A Mitral Hemi-Arcade: An Unusual Modification of a Rare Anomaly

A Rare Encounter of Mitral Arcade With Anomalous Papillary Muscles

A congenital mitral arcade is a rare heart structural abnormality that affects the structure of the papillary muscles and chordae tendinae. This structural deviation impacts the mitral valve’s functional capability, which is why most patients with this condition develop complications such as mitral stenosis or regurgitation. Some patients can obtain successful mitral valve repair. However, most will still need to get a mitral valve replacement. This case presents a young female who was found to have a mitral arcade and underwent mitral valve repair.

Undifferentiated Chordae Tendineae of the Mitral Valve: Large Cohort Study of a Rare Mitral Malformation

Aims: This study aimed to investigate the pathology, classification, diagnosis, and surgical prognosis of UCMV.

Methods and Results: Consecutive paediatric patients with ≥ moderate-severe mitral regurgitation (MR) and mitral stenosis (MS) were recruited between October 2016 and July 2020. UCMV was diagnosed and classified into three grades according to the involvement of chorda groups and MS presence or absence; other mitral lesions were included as controls. Of 207 eligible patients, 75 with UCMV (10.0 m [interquartile range (IQR): 6.0–21.5]) and 110 with other mitral lesions (16.0 m [IQR: 5.0–43.5]) were diagnosed using echocardiography and surgical exploration. The associated chorda groups of UCMV were confirmed to show high agreement between echocardiography and surgery (kappa = 0.857, p < 0.001). At baseline surgery assessment, the UCMV group exhibited worse New York Heart Association functional class, more severe MR and MS grades, and fewer associated complex anomalies (all, p < 0.05) than the control group. After a mean follow-up of 8.3 (IQR:2.7–14.4) months and adjustment for covariates, the UCMV group required longer cardiopulmonary bypass and aortic clamp times, but there were no differences in the incidence of adverse events (p = 0.584). Class III was associated with higher risk of adverse events than classes I and II (p = 0.002).

Conclusions: The UCMV spectrum constitutes a primary pathogenesis of paediatric MV dysfunction, which can be optimally diagnosed using echocardiography. Classification based on mitral anatomy and dysfunction can predict the risk of postoperative adverse events.

Familial Mitral Arcade, Tricuspid Dysplasia, Left Ventricular Noncompaction and Short-Chain Acyl-CoA Reductase Deficiency

Mitral arcade is a rare entity that is mostly reported in pediatric patients. We present the first 2 adult cases of mitral arcade in combination with tricuspid dysplasia, left ventricular noncompaction, and short-chain acyl-CoA deficiency in 2 brothers. We examined clinical and echocardiographic data on 2 brothers with a combination of short-chain acyl-CoA deficiency, mitral arcade, tricuspid dysplasia, and left ventricular noncompaction (LVNC), highlighting their clinical course and outcomes. Two-dimensional and 3-dimensional transthoracic echocardiography revealed direct attachment of the papillary muscles to the mitral leaflets, namely mitral arcade, as well as mild mitral regurgitation along with LVNC and tricuspid dysplasia. Over the past 7 years, both brothers have remained asymptomatic with excellent exercise capacity (13 and 10 metabolic equivalents (METS), respectively). Mitral and tricuspid regurgitation remain mild with unchanged left ventricular function (ejection fraction: 65% and 59%). In conclusion, we highlight 2 cases with a constellation of pathology including short-chain acyl-CoA deficiency, mitral arcade, tricuspid dysplasia, and LVNC, which has never been described before.

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.

Mitral Hemi-Arcade: A Rare Variant of a Rare Disease

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A case of a healthy young male with chest pain and borderline electrocardiogram is presented.

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Imaging showed a mitral hemi-arcade with left ventricular outflow tract obstruction during exercise.

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Previously postulated mechanisms for this obstruction are reviewed in this article.

Repair of anomalous mitral arcade in a child

A 13-year-old girl presented with exertional dyspnea and congestive heart failure. Echocardiography revealed severe congenital mitral stenosis due to anomalous mitral arcade with severe pulmonary hypertension. She underwent successful mitral valve repair. The case is reported for its rarity.