Hermann Eichstädt

Focal epilepsies: HM-PAO SPECT compared with CT, MR, and EEG.

Regional cerebral blood flow (rCBF) was evaluated quantitatively by 99mTc hexamethyl propyleneamine oxime and single photon emission CT (SPECT) during the interictal phase in 52 patients with focal epilepsy. The results were compared with those obtained by electroencephalography (EEG), CT, and magnetic resonance (MR) imaging. Twenty-four of the 52 patients had one area of local hypoperfusion whereas 7 patients showed an area of local hyperperfusion. In 20 of the 52 patients, both reduced and elevated rCBF values were found. One patient had a normal perfusion pattern. The SPECT findings correlated well with the foci shown by EEG, both with regard to the sides affected and the locations of the regions of altered perfusion. The MR images showed focal lesions in only approximately one-half of the patients examined, and CT in even fewer.

Use of nuclear magnetic resonance imaging to show regression of hypertrophy with ramipril treatment

Thirty-two patients with arterial hypertension (diastolic blood pressure greater than 95 mm Hg) were treated with ramipril for 3 months. The aim of the study was to achieve an effective decrease in blood pressure and demonstrate reliably and reproducibly that regression of left ventricular hypertrophy takes place with ramipril treatment. Nuclear magnetic resonance images and echocardiographic measurements of the left ventricle were therefore made before treatment started, 4 hours after the first dose, 14 days after the start of treatment and after 3 months of treatment. The thickness of the septum decreased from 19.57 to 15.20 mm on magnetic resonance scans and from 18.78 to 14.57 mm on echocardiograms. The values were reproduced 3 times at the same measuring point and means were calculated. The septum and posterior wall of the left ventricle were also measured at 3 different points. With negligible scatter, the values obtained were reproducible and the differences were highly significant (p = 0.001). A parallel decrease in blood pressure to levels 15% below baseline was also observed. The therapeutic aim of achieving diastolic blood pressure levels of less than or equal to 90 mm Hg was achieved in all patients. In addition to reducing the blood pressure significantly, the angiotensin converting enzyme inhibitor ramipril caused a significant regression of pathologic left ventricular hypertrophy, which was demonstrated clearly using magnetic resonance imaging and echocardiography.

Left ventricular hypertrophy and diastolic dysfunction: Their relation to coronary heart disease

SummaryDiastolic dysfunction is an early sign in the temporal sequence of ischemic events in coronary heart disease. The ischemic cascade, beginning with an oxygen demand supply imbalance and metabolic alterations, identifies diastolic disorders of the left ventricle (LV) as an early phenomenon, sometimes before systolic dysfunction, electrocardiographic changes, or chest pain occur. Although the physiology of diastolic function is complex, the factors contributing to diastolic disturbances can be differentiated intointrinsic andextrinsic LV abnormalities. Intrinsic mechanisms include (a) impaired LV relaxation, (b) the complex of LV hypertrophy, and (c) increased LV asynchrony. Myocardial hypertrophy leads to an increase of the myocardial mass/volume ratio, and the degree of hypertrophy is the main determinant of chamber stiffness. The main, if not unique, determinant of myocardial diastolic tissue distensibility is the structure and concentration of the collagen. Consequently, tissue stiffness is increased in coronary disease by reparative interstitial fibrosis or scar following myocardial infarction. In myocardial hypertrophy the LV collagen concentration is elevated due to reactive fibrosis. An increase in regional asynchrony of LV contraction and relaxation is a result of regional ischemia as well as of LV hypertrophy and tissue fibrosis. Factors extrinsic to the LV causing diastolic disorders include (a) increased central blood volume, which will increase left ventricular pressure without altering the LV pressure-volume relation, and (b) ventricular interaction mediated by pericardial restraint, which may cause a parallel upward shift of the diastolic LV pressure-volume relation. Improved insight into the mechanisms of LV relaxation and filling characteristics help in the treatment of LV diastolic dysfunction.

Noninvasive Assessment by Pulsed Doppler Ultrasound of Left Ventricular Filling Behavior in Long Distance Runners During Marathon Race

Abstract The cardiovascular responses to endurance training include an increase in left ventricular (LV) mass and mass index. 1,2 Although a significantly impaired LV diastolic function is known for pathologic hypertrophy, 3,4 LV filling behavior appears unchanged in athletes with exercise-induced hypertrophy as has been demonstrated using M-mode 5 and Doppler 1,2,6,7 eehocardiography or radionuclide scintigraphy. 8 Pulsed Doppler echocardiography of mitral flow has been shown to be a reliable method of assessing LV diastolic filling in healthy 4,9,10 and pathologic 9–11 states. This method has been validated compared with both cineangiographic 12 and radionuclide 13 techniques. We aimed at noninvasively evaluating LV filling behavior in long-distance runners at rest and during a marathon race.

Persistent myocardial sinusoids of the left ventricle

T first description of a rightsided persistent sinusoid dates from 1964, whereas only 1 publication from 1984 is known on leftsided persistent ventricular sinusoids. In a 56-year-old woman with angina at rest, a coronary 2-vessel disease (in the right coronary artery and left anterior descending artery [stenosis of 50% each]) was diagnosed on coronary angiography. Ventriculography of the left ventricle showed 4 distinct persistent myocardial sinusoids of the left anterior wall (Figures 1 and 2). Dimensions and function as well as intracavitary pressures were within normal ranges. Because the incidence of persistent myocardial sinusoids of the left ventricle is very rare, no report exists on the clinical relevance of this phenomenon. Yet in our patient, maximal dobutamine-atropine stress echocardiography did not reveal any hint of abnormal wall motion or ischemia in the region of interest.

Beneficial effects of fluvastatin on myocardial blood flow at two time-points in hypercholesterolemic patients with coronary artery disease.

Hypercholesterolemia is a major risk factor initiating and accelerating atherosclerosis and leading to severe stages of coronary artery disease (CAD) with a high risk of cardiovascular events. We investigated the impact of lipid lowering in patients with hypercholesterolemia and evident CAD on clinically relevant parameters like myocardial perfusion. Myocardial imaging was performed with thallium-201 single photon-emission computed tomography at rest and after maximal bicycle exercise in 22 patients after a 4-week lead-in period, and after 12 and 24 weeks of therapy with fluvastatin. Perfusion defects occurred in all patients, indicating stress-induced myocardial ischemia. After 12 weeks of therapy, the perfusion of the ischemic segments increased by 26% (277+/-99 to 349+/-96 cpm; p < 0.001), whereas the value of the normal segments was augmented only by 4% (478+/-44 to 497+/-28 cpm; p < 0.05). The results slightly improved further after 24 weeks. Moreover, a subgroup analysis elucidated a more pronounced effect in patients without lipid-lowering premedication. This nonpretreated group (n = 11) revealed an improvement of ischemic segments at stress by 42% at week 24. In contrast, pretreated patients had an increase of only 18% (between groups, p < 0.05), indicating a carryover effect of premedication. In conclusion, short-term therapy with fluvastatin acts beneficially on impaired vascular function in hypercholesterolemic patients with CAD.

Cardiac activation mapping by MRI

To establish cardiac MRI as a tool for noninvasive evaluation of activation patterns, 10 healthy volunteers were examined by cine segmented turboFLASH imaging sequences. Sequence modifications for low signal blood-pool appearance were applied, i.e., bilateral spatial saturation for segmented turboFLASH imaging. Pixelwise calculation of first-harmonic Fourier phase values (displayed as color-encoded maps) reveal either anterior septal or left ventricular free-wall sites as areas of earliest phase spreading towards posterior paraseptal sites in segmented turboFLASH scans. Phase scatter is lower in unsaturated than spatially presaturated segmented turboFLASH studies. Phase standard deviation in areas of endocardial displacement is higher in basal than apical slice positions in these scans. Early results indicate that first-harmonic Fourier phase analysis of cardiac-segmented turboFLASH MRI cine studies may provide a tool for noninvasive studies of cardiac activation sequence.