BackgroundCongenital mitral rings represent a rare subset of congenital mitral stenosis often associated with complex cardiac anomalies. Comprehensive literature on congenital mitral rings, particularly from large single-institution experiences, remains sparse. Methods: This retrospective study, conducted at All India Institute of Medical Sciences, New Delhi, analyzed data from 52 patients who underwent surgical correction for congenital mitral rings between 2014 and 2024. Data on demographics, clinical presentation, preoperative echocardiographic and cardiac catheterization parameters, associated cardiac anomalies, intraoperative findings, and postoperative outcomes were collected. Patients had a mean follow-up of 72 months.ResultsThe cohort had a mean age of 6 years. An isolated vestibular mitral ring was noted in only 1 patient, with 51 cases showing associated cardiac anomalies. The mean preoperative diastolic gradient was 13 mm Hg, significantly reduced to 2.69 mm Hg in the immediate postoperative period and 3.35 mm Hg at follow-up. Two distinct morphological types were identified: "distinct vestibular supramitral ring" (43 patients) and "adherent intramitral ring" (9 patients), with the latter demonstrating a higher association with subvalvular apparatus abnormalities. Preoperative transesophageal echocardiography proved crucial in detecting these rings in 4 cases where the diagnosis was doubtful on transthoracic echocardiography. Surgical outcomes were favorable, with 1 early postoperative mortality and 3 late mortalities. Four patients required reinterventions for residual lesions, achieving successful resolution.ConclusionThis large single institution series provides valuable insights into associated anomalies, morphological variants, and long-term surgical outcomes of congenital mitral rings. Accurate diagnosis and timely surgical intervention led to favorable outcomes, reinforcing the need for thorough preoperative evaluation.

The mitral valve apparatus comprises the annulus, valve leaflets, chordae tendineae, and papillary muscles, forming an integrated biomechanical unit essential for unidirectional blood flow. The leaflets and chordae are primarily derived from endocardial cells, and damage to these structures results in either mitral stenosis or mitral regurgitation, depending on the underlying pathology. This review compares three major mitral valve diseases, rheumatic mitral stenosis, congenital mitral stenosis, and myxomatous mitral valve prolapse, to highlight their distinct etiologies, molecular mechanisms, and structural endpoints. Rheumatic mitral stenosis is an acquired immune-mediated disease triggered by Group A streptococcal infection, in which molecular mimicry leads to autoantibody formation and chronic inflammation. Immune-cell infiltration and cytokine release drive the progression of leaflet fibrosis, commissural fusion, calcification, and pronounced chordal shortening, ultimately culminating in fixed obstruction. Large-scale genetic studies have not identified strong causal genes, instead revealing associations with immune-related risk loci, while valve-specific epigenetic mechanisms are poorly explored. Congenital mitral stenosis arises from developmental abnormalities of the mitral valve complex during embryogenesis and is classified into four anatomical subtypes. Due to its low incidence, the condition remains the least studied at the molecular and genetic levels. In contrast, myxomatous mitral valve prolapse is a degenerative, polygenic disorder driven by aberrant TGFβ-dependent endothelial-to-mesenchymal transformation, valve interstitial cell activation, and extracellular matrix remodeling. Genetic studies have identified multiple causal genes, including FLNA, DCHS1, DZIP1, and TNS1, underscoring its mechano-genetic origin. Despite their distinct causes, immune-mediated, developmental, and degenerative/genetic, all three diseases converge on progressive structural failure of the MV apparatus. Notably, pathological remodeling of the chordae plays a decisive role in disease progression and the need for surgical intervention. A deeper understanding of both shared and disease-specific mechanisms, particularly valve- and chordae-specific molecular regulation, is essential to advance translational research in mitral valve disease.

Parachute mitral valve (PMV) is a rare congenital anomaly where all chordae tendineae insert into a single papillary muscle, causing stenosis or regurgitation. Adult presentations are uncommon and often underdiagnosed. A 35-year-old male presented with exertional dyspnea. Echocardiography demonstrated severe mitral stenosis, reduced ejection fraction, a bicuspid aortic valve, and pulmonary hypertension. Intraoperative findings confirmed true PMV. Due to anatomical complexity, a 27-mm mechanical prosthesis replacement was performed successfully, with rapid postoperative recovery. Adult PMV requires high clinical suspicion and often surgical confirmation. Valve replacement is effective in complex cases, emphasizing the importance of early diagnosis and intervention.

This study investigated the long-term results of mitral valve replacement (MVR) using mechanical prostheses in children under 3 years of age. We retrospectively reviewed 24 patients who underwent MVR with mechanical prostheses before the age of 3 years between 1996 and 2019. Underlying diagnoses included isolated congenital mitral regurgitation (n=4), congenital mitral stenosis (n=4), and various congenital heart defects (n=16). The median follow-up duration was 9.8 years (interquartile range [IQR], 7.3-13.2 years). The median age and weight at MVR were 16.6 months (IQR, 5.3-24.7 months) and 7.6 kg (IRQ, 4.9-9.5 kg), respectively. The median prosthesis size was 19 mm (range, 16-29 mm). Supra-annular implantation was performed in 12 patients (50%), who were significantly younger and smaller at the time of surgery and received smaller prostheses than those receiving annular implants. Early mortality occurred in 2 patients (8.3%), and 2 late deaths were recorded. The overall survival rate was 83.3% at 15 years. Redo MVR was performed in 9 patients during follow-up. The median increase in valve size was 4 mm. The interval from initial to redo MVR was positively correlated with the increase in valve size (Spearman ρ=0.64, p=0.07). Freedom from redo MVR was 86.3% at 5 years and 75.8% at 10 years. MVR with mechanical prostheses in children under 3 years of age can yield acceptable long-term survival, although redo MVR is often required. Mechanical MVR remains a viable salvage option in small children when valve repair is not feasible. Mitral stenosis is a progressive valvular disorder that results in left atrial (LA) enlargement, atrial fibrillation, and heart failure. Despite advances in modern medicine, rheumatic heart disease remains the most common cause of mitral stenosis, especially in low- and middle-income countries. Rheumatic mitral stenosis usually presents in patients aged between 20 and 40 years, about 10 to 15 years after the onset of rheumatic fever. In the United States, mitral stenosis secondary to rheumatic heart disease most commonly presents in the immigrant population and those with limited access to healthcare facilities. Calcific degenerative mitral valve stenosis is another cause of mitral stenosis, but it is far less common and typically seen in older adults. Patients with symptomatic mitral stenosis usually present with symptoms of heart failure, atrial fibrillation, or thromboembolism. Risk factors for rheumatic mitral stenosis include a history of rheumatic fever and a previously untreated streptococcus infection. Some data suggest that patients with chronic kidney diseases and dialysis are at increased risk for calcific, degenerative mitral stenosis.  The key physical examination findings in hemodynamically significant mitral stenosis may include irregular pulse (due to atrial fibrillation), prominent a wave in the jugular venous examination, tapping apex beat, signs of pulmonary hypertension/right-heart failure, an opening snap, and the classic low-pitched, middiastolic rumbling murmur with presystolic accentuation. A chest radiograph may show the prominence of the pulmonary arteries, the straightening of the left heart border, the LA, and signs of pulmonary edema. The electrocardiogram may show atrial fibrillation or evidence of LA enlargement and right ventricular hypertrophy. The 2-dimensional and Doppler echocardiogram is the best imaging modality for diagnosing mitral stenosis and assessing its severity and hemodynamic consequences.  Medical therapy is used as an initial symptomatic treatment for severe mitral stenosis; however, it does not improve the long-term outcomes of the disease. As assessed by echocardiography, percutaneous mitral balloon commissurotomy (PMBC) is recommended as the first-line treatment for rheumatic mitral stenosis in patients with suitable mitral valve anatomy. Meanwhile, surgical mitral valve repair/replacement is limited to patients whose valves are unsuitable. Valves designed for transcatheter aortic valve replacement have been used in a percutaneous transcatheter mitral valve replacement technique to treat degenerative mitral stenosis. PMBC treats mitral stenosis by splitting the fusion of the mitral valve commissures, and it is most effective in rheumatic mitral stenosis and certain forms of congenital mitral stenosis. This activity will provide a detailed description of the mitral valve, the pathology of mitral stenosis, and possible options for catheter management, including indications, contraindications, complications, and the clinical significance of catheter management.