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S Globits

Publications and source records attributed to S Globits.

51 records · Page 3Linked to original sources
PubMed1992

Heart rate behaviour at different stages of congestive heart failure.

Depressed heart rate variation has been shown to predict a high mortality rate in patients with severe congestive heart failure. To determine whether the degree of altered heart rate correlates with the clinical state, 24-h Holter monitoring was performed in 21 patients (mean ejection fraction: 18 +/- 11%) at baseline and after 6 months of oral therapy. At baseline, the overall 24-h heart rate variation and night/day heart rate ratio was reduced, depending on the NYHA functional class. The typical morphology of R-R interval histograms was a sensitive marker of the clinical state at baseline: the higher the NYHA class, the smaller the R-R interval variability and standard deviation of R-R intervals (total variability NYHA III versus II: P less than 0.05). Clinical deterioration after 6 months (n = 8) was accompanied by a tendency to further shortening of the mean total R-R interval variability (676 +/- 34 to 586 +/- 25 ms). This was shown in three patients, who were reclassified to NYHA class IV. In stable patients (n = 5) and those with clinical improvement (n = 8) no significant change in R-R variability was observed. It is concluded that variations in R-R interval histogram shapes correspond to different NYHA functional classes. While severe clinical disease progression may be associated with further reductions in the heart rate variability, improvement in the clinical state of congestive heart failure is not necessarily associated with changes in heart rate behaviour.

Adult↗
PubMed1992

Doppler sonographic evaluation of the CarboMedics bileaflet valve prosthesis: one-year experience.

Between April 1989 and March 1991, 237 CarboMedics bileaflet valve prosthesis carriers (165 aortic and 72 mitral valves, mean age 54.4 years) were studied prospectively with pulsed- and continuous-wave Doppler at a mean interval of 11.4 months following surgery in order to establish ranges of normal flow velocities and pressure gradients. Physical examination revealed no signs of prosthetic dysfunction or heart failure. Postoperative left ventricular function as measured by fractional shortening was 37% for aortic valve carriers and 30% for mitral valve carriers (p = NS). Mean peak velocity (+/- SD) across the aortic valve was 2.6 m/sec (+/- 0.4) and calculated instantaneous peak pressure gradient ranged from 11 to 58 mmHg (mean 28.1 +/- 10.3). It has to be emphasized that occasional patients with normally functioning valve prostheses can show unusual high gradients. Ring diameters between 21 and 27 mm showed no significant difference with regard to flow velocities and pressure gradients, whereas in 19-mm valves, significantly higher values could be demonstrated. The 123 aortic valve carriers with normal left ventricular function (fractional shortening greater than 25%) showed significantly higher pressure gradients than the 19 patients with reduced left ventricular function (28.6 +/- 11.6 mmHg vs 16.2 +/- 5.1 mmHg, p less than 0.05). In the mitral position, the mean of peak velocity (+/- SD) was 1.7 +/- 0.4 m/sec and pressure half-time was 108 +/- 26 msec, representing a calculated valve area between 1.4 to 3.1 cm2 (mean orifice size 2.1 +/- 0.5 cm2). No significant difference between valves of different sizes was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1992

[Pimobendan (UDCG 115 BS) in long-term therapy of chronic heart failure].

Pimobendan is a positive inotropic agent with additional calcium-sensitizing effects of the phosphodiesterase III-inhibitor group. In short-term studies, beneficial hemodynamic effects have been demonstrated in patients with congestive heart failure. The aim of this prospective study was to examine the long-term effect of pimobendan (during at least 6 months) on subjective state, hemodynamic parameters, and arrhythmias in patients with congestive heart failure NYHA classes II and III. After double-blind randomization, 24 patients received pimobendan 5 mg bid or placebo orally in addition to a basic therapy (diuretics, digitalis). After 3 months, pimobendan-treated patients showed a significant clinical improvement (p < 0.03). In the placebo group, one patient underwent acute cardiac transplantation due to rapid clinical deterioration; another patient died suddenly after 5 months. No cardiac events occurred in the pimobendan group. In comparison to placebo, no proarrhythmogenic effect of pimobendan was detected. Clinical stabilization of patients in the pimobendan group was not paralleled by improvement of the hemodynamic parameters of left-ventricular performance.

Cardiac Volume↗
PubMed1991

Constrictive pericarditis without typical haemodynamic changes as a cause of oedema formation due to protein-losing enteropathy.

A 41-year-old man presented with physical signs of leg oedema and a laboratory value of decreased serum albumin of 2.4 g.dl-1. Loss of protein via the gastrointestinal tract was demonstrated by an increased faecal excretion of 51-chromium-labelled-albumin and by elevated stool clearance of alpha 1-antitrypsin. No anatomical lesions or intestinal disease were found to explain this protein loss. Constrictive pericarditis was suspected as the cause of protein-losing enteropathy but could not be confirmed by right heart catheterization, in which normal filling pressures and no sign of 'dip and plateau' pressure pattern were found. However, magnetic resonance imaging clearly demonstrated a thickening of the pericardium over the right heart and a tubular-shaped right ventricle as signs of constrictive pericarditis. Peripheral oedema disappeared and serum protein concentration returned to normal after pericardectomy. This demonstrates that moderate pericardial constriction not resulting in discernible pressure abnormalities in the right heart can be associated with protein-losing enteropathy and thus result in hypoproteinaemic peripheral oedema. In this condition a morphological investigation by magnetic resonance imaging is of importance in order not to miss the diagnosis of a potentially treatable disease.

Adult↗
PubMed1991

[Diagnosis of arrhythmogenic right ventricular disease using magnetic resonance tomography].

In our study, 12 patients with ventricular arrhythmias, but without any documented cardiac disease, and 10 healthy volunteers were investigated by spin echo magnetic resonance tomography (MRT) using a 0.5 Tesla magnet. Axial T1-weighted spin-echo sequences, as well as double angulated, multislice-multiphase sequences were acquired. Left- and right-ventricular volumes were then evaluated by outlining the endocardium in an end-systolic and an end-diastolic frame. The right-ventricular free wall and the right-ventricular outflow tract were investigated for myocardial thickness and intramural fat.

Adipose Tissue↗
PubMed1991

Evaluation of congenital diseases of the heart.

Three different new developments have taken place in the evaluation of congenital heart diseases. First, in the fetal period, intravaginal echocardiography allows earlier diagnosis of significant cardiac abnormalities that could lead to a wanted termination of pregnancy. Second, in adults and children, MR imaging has become a standard imaging modality in complex congenital heart diseases. Moreover MR imaging has become the best noninvasive imaging method in visualization of the great vessels. Finally, in surgery, the intraoperative epicardial echocardiography could improve operation results in the future (solving the regurgitation problem). Postoperatively, MR imaging has become an important diagnostic tool that helps to reduce repeated catheterization and angiography.

Diagnostic Imaging↗
PubMed1990

[Cine-MR for the quantification of regurgitation defects by a volume method].

We have examined 46 patients with angiographically confirmed regurgitant lesions (26 mitral insufficiency, 20 aortic insufficiency) using a 0.5 Tesla magnet. In each patient, multiplane and multiphase spin-echo sequences were obtained in a plane angled in the sagittal and coronal direction in the long axis of the heart; left and right ventricular volumes, ejection fractions and regurgitation fractions were calculated. In addition, a blood-flow sensitive gradient echo sequence was obtained in order to determine the direction and extent of the regurgitant jet. The data was compared with the results of angiography and echocardiography. By means of the gradient echo technique, MRI was able to show the regurgitant jet in every patient. There was a linear correlation between volumes determined by MRI and angiography. The best agreement was found for left ventricular contraction volume (R = 0.82, p is less than 0.0001). Comparison of the noninvasive and angiographic method showed a linear correlation for AI patients of R = 0.91 (p is less than 0.001), which is somewhat better than for patients with MI (R = 0.84, p less than 0.001). Semiquantitative grading of MI with a gradient echo technique showed a linear correlation with angiography of R = 0.73 (p less than 0.001), for AI there was agreement between both methods in 72% of cases. A comparison between MRI and colour Doppler sonography showed only moderately good correlation R = 0.69 (p less than 0.01).

Adult↗
PubMed1989

Cine-MR in dissection of the thoracic aorta.

Magnetic resonance imaging (MRI) of the thoracic aorta, including cine-MRI, was performed in 25 patients suspected of having dissection of the thoracic aorta. MRI was correlated with echocardiography, CT and angiography. The sensitivity of MRI (100%) was most closely followed by CT and angiography (83% and 77% respectively). The specificity of MRI and angiography was equally good, at 100% each. MRI was able to demonstrate the intimal flap in all 9 cases of aortic dissection, and there were no false-positive results. Differentiation of thrombosis and slow flow was possible on proton density images, gradient echo images permitted detection of the entry and re-entry sites. The nature of the dissection was determinated correctly in 8 out of 9 cases. MRI is capable of providing all the relevant parameters necessary to decide appropriate treatment of dissecting aneurysms of the thoracic aorta.

Adolescent↗
PubMed1989

[Magnetic resonance tomography in the assessment of questionable aneurysm of the thoracic aorta with or without dissection of the intima].

To assess the value of MRI in the diagnosis of aneurysm of the thoracic aorta with suspected or known dissection 23 patients were imaged with cardiac gating. Seven patients (group 1) had known dissection of the thoracic aorta; in 16 patients (group 2) an aneurysm was suspected by chest x-ray or 2D-echocardiography. Reference methods were: x-ray, 2D-echocardiography, angiography, and computered tomography. In the first group MRI clearly identified the intimal flap, could differentiate between true and false lumen, slow flow, and thrombus, respectively. In the second group MRI could exclude a dissection of the ectatic part of the thoracic aorta in 11 patients and demonstrate paracardiac or mediastinal mass in five patients. MRI can serve as an important diagnostic tool in known or suspected aneurysm of the thoracic aorta.

Adolescent↗
PubMedDate not supplied

Improved reproducibility in measuring LV volumes and mass using multicoil breath-hold cine MR imaging.

There is a generally recognized need for improvement in quality of fast cardiac MR images. Consequently, breath-hold cine MR images were obtained with multiple surface coils connected to phased array receivers, and C/N, intra-observer and inter-observer variabilities for LV volumes and mass were evaluated. Two sets of short-axis images of the LV, one with multiple surface coils and another with a body coil, were acquired in eight subjects with a fast cine MR sequence using k-space segmentation (TR/TE = 7/2.2 msec, temporal resolution = 56 msec). C/N with multicoil imaging was 32.2 +/- 7.6 (mean +/- SD), significantly higher than that with a body coil (11.0 +/- 3.3, P < .01). The mean percentage differences in intra-observer and inter-observer measurements with multicoil imaging were significantly better than those with a body coil. In conclusion, multicoil imaging provides significant gain in C/N on breath-hold cine MRI of the heart. In addition, intra-observer and inter-observer reproducibilities are improved with multicoil imaging.

Adult↗
PubMedDate not supplied

Breath-hold MR measurements of blood flow velocity in internal mammary arteries and coronary artery bypass grafts.

Breath-hold velocity-encoded cine MR (VENC-MR) imaging is a feasible method for measuring phasic blood flow velocity in small vessels that move during respiration. The purposes of the current study are to compare breathhold VENC-MR measurements of flow velocities in the internal mammary arteries (IMA) with nonbreath-hold measurements and to characterize the systolic and diastolic flow velocity curves in a cardiac cycle in native IMA and IMA grafts. Flow velocity in 30 native IMA and 8 IMA grafts were evaluated with a breath-hold VENC-MR sequence with K-space segmentation and view-sharing reconstruction (TR/TE = 16/9 msec, VENC = 100 cm/s). In 10 native IMA, nonbreath-hold VENC-MR images were acquired as well for comparison. Breath-hold VENC-MR imaging showed significantly higher systolic and diastolic peak velocities in native IMA (43.1 cm/second +/- 15.0 and 10.0 cm/second +/- 4.8), in comparison to those of nonbreath-hold VENC-MR imaging (27.6 cm/second +/- 10.2 and 7.3 cm/second +/- 3.9, P < .05). The diastolic/systolic peak velocity ratio in the IMA grafts (.88 +/- .41) was significantly higher than that in native IMA (.24 +/- .08, P < .01). Interobserver variability in the flow velocity measurement was less than 4%. Breath-hold VENC-MR imaging demonstrated higher peak flow velocity in the IMA than nonbreath-hold VENC-MR imaging. This technique is a rapid and effective method for the noninvasive assessment of blood flow velocity in IMA grafts.

Adult↗
PubMedDate not supplied

Quantification of regurgitant lesions by MRI.

We examined 46 patients with angiographically documented regurgitant lesions (26 patients with mitral regurgitation, 20 patients with aortic regurgitation) using an 0.5 Tesla magnet. In each patient a multislice-multiphase spinecho sequence in sagittal-coronal double angulated plane was performed to assess left and right ventricular volumes, ejection fraction and regurgitant fraction. Additionally a blood flow sensitive gradient echo technique was done to visualize direction and extension of the regurgitant jet. MRI data were compared with quantitative and qualitative assessment of regurgitation by angiography and echocardiography. Using the gradient echo technique MRI could demonstrate the regurgitant jet in all patients. A linear correlation for volume parameters by MRI and angio was found with best correlation for the left ventricular stroke volume (r = 0.82, p less than 0.0001). Furthermore MRI regurgitant fraction correlated with angiographically determined regurgitant fraction in patients with aortic regurgitation (r = 0.91, p less than 0.0001) and mitral regurgitation (r = 0.67, p less than 0.001), respectively. Semiquantitative assessment of regurgitation by gradient echo technique showed an agreement with angiographic grading by Sellers in 70% of mitral and 75% of aortic regurgitation, respectively. The comparison of MRI and color Doppler sonography showed only moderate correlation of r = 0.72 (p less than 0.01).

Aortic Valve Insufficiency↗
PubMedDate not supplied

Assessment of mitral regurgitation by magnetic resonance imaging.

To evaluate the potential of magnetic resonance imaging (MRI) in detection and quantification of mitral regurgitation, 26 pts. with echocardiographically or angiographically documented mitral regurgitation were examined using a 0.5 Tesla superconducting magnet. In each patient a multislice-multiphase study in a sagittal-coronal double angulated projection (four-chamber view equivalent) was performed to assess left and right ventricular volumes, ejection fraction and regurgitant fraction. Additionally a blood flow sensitive cine-study (fast field echo: FFE) was done to visualize direction and area of regurgitant jet. MRI data were compared with quantitative and quantitative assessment of mitral regurgitation by angiography, 2D echocardiography, Doppler sonography and color flow mapping. Using the FFE mode MRI was able to detect the regurgitant jet as a typical signal loss within the left atrium in all patients. The ratio of regurgitant jet area/left atrium area as determined by MRI showed a correlation with a comparable ratio from color Doppler sonography of R = 0.87 (p less than 0.001). There was also good agreement in semiquantitative grading of mitral regurgitation between MRI and angiography (R = 0.77, p less than 0.001). The determination of left and right ventricular stroke volume allowed the calculation of the regurgitant fraction, which showed a correlation with invasively determined regurgitation fraction of R = 0.84 (p less than 0.001). These data provide additional information that MRI may be useful as a noninvasive technique to detect and quantify mitral regurgitation.

Adult↗
PubMedDate not supplied

Value of three-dimensional echocardiography as an adjunct to conventional transesophageal echocardiography.

Three-dimensional imaging of cardiac structures could enhance the functional understanding and the interpretation of pathologies. Limited processing capabilities, relocation problems and inadequate two-dimensional image quality have previously limited its applicability. Recently, an integrated echocardiographic computerized tomography unit (echo-CT) which uses a transesophageal approach has been developed. This system is capable of sampling and processing multiple echocardiographic images and, thus, provides three-dimensional views. To evaluate the feasibility and potential of this technique, we studied 69 patients with various cardiac disorders. All but 3 patients (96%) tolerated the procedure well allowing at least one scan to be performed. No complications were encountered. The indication for echo-CT included coronary artery disease (n = 4), mitral valve disease (n = 18), suspected arterial embolism (n = 19), masses (n = 8), congenital malformation (n = 10), postcardiac surgery (n = 8), aortic aneurysm (n = 1) and suspected left-to-right shunt (n = 1). Conventional transesophageal echocardiography revealed a pathology in 45 patients. Of these pathologies, 37 (82%) could be reconstructed and displayed in three-dimensional views. Three-dimensional imaging provided an improved spatial understanding of the pathology in 21 cases (39%). Echo-CT was especially valuable in diseases of the mitral value (i.e. mitral valve prolapse, flail leaflets, mitral stenosis) where it had the potential to delineate the location, type and morphology of defects. In conclusion, three-dimensional transesophageal imaging enhances image interpretation and understanding. This could be of value in complex morphologies and cardiac disorders in which surgical repair is attempted.

Adult↗