| Objects:To evaluate the feasibility and clinical application value of dual-source CT in the assessment of left ventricular remodeling in patients with essential hypertension by comparing the morphology, functions and coronary artery diseases of different left ventricular geometry.Materials and Methods:233cases of essential hypertension patients (143males,90females, aged33-81years with a mean of58.29±10.64) and73cases of normal subjects (38males,35females, aged36-80years with a mean of58.29±10.64) were enrolled. All patients were subjected to coronary angiography using dual-source CT (Somatom Definition, Germany, Siemens). Each coronary artery was analysed at best-diastole and best-systole phase. All measurements were performed at the level of the chordae according to the international recommendations for chamber quantification in echocardiography. Short-axis MPR at end-diastole was used for wall thickness measurement of the interventricular septum (SWTd) and posterior wall (PWTd). LV inner diameter in end-diastole (LVIDd) and end-systole (LVIDs) was measured in the four-chamber MPR. Left ventricular mass index (LVMI) was calculated using the formula:LVMI=LVM/BSA, while relative wall thickness (RWT) using the formula:RWT=(LVPWTd+IVSTd)/LVIDd. According to Ganau categories, left ventricular remodeling in patients with essential hypertension were divided into four patterns:normal left ventricle, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), cardiac output (CO), left ventricular ejection fraction (LVEF), myocardial mass (MM), cardiac index (CI) and body surface area (BSA) were calculated directly using the left ventricular analysis software.Results:1. There were no significant differences in gender and heart rate among the control group and the four hypertensive groups (P>0.05). Age in the concentric remodeling group was greater than in the control and concentric hypertrophy groups. BSA in the concentric remodeling and concentric hypertrophy groups was greater than in the control and normal left ventricle groups. BMI in the normal left ventricle, concentric remodeling and concentric hypertrophy groups was greater than in the control group. Both SBP and DBP among the four hypertensive groups were higher than in the control group. While in the concentric hypertrophy group, both SBP and DBP were also higher in the normal left ventricle group. The rate of smokers was highest in the eccentric hypertrophy, followed by the concentric hypertrophy group, while the lowest in the control group (χ2=22.119, P=0.000). There were no significant differences in the diabetes, course, treatment and family history of EH among the four hypertensive groups (P>0.05). The prevalence of hyperlipemia was highest in the concentric hypertrophy group, followed by the eccentric hypertrophy group, the concentric remodeling group and the normal left ventricle group (χ2=9.053, P=0.029). 2. The prevalence of coronary artery disease was highest in the eccentric hypertrophy group, followed by the concentric hypertrophy group, the concentric remodeling group and the normal left ventricle group (χ2=18.250, P=0.000). The prevalence of coronary artery disease in both the eccentric hypertrophy and concentric hypertrophy group was significantly twice to thrice higher than in the normal left ventricle, while in the eccentric hypertrophy, the prevalence of coronary artery disease was about twice higher than in the concentric hypertrophy group. The incidence of more than fifty percent degree of coronary artery stenosis was highest at LAD, while the smallest at LM, RCA and LCX were in between (P<0.01).3. SWTd among the four hypertensive groups was significantly greater than in the control group. Meanwhile, SWTd among the concentric remodeling, concentric hypertrophy and eccentric hypertrophy groups was also greater than in the normal left ventricle group, and SWTd in the concentric hypertrophy group was greater than in the concentric remodeling group. IVSTd among the four hypertensive groups was significantly greater than in the control group. Among the four hypertensive groups, IVSTd was greatest in the concentric hypertrophy group and smallest in the normal left ventricle group. LVIDd was greater in the eccentric hypertrophy group and lower in the concentric remodeling group compared to the other groups. LVIDd was greater in the normal left ventricle group than in the control group. LVIDs was greater in the eccentric hypertrophy group and lower in the concentric remodeling group compared to the other groups. But the difference of LVIDs between the concentric remodeling and concentric hypertrophy group was not statistically significant. RWT was greatest in the concentric hypertrophy group, followed by the concentric remodeling group. RWT was greater in the normal left ventricle group than in the control group. LVMI among the four hypertensive groups was significantly greater than in the control group, especially in the eccentric hypertrophy group. LVMI in the concentric hypertrophy and eccentric hypertrophy groups was greater than in the normal left and ventricle control groups.4. EF was greater in the concentric remodeling group and lower in the eccentric hypertrophy group compared to the other groups. MM among the four hypertensive groups was significantly greater than in the control group, especially in the eccentric hypertrophy group. MM was greater in the concentric hypertrophy and eccentric hypertrophy groups than in the normal left ventricle and control groups. Both EDV and ESV were greatest in the eccentric hypertrophy group and lowest in the concentric remodeling group, while the other three groups had no significant difference. SV was significantly smaller in the concentric remodeling group than in the control, normal left ventricle and eccentric hypertrophy groups, and the other groups had no significant difference. CO in the eccentric hypertrophy and normal left ventricle groups was greater than in the concentric remodeling and concentric hypertrophy groups. CO in the control group was smaller than in the eccentric hypertrophy group, but greater than in the concentric remodeling group. CI in the concentric remodeling group was smaller than in the normal left ventricle and control groups, while in the concentric hypertrophy group, CI was also smaller than in the normal left ventricle group, and the other three groups had no significant difference.5. There were no significant differences in EF, MM, EDV, ESV, SV, CO and CI among different grades of EH groups (P>0.05). In regression analysis, EF was independently associated with IVSTd, RWT, LVIDs, SBP and Smoking (R2=0.693, P=0.000), while EDV was independently associated with LVIDd, LVIDs, LVMI and Gender (R2=0.755, P=0.000), and ESV was independently associated with LVIDd, LVIDs, LVMI and Smoking (R2=0.783, P=0.000).6. In correlation analysis, the degree of LV remodeling was positively correlated with the blood pressure level (rp=0.317, P=0.000), but the correlation was not very strong (r p<0.5). In correlation analysis, RWT was correlated with BSA (r=0.240, P=0.000), SBP (rp=0.189, P=0.004), Course (rp=0.186, P=0.004), BMI (r=0.182, P=0.005), DBP (rp=0.152, P=0.021), Gender (t=3.447, P=0.001), Smoking (t=-2.068, P=0.040) and Hyperlipemia (t=-2.403, P=0.017). In further regression analysis, RWT was independently associated with BSA, SBP, course and hyperlipemia (R2=0.131, P=0.000). In correlation analysis, LVMI was correlated with DBP (rp=0.303, P=0.000), Age (r=-0.239, P=0.000), SBP (rp=0.204, P=0.002), Gender (t=4.741, P=0.000) and Smoking (t=-5.077, P=0.000). In further regression analysis, LVMI was independently associated with Age, Gender, SBP and Smoking (R2=0.227, P=0.000).Conclusions:1. DSCT is an effective and novel modality to assess the LV remodeling in patients with EH and can provide one-stop noninvasive evaluation of cardiac morphology, function, as well as coronary artery anatomy.2. The prevalence of coronary artery disease increases with LV remodeling of EH. The prevalence of coronary artery disease in both the eccentric hypertrophy and concentric hypertrophy is twice to thrice higher than the normal left ventricle or concentric remodeling. The clinically meaningful coronary artery stenosis most commonly involves LAD, then RCA and LCX, while rarely involves LM.3. Each of the four patterns of LV remodeling is characterized by its own function, which is helpful to treat hypertensive heart disease in different way.4. The cardiac function of LV remodeling is independently associated with the morphometric parameters including LV inner diameter and/or wall thickness. It shows that cardiac systolic function is closely related with LV geometry.5. Both BP (primarily SBP) and other multiple risk factors of cardiovascular disease are involved in modulation of LV remodeling. Objects:To evaluate the feasibility and clinical application value of dual-source CT in the assessment of HCM by assessing its morphology, function and coronary artery anatomy.Materials and Methods:10cases of patients with confirmed HCM (8males,2females, aged42～60years with a mean of49.90±5.95) and13cases of normal subjects (8males,5females, aged36～63years with a mean of47.54±8.84) were enrolled. All patients were subjected to coronary angiography using dual-source CT (Somatom Definition, Germany, Siemens). Analysis of each coronary artery saw Part one. Left ventricular wall thickness measurement was according to the American Heart Association guidelines for standardized myocardial segmentation in tomographic imaging. Short-axis MPR at end-diastole and end-systole was used for maximum wall thickness measurement of each segment and record the thickened segment. The ratio of maximum wall thickness of the Left ventricular wall or apex to the PWTd in end-diastole and the wall thickening (WT) of the thickened segment was calculated. WT was calculated using the formula:WT=end-systole wall thickness (ESWT)-end-diastole wall thickness (EDWT)/EDWT×100%. Measurements of LV inner diameter in end-diastole (LVIDd) and end-systole (LVIDs) saw Part one. LA and LV outflow tract (LVOT) anterior posterior diameters in end-diastole (LADd and LVOTd) were measured on axial oblique MPR through the level of the aortic valve and parallel to the LV outflow tract in a strictly anterior-posterior orientation. Calculations of left ventricular mass index (LVMI) and relative wall thickness (RWT) saw Part one. HCM was diagnosed and classified according to the CT appearance. The left ventricular analysis saw Part one.Results:1. The rate of smokers in the HCM group was higher than that in the control group (χ2=7.304, P=0.007). There were no significant statistical differences in gender, age, BSA, BMI, HR, SBP, DBP and hyperlipemia between the HCM and control groups (P>0.05).2. The thickness of interventricular septum, anterior wall and apical in the HCM group was significantly greater than in the control group (P<0.01), while there was no significant difference in the thickness of free and posterior wall between them (P>0.05). The ratio of maximum wall thickness of the Left ventricular wall or apex to the PWTd in end-diastole was greater than1.5in the HCM group. Both LVIDd and LVIDs in the HCM group were smaller than in the control group (P<0.05), on the contrary, both RWTd and LVMI in the HCM group were greater than in the control group (P<0.01), which showed that the LV geometry of HCM transformed to concentric hypertrophy. LADd in the HCM group was significantly greater than in the control group (t=-6.009, P=0.000), instead, LVOTd in the HCM group was significantly lower than in the control group (t=2.998, P=0.007). It showed that HCM was accompanied by dilated LA and narrowed LVOT. WT in the control group was about (57.88±5.09)%, while it reduced to (20.10±4.89)%of the thickened segments in HCM group. HCM were classified into two forms:asymmetric HCM (n=9) and symmetric HCM (n=1). Asymmetric HCM included apical HCM (AHCM, n=6) and asymmetrical interventricular septal HCM (n=3). Only one of six cases of asymmetric HCM was accompanied by LVOT obstruction. Through LVOT MPR, we can observe that the LVOT was narrowed and obstructed by the thickened interventricular septum, at the same time, a continued anterior mitral valve leaflet-septal contact over8 consecutive phases throughout15%-55%R-R interval by reconstructing the volumetric data set every5%of the cardiac cycle. Because the heart rate during imaging acquisition was82beats per minute, the total duration of anterior mitral valve leaflet-septal contact was29ms. Long-axis MPR showed a distinct apical diffuse hypertrophy with a typical "ace-of-spade" appearance and obliteration of the apex during systole of the6cases of AHCM.3. Both MM and EF in the HCM group were greater than in the control group (P=0.000), on the contrary, both EDV and ESV in the HCM group were smaller than in the control group (P<0.05). There were no significant differences in SV, CO and CI between them (P>0.05).4. Of all the10cases with HCM,9cases did not have obvious lesions in coronary angiography and one case had atheromatous plaque. The degree of coronary artery stenosis was greatest at LAD, approximately85%.7cases had myocardial bridge (MB), and all of the MB were at LAD (5at middle,1at middle-distal and1at distal).Conclusions:1. HCM can be definitively diagnosed and further classified by DSCT; It typically presents as asymmetric concentric hypertrophy remodeling involving any region of LV, confined to relatively small region of the LV chamber, and possibly accompanied by dilated LA and LVOT obstruction.2. AHCM manifests as simple and mixed AHCM and both of the two subtypies can be clearly diagnosed by DSCT.3. The cardiac function reveals increased LV mass and reduced LV volume; Although global LV systolic function is often within the normal range or even increased, the hypertrophied regions show reduced systolic thickening.4. MB is the most common coronary artery disease of patients with HCM. Some of patients with HCM may combine with coronary artery disease (CAD).5. DSCT is a promising modality in the diagnosis and differential diagnosis of HCM, which can provide one-stop noninvasive evaluation of cardiac morphology, function, as well as coronary artery anatomy. DSCT is particularly suitable for clinical suspected patient wth HCM but false-negatieve ultrasound, especially for those suspected with AHCM, coronary artery disease and presence of contraindication to MRI. Objects:To evaluate the feasibility and clinical application value of dual-source CT in the assessment of DCM by assessing its morphology, function and coronary artery anatomy.Materials and Methods:13cases of patients with confirmed DCM (9males,4females, aged9～74years with a mean of48.85±18.96) and13cases of normal subjects (the same with Part two) were enrolled. All patients were subjected to coronary angiography using dual-source CT (Somatom Definition, Germany, Siemens). Analysis of each coronary artery saw Part one. Myocardial segmentation and wall thickness measurement of each segment saw Part two. WT of all17segments were calculated using the formula as the Part two. Measurements of LADd and LVOTd saw Part Two. LV long-axis dimension in end-diastole (Ld) was measured using the four-chamber view from the apex to the midpoint of the mitral valve and the short-axis dimension in end-diastole (Dd) was measured on the line that was perpendicular to the longaxis line at the level of the midpoint of the long-axis at end-diastole. The sphericity index (SI) was calculated using the formula:SI=Dd/Ld x100%. The left ventricular analysis saw Part one.Results:1. There were no significant differences in the clinical profiles (gender, age, BSA, BMI, HR, SBP, DBP, smoking and hyperlipemia) between the DCM and control groups (P>0.05).2. Dd, Ld, SI and LADd in the DCM group were significantly greater than in the control group (P<0.05). There were no significant differences in LVOTd between the DCM and control groups (t=-20.223, P=0.825). The basal wall thickness in the DCM group was smaller than in the control group (t=3.326, P=0.004), while there were no significant differences in both the middleand apical wall thickness between the DCM and control groups (t=-0.096, P=0.925; t=-2.015, P=0.060). WT increases gradually in the control group from basal to apical wall, and the difference was statistically significant (F=88.097, P=0.000). WT of all segments (S1～S17) in the DCM group were significant lower than in the control group, and there were no significant differences in WT from basal to apical wall in the DCM group (F=0.403, P=0.671).3. MM, LVMI, EDV and ESV in the DCM group were significantly greater than in the control group (P=0.000), instead, EF in the DCM group were significantly smaller than in the control group (t=8.022, P=0.000). In correlation analysis, EF was significantly negatively correlated with CI and LVMI(r=-0.632, P=0.020;r=-0.687, P=0.009). SV, CO and CI in the DCM group were smaller than in the control group, but the differences were not statistically significant (P>0.05).4. Of all the13cases with DCM,7cases did not have obvious lesions in coronary angiography and one case had mild atheromatous plaque. The degrees of all the coronary artery stenosis were below30%. Conclusions:1. DCM can be definitively diagnosed by DSCT; It is typically presented as the enlarged LV develops a spherical configuration and accompanies dilated LA, normal or relatively thin wall thickness, diffuse wall motion abnormalities and mitral regurgitation.2. The cardiac function reveals increased LV mass, enlarged LV volume and damaged LV global function.3. LV remolding of DCM is manifested as a spherical configuration and myocardial hypertrophy. The global LV function has decreased gradually as LV remolding develops.4. No obvious obstructive lesion, but a possibility to develop mild atheromatous plaque can be seen in the coronary artery of DCM.5. DSCT is a promising modality to assess DCM and can provide one-stop noninvasive evaluation of cardiac morphology, function, as well as coronary artery anatomy. |
PDF Full Text Request