Three-Dimensional Endo-Cardiovascular Volume-Rendered Cine Computed Tomography of Isolated Left Ventricular Apical Hypoplasia: A Case Report and Literature Review

We report multidetector computed tomography (MDCT) and cardiac magnetic resonance (CMR) findings of a 34-year-old female with isolated left ventricular apical hypoplasia. The MDCT and CMR scans displayed a spherical left ventricle (LV) with extensive fatty infiltration within the myocardium at the apex, interventricular septum and inferior wall, anteroapical origin of the papillary muscle, right ventricle wrapping around the deficient LV apex, and impaired systolic function. MDCT visualized morphologic and also functional findings of this unique cardiomyopathy.     

Clinical utility of a multigated modified anterior projection in the detection of left ventricular inferior and apical wall motion abnormalities

Recent evidence indicates that the left anterior oblique projection (LAO) multigated radionuclide ventriculogram (RVG) underestimates presence and extent of apical and inferior left ventricular (LV) wall motion abnormalities. We investigated, prospectively, the sensitivity and specificity of a modified anterior projection (MAP), which incorporates cephalad tilting. Thirty-three consecutive patients undergoing cardiac catheterization suspected to have coronary artery disease were studied with RVG, using both the MAP and LAO views. LAO views were analyzed using the ejection fraction image (REFI), and the regional ejection fraction (REF) of the inferoapical region. The MAP studies were analyzed using stroke volume image (SVI) to evaluate apical and inferior LV regions. Results were as follows: (Formula: see text), Both intraobserver and interobserver variabilities were comparable to those of conventional angiographic studies used in detection of apical and inferior asynergy. It is concluded that the multigated MAP offers additional information about abnormalities of the LV inferior and apical regions.     

Cardiac MRI in ischemic heart disease with severe coronary artery stenosis

RATIONALE AND OBJECTIVES: The aim was to evaluate the left ventricular wall motion abnormalities, perfusion and late contrast enhancement patterns on magnetic resonance imaging (MRI) in patients with 70% or higher degree stenosis or occlusion of coronary arteries on coronary angiography. MATERIALS AND METHODS: Twenty-four patients (5 women, 19 men, age range 38-78, mean age 59.1) who had 70% or higher degree stenosis or occlusion of coronary arteries on coronary angiography who had been referred for cardiac MRI were included. On coronary angiography, 20 vessels were totally occluded [left anterior descending artery (LAD) 12; left circumflex coronary artery (LCx) 2; right coronary artery 6] and 20 vessels were severely stenotic (70-99%). In 5 patients' three vessels, in 6 patients' two vessels, and in 13 patients' a single vessel was involved. Wall motion, perfusion abnormalities, and late contrast enhancement consistent with nonviable myocardium were analyzed at apical, at midventricular, and basal levels on short-axis images of cardiac MRI in concordance with the segmental irrigation areas of the coronary arteries. RESULTS: Impaired perfusion was observed on the corresponding irrigation segments of 39 vessels of 40 coronary artery branches. Wall motion abnormalities were present on corresponding irrigation areas of 30 severely stenotic vessels. Combined evaluation of wall motion and perfusion, segments with the decreased left ventricular contraction, and perfusion matched with the corresponding irrigation areas of all of the 40 stenotic or occluded vessels. CONCLUSION: A correlation was found between the combined assessments of myocardial perfusion, wall motion, and viability on late contrast enhancement on cardiac MRI with the clinical and angiography findings. Thus this combined MRI protocol can be used for the evaluation of ischemic heart disease.     

Lung Infarction due to Pulmonary Vein Stenosis after Ablation Therapy for Atrial Fibrillation Misdiagnosed as Organizing Pneumonia: Sequential Changes on CT in Two Cases

Pulmonary vein (PV) stenosis is a complication of ablation therapy for arrhythmias. We report two cases with chronic lung parenchymal abnormalities showing no improvement and waxing and waning features, which were initially diagnosed as nonspecific pneumonias, and finally confirmed as PV stenosis. When a patient presents for nonspecific respiratory symptoms without evidence of infection after ablation therapy and image findings show chronic and repetitive parenchymal abnormalities confined in localized portion, the possibility of PV stenosis should be considered.     

Scintigraphic assessment of patients with electrocardiographic left ventricular hypertrophy with ST-T changes without apparent cause

PURPOSE: Some patients who show electrocardiographic left ventricular hypertrophy with ST-T changes (ECG-LVH) are difficult to evaluate using routine examinations. To clarify the pathologic process in these patients, the authors performed several scintigraphic examinations. MATERIALS AND METHODS: Twenty-nine patients with ECG-LVH, without apparent cause, such as left ventricular (LV) systolic overloading or increased LV mass, were examined by myocardial I-123 MIBG imaging, I-123 BMIPP imaging, and exercise-induced stress perfusion imaging. In addition to the visual assessment of each image, we calculated global and regional myocardial washout of I-123 MIBG (%washout). The LV was assessed using conventional echocardiography. RESULTS: Visually observed abnormalities were located exclusively at the LV apex with all imaging methods and were detected in 76%, 52%, and 17% of patients by I-123 MIBG, I-123 BMIPP, and perfusion imaging, respectively. A follow-up study revealed that the apical defects of I-123 MIBG were subsequently followed by defects of I-123 BMIPP and then perfusion abnormalities. In patients with an apical defect revealed by I-123 MIBG imaging, apical %washout was high. In nine patients who underwent myocardial biopsy, myocardial disarray was observed at the apical regions. CONCLUSIONS: In many patients with ECG-LVH without apparent cause, sympathetic abnormalities are observed at the apex, similar to pathologic changes in hypertrophic cardiomyopathy. These abnormalities may lead to changes in fatty acid metabolism and perfusion.     

Changes in left and right ventricular cardiac function after valve replacement for aortic stenosis determined by cine MR imaging

The purpose of this study was to determine the changes in function of both the left and the right ventricles (LV, RV) before and after aortic valve replacement (AVR), compared with age-matched healthy volunteers using magnetic resonance (MR) imaging. Fourteen patients with aortic stenosis underwent MR imaging (1.5 T) before and 3 (n = 14) and 12 (n = 9) months after surgical valve replacement. An electrocardiographically triggered two-dimensional cine fast low-angle shot sequence was used for the evaluation of absolute values and indices related to 1 m(2) body surface area for function, mass, and LV wall thickening. Fourteen age-matched healthy volunteers served as controls. Before surgery, all patients showed significant abnormalities of LV mass and function, whereas RV mass and function were not different from those of volunteers and remained mostly unchanged. After surgery, normalization of LV ejection fraction, absolute mass, and end-systolic wall thickness was observed, whereas the LV mass index failed to normalize, and LV volumes remained elevated. Aortic stenosis combined with a significant, but not severe reduction in LV function only affects the LV, whereas the RV remains unaffected at this stage of disease. AVR leads to improved LV function and reduced hypertrophy, but without normalization of LV volumes or the LV mass index within 1 year.     

Multimodal imaging approach in hyponatremic hypertensive syndrome. A rare case of pediatric unilateral hypoplasia of the main renal artery combined itself with stenosis and review of literature

Renal artery stenosis (RAS) accounts for approximately 5%-10% of secondary renovascular hypertension in the pediatric population. It can occur as an isolated entity, or as a hypoplasia combined itself with stenosis. Hypoplasia, or long-segment developmental narrowing, is a rare cause of renovascular hypertension. Hyponatremic hypertensive syndrome (HHS) is a malignant complication of unilateral RAS and/or renal artery hypoplasia. Hyponatremia, hypokalemic hypochloremic metabolic alkalosis, nephrotic range proteinuria, polyuria, polydipsia, and weight loss are the most common findings. In particular, hypertension remains refractory despite aggressive antihypertensive therapy. Laboratory findings of elevated plasma levels of renin in most case suggest that the stimulation of renin release from the ischemic kidney plays an important pathophysiologic role. HHS is a diagnostic and therapeutic challenge in children. We report a case of a unilateral right renal artery hypoplasia, complicated by a segmental narrowing, in a 17-month-old male, clinically symptomatic for hypertension. We emphasize the role of ultrasound, computed tomography, and digital subtraction angiography that should be planned as reliable and non-invasive multimodal imaging approach.     

Coronary to pulmonary artery fistula associated with significant coronary atherosclerosis and severe aortic valve stenosis: A Case Report

Coronary artery fistulas are anomalous connections between one or two coronary arteries with either a cardiac chamber or any major blood vessels (coronary sinus, superior vena cava, pulmonary veins and pulmonary artery). It is rarely reported, occurring only in 0.1%-0.2% of patients who undergo coronary angiography. We report a very rare case where myocardial ischaemia may have resulted from the presence of coronary artery fistula, significant coronary artery stenosis and severe aortic valve stenosis. Transthoracic echocardiography showed severe aortic stenosis, while coronary angiography showed a tortuous coronary artery fistula originating from the proximal left anterior descending artery, with a single opening in the main pulmonary artery. Angiography also showed significant stenosis in the middle of the left anterior descending artery. Coronary artery fistula with concomitant significant coronary atherosclerosis and severe aortic stenosis requires optimal therapeutic planning.     

High count rate first-pass radionuclide angiography using a digital gamma camera

In this study, first-pass radionuclide angiography (FPRNA) was performed using a digital single-crystal gamma camera. Twenty-nine men and six women (ages 43-80, mean 61 yr) underwent FPRNA in the supine position immediately prior to cardiac catheterization. Total counts/sec in the whole field-of-view in the right ventricular phase were 150,352 +/- 26,006. Background uncorrected counts in the representative cycle were 7,651 +/- 2,527 at end-diastolie and 4,904 +/- 2,314 at end-systolie. A linear correlation between FPRNA left ventricular (LV) ejection fraction and contrast LV ejection fraction gave an r = 0.95 with an s.e.e. of 0.05. Analyses of intra- and interobserver variability gave r = 0.99 and 0.98 and an s.e.e. of 0.02 and 0.03, respectively. Spearman-Rank correlation coefficients between FPRNA and contrast angiographic wall-motion scores were greater than 0.8 for all walls, while sensitivity/specificity were 0.86/0.90, 0.76/1.00, 0.76/1.00 for anterior, apical, and inferior wall-motion abnormalities, respectively. We conclude that satisfactory counting statistics for FPRNA can be obtained with a digital gamma camera, and that accurate and reproducible measurements of global and regional left ventricular function can be obtained with this technique.     

单发右心室发育不良的影像学诊断

目的 报道6例单发右心室发育不良并评价其影像学诊断方法。方法 6例单发右心室发育不良患者均行X线平片、心电图、超声心动图、心导管及心血管造影检查，2例经外科手术证实。结果 6例中，5例小梁部发育不全，1例三尖瓣、流入道及小梁部皆发育不良。6例均伴有Ⅱ孔型房间隔缺损。结论 单发右心室发育不良是少见的紫绀属先天性心脏病，确诊需行心血管造影检查。     

Novel Resectable Myocardial Model Using Hybrid Three-Dimensional Printing and Silicone Molding for Mock Myectomy for Apical Hypertrophic Cardiomyopathy

ObjectiveWe implemented a novel resectable myocardial model for mock myectomy using a hybrid method of three-dimensional (3D) printing and silicone molding for patients with apical hypertrophic cardiomyopathy (ApHCM).Materials and MethodsFrom January 2019 through May 2020, 3D models from three patients with ApHCM were generated using the end-diastolic cardiac CT phase image. After computer-aided designing of measures to prevent structural deformation during silicone injection into molding, 3D printing was performed to reproduce anatomic details and molds for the left ventricular (LV) myocardial mass. We compared the myocardial thickness of each cardiac segment and the LV myocardial mass and cavity volumes between the myocardial model images and cardiac CT images. The surgeon performed mock surgery, and we compared the volume and weight of the resected silicone and myocardium.ResultsDuring the mock surgery, the surgeon could determine an ideal site for the incision and the optimal extent of myocardial resection. The mean differences in the measured myocardial thickness of the model (0.3, 1.0, 6.9, and 7.3 mm in the basal, midventricular, apical segments, and apex, respectively) and volume of the LV myocardial mass and chamber (36.9 mL and 14.8 mL, 2.9 mL and −9.4 mL, and 6.0 mL and −3.0 mL in basal, mid-ventricular and apical segments, respectively) were consistent with cardiac CT. The volume and weight of the resected silicone were similar to those of the resected myocardium (6 mL [6.2 g] of silicone and 5 mL [5.3 g] of the myocardium in patient 2; 12 mL [12.5 g] of silicone and 11.2 mL [11.8 g] of the myocardium in patient 3).ConclusionOur 3D model created using hybrid 3D printing and silicone molding may be useful for determining the extent of surgery and planning surgery guided by a rehearsal platform for ApHCM.     

Increase in left ventricular torsion-to-shortening ratio in children with valvular aortic stenosis.

Perfusion of left ventricular (LV) subendocardium in valvular aortic stenosis (AS) patients is impaired. It was expected that this may lead to a reduction of subendocardial fiber contraction and, consequently, to an increase of LV torsion per amount of ejection. Using MR tagging (MRT), it was investigated whether the torsion-to-shortening ratio (TSR) is elevated in valvular AS patients. Six asymptomatic children with valvular AS were investigated using echo Doppler, ECG, exercise test, and MRT. LV torsion and natural strain of the inner diameter were determined from measured tag displacements in two short-axis slices of the LV. In all AS patients TSR was approximately 40% increased (0.62 +/- 0.04 rad; mean +/- SD) as compared to pediatric (0.44 +/- 0.08 rad; n=5) and adult controls (0.46 +/- 0.08 rad; n=9), indicating subendocardial contractile dysfunction. With other techniques hitherto used this type of dysfunction could not be detected.     

Changes in cardiac sympathetic nerve innervation and activity in pathophysiologic transition from typical to end-stage hypertrophic cardiomyopathy.

Left ventricular (LV) systolic function in hypertrophic cardiomyopathy (HCM) is usually normal. Late in the disease, however, LV systolic dysfunction and dilatation are recognized. Although abnormalities in cardiac sympathetic nerve activity in patients with HCM have been demonstrated using (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, the changes of cardiac sympathetic nerve activity throughout the clinical course from typical to end-stage HCM are unclear. The objective of this study was to evaluate the relationship between abnormalities on (123)I-MIBG myocardial scintigraphy and pathophysiologic changes in patients with HCM. METHODS: We performed (123)I-MIBG scintigraphy on 46 patients with HCM and 18 age-matched control subjects. The patients were categorized into 3 groups: 28 patients with normal LV systolic function (group A), 9 patients with LV systolic dysfunction (group B), and 9 patients with LV systolic dysfunction and dilatation (group C). With planar (123)I-MIBG imaging, the heart-to-mediastinum ratio for early and delayed acquisitions and the washout rate were calculated. With SPECT, polar maps of the LV myocardium were divided into 20 segments. The regional uptake and washout rate were calculated from semiquantitative 20-segment bull's-eye analysis. RESULTS: The early uptake was significantly lower in group C than in the control group (P < 0.01). The washout rate was progressively higher in group A, group B, and group C (P < 0.01). Reduced regional early uptake was found in 2.9 +/- 3.4 (group A), 4.1 +/- 4.7 (group B), and 7.4 +/- 4.3 (group C) segments, respectively. In group C, regional early uptake was significantly reduced, predominantly in the interventricular septal wall, and regional washout rate was increased in the apex and lateral wall. CONCLUSION: These results suggest that cardiac sympathetic nerve abnormalities in patients with HCM may advance with development of LV systolic dysfunction and dilatation and that (123)I-MIBG myocardial scintigraphy may be a useful tool for the evaluation of pathophysiologic changes in HCM.     

Improved coronary in-stent visualization using a combined high-resolution kernel and a hybrid iterative reconstruction technique at 256-slice cardiac CT—Pilot study

Objectives

To investigate the diagnostic performance of 256-slice cardiac CT for the evaluation of the in-stent lumen by using a hybrid iterative reconstruction (HIR) algorithm combined with a high-resolution kernel.

Methods

This study included 28 patients with 28 stents who underwent cardiac CT. Three different reconstruction images were obtained with: (1) a standard filtered back projection (FBP) algorithm with a standard cardiac kernel (CB), (2) an FBP algorithm with a high-resolution cardiac kernel (CD), and (3) an HIR algorithm with the CD kernel. We measured image noise and kurtosis and used receiver operating characteristics analysis to evaluate observer performance in the detection of in-stent stenosis.

Results

Image noise with FBP plus the CD kernel (80.2 ± 15.5 HU) was significantly higher than with FBP plus the CB kernel (28.8 ± 4.6 HU) and HIR plus the CD kernel (36.1 ± 6.4 HU). There was no significant difference in the image noise between FBP plus the CB kernel and HIR plus the CD kernel. Kurtosis was significantly better with the CD- than the CB kernel. The kurtosis values obtained with the CD kernel were not significantly different between the FBP- and HIR reconstruction algorithms. The areas under the receiver operating characteristics curves with HIR plus the CD kernel were significantly higher than with FBP plus the CB- or the CD kernel. The difference between FBP plus the CB- or the CD kernel was not significant. The average sensitivity, specificity, and positive and negative predictive value for the detection of in-stent stenosis were 83.3, 50.0, 33.3, and 91.6% for FBP plus the CB kernel, 100, 29.6, 40.0, and 100% for FBP plus the CD kernel, and 100, 54.5, 40.0, and 100% for HIR plus the CD kernel.

Conclusions

The HIR algorithm combined with the high-resolution kernel significantly improved diagnostic performance in the detection of in-stent stenosis.     

Feature tracking computed tomography-derived left ventricular global longitudinal strain in patients with aortic stenosis: a comparative analysis with echocardiographic measurements

BackgroundLeft ventricular (LV) systolic function is a prognostic factor in patients with severe aortic stenosis (AS). Multi-detector row computed tomography (MDCT) data are key in the evaluation of patients undergoing transcatheter aortic valve implantation (TAVI) and when acquired retrospectively, LV systolic function can be assessed. Novel software permits assessment of LV global longitudinal strain (GLS) from MDCT data.ObjectivesThe present study investigated the feasibility of feature tracking MDCT-derived LV GLS and its agreement with echocardiographic LV GLS in patients treated with TAVI.MethodsLV GLS was measured on transthoracic echocardiography using speckle tracking analysis and on dynamic MDCT using feature tracking technology. Agreement between the measurements of two different modalities was assessed using Bland-Altman analysis.ResultsA total of 214 patients (51% male, mean age: 80 ± 7 years) were analysed. Mean LV GLS on echocardiography was −13.91 ± 4.32%, whereas mean feature tracking MDCT-derived GLS was −12.46 ± 3.97%. Correlation of measurements between feature tracking MDCT-derived LV GLS and echocardiographic LV GLS demonstrated a large effect size (r = 0.791, p < 0.001). On Bland-Altman analysis, feature tracking MDCT-derived strain analysis underestimated LV GLS compared to echocardiography with a mean difference of 1.44% (95% limits of agreement −3.85% - 6.73%).ConclusionsAssessment of LV GLS on dynamic feature tracking MDCT data is feasible in TAVI patients. Compared to speckle tracking echocardiography, feature tracking MDCT underestimates the value of LV GLS.     

Plasma lipids, lipoproteins and apolipoproteins and sudden cardiac death

To investigate the risk factors for sudden cardiac death, in particular that triggered by coronary heart disease, we analysed 17 different lipids, lipoproteins and apolipoproteins in the plasma of patients who had suffered sudden death, including sudden cardiac death. Studies were carried out on 107 cadavers comprising 78 subjects where the cause of death was diagnosed as sudden cardiac death and 29 subjects diagnosed with other causes of sudden death. All 107 cases were classified into four groups according to the degree of coronary stenosis and the degree of cardiac hypertrophy. Plasma levels of total cholesterol (T-CHOL), triglyceride (TG), β-lipoprotein (β-LIPO), free fatty acid, phospholipid, free cholesterol, high density lipoprotein cholesterol, lipoprotein(a) [Lp(a)], lipoproteins (VLDL, LDL, HDL) and apolipoproteins (apoAI, apoAII, apoB, apoCII, apoCIII, apoE) were determined. The level of apoB showed a significant difference and positive correlation with the degree of coronary stenosis by two different statistical methods, while the levels of T-CHOL, TG, β-LIPO, VLDL, apoCII, apoCIII and apoE showed significant differences with the degree of coronary stenosis by one statistical method. It was concluded that a high plasma level of apoB is a risk factor for coronary stenosis, with higher levels resulting in more severe degrees of coronary stenosis. Furthermore, a significant difference was found regarding only apoCIII both between the sudden cardiac death group and the sudden death from other causes group, and between each of the four groups classified according to the degree of coronary stenosis. It was thus concluded that a high plasma level of apoCIII indicates the possibility of a coronary stenotic origin for sudden cardiac death. Received: 25 February 1998 / Received in revised form: 24 August 1998     

Low whole-body insulin sensitivity in patients with ischaemic heart disease is associated with impaired myocardial glucose uptake predictive of poor outcome after revascularisation

We tested the hypothesis that low whole-body insulin sensitivity in patients with ischaemic heart disease and impaired left ventricular (LV) function is associated with abnormalities of insulin-mediated myocardial glucose uptake affecting outcome after coronary bypass surgery (CABG). We studied 29 patients with ischaemic heart disease and impaired LV ejection fraction (EF) and age-matched healthy volunteers ( n = 30). As assessed by euglycaemic glucose-insulin clamp, 15 patients had a low and 14 a normal whole-body insulin sensitivity. Using positron emission tomography, patterns of fluorine-18 fluorodeoxyglucose and nitrogen-13 ammonia uptake in addition to quantified glucose uptake, blood flow and hyperaemic blood flow were assessed before CABG in 16 myocardial segments of the left ventricle. Major adverse cardiac events and LVEF were evaluated 7 months after CABG. Glucose uptake in normokinetic PET-normal myocardium was found to be higher in patients with normal whole-body insulin sensitivity ( P < 0.001), whereas in patients with low whole-body insulin sensitivity more segments displayed a pattern of reduced glucose uptake in normoperfused myocardium (PET-reverse mismatch) ( P < 0.05). Hyperaemic blood flow was impaired in both patient groups. A major cardiac event after CABG could partly be predicted by the LV extent of normoperfused segments with PET-reverse mismatch. We conclude that low whole-body insulin sensitivity in patients with ischaemic heart disease and impaired LV function is associated with impaired insulin-mediated myocardial glucose uptake, which is partially predictive of a worse outcome after CABG.     

心脏瓣膜手术前行冠状动脉造影及同期行冠状动脉旁路移植术分析

目的探讨心脏瓣膜病患者术前选择性行冠状动脉造影及同期施行冠状动脉旁路移植术的效果及经验。方法对211例50岁以上行心脏瓣膜手术的患者进行统计,其中男104人,女107人,年龄50~75岁(60±3·5岁)。术前对有心绞痛等相关症状、糖尿病、高脂血症、心电图存在缺血等冠心病高危因素的患者行冠状动脉造影,冠状动脉狭窄超过50%为阳性,狭窄超过75%(左主干超过50%)者同期行冠状动脉旁路移植术。结果211例患者中行冠状动脉造影术128例(60·7%,其余患者无症状及相关危险因素未造影),其中30例冠状动脉存在单支或多支病变,狭窄程度>50%,造影阳性率23·4%。同期行冠状动脉旁路移植术24例(80·0%),手术死亡1例,其余患者随诊4~38个月,效果良好。结论50岁以上瓣膜病患者术前行冠状动脉造影可为术前诊断和排除冠心病、选择术式提供帮助。     

静息态下冠状动脉狭窄对左室壁透壁心肌灌注影响的640层CT研究

目的确定静息态下透壁心肌灌注指数(TPR)的正常值,并探讨静息态下不同分支的冠状动脉狭窄与各冠状动脉分支的不同狭窄程度对左室壁不同节段TPR的影响。方法 274例患者行Toshiba 640层CT检查,包括冠状动脉CTA及左心室室壁CT灌注(CTP)检查。根据冠状动脉狭窄程度及17节段进行分组。计算正常组及不同冠状动脉狭窄程度组之间相应节段内TPR是否存在差异,以及冠状动脉狭窄程度与相应节段TPR的相关性。结果前降支及左旋支病变对于左室壁心肌灌注影响较为明显,前降支狭窄主要影响中间段前壁(r=-0.288)、心尖段前壁(r=-0.263)及中间段间隔壁(r=-0.196),左旋支主要影响基底部前侧壁(r=-0.241)、基底部后侧壁(r=-0.279)及心尖段侧壁(r=-0.201),而右冠状动脉病变影响较小,主要影响中间段后壁(r=-0.195);冠状动脉中、重度狭窄组对于左室壁心肌灌注影响程度较大(P<0.05),轻度狭窄影响较小;左室前壁心肌灌注最易受到冠状动脉狭窄影响;在静息状态下前降支供血区域组、左旋支供血区域组及右冠状动脉供血区域组正常心肌和重度狭窄心肌平均TPR值分别为1.14±0.09和1.07±0.13、1.13±0.11和1.06±0.14、1.15±0.14和1.10±0.12。结论不同冠状动脉分支狭窄分别可以影响不同节段的心肌透壁灌注;不同冠状动脉狭窄程度可以不同程度地影响心肌的TPR,二者具有相关性;静息状态下TPR正常值大于负荷状态下TPR。本研究提供了TPR静息态下的正常值。     

Magnetic resonance imaging of apical left ventricular aneurysm and thinning associated with hypertrophic cardiomyopathy

PURPOSE: To describe magnetic resonance imaging (MRI) findings of apical left ventricular (LV) aneurysm and thinning associated with hypertrophic cardiomyopathy (HCM). METHODS: Thirty-nine patients with HCM underwent cine steady-state, free-precession and delayed contrast-enhanced, inversion-recovery, gradient-echo MRI. An apical LV aneurysm was defined as a thin-walled akinetic aneurysm, and an apical LV thinning was defined as the nonaneurysmal myocardial wall being thinner than 5 mm. The MRI findings were assessed in these patients. RESULTS: Among the 39 patients, 2 showed apical aneurysm and 17 showed apical thinning. Cardiac MRI demonstrated that apical LV aneurysm was associated with myocardial hyperenhancement and a lower ejection fraction and that apical LV thinning was a common finding in HCM with asymmetrical septal hypertrophy. A few patients with apical thinning had some common features to apical aneurysm such as myocardial apical myocardial hyperenhancement. CONCLUSION: Cardiac MRI was useful for the detection of apical LV aneurysm and thinning and the associated findings in HCM.