Kunihiko Teraoka

Delayed contrast enhancement of MRI in hypertrophic cardiomyopathy

Fibrotic lesions in the myocardium exhibit delayed contrast enhancement (DCE) on MR images. On the other hand, plexiform fibrosis is observed in hypertrophic cardiomyopathy (HCM), indicating an association of this condition with the pathogenesis of heart failure and arrhythmia. To examine the occurrence and extent of DCE and its relation to cardiac function and arrhythmia in HCM, we studied 59 patients with HCM who had undergone MRI. The relationship of DCE to cardiac function and arrhythmia was further investigated. DCE occurred in 45 (76.3%) of the 59 patients with HCM, with a high frequency of localization in regions, where the right ventricle is attached. As for the relationship of DCE to cardiac function, a significant decrease (P=0.007) in cardiac function was observed in the group in which 4 or more segments exhibited DCE, compared with the group in which DCE was observed in 3 or less segments. Regarding the relationship of DCE to arrhythmia, both the occurrence of DCE and the extent of DCE were significantly larger (p<0.05, p=0.026, respectively) in the group with VT. These results indicate that DCE may save to identify severe cases of HCM on the basis of cardiac function, arrhythmia, and pathophysiological aspects.

Progressive cardiac dysfunction in adriamycin-induced cardiomyopathy rats.

Cardiotoxicity is a limiting factor in the treatment of cancer with adriamycin. We administered adriamycin by a method which minimizes the risk of peritonitis in an adriamycin‐induced cardiomyopathy rat model. Sixty male Wistar rats were given 1 mg/kg of adriamycin intraperitoneally 15 times over a 3‐week period (total dose, 15 mg/kg) to induce the cardiomyopathy model. Fifteen control rats received 10 ml/kg body wt. saline 15 times over 3 weeks. The animals were observed for 12 weeks and assessed for mortality, and cardiac volume and function was analyzed by echocardiography at 4, 8, and 12 weeks. In rats treated with adriamycin, the cumulative mortality was 35.8% while in the controls, none of the rats died. Left ventricular diameter of the systole (LVDs) was significantly increased at 4 weeks (4.5 vs. 3.3 mm; P<0.001). Left ventricular diameter of the diastole (LVDd) was significantly increased at 12 weeks (7.9 vs. 7.0 mm; P<0.01) and the fractional shortening (FS) was significantly decreased at 8 weeks (33.4% vs. 50.0%; P<0.01) in the adriamycin‐treated rats. This administration method appears to be useful for investigating the cardiac effect of adriamycin while avoiding the influence of peritonitis typically caused by an intraperitoneal injection of higher single doses of adriamycin.

No Delayed Enhancement on Contrast Magnetic Resonance Imaging With Takotsubo Cardiomyopathy

An 88-year-old woman was referred to our hospital because of severe chest pain. The ECG in leads II, III, aVF, and V1 through V5 showed ST elevation (Figure 1). The creatinine kinase and creatinine kinase MB were 324 and 18 IU/L, respectively. Emergency coronary angiography revealed 75% stenosis of the high lateral branch, but left ventriculography confirmed the …

Synergistic effect of smoking and blood pressure on augmentation index in men, but not in women

This study was conducted in healthy Japanese subjects to examine the effects of age and gender on the relationship between the risk factors for cardiovascular disease (CVD) and augmentation index (AI), and the effects of clusters of those risk factors on AI. Radial arterial pressure wave analysis was used to obtain AI in 3675 men and 2919 women. AI was found to be higher in women than in men, and age-related increase in AI showed an attenuated curve in subjects aged ⩾50 years. A step-wise multivariate linear regression analysis showed that mean blood pressure and smoking are independent significant variables related to AI in men regardless of age, and in women aged <50 years, but not in women aged ⩾50 years. A general linear model univariate linear regression analysis showed that mean blood pressure and smoking had a significant interaction for their relation with AI in men, but not in women. In conclusion, among the risk factors for CVD, smoking and blood pressure were found to be independent factors related to increase in AI. Although age-related attenuation of increase in AI was confirmed in Japanese subjects, these risk factors may act to increase AI even in elderly subjects, at least in part. However, the effects of these factors on AI may differ based on gender, and these factors may act synergistically to increase AI in men. On the contrary, these factors may act independently in young women to increase AI without interaction, whereas only the blood pressure seems to increase AI in elderly women.

Extent of Late Gadolinium Enhancement on Cardiac Magnetic Resonance Imaging in Japanese Hypertrophic Cardiomyopathy Patients.

BACKGROUND In addition to the presence of late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR), the extent of LGE is considered clinically important in hypertrophic cardiomyopathy (HCM). We evaluated the extent of LGE on CMR in a large series of Japanese HCM patients. METHODSANDRESULTS CMR was performed in 317 HCM patients (147 male). The extent of LGE was scored as the sum of LGE-positive segments in a left ventricle (LV) 17-segment model. LGE was present in 246 patients (77.6%). LGE was detected in 3.5±3.1 segments on average. When the patients were divided according to maximum wall thickness (mild, <20 mm; moderate, 20-29 mm; severe, ≥30 mm), median LGE score increased as wall thickness increased (mild, 2 vs. moderate, 4 vs. severe, 5; P=0.000). When the patients were divided according to ejection fraction (EF) (reduced, <50%; low-normal, 50-65%; normal, >65%), median LGE score increased as EF decreased (reduced, 7 vs. low-normal, 4 vs. normal, 2; P=0.000). On multivariate analysis, reduced EF (OR, 0.947, P=0.015), pressure gradient <30 mmHg (OR, 0.359, P=0.000) and increased maximum wall thickness (OR, 1.236, P=0.000) were independent factors associated with extensive LGE. CONCLUSIONS Progression of LGE was related to increased wall thickness, decreased contractility, and reduced intraventricular pressure gradient.

Delayed contrast enhancement in a patient with perimyocarditis on contrast-enhanced cardiac MRI: case report

The findings of contrast-enhanced cardiac magnetic resonance imaging of a 19-year-old man with perimyocarditis in the subacute and chronic stage are presented. In perimyocarditis., it is useful to check the presence of delayed contrast enhancement to confirm the presence of the lesion and to evaluate the severity of inflammation in the acute stage as well as to determine the extent of fibrosis in the pericardium and myocardium in the chronic stage.

Significance of the second peak of systolic blood pressure for identifying both high and low cardiovascular risk states

This study was conducted to clarify whether the second peak of the systolic blood pressure (SBP2) has significant information about cardiovascular (CV) risk state, independent of the brachial BP. SBP2 was measured by radial pressure wave analysis in 7847 Japanese subjects (50±10 years old), and the Framingham risk score (FRS) and general cardiovascular disease risk score were calculated (FRSgen). The results of multivariate analysis revealed that the SBP2 showed a significant correlation with the FRS (β=0.04, t-value=3.92, P<0.01) and FRSgen (β=0.05, t-value=6.55, P<0.01), independent of the brachial SBP. The non-standardization coefficient of SBP2 was smaller than that of brachial SBP. The logistic regression analysis showed that SBP2 (2 mm Hg per increase) had a significant odds ratio to identify not only subjects with a high risk for coronary heart disease (CHD) and general CV disease (CVDgen), but also subjects with a low risk for CHD and CVDgen, independent of the brachial SBP. However, when the analysis was limited to subjects of ⩾49 years of age, SBP2 could not identify either high or low CV risk subjects. Thus, in middle-aged Japanese subjects, SBP2 may provide little, yet significant, information reflecting both high and low CV risk states, independent of the brachial BP. SBP2 seems to be more applicable for CV risk stratification in younger subjects than in older subjects.

The study about the difference of extra cellular volume calculated with T1mapping in dilated cardiomyopathy with and without late gadolinium enhancement

Background It is well known that the DCM patients having Late Gadolinium Enhancement at Mid-layer of LV septal wall (Mid-LGE) shows poor prognosis compared to the case not having Mid-LGE However, about the other histopathological differences by the existence of Mid-LGE, it is not clear. On the other hand, in recent years, it became possible to calculate ECV from measurement of T1 value of the myocardium before and after of enhanced imaging which used the Modified Look-Locker Inversion Recovery(MOLLI) method, and the usefulness in the quantitative evaluation of histopathological changes, such as diffuse fibrosis observed in hypertrophic cardiomyopathy, has been reported. We will study about the difference of extra cellular volume(ECV) calculated with T1mapping in DCM with and without LGE

Effects of heart rate in modified look-locker inversion recovery (MOLLI) T1 mapping

MOLLI is a method of producing a T1 map at end diastole by using the electrocardiogram (ECG) under respiratory arrest to obtain consecutive inversion recovery images with an arbitrary number of MOLLI cycles. Since a variety of heart rates are presumed clinically, it is important to understand their effects on the T1 value and the error of measurement. We investigated the error of measurement in MOLLI T1 mapping caused by changes in the heart rate. Methods MAGNETOM Avanto 1.5T, simulation ECG, and a phantom with an aqueous dilution of Gd-DTPA were used. The phantom contents and T1 values were as follows: olive oil = 213 ms, physiological saline = 3122.9 ms and aqueous dilutions of Gd-DTPA 103.6 ms-1739.9 ms were used. The imaging conditions were as follows: Sequence is single-shot TrueFISP, TR = 700 ms, TE = 1.13 ms, FA = 35 deg, FOV = 360 mm, Resolution=256 x 65%, shot duration time = 123 ms, Bandwidth = 1028 Hz/Px, Reordering=linear, MOLLI TI start = 82 ms, MOLLI TI increment =18 ms resting heart cycle 0-8, iPAT (+). In the experiment, #1 the T1 value was measured by using RR = 800 ms and two sets of MOLLI cycles (LL1=4 images, LL2=4 images) and changing the number of resting heart cycles (RT) between LL1 and LL2 from 0 to 8, and #2 The T1 value was measured by varying RR in the range 400-1000 ms and both for the case of using two sets of MOLLI cycles (LL1=8 images, LL2=2 images) with RT fixed to be 1. and for the case of changing RT from 0 to 10 so that the IR interval between LL1 and LL2 becomes approximately 7200 ms. Results The results #1, The error of measurement was approximately 45% for a T1 value of 103.6ms and approximately 5% for T1 values of 347.8-1044.2 ms, with no dependence on RT. However, for T1 values in the range 1739.9-3122.9 ms, there were large changes with RT, in the range of 10-175%. The results #2, in which RT was fixed, With RT=1, as the heart rate increased the change in the error of measurement became greater, approximately 25-50% for T1 values of 1739.9-3122.9 ms. The results of varying RT are shown in Figure 1 and Figure 2. When RT was adjusted to make the IR interval constant the change in the error of measurement improved to approximately 20-27% for T1 values of 1739.9-3122.9 ms.

The impact of mid-wall striate of LGE at interventricular septum to the beta-broker (Carvedilol) titrating to the target dose and the improvement of cardiac function with DCM

It was reported that mid-wall striate late gadolinium enhancement at interventricular septum (MWS-LGE) definite by CMR was strong predictor of prognosis including sudden death with dilated cardiomyopathy (DCM). On the other hand, randomized trial have shown that beta-brokers lead symptomatic improvement, reduced hospitalization and enhanced survival in many patients with heart failure.