Mitral annular disjunction prevalence and its association with ventricular arrythmias in Upper Egypt
Authors: Ali W , Hammouda T H , Nasr A N , Sayed M S , Mahfouz A M , Haroun D H , El Kafrawy F E , Nabil S N , Shaaban M S , Kamel O K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Mitral annular disjunction (MAD) was first described more than 3 decades ago as an abnormal atrial displacement of the hinge point of the mitral valve away from the ventricular myocardium. MAD was associated with ventricular arrythmias and sudden cardiac death, yet some studies suggested that the presence of MAD can be potentially normal physiological function . (1)

Purpose
Our primary end point was assessment of the incidence of mitral annular disjunction among the cohort of mitral valve prolapse at our center and the secondary end point was the incidence and predictors of ventricular arrythmias(VAs) in our cohort.

Methods
It is an observational cross section study where we recruited all the patients who were diagnosed to have MAD at our center representing the area of Upper Egypt, MAD was defined as distinct separation of the mitral valve annulus and the left atrial wall and myocardial continuum, and it was initially diagnosed by the means of transthoracic echocardiography. All patients’ demographics and family history (FH) of sudden cardiac death (SCD) were collected,symptoms were assessed as regard palpitations, shortness of breathing, chest pain, pre syncope and syncope, data from echocardiography including LV internal dimensions, leaflets affection, degree of mitral regurgitation, careful ECG analysis was done extracting the data for PR interval, corrected QTc, T wave inversion, PVCs in surface ECG and in 24 hours Holter, cardiac MRI parameters including late gadolinium enhancement, its distribution and systolic curling.

Results
We analyzed the data of 300 patients with mitral valve prolapse, 7 % of them showed mitral annular disjunction, 33 % of the cohort were female patients, the mean age was 34 years old, the mean follow up period was 3 years, main presenting complain was palpitations with an incidence of 66 %, FH of SCD was noticed in 9 % of our cohort, Mean QRS width was 81 mseconds, mean QTc was 423 mseconds, the mean EF was 60 %, mean displacement distance was 3 mm, while the mean LA volume was 36 cm3, 80 % of the cohort showed bileaflet affection, while only 19 % of them had late gadolinium enhancement, 50 % of them had fibrosis in the papillary muscles, while systolic curling was noticed in only 9 %.VAs were defined as having premature ventricular complexes in the surface ECG or documented monomorphic ventricular tachycardia and it was noticed in 19 % of our cohort with an average burden of 10 % during a 24 hours Holter.There was a positive correlation between the FH of SCD and the Prescence of PVCs in surface ECG with a significant P value of 0.02, while there was no correlation between fibrosis and the incidence of ventricular arrythmias.

Conclusions
Incidence of MAD was 7 % among the MVP population at our center. Only FH of SCD was a predictor of the incidence of VAs, while ECG, echo and cardiac MRI parameters couldn`t be proved to be positively correlated with the VAs.