A Clinical Study To Detect Early Myocardial Damage In Patients With Primary Mitral Valve Prolapse Using Two-dimensional Speckle Tracking Imaging

Objective: We previously found that patients with mitral valve prolapse(MVP)with normal left ventricular ejection fraction(LVEF)had poor recovery of LVEF after operation,indicating that irreversible myocardial lesions had occurred.This study investigated the early myocardial damage of MVP patients with normal LVEF,normal left ventricular diameter,and slightly enlarged left atrium.Methods: From June 2022 to November 2022,29 patients with early primary MVP lesions(MVP group)who were treated in the General Hospital of Northern Theater Command were selected,and the left atrial diameter was less than 45mm;We selected 31 normal people(normal control group)who had physical examination in our hospital at the same period.The left atrial diameter was less than 38 mm,and the other indicators were matched between the two groups.Respectively: for the general measurement,in addition to the conventional echocardiographic parameter measurement,it is necessary to retain the dynamic images of three apical sections,and use the auto-strain technical software provided by the instrument for strain analysis.Results: The results were compared between groups and within groups by Two-way ANOVA and One-way ANOVA analysis.The results showed that:1.The average left ventricular peak longitudinal strain(PLS)of 18 segments in MVP group was lower than that in the normal control group,and the PLS of posterior septal apical segment in the MVP group was significantly higher than that of posterior septal base segment(P <0.05),and the PLS of the apical segment was significantly greater than that of the middle segment(P<0.05);In normal control group,the PLS of the basal segment of the left ventricular anterior wall was significantly greater than that of the middle segment of the anterior wall,and the PLS of the basal segment was significantly greater than that of the middle segment(P<0.05).This indicates that the overall left ventricular systolic amplitude of MVP group has decreased.2.The average time to peak longitudinal strain(TTPLS)of 18 segments,six walls and three segments in MVP group was significantly shorter than that in the normal control group.There was no significant difference in TTPLS between 18 segments and six walls in MVP group(P>0.05).The TTPLS of basal segment was significantly greater than that of apical segment;In normal control group,the posterior septal basal segment was significantly greater than the anterior septal basal segment,the TTPLS of anterior lateral wall was significantly greater than the anterior septal,and TTPLS of the basal segment was significantly greater than the apical segment(P<0.05).This indicates that the myocardial damage of MVP leads to the change of cardiac electrical conduction,which is manifested as the loss of TTPLS difference in each segment.Conclusion: In this study,it was found for the first time that left ventricular longitudinal strain peak(PLS)and longitudinal strain peak time(TTPLS)could detect early left ventricular myocardial damage in patients with MVP,which were mainly characterized by significant increase of PLS in apical segment,decrease of PLS in basal segment of posterior septum,significant increase in apical segment of posterior septum,prolongation of TTPLS in anterior septum and shortening of TTPLS in anterior lateral wall,and prolongation of TTPLS in basal segment of anterior septum and shortening of TTPLS in basal segment of posterior septum.