The Trileaflet Mitral Valve

Double outlet right atrium in a dog

Double outlet right atrium is a rare congenital cardiac abnormality that has been previously reported in humans and cats, but not in dogs. A double outlet right atrium is typically characterized by the presence of a leftward deviation of the interatrial septum and atrial septal defect. Therefore, the right atrium drains into both ventricles. The unique features consistent with double outlet right atrium were identified by transthoracic echocardiography and computed tomography in a puppy. This case report describes the clinical, echocardiographic, and tomographic findings of a five-month-old Cocker Spaniel diagnosed with this rare congenital abnormality.

Double-Outlet Right Atrium in a Young Cat

•DORA is a rare variant of endocardial cushion defect reported in both people and cats. •DORA is associated with variable clinical presentation and prognosis. •DORA is a possible differential diagnosis in cats with ASD and obstruction to LA outflow.

A tricuspid mitral valve with severe regurgitation

Tricuspid mitral valve is a rare entity, distinct from isolated clefts of the mitral leaflets. Echocardiographically, it manifests as the presence of three commissures, separate papillary muscles and concordant atrioventricular or ventriculoarterial connections. Three-dimensional transesophageal echocardiography helps distinguish the three cusps from clefts. Herein, we present a case of tricuspid mitral valve that led to severe mitral regurgitation.

A rare case of quadrileaflet mitral valve and ostium primum atrial septal defect

A 60-year-old woman was referred to our clinic for evaluation of her rapidly progressive dyspnea, and she had no previous history of heart disease. A murmur was noted on her examination, and transthoracic echocardiography was so difficult to be performed due to poor acoustic windows so she was referred to do a transesophageal echocardiography that showed an ostium primum atrial septal defect (ASD) with left-to-right shunt and a quadrileaflet mitral valve with severe regurgitation. Later on, she underwent surgery with ostium primum ASD closure by a patch and double cleft repair by suture after right heart catheterization.

Accessory mitral valve tissue: anatomical and clinical perspectives

Mitral valve is a complex cardiac structure composed of several components to work in synchrony to allow blood flow into left ventricle during diastole and not to allow blood flow into left atrium during systole. Accessory mitral valve tissue (AMVT) was defined as existence of any additional part and parcel of valvular structure which has an attachment to normal mitral valve apparatus in left-sided cardiac chambers. AMVT may present itself in different clinical circumstances ranging from a silent clinical course to thromboembolic events, heart failure, left ventricular outflow tract obstruction, and severe arrhythmia. This article reviews the clinical perspectives of AMVT in terms of symptoms, diagnosis, and treatment, providing a new anatomical classification regarding the location of AMVT. Briefly type I refers to AMVT having attachments on the supra leaflets level, type II refers to attachments on the mitral leaflets, and type III refers to attachment below the mitral leaflets. Increased awareness and widespread use of echocardiographic techniques would increase recognition of AMVT in patients with heart murmurs but otherwise healthy and in those with left ventricular outflow tract obstruction or tissue which causes subaortic stenosis and with unexplained cerebrovascular events.

Recent advances in understanding and managing mitral valve disease

Interest in the mitral valve has increased over the past few years with the development of new technologies that allow intervention in patients previously deemed too ill for treatment. This increased attention has resulted in a significant increase in publications on the mitral valve, the majority of which focus on mitral regurgitation and mitral valve surgery/intervention. The focus of this review is on publications in the past few years that offer additional insights into our understanding and management of mitral valve disease and specifically mitral regurgitation. It will discuss mitral valve anatomy, epidemiology of mitral valve disease, changes in the 2017 management guidelines, management of mitral bioprosthetic valves, transcatheter mitral valve procedures and the repair of rheumatic valves.

Case of trileaflet mitral valve: an important differential for non-classical intracavitary gradient in suspected hypertrophic cardiomyopathy

There are nine published reports of trileaflet mitral valves globally. As such their implication on health outcomes and associations with other disease is uncertain. This case describes a 62-year-old man presenting with exertional dyspnoea and hypertension. It describes an early misdiagnosis of hypertrophic cardiomyopathy and highlights that clinicians should be alerted in cases of very high left ventricular outflow gradients in the presence of eccentric mitral regurgitation (MR). Here the MR was caused by a rare congenital deformity whereby a deep cleft in the posterior leaflet resulted in a tricuspid appearance. We present the natural disease course of a trileaflet mitral valve and without intervention over 13 years from symptom onset to the development of severe MR.

A rare case series of mitral valve clefts diagnosed by 3D echocardiography and mini-review of the literature

Mitral valve cleft is a rare entity. However, it must be recognized as a differential mechanism for mitral valve regurgitation. 3D transesophageal echocardiography plays an essential role in the evaluation of single and multiple mitral valve clefts, improving morphological and functional assessment of the valve, with potential implications on surgical planning. The authors present four rare cases of mitral valve cleft presenting during adulthood, followed by a mini-review about the role of 3D echocardiography, as well as its pitfalls, in the assessment of this complex congenital mitral valve disease.