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Biomedical subjects

H Egeblad

Publications and source records attributed to H Egeblad.

At least 73 records · Page 4Linked to original sources
PubMed1986

Different patterns of hemodynamic abnormalities in patients with ischemic heart disease compared with patients with congestive cardiomyopathy.

48 patients with chest pain or unexplained heart failure were examined with exercise test, systolic time intervals, apexcardiogram and left- and right-sided heart catheterization including coronary arteriography. The 23 patients with ischemic heart disease (IHD) and 19 patients with congestive cardiomyopathy (COCM) could as groups be separated by several of the parameters. Two major patterns of change were present when using the whole range of parameters, probably reflecting that the heart and circulation had compensated for left ventricular dysfunction in different ways in IHD and COCM. Comparing patients with the same ejection fraction (EF), preejection-period index (PEPI) pre-ejection-period/left ventricular ejection time (PEP/LVET) and systolic blood pressure/left ventricular end systolic volume index (SBP/LVESVI), were all more abnormal in patients with COCM than with IHD at most EF levels. The best separation between the diseases was obtained using exercise capacity in combination with PEP/LVET. The correlations between invasive and noninvasive parameters underlined that no single parameter can satisfactorily characterize the circulatory function in patients with individual differences in preload, afterload, pulse rate, cardiac volumes, compliance and contractility. No or poor correlations were found between exercise capacity and the different function parameters used.

Adult↗
PubMed1986

Analysis of arrhythmias based on atrial wall motion. Usefulness and feasibility of recording left and right atrial systole by echocardiography.

The usefulness and feasibility of recording atrial wall motion by M-mode echocardiography guided by two-dimensional examination was evaluated in three groups of consecutive patients: 7 with undefined tachyarrhythmias, 25 in sinus rhythm, and 20 with atrial flutter or fibrillation. Atrial systole was recorded in the left and right atrium in 58 and 98% of the patients, respectively (p less than 0.05). Six of the patients with undefined tachyarrhythmias exhibited electrocardiographic atrioventricular dissociation revealed by preceding echocardiography in all. The precise timing of left and right atrial systole could be recorded in patients in sinus rhythm; right atrial contraction preceded left atrial systole by 42 +/- 31 msec (mean +/- SD). Among patients with atrial flutter or fibrillation, one case of dissimilar atrial rhythms was revealed by echocardiography. Thus, recording of atrial wall motion is feasible in the majority of patients and provides information which is otherwise available only by esophagus ECG or by invasive means.

Adult↗
PubMed1984

Prevalence of mitral valve prolapse in younger patients with cerebral ischaemic attacks. A blinded controlled study.

The association between cerebral ischaemic attacks (CIA) and mitral valve prolapse (MVP) was investigated in a blinded study of 30 consecutive patients with cerebrovascular disease and 30 control patients matched by age, sex, and immediately apparent neurological signs. All patients were below the age of 40 years. Phonocardiography, motion-mode and two-dimensional echocardiography were performed at rest and during various manoeuvres. MVP demonstrated by all three diagnostic modalities was classified as definite and prolapse in at least one but not in all three tests were designated as ambiguous. Regarding the frequency of definite MVP, no statistically significant difference was demonstrated between patients with CIA (3%) and controls (0%). Ambiguous MVP was rather common in patients with cerebrovascular disease (13%) but equally frequent in control patients (20%). It is concluded that MVP does not appear particularly common in Northern Europe in younger patients with cerebral ischaemic events.

Adult↗
PubMed1984

Static contraction of the quadriceps muscle in man: cardiovascular control and responses to one-legged strength training.

Knee extension strength training of one leg (ST) (120 maximal contractions per day, 5 days per week for 9 weeks) was performed by 9 healthy young men. Before and after ST, biopsies were obtained from the vastus lateralis muscle of each leg and static quadriceps contractions (SQC) lasting 2 min were performed with each leg under control conditions and after combined vagal and beta-adrenergic blockade with atropine and metoprolol. Maximal voluntary contraction strength (MVC) increased more for the trained leg (TL) than for the untrained leg (UTL) but thigh circumferences and muscle fibre diameters gave little evidence for muscle hypertrophy. In pre- vs. post-training comparisons during SQC at the same relative force (40% of MVC) mean blood pressure (MBP), heart rate (HR) and smoothed rectified electromyographic activity were similar for TL and UTL. Similar findings were obtained for MBP after attenuation of the HR response by autonomic blockade, indicating that MBP, per se, was closely linked to the relative force of SQC. Pre- to post-training reductions in MBP and HR during SQC with each leg at an absolute force of 40% of pre-training MVC were likely due to changes in the pattern of motor unit activation. A lower MBP response to SQC and TL than of UTL after training correlated with a greater capillary density and a lower muscle lactate level for TL.

Adaptation, Physiological↗
PubMed1984

Clinically suspected severe ischaemia-induced mitral regurgitation. Spectrum of lesions and features of high surgical risk by echocardiography.

Eighteen patients with clinical signs suggesting severe mitral regurgitation secondary to ischaemic heart disease were assessed by echocardiography. Non-ischaemic diseases needing specific therapy were revealed in six patients. In the other 12 patients echocardiography demonstrated myocardial lesions explaining the mitral regurgitation. Apart from the distinction between non-ischaemic conditions and lesions induced by ischaemia, echocardiography seems to be helpful in the demonstration of severe yet operable mitral valve regurgitation due to a small ischaemic lesion. Such cases are opposed to functional mitral regurgitation caused by extensive myocardial injury as demonstrated by two-dimensional echocardiography and reflected by a minimum mitral valve/septum separation of more than 2 1/2 cm on the M-mode echocardiogram. These conditions make symptomatic improvement by mitral valve surgery unlikely and carry an extremely high operative mortality. A more precise definition by heart catheterization is required when serious clinical heart failure is not explained by the echocardiographic finding of severe global myocardial impairment.

Aged↗
PubMed1983

Interactions between digoxin and potassium-sparing diuretics.

A kinetic and hemodynamic study of digoxin was performed in six healthy subjects and similar studies were performed during digoxin with spironolactone and with triamterene. Spironolactone reduced renal tubular secretion of digoxin and attenuated its positive inotropic effect (evaluated by systolic time intervals and echocardiography) and triamterene reduced the extrarenal elimination of digoxin, but induced no changes in digoxin-elicited inotrophy. It is suggested that the renal handling of digoxin is influenced by the intracellular potassium concentration in the renal tubular cell. The results indicate a drug-receptor interaction between spironolactone metabolites and digoxin at the hypothetical inotropic digitalis receptor. Amiloride has been reported to suppress digoxin inotropism, whereas spironolactone induces minor inhibition and triamterene does not affect digoxin inotropism.

Adult↗
PubMed1983

Echocardiography in lone atrial fibrillation.

Twenty-seven consecutive patients with suspected lone atrial fibrillation were studied by M-mode echocardiography. Echocardiography disclosed structural or functional cardiac abnormalities in only two (12%) of 17 patients without any sign of underlying heart disease by history or physical examination, whereas an accompanying or underlying cardiac disorder was found in 6 (60%) of 10 patients with ambiguous clinical findings. It is concluded that echocardiography is of minor value in patients with lone atrial fibrillation if symptoms and signs of other cardiac disorders are totally absent, but the presence of even minor or ambiguous clinical abnormalities seems to be a clear indication for echocardiography in these patients. It is, however, emphasized that echocardiography appears to guide the clinical management in less than 20% of patients with clinically suspected lone atrial fibrillation.

Adult↗
PubMed1983

Assessment of rheumatic mitral valve disease. Value of echocardiography in patients clinically suspected of predominant stenosis.

The value of echocardiography as compared with cardiac catheterisation was evaluated prospectively in 33 consecutive patients clinically suspected of predominant mitral stenosis. Patients with clinical signs of accompanying mitral regurgitation, no matter how severe, and patients with clinical findings indicating insignificant aortic valve disease were included. Critical mitral stenosis was defined by a valve area of less than or equal to 1 cm2. Severe mitral regurgitation was diagnosed by echocardiography on the basis of left ventricular dilatation (more than 3.2 cm/m2 at end-diastole) if not explained otherwise. Significant aortic valve disease was suspected in cases with aortic valve deformity and left ventricular dilatation or hypertrophy as defined by echocardiography. Mitral valve area by echocardiography correlated well with mitral valve area calculated from catheterisation data and a good interobserver correlation was found for echocardiographic measurement. Mitral stenosis, critical or non-critical, may mask significant coexistent valve lesions; echocardiography failed to discover severe mitral regurgitation requiring valve replacement in two patients with non-critical stenosis, and significant aortic regurgitation needing valve replacement was underestimated in one patient with critical mitral stenosis. A correct echocardiographic classification with respect to surgery, however, was obtained in: (1) all patients with clinically pure mitral stenosis (nine patients), and (2) all patients with combined mitral stenosis and regurgitation when either critical stenosis or severe regurgitation was found at echocardiography (12 patients). It thus appears that two out of three patients with mitral valve disease in whom the clinical findings indicate predominant stenosis can be correctly evaluated with the echocardiogram.

Adult↗
PubMed1983

Transience of left ventricular thrombosis.

A left ventricular mural thrombus with a mobile appendix of 0.5 x 0.5 x 3 cm was shown by two dimensional echocardiography in a 31 year old man who had dilated congestive myocardial disease. Serial echocardiograms showed formation of the thrombus within three weeks and uncomplicated disappearance of the mobile clot within less than two days. Heparin and phenprocoumon were given in doses generally not accepted to affect left ventricular thrombosis adequately. Such transience of left ventricular thrombosis may be worth considering when deciding whether to treat patients with thrombi accidentally demonstrated by echocardiography; it also might explain some of the many negative examinations in the echocardiographic screening of patients with embolism.

Adult↗
PubMed1983

Endomyocardial biopsy guided by cross-sectional echocardiography.

The usefulness of cross-sectional echocardiography during endomyocardial biopsy was examined in 10 consecutive patients with myocardial disease of undetermined origin. Twenty-eight endomyocardial biopsies were obtained from the left ventricle and 34 from the right ventricle. Echocardiography was performed simultaneously with monitoring of the biopsy procedure by means of fluoroscopy, pressure measurement, and electrocardiographic recording from the bioptome. Echocardiographic visualisation of the biopsy procedure was feasible in 100% of left and in 18% of right ventricular biopsies. Conventional positioning of the bioptome was corrected in a total of five cases because of inappropriate localisation as apparent from cross-sectional echocardiography. In the left ventricle the site of biopsy could be defined more precisely by echocardiography than by fluoroscopy. At the present stage of technical development the most important potential of ultrasonically guided endomyocardial biopsy seems to be the feasibility of obtaining selective biopsies from well defined areas of the left ventricle when serial analysis from a reproducible area is necessary.

Adult↗
PubMed1982

Regional dynamic behaviour of the canine myocardium following brief ischaemia: wall thickness, wall thickening and blood flow.

Regional myocardial wall characteristics were studied in open-chest anaesthetised dogs. End-diastolic wall thickness and systolic wall thickening were measured by echocardiography and blood flow was quantified by the local 133Xe washout technique during and following coronary artery occlusion of 10 s to 10 min duration. End-diastolic wall thickness exhibited a small temporary increase over baseline value during reperfusion. Maximum value was observed following ischaemic periods of 1 min duration (9.0 +/- 0.5 mm [(Mean +/- 2 SEM) versus a baseline value of 8.2 +/- 0.5 mm (P less than 0.01)]. A post-ischaemic, hyperkinetic and transient systolic wall thickening was most prominent following periods of 2 min of ischaemia (7.1 +/- 0.7 mm; baseline value 4.2 +/- 0.2 mm, P less than 0.01). Extension of ischaemia from 2 min to 10 min provoked no essential change of reactive hyperaemia characteristics (maximum blood flow 257.6 +/- 27.4 cm3 . min-1 . 100 g-1 versus 238.3 +/- 57.0 cm3 . min-1 . 100 g-1, P less than 0.05; duration 62.8 s versus 71.8 s, P less than 0.05). Such extension of the ischaemia, however, made the post-ischaemic, hyperkinetic systolic and transient wall thickening disappear. Considerable asynchrony between variations of blood flow, wall thickness and wall thickening was observed. Determinants with influence on post-ischaemic wall thickness and wall thickening are discussed in relation to the data presented. The resultant of these determinants increasingly favours transient post-ischaemic hyperkinesia following ischaemia of up to 2 min duration, whereas further prolongation of the ischaemia will result in progressive impairment of the myocardial function during reperfusion.

Animals↗
PubMed1981

Amiloride-induced changes in digoxin dynamics and kinetics: abolition of digoxin-induced inotropism with amiloride.

Digoxin dynamics and kinetics were studied in six healthy subjects with and without amiloride. Amiloride increased mean renal digoxin clearance from 1.3 to 2.4 ml . kg-1 . min-1 (p less than 0.001) due to increased tubular secretion of digoxin, while the glomerular filtration rate was unchanged. This might be caused by an increase in intracellular potassium concentration in the tubular cells provoked by amiloride. In contrast, the extrarenal clearance of digoxin was almost blocked by amiloride; it fell from a mean of 2.1 to 0.2 ml . kg-1 . min-1 (p less than 0.025). Total body clearance tended to fall, but the decrease was not statistically significant. EValuation of myocardial contractility by systolic time intervals revealed a concentration-response relationship between digoxin and changes in preejection period index when digoxin was given alone (rs = 0.750, p less than 0.001). Pretreatment with amiloride abolished this relationship (rs = 0.307, p = NS). Blood pressure and echocardiographically determined left ventricular end-diastolic diameter measurements indicated no changes in the left ventricular post- and preload. It is concluded that amiloride suppressed digoxin-induced inotropism.

Adult↗