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Biomedical subjects

M Pfisterer

Publications and source records attributed to M Pfisterer.

At least 163 records · Page 9Linked to original sources
PubMed1984

Hepatitis A-virus in cell culture. IV. Comparison of cell-culture-produced HAV with stool-derived HAV in diagnostic test systems.

Hepatitis A-virus produced in Frhk-4/R cells is used and compared with stool-derived HAV as an antigen in diagnostic test systems. It is shown that the two antigens react identically in the anti-HAV test with anti-HAV-IgG positive human sera. In the anti-HAV-IgM test, too, stool-derived HAV and cell-culture-produced HAV react very similarly. The titres of anti-HAV-IgG and anti-HAV-IgM positive sera, obtained with stool and cell-culture HAV in quantitative antibody determinations, are shown to be identical. It is shown that the problem of HAV antigen production can now be solved by propagation of HAV with Frhk-4/R cells and that this antigen is very useful in diagnostic test systems.

Animals↗
PubMed1984

Persisting symptoms despite permanent pacing. Incidence, causes, and follow-up.

Persisting symptoms, consisting of palpitations, dizziness, or syncope, were found in 49 of 570 consecutively followed patients (8.6 percent) with permanent pacemakers (PM). Among 540 patients with ventricular PM, 19 had syncope and 24 dizziness; among 30 patients with dual-chamber PM, five had palpitations and one dizziness. Symptoms were PM-related in 17, caused by tachyarrhythmias in 12, of noncardiac origin in 16, and of unknown origin in four patients. Holter monitoring was necessary for evaluating the persisting symptoms in 36 patients and helpful in 32 studies (89 percent). Symptoms were relieved in all patients with PM-related causes but only in 6/16 patients (38 percent) with syncope or dizziness of noncardiac origin despite various therapeutic measures. In patients with either documented tachyarrhythmias or unknown cause of syncope or dizziness, antiarrhythmic drugs led to symptomatic improvement in 11 of 12 treated patients during an average follow-up of 15 months. We concluded that: (1) persistent syncope, dizziness, or palpitations occurred in 8.6 percent of 570 patients after PM-implantation; (2) symptoms were more frequent but less severe in patients with dual-chamber PM than in those with ventricular PM; (3) tachyarrhythmias as a possible cause of symptoms were found in 25 percent of patients; (4) symptomatic improvement was noted in 28 of 29 patients when a PM-related cause or tachyarrhythmias were treated.

Adult↗
PubMed1984

Antianginal drug effects on normal, ischemic and scar myocardial segments in man.

In order to assess acute effects of nitroglycerin, nifedipine and metoprolol on normal, ischemic and scar myocardial segments in man, non-invasive hemodynamic and radionuclide measurements of left ventricular function were performed. Sixteen patients with single left anterior descending (LAD) disease were studied at rest and during exercise: 9 patients with angina and exercise-induced ischemia (LAD stenosis) and 7 patients with previous transmural myocardial infarction and no ischemic changes at thallium imaging (LAD occlusion). Effects on regional ejection fraction were compared between involved antero-septal and normal postero-lateral areas. Global ejection fraction at rest was unchanged after nitroglycerin, increased after nifedipine and decreased after metoprolol. In patients with ischemia, improvement in exercise ejection fraction after all drugs was due to increased regional ejection fraction in ischemic segments, i.e. a real anti-ischemic effect could be demonstrated. In regions of myocardial scar, regional ejections fraction was not changed after either drug. In normal areas, regional ejection fraction remained unchanged after nitroglycerin and nifedipine but decreased after acute beta-blockade. Despite the very similar anti-ischemic effects of all drugs, underlying hemodynamic mechanisms were quite different: Reduction in preload and afterload after nitroglycerin, vasodilatation and reflex sympathetic activity after nifedipine and reduction in double product and contractility after metoprolol. Thus, the mode of action of nitroglycerin, nifedipine and metoprolol on normal, ischemic and scar myocardial segments could be demonstrated in man. Non-invasive antianginal drug testing as shown in this study should allow optimal medical therapy for patients with chronic ischemic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Clinical evaluation of the St. Jude Medical heart valve prosthesis. A two-year follow-up of 150 patients.

To evaluate the clinical performance of the St Jude Medical bileaflet heart valve prosthesis, we followed 150 consecutive patients (95 male and 55 female patients, mean age 54 years, range 1 to 74 years) for an average of 24 months. These included 74 patients with aortic, 56 patients with mitral, and 20 patients with multiple valve replacement. During the 2 year follow-up, there were a total of four perioperative and seven late deaths, two of which were prosthesis related. Reoperation was necessary in four patients, because of paravalvular leaks in two patients with mitral and one patient with aortic prostheses and because of leaflet dislodgment in one patient with a mitral prosthesis, a postoperative complication that has not been reported previously. The thromboembolic rate per 100 patient-years was 2.6 in aortic and 2.9 in mitral valve replacement, the symptoms being reversible in all patients. All patients were receiving anticoagulant therapy. A total of four complications of anticoagulant therapy (three minor and one fatal) were observed. Significant hemolysis was observed in none of the patients. In patients with dyspnea, the New York Heart Association functional classification was 2.7 +/- 0.8 preoperatively versus 1.3 +/- 0.6 postoperatively. In patients with angina, it was 2.6 +/- 0.6 preoperatively versus 1.03 +/- 0.2 postoperatively. Noninvasive Doppler measurements revealed excellent flow characteristics, values being close to those obtained in natural valves (mean +/- standard deviation of maximal flow velocity: 1.5 +/- 0.5 versus 0.9 +/- 0.1 m/sec in the aortic position; 1.1 +/- 0.3 versus 0.8 +/- 0.3 m/sec in the mitral position).

Adolescent↗
PubMed1984

[Enzymatic and scintigraphic determined infarct size: significance for left ventricular function following infarct].

In a prospective study, the relationship between extent and location of myocardial infarction and the resulting left ventricular dysfunction was assessed and the question asked, how well these parameters may be assessed non-invasively a few weeks after the acute event. One hundred and fifty survivors of a first myocardial infarction were studied in the acute stage by serial ECG and CPK recordings and 5 weeks later by thallium201-(Tl)-scintigraphy and radionuclide angiocardiography. Myocardial damage was assessed enzymatically (maximal CPK; CPKmax) in the acute phase and scintigraphically in the subacute phase using a Tl-score considering extent (in percent of total myocardium in each projection) and severity (decrease in thallium-uptake) of scintigraphic infarct defects. There were significant correlations between Tl-score and max. CPK (r = .69) as well as between Tl-score and left ventricular ejection fraction (LVEF) (r = .65; p less than .001 each), but this correlation was better for subgroups with anterior vs. inferior infarctions (r = -.68 vs. r = -.59; p less than or equal to .001 for each). Furthermore, LVEF could be predicted based on the Tl-score: 88% of patients with values less than 7 had an LVEF of greater than 45%, whereas 77% of patients with a thallium-score of more than 12 had an LVEF less than 45%. Reproducibility of the Tl-score assessed in 30 patients over 3 months was excellent (r = .96) with low variability between the two analyses (+/- 1.5). Thus, after a first myocardial infarction, a direct relationship between enzymatically and scintigraphically, assessed infarct size and LVEF could be demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Ambulatory evaluation of patients with suspected coronary heart disease].

With the introduction of myocardial perfusion scintigraphy with thallium-201, and of radionuclide angiocardiography, patients with suspected coronary artery disease can be evaluated on an out-patient basis. Indications, diagnostic value and limitations of these non-invasive diagnostic procedures are discussed and compared with other non-invasive methods in cardiology. Based on long experience, a new plan for diagnostic workup of patients with suspected coronary artery disease is presented as a guideline for daily practice in optimizing the use of the various non-invasive and invasive procedures.

Adult↗
PubMed1984

[Incidence and extent of right ventricular functional disorders following the 1st myocardial infarction].

A series of 63 patients were studied by gated radionuclide angiocardiography 51/2 weeks after their first acute myocardial infarction. Left (LVEF) and right (RVEF) ventricular ejection fraction were assessed in three groups of patients: 12 patients with transmural anterior infarctions, 35 patients with transmural inferior infarctions and 16 patients with non-transmural infarctions. LVEF was depressed only in the group of patients with anterior infarctions (34.4 +/- 16.3%) but remained within normal limits in the other two groups. RVEF was reduced in 64% of patients with inferior infarctions; the mean value in this group was 36.3 +/- 10.2% (normal range 48 +/- 8%, p less than 0.02). In the other two groups RVEF was only rarely reduced and the mean values were within normal limits. Regional wall motion abnormalities ( WMA ) were found in 47% of all patients, those localised in the left ventricle matching ECG localisation of necrosis in 86% of cases. Only patients with infarctions of the inferior left ventricular wall were found to have WMA in the right ventricle. Functional signs of ischemia (decrease of RVEF or LVEF during physical exercise) were found in 34% of patients with transmural infarctions and 57% of patients with non-transmural infarctions. Radionuclide angiocardiography showed itself a valuable method for assessing persistent dysfunction after acute myocardial infarction not only of the left but also of the right ventricle, a phenomenon not easily detected clinically.

Female↗
PubMed1983

[Asymptomatic ischemia following myocardial infarct].

To assess the incidence of silent ischemia after myocardial infarction, a prospective series of 100 consecutive patients was studied 5 weeks after the acute event. Objective evaluation of myocardial ischemia included a 9-lead ECG, thallium-201 scintigraphy and radionuclide ventriculography, each at rest and during symptom-limited bicycle ergometry. Diagnostic criteria were ECG: greater than or equal to 1 mm horizontal or downsloping ST depression or greater than or equal to 1 mm ST elevation; thallium scintigraphy: a clearly reversible perfusion defect at rest, detectable only after exercise; radionuclide ventriculography: an exercise-induced decrease in global LVEF greater than or equal to 5% and/or in anyone regional EF greater than or equal to 14%. Presence of ischemia was assumed if at least 2 of 3 objective ischemic signs were found. This was the case in 28 of 100 patients. During exercise, 15 of 100 patients complained of chest pain, but only 8 (54%) had objective evidence of ischemia. Thus, silent ischemia was demonstrated in 20 of 100 patients. The sensitivity of both nuclear cardiology procedures was markedly superior to that of the ECG in diagnosing post-myocardial ischemia.

Coronary Disease↗
PubMed1983

[Re-entry tachycardias: a fragment problem during physiologic heart stimulation].

In a prospective study, reentry tachycardias (RT) due to retrograde VA-conduction were sought in 30 patients after implantation of an atrial synchronous (VDD, DDD) pacemaker (PM) by frequent clinical controls and by 24-hour Holter monitoring. At least one RT was detected in 9/30 patients (in 5 during clinical control, in 4 on Holter monitoring only). 6 patients had symptoms due to RT (6 had palpitations, 1 complained of dizziness and 1 of ischemic heart pain). RTs were initiated by VPBs in 6 patients, by sinus bradycardia in 2 (VDD) and by magnet application in 1. Rates of RT varied from 100 bpm to 128 bpm. RT necessitated reprogramming of the PM in 5 patients (in 3 of them reprogramming to VVI-stimulation). RTs are thus a frequent complication after implantation of an atrial synchronous pacemaker.

Adult↗
PubMed1983

[Atypical and ischemic chest pain more than a year after aortocoronary bypass].

215 consecutive patients were followed up for more than a year (22 +/- 9 months) after aortocoronary bypass. Recurrence of ischaemic (anginal) and atypical chest pain was assessed: 54% of all patients were completely without pain postoperatively, 76% free of angina and 93% improved by at least one NYHA class. The frequency of severe atypical chest pain was similar pre- and postoperatively (11% and 13%, respectively), but nearly double that of postoperatively severe angina (13% vs 7%, P less than 0.05). Limiting atypical chest pains in patients with pre-operative atypical chest pain was much more frequent postoperatively than in patients who pre-operatively had only angina (30% vs 11%, P less than 0.005). These two patient groups did not differ with respect to age, sex, degree of vessels disease, exercise-induced ischaemia or number and patency of bypasses. Thus, exercise-limiting atypical chest pain can influence the surgical results in up to 30% of patients with pre-operative atypical chest pain (with or without typical angina).

Adult↗
PubMed1983

Comparative effects of nitroglycerin, nifedipine and metoprolol on regional left ventricular function in patients with one-vessel coronary disease.

To compare acute effects of nitroglycerin (0.8 mg sublingually), nifedipine (5 ng/kg/min i.v.) and metoprolol (0.15 mg/kg i.v.) on normal, ischemic and scarred myocardial segments in man, we performed simultaneous hemodynamic and radionuclide measurements of left ventricular functions. Sixteen patients with isolated left anterior descending (LAD) disease were studied at rest and during exercise. Nine patients had angina and exercise-induced ischemia (LAD stenosis) and seven patients had previous transmural myocardial infarction and no ischemic changes during thallium imaging (LAD occlusion). The effects of the drugs on regional ejection fraction of the involved anteroseptal region and the normal posterolateral area were compared. Global ejection fraction at rest did not change after nitroglycerin, increased after nifedipine and decreased after metoprolol. In patients with ischemia, the exercise ejection fraction improved after all drugs due to increased regional ejection fraction in ischemic segments: i.e., a regional antiischemic effect evidenced by improved regional function could be demonstrated with all three agents. Regional ejection fraction increased from 35.8 +/- 19.5% to 66.2 +/- 15.2% (+/- SD) after nitroglycerin (p less than 0.001), to 61.7 +/- 8.7% after nifedipine (p less than 0.001), and to 48.4 +/- 7.0% after metoprolol (p less than 0.01). In regions of myocardial scar, regional ejection fraction was not changed after any drug. In normal areas, regional ejection fraction remained unchanged after nitroglycerin and nifedipine, but decreased after metoprolol. Despite similar antiischemic effects of all three drugs, underlying hemodynamic mechanisms were quite different and may provide a rationale for combined forms of treatment. These results may help to select optimal drug combinations to improve myocardial performance in patients with chronic ischemic heart disease.

Adult↗
PubMed1982

Virus capping on mycoplasma cells and its effect on membrane structure.

The capping of mycoplasmavirus L3 on the surface of Acholeplasma laidlawii was investigated. In electron microscope studies we observed a reduced capping after treatment of the host cell with energy-blocking agents. Other drugs inhibiting ligand capping on eucariotic cells had no effect. Changes in membrane structure after virus adsorption were observed spectroscopically using the excimer fluorescence technique. The results are interpreted in terms of a lipid-protein phase separation in connection with virus capping.

Acholeplasma laidlawii↗
PubMed1982

Combined acebutolol/nifedipine therapy in patients with chronic coronary artery disease: additional improvement of ischemia-induced left ventricular dysfunction.

To assess acute hemodynamic effects of combined oral nifedipine (10 mg) and acebutolol (100 mg), 21 patients with angiographically documented coronary artery disease and stable angina pectoris were studied (three groups of seven randomized patients). Simultaneous hemodynamic and equilibrium radionuclide ejection fraction measurements were performed at rest and during exercise before treatment, 1 hour after administration of nifedipine, acebutolol or a combination of the two and again 1 hour after combined nifedipine and acebutolol. At the same exercise level achieved without drugs, angina, subjectively scored by the patients, decreased significantly after nifedipine, acebutolol and a combination of the two in association with a significant improvement in left ventricular ejection fraction (p less than 0.01). There was an additive effect of both drugs on heart rate, systolic blood pressure and therefore the double product (p less than 0.01 each). The negative effects of acute beta receptor blockade on cardiac index, resting ejection fraction and total peripheral resistance were balanced by the vasodilatory action of nifedipine. In patients with borderline heart failure no untoward effects were seen after combined therapy. Thus, acute combined acebutolol/nifedipine therapy in patients with stable angina proved to be hemodynamically superior to therapy with either drug alone and safe even in patients with moderately depressed left ventricular function. This finding provides a basis for appropriately designed long-term studies.

Acebutolol↗
PubMed1982

Prevalence and significance of reversible radionuclide ischemic perfusion defects in symptomatic aortic valve disease patients with or without concomitant coronary disease.

To determine the prevalence and significance of exercise-induced localized perfusion defects in symptomatic patients with aortic valve disease, thallium-201 rest and exercise studies were performed in a consecutive series of 29 such patients prior to left heart catheterization with coronary arteriography. Eight patients had repeat studies after aortic valve replacement. Twelve of 17 patients with predominant aortic regurgitation (AR) had distinct LV apical defects during exercise despite normal coronary arteries, while 10 of 12 patients with aortic valve disease and associated coronary artery disease (CAD) had localized perfusion defects in LV areas other than the apex. In patients with AR, reversible apical perfusion defects can occur without CAD; these apical defects are probably a reflection of severe LV volume overload in AR. LV perfusion defects in areas other than the apex are specific for CAD in aortic valve disease, and concomitant CAD may not provoke regional LV perfusion deficits in aortic stenosis patients with severe LV hypertrophy.

Adult↗