Cardiac MRI assessment of left and right ventricular parameters in healthy Australian normal volunteers

Cardiac magnetic resonance imaging (MRI) is being utilised increasingly for the purposes of cardiovascular imaging. Limited data suggest a high degree of reproducibility for parameters such as left ventricular (LV) ejection fraction (EF), mass, end-diastolic and end-systolic volumes (EDV and ESV). We sought to investigate reproducibility and establish means for these parameters in a selected normal non-Aboriginal Australian population, using cardiac MRI. Sixty normal volunteers underwent cardiac MRI investigation using a 1.5 T MRI system. Steady state free precession imaging was performed with short axis cine images through the left ventricle obtained. All images were acquired with cardiac gating. Two independent observers then analysed the data set. Data were collected for assessment of left ventricular EF, EDV, ESV, mass and right ventricular volumes. Data are presented as mean+/-S.D. Total imaging time was approximately 15 min. All patients were able to complete the full protocol. Left ventricular parameters: EF 58.5+/-8.0%, LV mass 114.2+/-40.6g, EDV 117.3+/-33.4 mls and ESV 50.0+/-22.2 mls. Right ventricular parameters: EF 45.6+/-11.6%, EDV 163.5+/-52.2 mls and ESV 89.5+/-34.3 mls. Intraclass correlation coefficients for LV: EF 0.84, LV mass 0.84, EDV 0.85 and ESV 0.89. Cardiac MRI provides high quality information about cardiac function with a high level of reproducibility. Cardiac MRI parameters in a normal non-Aboriginal Australian population are provided.     

Evaluation of left ventricular contractile pattern by intravenous digital subtraction ventriculography: Comparison with cineangiography and assessment of interobserver variability

The accuracy and reproducibility of measurements of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and regional wall motion obtained by digital subtraction ventriculography (DSV) were compared with values of direct cineangiography in 40 patients, 21 of whom were ambulatory. DSV was performed with a 1-second, 30-ml contrast injection, which yielded real-time fluoroimages composed of 512 × 512 pixels at 30 frames/s. Single-plane right anterior oblique LV volumes were calculated by area-length methods for both DSV and cineangiography. Wall motion was assessed as percent area shortening for 12 equal myocardial segments, with results classified as abnormal if greater than 2 standard deviations below the mean of 20 normal values. DSV exhibited close correlation with angiography for EDV (r = 0.88), ESV (r = 0.92) and EF (r = 0.93). Intravenous DSV and direct cineangiography were concordant in classification of LV contractile pattern in 436 of 480 (91%) myocardial segments. Measurements of DSV obtained by 2 observers showed close correlations for EDV (r = 0.88), ESV (r = 0.95) and EF (r = 0.94), and wall motion classification was in agreement in 434 of 480 (90%) LV segments. Artifacts induced by respiratory motion, persistence of contrast in the right ventricle or left atrium, or low cardiac output may have contributed to the discrepancies observed. These data indicate that DSV is accurate in assessing LV volume and EF, correlates well with cineangiography and exhibits good interobserver reproducibility.     

Comparison of morphological and functional adaptations of the heart in highly trained triathletes and long-distance runners using cardiac magnetic resonance imaging

“Athlete’s heart” is characterized by an increase in ventricular chamber sizes and myocardial mass (MM), and is mainly observed in endurance athletes. At present, it remains unclear whether cardiac adaptations in long-distance runners differ from those in triathletes. Twenty male triathletes (mean age 38.7 ± 6.2 years) and 20 male marathon runners (mean age 44.1 ± 7.9) underwent cardiac magnetic resonance imaging to calculate left and right ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and MM. Late-enhancement (LE) imaging was used to exclude structural alterations or myocardial scarring. EDV, ESV, SV, and EF for the left and right ventricles, as well as MM, did not differ between long-distance runners and triathletes, although the weekly training volume was significantly higher in triathletes (17.05 vs 9.95 h/week, P < 0.0001). There was a significant correlation between weekly training volume and right and left EDV, right and left ESV as well as MM within the study group. Myocardial LE was absent in all athletes. Highly trained male long-distance runners and triathletes have comparable cardiac parameters. However, the extent of physical training seems to be associated with the degree of cardiac adaptation in endurance athletes. The absence of LE supports the idea that athlete’s heart is a nonpathological adaptation of the cardiovascular system.     

Comparison of single plane videodensitometry-based right ventricular ejection fraction in right and left anterior oblique views to biplane geometry-based right ventricular ejection fraction

To evaluate the reliability of the videodensitometric assessment of right ventricular ejection fraction, 38 patients were studied during diagnostic cardiac catheterization. Digital subtraction images of the right ventricle were obtained in both the right anterior oblique and the left anterior oblique views, using direct intraventricular injection of dilute contrast medium. From the end-diastolic and end-systolic images obtained in each view, analysis of the relative brightness values generated a videodensitometry-based right ventricular ejection fraction for both the right and the left anterior oblique views. These values were compared with those generated by applying the geometry-based Simpson's rule to the orthogonal images. Right ventricular ejection fraction ranged from 22 to 88%. Videodensitometric ejection fraction in the right anterior oblique view correlated well with that in the left anterior oblique view (r = 0.88) and each correlated well with geometry-based ejection fraction (r = 0.91 and 0.82, respectively). In a subset of 18 patients without significant cardiac disease, mean videodensitometric right ventricular ejection fraction was 68% (versus 61% in the abnormal subset), and it correlated closely with left ventricular ejection fraction (r = 0.82). Videodensitometric analysis of digital subtraction images provides a reliable method for calculating right ventricular ejection fraction that is independent of geometry and reliably separates normal from abnormal values. Application of videodensitometric techniques should simplify analysis of the response of the right ventricle to different interventions in patients with cardiac disease.     

磁共振电影成像评价左右心室整体收缩功能

目的对照超声心动图研究磁共振(MR)电影成像评价左右心室功能的应用价值。方法应用屏气真实稳定进动快速成像(TrueFISP)电影序列和右室改良定位方法对36名健康成人志愿者进行MRI检查,以及超声心动图左心功能对照检查。MRI图像经Argus心脏功能软件进行左右室功能的分析及评价。结果(1)MRI测量正常组的左心室整体收缩功能各指标:舒张末期容积(EDV)为(101.3±19.2)ml,收缩末期容积(ESV)为(42.1±13.3)ml,每搏输出量(SV)(69.2±9.8)ml,射血分数(EF)(59.1±7.2)%;右心室整体收缩功能EDV(118.9±27.1)ml,ESV(57.6±16.1)ml,SV(61.2±12.7)ml,EF(51.9±4.5)%。(2)MRI测量左心功能与超声心动图检查结果对照:EDV与超声心动图测值[(97.2±17.6)ml]比较,差异无统计学意义;ESV测值大于超声心动图测值[(33.2±9.4)ml],其余指标均低于超声检查[SV为(64.0±11.3)ml,EF为66.1%±6.2%,P<0.01]。两种方法各指标测量值相关性良好(r=0.66～0.80,P<0.05)。(3)右心室短轴定位改良前后心功能指标测值比较:除ESV测值与改良前差异无统计学意义外,EDV、SV、EF均明显大于改良前(P<0.05)。结论MRI是综合准确无创的心脏检查技术。其电影成像技术结合改良定位对左右心室功能测量准确,兼获心脏解剖和形态信息,可以用于心脏疾病的功能评价及疗效监测。     

应用Amplatzer封堵器治疗儿童动脉导管未闭封堵术前左心功能的变化

目的：应用超声心动图评价Amplatzer封堵器治疗儿童动脉导管未闭（PDA）患者封堵前后左心功能的变化。方法：应用超声心动图测量PDA封堵前后左室舒张末期内径（EDD）和收缩末期内径。应用椭圆体体积法计算出左室舒张末期容积（EDV）、收缩末期容积（ESV）、每搏搏出量（SV）、射血分数（EF）和短轴缩短率（FS）,将封堵前后测量数据分别用统计学配对t检验。结果：封堵后EDD,EDV,ESV,SV恢复至正常,封堵前后差别有统计学意义（P＜0．05）,EF和FS变化不大。结论：应用Amplatzer封堵器治疗儿童PDA是一种有效的方法,能缩短EDD和改善PDA患者的左心功能。     

The discrepancy between echocardiography, cineventriculography and thermodilution

We have often experienced disagreement in left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) between cineventriculography and echocardiography not performed simultaneously, and unnaturally hyperdynamic left ventricular wall motion. We determined EDV, ESV, stroke volume, and EF (with modified Simpson's rule) in 65 consecutive patients using 2-dimensional echocardiography with a 2.5 MHz, 128-element phased-array transducer within three days of cardiac catheterization and compared our results with those obtained by the thermodilution technique and biplane cineventriculography. Heart rate and stroke volume were significantly different among the three techniques: cineventriculography yielded the highest values. These findings suggest that patients may have been in a hyperadrenergic state caused by anxiety experienced during invasive cineventriculography and thermodilution examinations. Inter- and intraobserver variabilities for echocardiography differed little from the variability in cineventriculography. Although there were good correlations between echocardiographic and cineventriculographic findings for EDV (r=0.67), ESV (r=0.80), and EF (r=0.78) by two independent observers, there was a lack of agreement for EDV, ESV, and EF. Echocardiographic EDV values were significantly lower than cineventriculographic values. When left ventricular function is good, the left ventricle tends to be hyperadrenergic and in a more hyperdynamic state with smaller ESV than echocardiographic values during cineventriculography. When left ventricular function is poor, the left ventricle tends to be influenced by the effect of the contrast medium and stress during the invasive examinations and in a more hypodynamic state with larger ESV than echocardiographic values during cineventriculography. The echocardiography is highly reproducible and may provide information that is not available from cineventriculography and thermodilution. Cineventriculography may provide another manifestation of cardiac reserve. In conclusion, we must take into account each peculiar property of the echocardiography, the cineventriculography, or the thermodilution technique when patients are examined with cardiac conditions by different methods at different days.     

时间-空间相关成像技术初步评价正常胎儿心脏心室容积及心室收缩功能

目的 探讨时间-空间相关成像技术(STIC技术)在正常胎儿心脏心室容积及心室收缩功能方面的应用.方法 选取进行胎儿超声心动检查的正常妊娠孕妇136例,按孕周分为22～周、23～周、24～周、25～周、26～周、27～周、28～周7组.运用时间-空间相关成像技术后处理软件获得容积参数,包括舒张末期容积(EDV)、收缩末期容积(ESV)及心室收缩功能参数(EF值)等,分析胎儿心室容积发育与孕周的关系,比较左右心室容积和收缩功能的差异.结果 胎儿左右心室容积参数EDV、ESV与孕周间均有线性相关关系,随孕周增长而增加,而收缩功能参数EF与孕周之间无明显线性关系,随孕周增长无明显变化;容积参数EDV、ESV左右心室之间差异无统计学意义,而EF左右心室间差异有统计学意义(P＜0.05).结论 时间-空间相关成像技术对胎儿心内膜清晰成像时能够获得心室腔容积,进而评价心脏收缩功能,有助于进一步研究胎儿心脏容积发育和收缩功能变化.     

成人先天性心脏病合并肺动脉高压患者的心脏磁共振评估

目的 探讨心脏磁共振（cardiac magnetic resonance,CMR）评价先天性心脏病合并肺动脉高压患者心室功能的临床价值.方法 对26例先天性心脏病合并肺动脉高压的患者行CMR检查,分别测量并计算右心室与左心室的短轴缩短率、舒张末期直径、舒张末期容积、收缩末期容积、每搏排血量、射血分数等心功能参数及主动脉、肺动脉直径,同时评价室间隔运动、心肌延时强化.采用配对样本t检验比较左、右心室功能参数,采用两个独立样本t检验比较室间隔运动正常组和异常组的右心功能情况,采用卡方检验比较室间隔运动异常与心肌延时强化的关联.结果 右心室舒张末期直径、舒张末期容积、收缩末期容积均显著高于左心室,差异有统计学意义（P＜0.05）;右心室短轴缩短率、射血分数均显著低于左心室,差异有统计学意义（P＜0.05）.26例患者中,14例室间隔运动异常,14例出现心肌延时强化.室间隔运动异常组心肌延时强化出现比例明显高于室间隔运动正常组,差异有统计学意义（P＜0.05）.同时,室间隔运动异常组的右心室舒张末期直径、舒张末期容积均显著高于正常组,差异有统计学意义（P＜0.05）;右心室短轴缩短率显著低于正常组,差异有统计学意义（P＜0.05）;射血分数低于正常组,但差异无统计学意义（P=0.08）.结论 合并肺动脉高压的成人先天性心脏病患者右心功能较左心功能差,室间隔运动异常患者的右心功能更差,室间隔运动异常患者出现心肌延时强化比例高.CMR能够提供先天性心脏病合并肺动脉高压患者的左、右心室功能及相关结构信息,对治疗和预后有重要价值.     

Evaluation of left ventricular residual function using postextrasystolic potentiation. Relation between systolic time intervals and angiographic study

The effects of postextrasystolic potentiation (PESP) on systolic time intervals and left ventricular wall motion were studied during diagnostic cardiac catheterization in 20 patients (4 normal individuals, 11 patients with coronary artery disease and 5 patients with idiopathic dilated cardiomyopathy). Postextrasystolic changes in the aortic pressure and systolic time intervals were measured from the electrocardiogram and aortic pressure tracing. After a micromanometer-tipped catheter was positioned in the ascending aorta just above the aortic valve, a single ventricular premature beat was introduced using an R-wave coupled stimulator. PESP was then studied during left ventriculography which was undertaken simultaneously in the right anterior oblique 30 degrees and left anterior oblique 60 degrees positions. Following two or three normal sinus beats, a right ventricular extrastimulus was delivered again under the same stimulating condition. PESP in all patients caused a decrease in the ratio of the preejection period to the left ventricular ejection time (PEP/ET). The average percent decrease was 21% (from 0.429 +/- 0.162 to 0.339 +/- 0.102, p less than 0.001). The left ventricular ejection fraction (EF) increased in all patients with PESP from 0.52 +/- 0.20 to 0.61 +/- 0.17 (p less than 0.001). The postextrasystolic changes in the PEP/ET ratio and EF were greater in patients with low cardiac performance. There was a good correlation (r = -0.85, p less than 0.001) between the changes in the EF and those in PEP/ET in PESP. Thus, it is possible to determine left ventricular residual function (the postextrasystolic change in the global EF) using the postextrasystolic change in PEP/ET in patients with coronary artery disease and dilated cardiomyopathy.     

Reduced right ventricular ejection fraction in endurance athletes presenting with ventricular arrhythmias: a quantitative angiographic assessment.

AIMS: Spontaneous or inducible sustained ventricular arrhythmias (VA) in endurance athletes frequently originate from the right ventricle (RV), even in the absence of familial arrhythmogenic RV cardiomyopathy (ARVC). The goal of this study was to determine whether the RV arrhythmogenic predilection in these patients is associated with RV functional abnormalities. METHODS AND RESULTS: Biplane RV angiography was performed in three groups: 22 endurance athletes with VA, 15 matched athletes without VA, and 10 non-athletes without VA. Four methods for quantitative RV angiographic analysis (area length, Boak, pyramid monoplane, and pyramid biplane) were used to calculate RV end-diastolic volume (EDV) and end-systolic volume (ESV) (both corrected for body surface area) and ejection fraction (EF). In addition RV outflow tract shortening fraction (SF) was determined. Although only 6 of 22 (27%) athletes with VA fulfilled the diagnostic criteria for ARVC, RV arrhythmogenic involvement was manifest or probable in 82%, based on a combination of electrophysiologic, electrocardiographic, and morphologic criteria. RV EDV in athletes was higher than in non-athletes (area length: 100.3 +/- 26.9 vs. 69.6 +/- 14.3 mL/m(2), P = 0.001), without significant difference between athletes with and without VA. RV ESV, in contrast, was significantly higher in athletes with VA than in athletes without VA (52.6 +/- 22.3 vs. 35.5 +/- 11.2 mL/m(2), P = 0.004), resulting in a significantly lower RV EF, a consistent finding across all methods (area length: 49.1 +/- 10.4 vs. 63.7 +/- 6.4%, P < 0.001). This functional impairment was also reflected in a lower RV outflow tract SF (SF right anterior oblique 32.2 +/- 10.1 vs. 40.0 +/- 11.6%, P = 0.09; SF left anterior oblique (LAO) 31.9 +/- 7.8 vs. 39.0 +/- 10.5%, P = 0.10). CONCLUSION: VA in high-level endurance athletes frequently originate from a mildly dysfunctional RV. This raises the question whether endurance exercise not only acts as a trigger for these arrhythmias but also as promoter of the RV changes.     

Comparison of ventricular function after Senning and Jatene procedures for complete transposition of the great arteries

Postoperative right (RV) and left ventricular (LV) volume characteristics in patients with complete transposition of the great arteries were studied to compare ventricular function after Senning and Jatene procedures and to analyze RV dimensional change during systole in patients after the Senning procedures. RV end-diastolic volume (EDV) was 181 +/- 74% of normal (mean +/- standard deviation) and RV ejection fraction (EF) was 0.48 +/- 0.09 in 15 patients who underwent the Senning procedure. In 9 patients who underwent the Jatene procedure, LVEDV was 152 +/- 27% of normal and LVEF was 0.61 +/- 0.09. One patient with aortic regurgitation, 1 with aortic regurgitation and residual ventricular septal defect, and 1 with aortic regurgitation and generalized LV wall hypokinesia of unknown cause had large LVEDVs. Pulmonary ventricular EDV and EF were within normal ranges except in the patients with persistent pulmonary hypertension, who had large EDVs and low EFs regardless of the anatomic type of ventricle, either the left or right. The study of RV dimensional change in the Senning group showed a reduced systolic shortening of the anteroposterior diameter compared with the preoperative transposition of the great arteries and normal. This reduced shortening may be related to postoperative adhesion of the RV free wall to the anterior chest wall and fixation of the atrium secondary to the intraatrial repair. In conclusion, systemic ventricular function after intraatrial repair for complete transposition of the great arteries is depressed by unavoidable residua and sequelae: persistent RV hypertension, anatomy of the right ventricle and, possibly, postoperative adhesions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative variability in regional wall motion during serial left ventricular cineangiography: guidelines for assessing changes in segmental function with intervention studies

To assess the random variation in left ventricular (LV) volume and regional wall motion that occurs with quantitative analysis of LV cineangiography, 15 patients underwent 2 serial biplane LV cineangiograms in the 30 degrees right anterior oblique and 60 degrees left anterior oblique projections. Cineangiograms were separated by a waiting period of at least 15 minutes. Regional wall motion was quantitated with an area ejection fraction (EF) technique that divides the left ventricle into 8 areas. There were no significant changes in heart rate, mean arterial pressure or LV pressure or volume between the first and second angiograms. However, global EF increased from 0.57 +/- 0.11 to 0.58 +/- 0.10 (p = 0.055). Random variability in area EF was greatest in the septal and low posterolateral regions and least in the inferior and inferobasal regions of the left ventricle. Using linear regression analysis to obtain 95% confidence intervals, we determined the amount of absolute increase in area EF that must occur to be considered significant for each LV region. This amount varies from area to area and is as little as +/- 0.06 in the inferior region (area 4) and as high as +/- 0.16 in the septum (area 8). These data provide guidelines for the determination of the influence of interventions on regional wall motion in individual patients with cardiac disease, and indicate that statistically significant changes in regional wall motion are clinically important.     

Scintigraphic determination of ventricular function and coronary perfusion in long-distance runners

Left ventricular function and coronary perfusion were evaluated with rest-exercise gated blood pool and stress-redistribution thallium scans in a group of long-distance runners and compared to a group of catheterization-proved normal subjects. Exercise duration, work load, and oxygen consumption were significantly greater for long-distance runners. Rest end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volumes (SV) were significantly larger in long-distance runners than in control subjects, while ejection fraction (EF), cardiac index (CI), and ejection rate were similar in both groups. Exercise EDV increased and ESV decreased, producing an increase in SV and EF in long-distance runners. Exercise EDV did not change and ESV decreased less, producing lesser increase in SV and EF in the control group. Qualitative evaluation of thallium scans showed apparent perfusion defects with normal redistribution in six myocardial segments in five long-distance runners. Quantitative evaluation demonstrated initial defects, which persisted on delay scans, but were associated with normal relative redistribution in three ventricular walls in three long-distance runners. In conclusion, left ventricular reserve function was greater in long-distance runners than in control subjects. Endurance exercise can be associated with apparent myocardial perfusion defects, which may be due to uneven ventricular hypertrophy resulting from the pressure and volume loads imposed by exercise.     

Left ventricular function before and following surgical treatment of mitral valve disease.

Nineteen patients with mitral valve disease were studied before and a mean 11 months +/- 9 months following valve replacement or reconstruction, which resulted in good postoperative valve function. Biplane left ventricular angiography and pressures were utilized to determine end-diastolic volume/M. (EDV), end-systolic volume/M. (ESV), ejection fraction (EF), left ventricular mass/M. (LVM), and stroke work/M. (SW). There were 19 patients--six with mitral stenosis (MS), six with mitral stenosis and regurgitation (MS + MR), and seven with mitral regurgitation (MR). Those with MS and MS + MR preoperatively had no significant change in left ventricular end-diastolic pressure (LVEDP), EDV, ESV, LVM, or EF following surgery. Patients with MR had a significant reduction in LVEDP, EDV, SV, and SW. More importantly, the EF fell in four of these seven patients and LVM did not decrease following surgery. It is concluded that surgical treatment for MS and MS + MR had little effect on left ventricular performance. Following surgical treatment for MR, reduction in EDV is not associated with reduction in LVM, and frequently left ventricular performance deteriorates as judged by the EF.     

Difference in the residual left ventricular pump function between anterior and inferior myocardial infarctions.

To evaluate the left ventricular regional ejection fraction (EF) of noninfarcted area in relation to the left ventricular end-diastolic volume (EDV) in patients with recent myocardial infarction (MI), 75 patients with Q-wave MI (anterior: 51 patients; inferior; 24 patients) were studied. The regional EF of noninfarcted area was obtained by radionuclide angiocardiography 4 weeks after the onset of MI and was used to estimate the left ventricular regional function of the noninfarcted area. Peak creatine kinase and QRS scores were not significantly different between anterior and inferior MI in each left ventricular EDV (EDV < or = 100, 101-139 and > or = 140 ml). Global EF and regional EF of noninfarcted area in anterior MI with left ventricular EDV > or = 140 ml was significantly lower than in those with EDV < or = 139 ml (p < 0.01), whereas there were no significant differences in global EF and regional EF of noninfarcted area in the three groups of left ventricular EDV in inferior MI. Thus, the effect of left ventricular EDV on regional EF of noninfarcted area and on the total cardiac performance was more important in anterior than in inferior MI, because a similar degree of left ventricular dilatation resulted in more severe derangements after anterior MI.     

Electrocardiogram-gated single-photon emission computed tomography versus cardiac magnetic resonance imaging for the assessment of left ventricular volumes and ejection fraction: a meta-analysis

OBJECTIVES: The purpose of this study was to evaluate the accuracy of electrocardiogram (ECG)-gated single-photon emission computed tomography (SPECT) for assessment of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) compared with the gold standard of cardiac magnetic resonance imaging (MRI). BACKGROUND: Several comparisons of ECG-gated SPECT with cardiac MRI have been performed for evaluation of LV volumes and EF, but each has considered few subjects, thus leaving uncertainty about the frequency of discrepancies between the two methods. METHODS: We performed a meta-analysis of data on 164 subjects from nine studies comparing ECG-gated SPECT versus cardiac MRI. Data were pooled in correlation and regression analyses relating ECG-gated SPECT and cardiac MRI measurements. The frequency of discrepancies of at least 30 ml in EDV, 20 ml in ESV and 5% or 10% in EF and concordance for EF < or =40% versus >40% were determined. RESULTS: There was an overall excellent correlation between ECG-gated SPECT and cardiac MRI for EDV (r = 0.89), ESV (r = 0.92) and EF (r = 0.87). However, rates of discrepancies for individual subjects were considerable (37% [95% confidence interval [CI], 26% to 50%] for at least 30 ml in EDV; 35% [95% CI, 23% to 49%] for at least 20 ml in ESV; 52% [95% CI, 37% to 63%] for at least 5% in EF; and 23% [95% CI, 11% to 42%] for at least 10% in EF). The misclassification rate for the 40% EF cutoff was 11%. CONCLUSIONS: Electrocardiogram-gated SPECT measurements of EDV, ESV and EF show high correlation with cardiac MRI measurements, but substantial errors may occur in individual patients. Electrocardiogram-gated SPECT offers useful functional information, but cardiac MRI should be used when accurate measurement is required.     

Postoperative left ventricular function in patients with mitral stenosis. The effect of commissurotomy and valve replacement on left ventricular systolic function

Preoperative and postoperative left ventricular cineangiograms of 26 patients with mitral stenosis (MS) were analyzed to calculate left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF) and systolic regional wall motion. Nine patients underwent commissurotomy (OMC group) and 17 patients underwent mitral valve replacement (MVR group). In both groups, postoperative EDV, SV and EF tended to increase, while ESV remained unchanged. In the OMC group, systolic wall motion of the left ventricle was found to be improved postoperatively, whereas systolic wall motion in the MVR group was found to be impaired postoperatively. The latter finding was assumed to be due to excision of the papillary muscles and chordae tendineae. Preservation of these structures is likely to be important for better postoperative functional recovery of the left ventricle.     

Comparison of intravenous digital subtraction cineangiocardiography with conventional contrast ventriculography for the determination of the left ventricular volume at rest and during exercise

Left ventricular volumes were determined by means of digitalsubtraction cineangiocardiography (DSA) which was performedin the right anterior oblique projection after contrast agentinjection into the superior vena cava. Monoplane end-diastolic(EDV), end-systolic volumes (ESV), and ejection fraction (EF)were calculated using the ‘area–length’ methodand were compared with the same parameters obtained by conventionalleft ventricular cineangiocardiography. A first group of 20patients was studied at rest and a second group of 10 patientsduring bicycle exercise at a work load of 64 watts during 2min, by DSA and conventional cineangiocardiography. Three differentsubtraction modes were evaluated: (1) mask mode subtraction(MMS), (2) time interval difference (TID) method and (3) a combinationof MMS and TID called MMS+TID method. With the MMS method goodcorrelations were obtained for EDV, ESV and EF at rest (r>0.91)and during exercise (r>0.91). The TID method showed onlymoderate correlations for patients at rest (r>0.86) and duringexercise (r>0.79). Similar results as with MMS were achievedby the combined method (MMS+TID) at rest (r>0.91) and duringexercise (r>0.91). Interobserver variability indicated ahigh reproducibility for all methods except for TID during exercise.Itis concluded that DSA is an accurate technique for left ventricularvolume determination not only at rest but also during exercise.The best results are obtained with MMS or MMS+TID methods, whileleft ventricular contour detection is easier and more convenientwith MMS+TID.     

实时三维超声心动图在肥厚型心肌病中的应用价值

目的探讨实时三维超声心动图(RT-3DE)在肥厚型心肌病(HCM)患者中的应用价值。方法选取肥厚型心肌病患者42例,另选健康体检者40名为对照组。全容量实时三维显示(full-volume),启动切割键(crop)对图像进行切割后,观察心腔立体形态及二尖瓣叶收缩期前向运动(SAM)现象,并将图像存储后于TomTec工作站进行分析。结果应用RT-3DE能清晰显示HCM患者心腔立体空间结构及SAM现象,并可以准确测量左心室舒张末容积(EDV)、收缩末容积(ESV)、每搏量(SV)和左心室射血分数(LVEF)等指标,结果显示:HCM组EDV(70.8±15.2)ml,SV(46.2±8.1)ml,与对照组比较均减低(均为P0.01),ESV(26.0±8.2)ml,EF64.4%±6.4%,与对照组比较差异无统计学意义(均为P0.05)。结论应用RT-3DE能够反映HCM患者心脏的立体空间结构,确定二尖瓣前叶运动与左心室流出道梗阻的关系,是准确评价HCM患者左心室收缩功能的方法。