The Value Of Apical Vertical Angle And Dynamics In The Diagnosis Of Apical Hypertrophic Cardiomyopathy

ObjectivesThis study was to evaluate the apical vertical angle as well as dynamic features in patients of clinically suspected apical hypertrophic cardiomyopathy?AHCM?with specific deep T wave inversion and search for potential echocardiographic indicators for the early detection of AHCM using echocardiography and velocity vector imaging?VVI?.MethodsA total of 53 consecutive outpatients with suspected AHCM?40 males?,including32 typical AHCM?T-AHCM?and 21 pre-AHCM?P-AHCM?patients with a median age of 60 years?range 23 to 85 years?were enrolled from August 2015 to August 2017.And43 age and sex matched volunteers?35 males?with a median age of 55 years?range 42to 77 years?were recruited as normal controls?NC?.None of them had history of cardiovascular disease or relevant medical history.Height,weight,blood pressure,ECG and other clinical data were collected.Conventional echocardiographic parameters were acquired including left ventricular diameter,wall thickness,left ventricular ejection fraction?LVEF?,left atrial volume?LAV?,transmitral diastolic inflow velocities?E,A?,mitral annuluar lateral and septum velocities in late diastole?e₁,e₂?;Apical morphology measurements included apical maximal thickness and vertical angle in end-diastole and end-systole??ap-d,?ap-s?;Apical dynamics measurements included fractional angle change???ap=?ap-d-?ap-s?/?ap-d)and apical ejection velocity?Vap?;Myocardial systolic strain including circumferential,radial,longitudinal strain and rotation were evaluated with VVI software.Results1)No significant difference was found in left ventricular diameter among 3 groups;P-AHCM patients had mildly higher LVEF than that of T-AHCM patients and NC group?P<0.05?,and both P-AHCM and T-AHCM had higher LA volume index?LAVI?,E/e'ratio,and lower e1,e2 velocities compared with normal controls?all p<0.05?,but there were no differences between patients with P-AHCM and T-AHCM.2)Lower apical vertex angle??ap?in end-diastole and end-systole were observed in both P-AHCM and T-AHCM groups?all P<0.05?,where about 27 patients?6P-AHCM,21 T-AHCM?were found to have apical obliteration;and higher fractional angle change???ap?were found in P-AHCM and T-AHCM groups compared with NC group?all P<0.05?[P-AHCM:0.74±0.23;T-AHCM:0.80±0.33;NC:0.16±0.08],no differences was found in?ap and??ap between P-AHCM and T-AHCM.3)Increased apical ejection velocity?Vap?was noted in two AHCM groups compared with NC group?all P<0.05?[P-AHCM:0.49±0.20 m/s;T-AHCM:0.88±0.50 m/s;NC:0.24±0.06 m/s],but there was no significant difference between the two subgroups.4)Compared with NC group,P-AHCM and T-AHCM groups had lower apical circumferential strain?CS?and radial strain?RS??all P<0.05?,without significant differences between the two subgroups,but higher apical rotation was observed in P-AHCM group?P<0.05?.Conclusions1.Decreased apical vertical angle as well as increased apical ejection velocity and fractional angle change occurred in both P-AHCM and T-AHCM patients,but enhanced apical rotation was found only in P-AHCM.2.Echocardiographic apical vertical angle and local ejection velocity might be helpful in the detection of AHCM in its early stage.