Related Experiment Videos
Mitral valve prolapse in five members of a family including the identical twins
Abstract:
A family in which the five members including the identical twins had a mitral valve prolapse was described. None of these members had any known stigmata of Marfan syndrome and their auscultatory findings were different each other. M-mode echocardiograms disclosed a midsystolic buckling of the mitral valve in the identical twins, their parents and the mother's brother, but all were asymptomatic. Electrocardiograms revealed a wandering pacemaker in two members. The index case was a 13-year-old girl whose apical late systolic murmur was detected incidentally by the mass screening examination for cardiac diseases. Both the inhalation of amyl nitrite and injection of methoxamine induced the augmentation of this murmur and made it holosystolic. The identical twin of the index case had multiple apical non-ejection clicks. However, a mitral regurgitant murmur was not induced by pharmacological provocations. Two-dimensional echocardiograms revealed prolapse of both the anterior and posterior mitral valve leaflets in both of them. Their mother had a late systolic click and the mother's brother had a cardiopulmonary murmur. The abnormal auscultatory findings were not observed in their father. This familial study suggested the genetic background and the various clinical manifestations of mitral valve prolapse.
Insights
This study describes a family with mitral valve prolapse (MVP) showing varied clinical signs across members. The findings suggest a genetic basis for MVP and its diverse presentations, even without Marfan syndrome indicators.
Area of Science:
- Cardiology
- Genetics
- Echocardiography
Background:
- Mitral valve prolapse (MVP) is a common cardiac condition with varied clinical presentations.
- Familial clustering of MVP suggests a potential genetic component.
- Differentiating MVP from other conditions, like Marfan syndrome, is crucial for accurate diagnosis and management.
Purpose of the Study:
- To investigate the familial occurrence and clinical spectrum of mitral valve prolapse (MVP).
- To explore the genetic background and diverse manifestations of MVP within a single family.
- To characterize echocardiographic and auscultatory findings in affected family members.
Main Methods:
- Descriptive case series of a family with five affected members, including identical twins.
- Clinical examination including auscultation.
- Pharmacological stress testing (amyl nitrite inhalation, methoxamine injection) to assess murmur changes.
- M-mode and two-dimensional echocardiography to evaluate mitral valve structure and function.
- Electrocardiography (ECG) to assess cardiac electrical activity.
Main Results:
- Five family members, including identical twins, presented with mitral valve prolapse (MVP), with varying auscultatory findings.
- M-mode echocardiograms showed midsystolic buckling of the mitral valve in affected individuals, all asymptomatic.
- Pharmacological provocation augmented the murmur in the index case, changing it from late systolic to holosystolic.
- Two-dimensional echocardiography confirmed prolapse of both anterior and posterior mitral valve leaflets in the twins.
- Electrocardiograms revealed a wandering pacemaker in two members; abnormal auscultatory findings were absent in the father.
Conclusions:
- Familial aggregation of mitral valve prolapse (MVP) indicates a significant genetic influence.
- MVP exhibits diverse clinical and auscultatory manifestations within affected families.
- Echocardiography is essential for diagnosing MVP, even in asymptomatic individuals.
- Further research into the genetic underpinnings of MVP is warranted.