVC syndrome, appropriate studies should be conducted to exclude potential congenital abnormalities such as this AMB in the RA. Open-heart surgery is a viable treatment option in select cases.

Papillary muscles of right ventricle-morphological variations and its clinical relevance.

INTRODUCTION: Papillary muscle plays an important role in stabilizing the position of the tricuspid valve. Several pathologies can result in anatomical and functional abnormalities of the papillary muscles. The aim of the study is to deliberate the morphometry of papillary muscles in tricuspid valve and to analyze with the eminent research works previously done. MATERIALS AND METHODS: The study was carried out in 52 formalin-fixed adult apparently normal cadaveric hearts belonging to either sex obtained from the Department of Anatomy. These hearts were dissected carefully to open the right ventricle and to expose the papillary muscles. Different morphological features of papillary muscles were noted, and measurements were taken. RESULT: The classical picture of three papillary muscles existed in 23.07% of the specimens. Anterior papillary muscle was in all hearts, but posterior and septal muscle was off in 15.38% and 55.76%, respectively. Double and triple papillary muscles were seen too. Anterior and posterior muscle appeared predominantly flat-top and arose from the middle third (mostly), while septal muscle was chiefly conical and originated basically from the upper third of the ventricular wall. Chordopapillary relationship with tricuspid valve leaflets was beyond conventional. Mean length and breadth of anterior muscle were 2.19±0.59 cm and 0.76±0.26 cm, those of posterior muscle were 1.39±0.63 cm and 0.67±0.43 cm, and those of septal papillary muscle were 0.95±0.38 cm and 0.59±0.09 cm. CONCLUSIONS: Detailed knowledge of normal and variable anatomy of papillary muscles is not only necessary for better understanding of tricuspid pathologies but also valuable for successful newer surgical approaches in cardiac treatment.

Anatomy of the mitral subvalvular apparatus.

OBJECTIVES: To characterize morphologic variations in the papillary muscles and tendinous cords of the left ventricle and ventricular zones of the mitral valve leaflets. METHODS: A total of 100 autopsied human hearts from healthy donors with classical mitral valve type were investigated. RESULTS: In 1 heart, only 1 group of papillary muscles was found, and in the remaining 99%, we could distinguish 2 groups of muscles: Superolateral (SLPM) and inferoseptal papillary muscle (ISPM) groups. The SLPM group had 1 papillary muscle (75.8%), 2 in 20.2%, and >3 in 4.0%. In the ISPM group, the muscle percentages were 38.4%, 36.4%, and 25.2%, respectively. The apex of at least 1 papillary muscle was situated higher than the plane of the opened anterior leaflet (AML) in 47.5% and 50.5% for the SLPM and ISPM groups, respectively. The number of strut cords arising from the SLPM group was 0 (2.0%), 1 (50.5%), 2 (33.3%), 3 (12.1%), and 4 (2.0%), and from the ISPM group was 0 (6.1%), 1 (52.5%), 2 (35.4%), or 3 (6.1%). Cords to left ventricular outflow tract were present in 14 specimens. Muscular cords were found in eight hearts. In all hearts specimens AML had rough and clear zones. The classical zones (rough, clear, and basal) in the posterior mitral leaflet were observed in 38.4%. CONCLUSIONS: There is a high variability in the papillary muscles and tendinous cords in the mitral valve complex. Proper nomenclature, simple classification, and the most common variants for papillary muscle groups and tendinous cords were presented.

Correction of Left Ventricular Outflow Tract Obstruction Caused by Anomalous Papillary Muscle and Subaortic Membrane.

This paper presents a case study of a 30-year-old male patient with dyspnea on exertion had echocardiographic diagnosis of aortic subvalvar stenosis. Discrete mitral regurgitation and aortic valve dysplasia with mild to moderate insufficiency and hypertrophic cardiomyopathy were also noted. During surgery, a rare condition was identified: presence of papillary muscle anomaly associated with the subaortic membrane as a cause of obstruction of the left ventricular outflow tract. With the resection of these structures and a mitral valve annuloplasty, the patient evolved with a significant improvement of clinical condition and heart failure, with no residual mitral insufficiency.

Edge-to-edge repair for mitral regurgitation associated with isolated double-orifice mitral valve.

We report the case of a patient with severe mitral regurgitation who was diagnosed with double-orifice mitral valve by preoperative transthoracic and transoesophageal echocardiography. During surgery, it was revealed that the mitral valve was divided into 2 orifices, anterolateral and posteromedial, by a fibrous bridging tissue that was supported by the chordae tendineae originating from an accessory middle papillary muscle. The posterior scallop of the anterolateral orifice was prolapsed due to chordal elongation. Six interrupted sutures were made between the anterior leaflet and the posterior leaflet at the prolapsed site. Additional interrupted sutures were made at the sites of 2 clefts, and a ring annuloplasty was added. Residual mitral regurgitation was trivial, and the mean postoperative pressure gradient through each orifice was approximately 6 mmHg. To the best of our knowledge, this is the first case report of an edge-to-edge mitral repair for mitral regurgitation associated with a double-orifice mitral valve.

Multimodality imaging in the diagnosis of a large accessory papillary muscle.

An accessory papillary muscle is an uncommon congenital anomaly usually found incidentally on routine cardiac imaging. While frequently asymptomatic, it is occasionally associated with mitral regurgitation, left ventricular dynamic outflow obstruction and hypertrophic cardiomyopathy1 and it is important to differentiate it from other pathological processes including papillary fibroelastoma, left ventricle thrombus, hemangioma, a single papillary muscle with a parachute mitral valve and a left ventricle false tendon. The clinical implication of these findings varies according to the degree of left ventricular out flow obstruction, location and pathology. We report a case that underscores the importance of multimodality imaging in the diagnosis and differentiation of an accessory papillary muscle from other intracardiac masses. [Full article available at http://rimed.org/rimedicaljournal-2017-09.asp].