Prospective, adaptive navigator correction of image position for free-breathing coronary MR angiography is a promising, novel approach to compensate for respiratory motion.

The effect of basic fibroblast growth factor (bFGF) administration on regional myocardial function and blood flow in chronically ischemic hearts was studied in 26 pigs instrumented with proximal circumflex coronary artery (LCX) ameroid constrictors. In 13 animals bFGF was administered extraluminally to the proximal left anterior descending (LAD) and LCX arteries with heparin-alginate beads and 13 other animal served as controls. bFGF-treated pigs showed a fourfold reduction in left ventricular infarct size compared to untreated controls (infarct size: 12+0.4% vs. 5.1+13% of LV mass, mean±SEM, P < 0.05). Percent fractional shortening (% FS) in the LCX area at rest was reduced compared with the LAD region in both bFGF and control pigs. However, there was better recovery in the LCX area after rapid pacing in bFGF-treated pigs (% FSLCX/% FSLAD, 22.9_73% -+ 30.5±8.5%, P < 0.05 vs. prepacing) than in controls (16.0±7.8% --143+7.0%, P = NS). Furthermore, LV end-diastolic pressure rise with rapid pacing was less in bFGF-treated than control pigs (pre-pacing; pacing; postpacing, 10±1; 17±3; 11±1* mmHg vs 10±1; 24±4; 15±1 mmivg, *P < 0.05 vs. control). Coronary blood flow in the LCX territory (normalized for LAD flow) was also better during pacing in bFGF-treated pigs than in controls. Thus, periadventitial administration of bFGF in a gradual coronary occlusion model in pigs results in improvement of coronary flow and reduction in infarct size in the compromised territory as well as in prevention of pacing-induced hemodynamic deterioration.(J. Clm Invest 1994. 94:623-630.) Key words: basic fibroblast growth factor -regional myocardial function * chronic ischemia * coronary artery disease * angiogenesis

Breath-hold MR coronary angiography provides visualization of the major epicardial vessels. In the future, MR coronary angiography may provide a noninvasive means for the evaluation of patients with known or suspected coronary artery disease.

Patients with asymmetric septal hypertrophy undergoing noncardiac surgery have a high incidence of adverse cardiac events, frequently manifested as congestive heart failure. However, irreversible cardiac morbidity and mortality was extremely low. Important independent risk factors for adverse outcome in all patients include major surgery and increasing duration of surgery.

To evaluate the ability of electrocardiogram (ECG)-gated magnetic resonance (MR) imaging to assess in vivo left ventricular (LV) mass in the rat, we studied 20 healthy adult Sprague-Dawley and Fischer 344 rats and 8 additional rats that underwent scanning after induction of volume overload by aortic leaflet disruption. ECG-gated spin-echo pulse sequences were used to acquire a series of 1-mm thick modified short-axis images of the left ventricle. The area enclosed by the endocardial and epicardial borders of the left ventricle was multiplied by the interslice distance and specific gravity of myocardium to obtain calculated slice mass. Total LV mass was obtained by summing the individual slices. The calculated value for LV mass was then compared with the LV mass as determined at postmortem examination. Linear regression analysis showed an excellent correlation of MR-estimated mass (x) with autopsy-measured LV mass (y) (y = 0.90x + 65, r = 0.98). For this method intraobserved and interobserver slice correlations were 0.97 and 0.96, respectively. There was no significant difference in LV mass as determined from a series of diastolic vs. systolic images in a subset of six animals. Over a mean of 6.5 wk of observation, LV mass increased by 40% in the animals subjected to aortic leaflet disruption. These results demonstrate that MR imaging is highly accurate for the non-invasive in vivo assessment of LV mass in the adult rat.

Coronary WH-MRI was inferior to coronary CTA regarding image quality and number of evaluable segments but both had similar diagnostic value for the detection and exclusion of CAD when only evaluable segments were included.

Objective. To determine the value of routine transthoracic echocardiography in patients with cerebral ischemia without known cardiac disease. Design. The literature from 1990 to 1995 was searched and relevant bibliographies from these papers reviewed. Articles reporting the prevalence and/or risk of stroke for myxoma, vegetation, mitral stenosis, left atrial thrombus, left ventricular thrombus or cardiomyopathy, patent foramen ovale, and atrial septal aneurysm were used. Prevalences and recurrent stroke risk were examined for adult patients less than and greater than 45 years.Results. Both the prevalence of transthoracic echocardiographic findings and recurrent risk of stroke differ by age. The finding of a patent foramen ovale can be expected in nearly half of younger patients with stroke, whilst transthoracic echo can be expected to yield no relevant lesion in three quarters of patients > 45 years. Warfarin anticoagulation appears beneficial in patients with mitral stenosis, left atrial thrombus, left ventricular thrombus, and left ventricular dysfunction, but is of unproven benefit for patent foramen ovale, atrial septal aneurysm, or in the absence of a risk-associated abnormality. Conclusion. For most transthoracic echo findings in stroke, optimal management strategies have not been well defined. Future research is needed to evaluate the appropriate therapeutic approaches.

The authors sought to render projection magnetic resonance (MR) angiograms depicting a substantial length of human coronary arteries from sequential breath-hold two-dimensional MR images. Tomographic images of the right and left anterior descending coronary arteries were collected with use of a segmented gradient-recalled sequence that incorporated fat suppression and prone positioning of the patient over a surface coil. After editing the images to eliminate overlapping chamber signals and after realigning the images, a maximum-intensity-projection algorithm was applied to create projection angiograms. For the 10 coronary arteries without severe narrowing, visualized length with projection MR angiography was 109 mm +/- 29 (mean +/- standard error of estimate) versus 121 mm +/- 29 with conventional coronary angiography (ranges, 62-147 mm and 70-180 mm, respectively). At conventional angiography linear regression indicated vessel length to be 1.03 times the length depicted at MR angiography with good correlation (r = .8). Results indicate good correlation between measurements of vessel length with both conventional and MR angiography.