The International Journal of Cardiovascular Imaging

Hirooka, Keiji; Yasumura, Yoshio; Tsujita, Yuko; Hanatani, Akihisa; Nakatani, Satoshi; Miyatake, Kunio; Yamagishi, Masakazu

doi: 10.1023/A:1011607012559pmid: 11599864

To elucidate the validity and reproducibility of the use of intravenous echo-contrast agent in the evaluation of left ventricular (LV) performance, we measured LV volume and ejection fraction (EF) in 42 patients with triggered harmonic contrast imaging (THCI), compared with continuous harmonic imaging without contrast agent (CHI) and with cineventriculography (CVG). In 10 of 42 patients, THCI improved LV border delineation which could not be obtained even with CHI. LV end-diastolic, end-systolic volumes and EF by both CHI and THCI correlated well with those by CVG. Although LV volumes are underestimated, THCI lessened the mean differences to about in half, compared with CHI. The observer variabilities obtained using THCI were smaller than those by CHI. These results indicate the validity of LV enhancement and the measurement of EF using THCI. We suggest that this method noninvasively provides more accurate LV systolic function with the acceptable reproducibility.

Mittal, S.R.; Barar, R.V.; Arora, H.

doi: 10.1023/A:1011660827368pmid: 11599865

Thirty-one cases of untreated `mild hypertension' and equal number of age and sex matched controls with `normal' blood pressure were evaluated by echocardiography. Patients with mild hypertension had significantly increased left ventricular mass index, concentric remodeling, and diastolic dysfunction. Thickness of right ventricular anterior wall, flow velocities across tricuspid and pulmonary valves were also significantly higher in hypertensives. Pulmonary flow acceleration time was significantly less in hypertensives. On multiple regression analysis, mitral valve `A' wave velocity alone correlated with systolic blood pressure. Other echocardiographic variables did not have any relation with blood pressure readings. Height, weight, body surface area and body mass index could also explain only around 50% of variability in echocardiographic parameters. Cardiac structure and functions in hypertensives are affected by factors other than blood pressure reading, body surface area or body mass index. Routine echocardiography can be useful in identifying those patients of mild hypertension who have disproportionate increase in left ventricular mass or disproportionate impairment of diastolic functions.

Sun, Shung-Shung; Huang, Jin-Long; Tsai, Shih-Chuan; Ho, Yung-Jen; Kao, Chia-Hung

doi: 10.1023/A:1011661300903pmid: 11599866

`Syndrome X' describes patients with exertional chest pain and a normal coronary arteriogram. In some patients, acute myocardial ischemia can be demonstrated by regional myocardial perfusion defects on thallium-201 exercise test. However, some patients with typical angina have normal perfusion on thallium-201 heart scintigraphy. It is not clear whether there are different prognoses for patients with normal and abnormal thallium studies. In this study, the clinical features, long term follow-up and clinical results of syndrome X patients with normal and abnormal thallium studies were evaluated to determine the differences between these two groups. Fifty-nine patients (52 males, seven females, mean age 62 ± 6 years) with syndrome X were enrolled and divided into two groups on the basis of results of thallium-201 heart scintigraphy. Group I was comprised of 22 patients with normal thallium-201 perfusion scan and group II was comprised of 37 patients with abnormal thallium-201 heart scan. All subjects received coronary arteriography, exercise test, thallium-201 myocardial SPECT, ejection fraction of left ventricle, echocardiography, blood analysis and long term follow-up with questionnaire for 10 years. Lower maximal rate–pressure product and higher angina scores were found in group II. More patients developed cardiomegaly (nine of 33 patients) in group II than in group I (one of 21 patients). Both groups, however, were at low risk for cardiac events (cardiac death or myocardial infarction).

Latson, L.A.; Powell, K.A.; Sturm, B.; Schvartzman, P.R.; White, R.D.

doi: 10.1023/A:1011690219671pmid: 11599867

The goal of this research was to develop an automated algorithm for tracking the borders of the left ventricle (LV) in a cine-MRI gradient-echo temporal data set. The algorithm was validated on four patient populations: healthy volunteers and patients with dilated cardiomyopathy (DCM), left ventricular hypertrophy (LVH), or left ventricular aneurysm (LVA). A full tomographic set (∼11 slices/case) of short-axis images through systole was obtained for each patient. Initial endocardial and epicardial contours for the end-diastolic (ED) and end-systolic (ES) frames were manually traced on the computer by an experienced radiologist. The ED tracings were used as the starting point for the algorithm. The borders were tracked through each phase of the temporal data set, until the ES frame was reached (∼7 phases/slice). Peak gradients along equally spaced chords calculated perpendicular to a centerline determined midway between the endocardial and epicardial borders were used for border detection. This approach was tested by comparing the LV epicardial and endocardial volumes calculated at ES to those based on the manual tracings. The results of the algorithm compared favorably with both the endocardial (r 2 = 0.72 − 0.98) and epicardial (r 2 = 0.96 − 0.99) volumes of the tracer.

Du, Yiping; McVeigh, Elliot; Bluemke, David; Silber, Harry; Foo, Thomas

doi: 10.1023/A:1011675130904pmid: 11599868

A comparison between the prospective and retrospective respiratory navigator gating in MR coronary angiography was performed with eight normal subjects. A three-dimensional (3D) ECG-gated fast gradient echo pulse sequence was used for image data acquisition. The results show that the MR coronary angiography obtained using retrospective gating retains a considerable amount of motion artifacts. In this study, the images acquired using prospective navigator gating demonstrated significantly reduced motion artifacts (p = 0.009), improved vessel visibility (p = 0.021) with reduced imaging time (p = 0.013) compared to the images obtained using retrospective navigator gating.

doi: 10.1023/A:1017421800710pmid: N/A

Midiri, Massimo; Finazzo, Mario

doi: 10.1023/A:1011628121778pmid: 11599869

Arrhythmogenic right ventricular displasia (ARVD) is a heart disease characterized by a total or partial fat replacement of the myocardium. Echocardiography, which has been most commonly used for the diagnosis of ARVD, usually only demonstrates right ventricular enlargement with associated hypokinesia and with normal left ventricular chamber size. Angiocardiography is very effective in the evaluation of ARVD, especially, in the detection of wall motion abnormalities and bulgings. However, angiocardiography is invasive. Magnetic resonance imaging is a non-invasive, repeatable technique, which allows a more accurate evaluation of the right ventricular chamber and free wall. Therefore MRI is very effective in the differentiation of the high signal intensity of the fat from other medium intensity tissue, such as muscle, and in detection of fibro-fatty replacement of myocardium. It provides an accurate assessment of right-chamber enlargement, right ventricle outflow tract ectasia and wall motion abnormalities by cine-MR GE technique.

Hamamichi, Yuji; Ichida, Fukiko; Hashimoto, Ikuo; Uese, Keiichi; Miyawaki, Toshio; Tsukano, Shinya; Ono, Yasuo; Echigo, Shigeyuki; Kamiya, Tetsuro

doi: 10.1023/A:1011658926555pmid: 11599870

This study was undertaken to evaluate the feasibility of ultrafast computed tomography (CT) and magnetic resonance imaging (MRI) for anatomical and pathophysiological diagnosis of isolated noncompaction of the left ventricular myocardium (INVM) compared with other imaging modalities including thallium myocardial imaging. Six patients, three sets of siblings, ranging in age from 13 to 18 years, were included in this study. Two-dimensional echocardiograms revealed numerous prominent trabeculations and deep intertrabecular recesses in one or more ventricular wall segments in all cases. Thallium-201 myocardial imaging disclosed a hypoperfusion area corresponding to the zones where noncompacted ventricular myocardium was localized. Ultrafast CT showed early defects of varying degrees and rate enhancement of the noncompacted ventricular myocardium, implying fibrosis in this area. MRI disclosed inner zones of noncompacted myocardium distinguishable from thin outer zones of compacted myocardium. T2-weighted imaging revealed high intensity areas at the apex of the left ventricle, suggesting disturbed microcirculation due to fibrosis, thrombus formation, and hypokinesis. Cine MRI revealed hypokinesis of the noncompacted ventricular wall during the cardiac cycle. In conclusion, ultrafast CT and MRI provide high-resolution imaging of noncompacted myocardium, and also pathophysiological details regarding this rare disease.

Leder, Uwe; Haueisen, Jens; Pohl, Peter; Surber, Ralf; Heyne, Jens; Nowak, Hannes; Figulla, Hans

doi: 10.1023/A:1011623103742pmid: 11599871

Introduction: Late potentials (LP) are markers of arrhythmogenic events after myocardial infarction (MI). The localization of LP sources would help to identify arrhythmogenic myocardium. The purpose of this study was to localize these LP sources from non-invasive body surface mapping data. Methods and Results: Six patients were investigated with cardiac MRI and signal averaged 62-lead magnetocardiography after MI. Three of them were suffering from sustained ventricular tachycardia (VT). Sophisticated computer algorithms were used in order to compute the current density on the surface of the left ventricle. We compared these current density distributions for the entire QRS complex and the high frequency LP signals. In the three patients which had premature ventricular complexes (PVCs) we localized the exit sites of these arrhythmias. We found a close matching of the low current density areas based on the QRS complexes and the high current density areas based on the LP signals. These areas predominantly corresponded to sites of the infarctions. Exit sites of PVCs were located close to these areas. Conclusions: By means of sophisticated computer algorithms we were able to localize LP sources. This would be useful in steering catheter ablation and coronary revascularization therapies. However, the method has to be proven with the help of invasive mapping in a larger number of patients.