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H H Hilger

Publications and source records attributed to H H Hilger.

At least 19 recordsLinked to original sources
PubMed1992

Feasibility of high-dose dipyridamole-magnetic resonance imaging for detection of coronary artery disease and comparison with coronary angiography.

To assess the feasibility, safety and usefulness of gradient-echo magnetic resonance imaging (MRI) combined with pharmacologic stress testing for the detection of coronary artery disease, 23 patients without previous myocardial infarction but with significant stenosis (greater than 70% diameter stenosis) of greater than or equal to 1 major coronary artery were selected for dipyridamole-MRI stress testing. Each patient underwent MRI at rest, and high-dose dipyridamole-MRI (0.75 mg/kg over 10 minutes) of corresponding basal and midventricular short-axis tomograms. Additionally, these patients performed symptom-limited exercise stress tests. All short-axis tomograms were evaluated on a standardized segmental basis by grading each segment as normal, hypokinetic, akinetic or dyskinetic. Dipyridamole-MRI was considered pathologic if segmental wall motion deteriorated by greater than or equal to 1 grade after dipyridamole. For comparison with coronary angiography, segmental wall motion gradings were related to the respective coronary artery territories in the short-axis plane. Pathologic dipyridamole-MRI was obtained in 18 of 23 (78%) patients. For 1- and 2-vessel diseases, sensitivity was 69 and 90%, respectively. Exercise stress tests were pathologic in 14 of 23 (66%) patients. For 1- and 2-vessel diseases, sensitivity of exercise stress test was 58% (7 of 12 patients) and 77% (7 of 9), respectively. Sensitivity/specificity of dipyridamole-MRI for the localization of the stenosed coronary artery was 78/100% for left anterior descending, 73/100% for left circumflex, and 88/87% for right coronary artery stenoses. It is concluded that dipyridamole-MRI is a feasible nonexercise-dependent test for detection and localization of functionally significant coronary artery disease.

Aged↗
PubMed1992

Cardiac involvement during and after malaria.

In 22 patients without a previous history of cardiac disease, we prospectively evaluated cardiac involvement during acute malaria and 9 +/- 5 months after recovery using non-invasive methods including resting electrocardiogram (ECG) and two-dimensional (2D) echocardiography. During the acute phase ECG abnormalities were common (5/22); pericardial effusion was found in 2 patients and global left ventricular hypokinesia in 1 patient infected with Plasmodium falciparum. At a follow-up of 19 patients, the resting ECG and echocardiography were normal or had normalized in all patients. The results of our study suggest that persistent cardiac damage following malarial infection seems to be rare; however, further trials in a larger patient population are needed to confirm our findings.

Adolescent↗
PubMed1992

Chronic myocardial infarction: assessment of morphology, function, and perfusion by gradient echo magnetic resonance imaging and 99mTc-methoxyisobutyl-isonitrile SPECT.

To assess the ability of magnetic resonance imaging (MRI) to identify the anatomic and functional abnormalities associated with completely scarred myocardium, 20 patients with chronic transmural myocardial infarction confirmed by electrocardiography and cineventriculography were examined by gradient echo MRI. Myocardial perfusion at rest was assessed in corresponding transverse sections using 99mTc-methoxyisobutyl-isonitrile single-photon emission computed tomography (MIBI-SPECT). MRI scar was defined as diastolic wall thickness (DWT) 2.5 SD below corresponding normal values or systolic wall thickening (delta WT) less than or equal to 1 mm. For MIBI-SPECT images, scar was defined as a MIBI uptake less than 2.5 SD below normal values. By MIBI-SPECT, 152 segments contained normal tissue and 88 contained scarred myocardium. In 226 of 240 (94%) segments, MRI gradings by DWT and MIBI-SPECT gradings were identical. DWT by MRI was higher in normal than in scarred MIBI-SPECT segments (10 +/- 1 versus 4 +/- 2 mm, p less than 0.001). In 230 of 240 (96%) segments, MRI gradings by delta WT and MIBI-SPECT gradings were identical. Segments graded normal by MIBI-SPECT showed higher delta WT by MRI than scar segments (5 +/- 1 versus 0.3 +/- 1 mm, p less than 0.001). MIBI-SPECT perfusion defect size and regions with reduced DWT on MRI tomograms correlated well (r = 0.85). This study indicates that myocardial regions fulfilling electrocardiographic and ventriculographic criteria for transmural myocardial scar are clearly depicted by regional diastolic wall thinning and delta WT less than or equal to 1 mm on gradient echo MR images.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Regurgitant flow in cardiac valve prostheses: diagnostic value of gradient echo nuclear magnetic resonance imaging in reference to transesophageal two-dimensional color Doppler echocardiography.

Gradient echo nuclear magnetic resonance (NMR) imaging and transesophageal two-dimensional color Doppler echocardiography are flow-sensitive techniques that have been used in the diagnosis and grading of valvular regurgitation. To define the diagnostic value of gradient echo NMR imaging in the detection of regurgitant flow in cardiac valve prostheses and the differentiation of physiologic leakage flow from pathologic transvalvular or paravalvular leakage flow, 47 patients with 55 valve prostheses were examined. Color Doppler transesophageal echocardiography was used for comparison. Surgical confirmation of findings was obtained in 11 patients with 13 valve prostheses. Gradient echo NMR imaging showed regurgitant flow in 37 of 43 valves with a jet seen on transesophageal echocardiography and it detected physiologic leakage flow in 4 additional valves. There was 96% agreement between the two methods in distinguishing between physiologic and pathologic leakage flow. The methods differed on jet origin of pathologic leakage flow in six prostheses. The degree of regurgitation was graded by both NMR imaging and transesophageal echocardiography, according to the area of the regurgitant jet visualized; gradings were identical for 75% of valve prostheses. Quantification of jet length and area showed a good correlation between the two methods (r = 0.85 and r = 0.91, respectively). Gradient echo NMR imaging is a useful noninvasive technique for the detection, localization and estimation of regurgitant flow in cardiac valve prostheses. However, because transesophageal echocardiography is less time-consuming and less expensive, gradient echo NMR imaging is unlikely to displace transesophageal echocardiography and should be used only in the occasional patient who cannot be adequately imaged by echocardiography.

Coronary Circulation↗
PubMed1992

A prospective study on percutaneous coronary angioscopy with different guiding techniques in patients with coronary heart disease.

The technical success of percutaneous coronary angioscopy using different guiding techniques was evaluated in 17 patients before (n = 17) and after (n = 8) coronary angioplasty. Steering the angioscope along or over a guidewire was successful in both groups; failures were predominantly due to insufficient alignment of the angioscope using along-the-wire guiding. Although over-the-wire angioscopy promises superior guiding and alignment capabilities, several technical problems remain unsolved.

Adult↗
PubMed1992

Left ventricular thrombi: evaluation with spin-echo and gradient-echo MR imaging.

Gradient-echo (GRE) and spin-echo (SE) magnetic resonance (MR) imaging was performed in 31 patients with chronic left ventricular (LV) thrombi. Thrombi were confirmed or excluded at surgery or by means of other corroborative diagnostic techniques. MR images were evaluated by three reviewers without knowledge of results of corroborative studies. Diagnoses were graded unequivocal if agreed on by three observers and probable if agreed on by two observers. With SE imaging, 12 of 18 confirmed thrombi were detected unequivocally, five were considered probable, and one was not detected. With GRE imaging, 16 of the 18 thrombi were visualized unequivocally; two were considered probable. With SE technique, thrombus was unequivocally excluded in nine of 13 cases and exclusion was considered probable in four. One finding was false-negative. Exclusion of thrombus with GRE imaging was unequivocal in 10 of 13 cases and probable in two, and one finding of thrombus was false-positive. GRE imaging resulted in improved differentiation of thrombi from the surrounding blood pool and myocardium and thus was diagnostically superior to SE imaging in detection of LV thrombi.

Adult↗
PubMed1992

Reversible volume changes of trapped gas in nonspecific bronchoprovocation tests.

Thirty patients with a history of asthma and ten patients with suspected bronchial hyperreactivity underwent nonspecific provocation testing. The control group consisted of ten normal volunteers without a history of lung disease. The patients' baseline FEV1 (percent predicted) revealed mild obstructive disease (72.9 +/- 8.9 percent and 74.6 +/- 7.7 percent) compared with controls (87.2 +/- 8.5 percent, p less than 0.001). The mean volume of trapped gas (D) (ie, TLCB-TLCHe) was not significantly different between groups (0.11 +/- 0.49 L vs 0.15 +/- 0.4 L vs 0.18 +/- 0.45 L), and no correlation was established with any of the remaining lung function data. Bronchial hyperreactivity in response to inhaling acetylcholine could be observed in the asthma group only. Their mean D increased significantly from 0.11 +/- 0.49 L to 0.62 +/- 0.66 L (p less than 0.001), and returned to baseline (0.26 +/- 0.55, NS) subsequent to inhaling salbutamol. D changes induced by acetylcholine correlated weakly with concurrent changes of FEV1 (r = -0.44, p = 0.01), RV (r = 0.59, p less than 0.001), and Rs (r = 0.59, p less than 0.001). In response to bronchodilating doses of salbutamol, however, D was changed in close correlation with FEV1 (r = -0.82, p less than 0.0001), RV (r = 0.85, p less than 0.0001), and Rs (r = 0.76, p less than 0.0001). Provided that D is a valid parameter of small airways function, these data may give a clue to the site of action of both drugs. Acetylcholine affects small and large airways alike with no clear-cut preference, whereas salbutamol's predominant target appears to be the small airways. These conclusions are only partially supported by the pertinent literature.

Acetylcholine↗
PubMed1992

[Transesophageal echography in staging of bronchial cancers].

The kind of relation of central lung cancer (c) to the walls of the central pulmonary arteries (PA) and the aorta is an important information prior to operative or interventional (laser/afterloading) therapy. As computed tomography (CT) and angiography are often inaccurate in the assessment of PA-infiltration, we assessed the diagnostic value of transesophageal echography (TEE) in the staging of LC. 16 patients (pts.) were investigated using TEE in addition to CT or magnetic resonance imaging (MRI). Eleven pts. had central LC, 3 peripheral LC, 1 anterior mediastinal mass and 1 central pneumonia (cancer excluded). 2 pts. with central LC were unable to swallow the probe. In 9/9 pts. with central LC, 1/3 pts. with peripheral LC and 1 pt. with enlarged anterior mediastinum the tumour mass could be visualized. In the pt. with a centrally located infiltrate on chest radiogram TEE demonstrated enlarged hilar lymph nodes, but excluded a central tumour. Main PA branches could be identified in all 14/14 pts. Central left or right PA were compressed slightly in 3 pts. and severely in 2 pts., with a near total occlusion in one (confirmed by MRI/CT). TEE revealed PA-infiltration in 2 pts. and aortic wall infiltration in 2 other pts. Despite adjacent tumour mass aortic wall infiltration was excluded in 2 pts. Enlarged hilar lymph nodes could be demonstrated in 2/9 pts. with central LC, whereas CT/MRI showed enlarged mediastinal lymph nodes in 7/9 pts. In conclusion, TEE is able to visualize central lung cancer and gives useful additional informations about the kind of relation to central PA and the aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Magnetic resonance tomography image of transmural myocardial infarct in comparison with 99mTc-methoxyisobutylisonitrile SPECT].

To assess the ability of magnetic resonance imaging (MRI) to identify morphologic and functional abnormalities associated with transmural anterior and inferior myocardial infarction, 18 patients with anterior myocardial infarcts and 11 patients with inferior myocardial infarcts confirmed by ECG and cine-ventriculography underwent gradient-echo MRI of transverse and short-axis imaging planes. Myocardial perfusion of corresponding imaging planes was measured by 99mTc-methoxyisobutyl-isonitrile single-photon emission computed tomography (MIBI-SPECT). Transmural scar by MRI was defined as diastolic wall thickness 2.5 SD below corresponding normal values of a healthy control group (n = 21). MIBI-SPECT scar was defined as a MIBI uptake less than 2.5 SD below mean values of a healthy control group (n = 11). By MIBI-SPECT, 231 segments contained normal tissue and 161 contained scarred myocardium. In 352/392 (90%) segments gradings based on diastolic wall thickness and MIBI-SPECT gradings were identical. Diastolic wall thickness was significantly higher in normal than in scarred MIBI-SPECT segments (10.3 +/- 1.5 vs 5.2 +/- 2 mm, p less than 0.0001). Additionally, normal segments by MIBI-SPECT showed significantly higher systolic wall thickening than scar segments (5.5 +/- 1.5 vs 0.6 +/- 1.6 mm, p less than 0.0001). The correlation between MRI and MIBI-SPECT assessed infarct size was r = 0.91 for anterior and r = 0.77 for inferior myocardial infarcts. The agreement between MIBI-SPECT perfusion defect size and regions with reduced diastolic wall thickness on MRI tomograms was significantly better for anterior myocardial infarcts than for inferior myocardial infarcts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Effort-induced myocardial wall motion abnormalities in the magnetic resonance tomogram: a comparison with effort MIBI SPECT].

In 20 patients with an angiographically documented coronary artery stenosis of > or = 70% and normal LV function at rest MRI was performed before and after dipyridamole infusion (0.75 mg/kg BW). In all patients MIBI-SPECT was obtained at rest and after dynamic symptom-limited exercise. In 18 patients MIBI-SPECT showed ischemia and in 18 patients dipyridamole MRI showed a wall motion impairment. In the segments representing the 29 stenosed vessels ischemia in MIBI-SPECT was diagnosed correctly in 24 instances (sensitivity 83%, specificity 90%) and a wall motion abnormality was present in MRI in 23 instances (sensitivity 79%, specificity 90%). Dipyridamole GE-MRI is not superior to MIBI-SPECT in the diagnosis of ischemia.

Aged↗
PubMed1992

[Pulmonary function tests after pneumocystis carinii pneumonia in HIV infected patients].

UNLABELLED: Significant impairment of lung volumes and gas exchange in HIV-infected patients with acute Pneumocystis carinii pneumonia (PCP) has been reported, whereas little is known about lung function compromise following successful therapy. In 9 patients with acute PCP and 9 patients 1-5 month after PCP lung function testing including spirometry, diffusing capacity for carbon monoxide and exercise blood gas analysis were performed serially at monthly intervals. The results were summarized in a total score. The mean period of follow-up for each patient was 7.2 +/- 2 months. A decrease in lung volumes (FEV1 67 +/- 14.2% pred.norm., VC 72.7 +/- 11.9% pred.norm.) and gas exchange (CO-transfer factor 53.2 +/- 18.5% pred.norm., CO-transfer coefficient 67.8 +/- 14.2 pred. norm.) was observed in all 9 patients with acute PCP. Post-PCP lung volumes normalized within 1 month, whereas disorders in gas exchange persisted for 1-3 months. The total score normalized in 16/18 patients. One of the remaining patients with persisting functional impairment had chronic obstructive airway disease, whereas in the other dysfunction was even observed prior to PCP and no diagnosis could be obtained. 2-6 months following acute disease a second period of decreased lung function occurred in 6 pts. In 3 of the 6 there were no clinical signs of infection (rebronchoscopy refused), in 1 patient infection with cytomegalovirus was suspected. In the other 2 patients a relapse of PCP was diagnosed by bronchoscopy. CONCLUSIONS: Acute PCP compromises lung mechanics and gas exchange. During recovery deficits in gas exchange persist longer than diminished lung volumes.(ABSTRACT TRUNCATED AT 250 WORDS)

Follow-Up Studies↗
PubMed1992

[Determination of normal values of the aortic blood flow profile using continuous Doppler echocardiography from apical and suprasternal echo position].

The present study was undertaken to measure normal aortic blood velocity profiles by means of continuous wave Doppler echocardiography from apical and suprasternal positions in 40 healthy adults. The profiles in the ascending aorta were measured from both positions, whereas the profiles in the descending aorta were measured only from the suprasternal position. The highest values for the maximal flow velocities were found in the ascending aorta from the suprasternal position (1.28 +/- 0.18 m/s), the lowest values for the maximal flow velocities were found in the descending aorta (1.17 +/- 0.22 m/s). This trend was also found for the mean velocity values. As to the time parameters, a longer acceleration time for the descending aorta was remarkable (106 +/- 24 ms), whereby the mean values for the ejection time for the descending aorta (308 +/- 25 ms, suprasternal: 320 +/- 30 ms). The highest values for the acceleration were found in the ascending aorta (suprasternal: 1526 +/- 531 cm/s2, apical: 1422 +/- 330 cm/s2) and the lowest values in the descending aorta (1208 +/- 378 cm/s2). Regarding the maximal velocity index there was no significant difference for the maximal values between the different transducer positions. The results of the regression analysis showed only a weak correlation of the maximal velocity values in the different transducer positions. This means that for follow-up examinations only those values should be used that were obtained from the same transducer position.

Adult↗
PubMed1992

[Assessment with magnetic resonance tomography of anatomy and ventricular function after Mustard correction of transposition of the great arteries].

In order to evaluate postoperative sequelae and ventricular function after Mustard-operation in patients with transposition of the great arteries (TGA), 30 patients were assessed by magnetic resonance imaging in EKG-triggered spin-echo (SE) and gradient-echo (GE) technique. Twenty-three patients, aged 4.7 to 15.8 years, had transposition of the great arteries with intact ventricular septum with or without left-ventricular outflow tract obstruction (TGA+IVS +/- SPS). Seven patients aged 9.5 to 21.7 years had transposition of the great arteries with ventricular septal defect (TGA+VSD). Five patients showed a residual baffle leak, one had a pulmonary venous obstruction, five an obstruction at the caval veins, 13 a left-ventricular outflow tract obstruction, and 14 a tricuspid regurgitation. Right-ventricular enddiastolic volume in patients with TGA+VSD (77.0 +/- 25.5 ml/m2) was significantly higher than in patients with TGA+IVS +/- SPS (61.2 +/- 12.0 ml/m2). In TGA+VSD right-ventricular ejection fraction (47.6 +/- 13.0%) was significantly lower than in patients with TGA+IVS +/- SPS (56.7 +/- 10.7%). The ratio of muscle masses of right to left ventricle was 1.8:1 in patients with TGA+IVS +/- SPS and 2.5:1 in patients with TGA+VSD. In conclusion, after Mustard-operation in patients with transposition of the great arteries (TGA) magnetic resonance imaging provides a comprehensive and noninvasive assessment of postoperative sequelae, residuae, and ventricular function and will, therefore, become the method of choice for postoperative evaluation.

Child, Preschool↗
PubMed1991

New option for balloon recanalization of total coronary occlusions.

In 9 out of 12 patients with a total coronary occlusion but definite signs of viable myocardium a new approach for the recanalization procedure was successfully employed: Following recanalization using an on-the-wire 2.0 or 2.5 mm angioplasty catheter, a standard coronary guidewire was placed along the angioplasty catheter. After withdrawal of the catheter, over-the-wire angioplasty with an appropriately sized balloon was performed for final dilatation. Pending further studies in a larger patient population, this new method may offer an alternative approach for revascularization of total coronary occlusions.

Aged↗
PubMed1991

[Magnetic resonance tomography in patients with a heart valve prosthesis].

Artificial valve prostheses are often regarded as a contraindication for magnetic resonance imaging (MRI), although preliminary in vitro studies suggested, that patients with these metallic implants might safely undergo MR examination. This study reports on the experience with a group of 89 patients with 100 heart valve prostheses who were examined by spin-echo MR and gradient-echo MR. MR examination was performed in all patients without complications. The spin-echo sequence showed advantages in the depiction of anatomical structures like paravalvular abscesses. Anatomical structures adjacent to the artificial valve were clearly visible and the metal components of the valves showed no or only small artifacts. Artifacts were accentuated when using gradient-echo sequences. Gradient-echo sequences provided valuable information regarding the presence of valvular insufficiency. Physiological valvular regurgitation was easy to differentiate from pathological paravalvular or transvalvular regurgitation. These results demonstrate that patients with artificial valve prostheses can be imaged by MR without risk and that prosthesis-induced artifacts do no interfere with image interpretation.

Abscess↗
PubMed1991

[Diagnosis and classification of tricuspid valve insufficiency with dynamic magnetic resonance tomography: comparison with right ventricular angiography].

To evaluate the diagnostic potential of magnetic resonance imaging (MRI) to diagnose and evaluate tricuspid incompetence (TI), right ventricular angiography (RVA) and MRI were compared in 51 patients. For angiographic semi-quantification a 4-grade modified Sellers classification was used. Several MRI-parameters (jet volume, jet area, number of slices with visible jet, duration of the regurgitation and volume of the right atrium) were examined concerning their validity to evaluate TI and compared to the angiographic data. Limits for MRI jet areas and volumes for each angiographic group were defined to obtain the best agreement with angiographic results. Thirty of 34 patients with angiographically visible TI (sensitivity = 88%) were diagnosed correctly with MRI. The 4 remaining patients also showed a small regurgitant jet which was, however, interpreted as physiologic. One of the 17 patients without angiographic TI was diagnosed as mild TI by MRI (specificity = 94%). MRI classification using jet volume (46/51 = 90% correct classifications) was not significantly better than the easier and faster MRI classification using jet area (43/51 = 84%). The other parameters (number of slices, duration of regurgitation and volume of the right atrium) showed considerable overlap between angiographic groups and did therefore not allow a classification into 4 grades. However, simple classification into hemodynamic relevant and irrelevant TI was possible. Thus MRI is able to diagnose TI with good sensitivity and specificity. Classifications based on jet volume and jet area showed good agreement with angiographic results. However, both parameters depend on the magnet and the pulse sequence used and must therefore be specifically determined for each imaging routine.

Adult↗