Search PubMed⌕ Search

Biomedical subjects

T Meinertz

Publications and source records attributed to T Meinertz.

At least 289 records · Page 16Linked to original sources
PubMed1987

[Relation between spontaneous and electrically inducible ventricular arrhythmias in patients with coronary heart disease].

In a prospective study, 267 patients with invasively diagnosed coronary artery disease were studied by programmed electrical stimulation (PES) and induced ventricular arrhythmias were compared to spontaneous arrhythmias occurring during 24 h Holter registration. In 89 patients (33%) no evidence of myocardial infarction was present, 61 patients (23%) were studied for 6 weeks to 3 months, 36 patients (13%) for 3-6 months and 81 patients (31%) for more than 6 months after myocardial infarction. PES was performed in the right ventricular apex with 1 and 2 extrastimuli during pacing with 100, 120 and 140 beats/min. Endpoint of the study was defined by the induction of 4 repetitive ventricular responses (RVR). Within 72 hours after PES a 24 h Holter registration was performed in all patients. During PES, 15 patients (6%) were not inducible for any RVR. Single RVR (1-2) were induced in 146 patients (55%) and 3-5 RVR in 68 patients (25%). Ventricular tachycardia and ventricular fibrillation were induced in 38 patients (14%); 6 patients showed a sustained, monomorphic tachycardia. Altogether, the incidence of RVR was higher when a history of myocardial infarction was present. With increasing time after infarction the incidence of inducible 3-5 RVR remained stable; however, the number of greater than 6 RVR decreased. During Holter registration, 54/255 patients (21%) showed no spontaneous ventricular arrhythmias, 70 patients (28%) had arrhythmias of Lown-class I/II, 84 patients (33%) of Lown-class III. Complex arrhythmias were observed in 47 patients (18%) (Lown-class IVA: 33 patients, IVB: 14 patients).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1987

[Anti-arrhythmia effectiveness and tolerance of retard in comparison with standard mexiletine].

In a controlled randomized cross-over trial, 21 patients with coronary artery disease and frequent ventricular arrhythmias were studied to test the efficacy and tolerance of mexiletine 200 mg t.i.d. in comparison to a released application form of mexiletine perlongettes 360 mg b.i.d. During 24-hour Holter monitoring, all patients but one showed more than 30 ventricular premature beats/h; additionally, in 16 patients, complex ventricular arrhythmias (Lown class IV) were documented. In all patients each medication was given for 5 days. Before treatment and during both medication periods, a 4 days' wash-out period was interposed. Mexiletine and mexiletine perlongettes each resulted in a suppression of ventricular ectopy of more than 84% in 10/21 patients (47%); in two patients the response was different. The mean reduction rate in all patients was 68% for mexiletine and 64% for mexiletine perlongettes. In the responder group, the mean reduction rate amounted to 95% under both medications. Ventricular pairs and tachycardia were reduced by more than 90%. Plasma concentration under mexiletine perlongettes was slightly higher, as compared to the standard form of mexiletine; however, under mexiletine, significant changes of plasma concentration were observed during the day only when the standard form was used. Side effects were observed in 8/21 patients (38% for mexiletine) and in 5/21 patients (24% for mexiletine perlongettes). These were mainly gastrointestinal or neurological, but were mild in all patients and did not necessitate discontinuation of the medication in any patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Physical training, vegetative regulation, and cardiac hypertrophy.

Dynamic physical training leads to functional and structural adaptations in the cardiovascular system. Functional changes, such as bradycardia, occur after only relatively little training and in advance of structural changes. They are the result of elevated parasympathetic tone at rest and reduced sympathetic activity in the submaximal range. Sympathetic activity cannot be correlated only with the plasma catecholamine level because the affinity and density of the beta-receptors and alpha receptors are influenced by training. In humans, endurance training appears to result in an elevation in beta 2-receptors and a decrease in alpha 2 receptors; the results of animal experiments are discrepant. Conformant, however, is the increased responsiveness of the myocardium to isoproterenol with respect to the mechanical response. Independent of this, other changes at the membrane level must be discussed since the intrinsic heart frequency is reduced in athletic individuals following autonomic blockade, even before hypertrophy can be observed. The functional changes remain intact or intensify when cardiac hypertrophy is induced by increased training. The maximum values for training-induced hypertrophy [left ventricular muscle mass (LVM) = 3.5 g/kg] are about 70-80% of the baseline weights (LVM = 2.1 g/kg). The left ventricle is enlarged during end diastole and end systole, the ejection fraction is normal, and the stroke volume is increased. The mass/volume ratio remains constant (LV = 1.2 g/ml), as does the maximum systolic wall stress (196 x 10 dyn/cm). Compared with pathological forms of hypertrophy and to the normal heart, the trained heart is capable of increasing the stroke volume considerably with exercise and maintaining the increase to a high-frequency range.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗
PubMed1987

The sliding rail system (monorail): description of a new technique for intravascular instrumentation and its application to coronary angioplasty.

The sliding rail technique is a new technique for intravascular instrumentation, especially coronary stenosis dilatation. The so-called monorail balloon catheter is the first device which can be used according to this technique. The monorail catheter has a single lumen shaft and only a short central tube within the distal balloon part. With the guidewire inserted into the tube, the balloon can be advanced or retracted on the guidewire as on a sliding rail. The most relevant improvements for coronary dilatation are steerability, contrast flow and rapid and easy exchangeability of balloon catheters and other intracoronary devices. These characteristics are felt to result in a more simple and time- and fluoroscopy-saving dilatation procedure. A special transfusion catheter may also improve procedural safety. The first clinical results in 69 patients with a success rate of 96%, an emergency bypass rate of two patients (one infarction) and a stenosis improvement of 58% confirm the theoretically conceived advantages.

Adult↗
PubMed1987

[Relation between hemodynamics and ventricular arrhythmia in patients with heart valve diseases].

The incidence and severity of ventricular arrhythmias were compared with hemodynamic findings of cardiac catheterization, in 160 patients with mitral and aortic valve disease. All patients underwent right and left heart catheterization, as well as M-mode and 2D-echocardiography, and 24-hour ambulatory electrocardiographic monitoring. Out of 160 patients, 68 had mitral valve disease and 92 had aortic valve disease. In mitral regurgitation the degree and frequency of ventricular arrhythmias showed a positive correlation to the degree of regurgitation (rs = 0.44, rs = 0.56, respectively) and a negative correlation to left ventricular ejection fraction (rs = -0.49, rs = -0.57) and to cardiac index (rs = 0.48, rs = 0.53). In aortic valve disease the incidence and severity of ventricular arrhythmias were not related to the type of valve lesion, to the transvalvular pressure gradient nor to the degree of regurgitation. In aortic stenosis, the degree of arrhythmia showed a negative correlation to left ventricular ejection fraction (rs = 0.55) and a positive correlation to left ventricular endsystolic volume index (rs = 0.40) and to peak systolic left ventricular wall stress (rs = 0.59). In aortic regurgitation the number of ventricular arrhythmias showed a negative correlation to left ventricular ejection fraction (rs = -0.43) and a positive correlation to left ventricular endsystolic volume index (rs = 0.43) and to peak systolic left ventricular wall stress (rs = 0.37). These data demonstrate that the incidence and severity of ventricular arrhythmias, in patients with aortic valve disease and mitral regurgitation, are strongly associated with the impairment of left ventricular function.

Adult↗
PubMed1986

Coronary thrombolysis during acute myocardial infarction by intravenous BRL 26921, a new anisoylated plasminogen-streptokinase activator complex.

The safety and fibrinolytic efficacy of a new anisoylated plasminogen-streptokinase activator complex (APSAC) was tested in 50 patients with acute myocardial infarction (AMI) less than 4 hours in duration. APSAC (30 mg) was given intravenously as a bolus injection 151 +/- 47 minutes after clinical symptoms. Coronary angiography was then performed to assess coronary artery patency: 28 patients had an inferior AMI and 22 an anterior AMI. A patent infarct-related artery was found in 32 patients (64%) on first coronary angiography 66 +/- 21 minutes after administration of APSAC. Subsequent reperfusion was observed in 10 patients after 74 +/- 16 minutes (84%). Bleeding complications or hematomas were observed in 18 patients, of whom 3 required blood transfusions. Marked hypofibrinogenemia was observed within 24 hours in most patients. A control coronary angiogram was recorded in 37 patients (74%) after 25 +/- 19 days and showed reocclusion in 5 patients.

Adult↗
PubMed1986

[Thrombolytic therapy and balloon dilatation. The effect on infarct time, reperfusion and reocclusion].

127 patients, admitted within six hours of onset of symptoms of acute transmural myocardial infarction, received at first 250 000 U streptokinase intravenously over 20 min, followed by an intracoronary infusion of 250 000 U after coronary angiographic demonstration of the infarct vessel. Those in whom the infarct vessel was closed were randomized into two groups. An attempt at recanalization was made either by thrombolysis alone, through a specially developed 3F catheter (group I, 64 patients), or by thrombolysis and dilatation with 4F Grüntzig balloon catheter (group II, 63 patients). There was no significant difference between the two groups with regard to sex, age, infarct site, creatine-kinase level and interval between onset of symptoms and treatment. Re-perfusion rate for group I was 92% (59 patients), for group II 89% (56 patients). Re-occlusion during the hospital stay occurred in 10 of 59 patients in group I, in 9 of 55 in group II. Re-occlusion occurred in only 8% (3 patients) after successful dilatation, but in 35% (6 patients) after failed dilatation. In the subsequent six months further occlusions were observed in seven group I and two group II patients. Combined drug-mechanical recanalization thus increased the re-perfusion rate, shortened the infarction time and made possible full revascularization by subsequent dilatation which led to a reduction in the re-occlusion rate.

Aged↗
PubMed1986

Intravenous fibrinolytic therapy of acute myocardial infarction: new perspectives from plasminogen activators?

The early treatment of acute myocardial infarction has changed rapidly in recent years. Given the fact that an occlusive coronary thrombus can be found in most infarct patients within 4 h after clinical symptoms, the idea of instituting medical or mechanical recanalization of the occluded vessel is intriguing. However, invasive measures are time consuming, expensive and not freely available to a great number of patients. Thus, only i.v. fibrinolytic therapy of acute myocardial infarction will gain wider application in the near future. Several concepts have been worked out, one of which uses a high-dosage streptokinase or urokinase regimen. A different therapeutic alternative has been made possible by the development of selective fibrinolytic substances, such as the tissue-type plasminogen activator (t-PA) or the anisoylated plasminogen-streptokinase activator complex (APSAC). Preliminary clinical data have shown that the coronary artery patency rate achieved after i.v. administration of t-PA or APSAC is higher than that after conventional treatment with streptokinase or urokinase. The incidence of severe bleeding complications is low and comparable in these studies. However, until myocardial salvage has been demonstrated with early i.v. fibrinolytic therapy in acute myocardial infarction in a placebo-controlled randomized trial, this therapeutic concept will still be unsettled.

Anistreplase↗
PubMed1986

Echocardiographic findings in patients with proved pulmonary embolism.

Echocardiographic studies were performed in 105 patients with acute and recurrent pulmonary emboli. Pulmonary embolism was confirmed by pulmonary angiography (n = 48), autopsy (n = 6), and lung perfusion scintigraphy (n = 51). Seventy of 93 patients (75%) displayed a dilated right ventricle, 38 of 91 patients (42%) had reduced left ventricular cavity dimension, 41 of 82 patients (50%) had a decreased EF slope of the mitral valve, and 78 of 101 patients (77%) showed dilatation of the right pulmonary artery. The motion of the interventricular septum was abnormal in 41 of 93 patients (44%). Right-sided thrombi were seen in 13 patients within the right pulmonary artery (n = 11) and in the right ventricle (n = 3); in one patient they were found in the superior vena cava, in the innominate vein, and the right atrium. Two patients suffered from right-sided endocarditis. Thus echocardiographic changes were frequently found in patients with proved pulmonary emboli. The echocardiographic findings of right-sided cardiac and pulmonary artery abnormalities indicate hemodynamically active pulmonary emboli.

Acute Disease↗
PubMed1986

Methods for non-invasive detection of ventricular late potentials--a comparative multicenter study.

To evaluate the methodological problems of the non-invasive registration of late potentials the results obtained with four different averaging devices in the same 109 patients were compared. The high-resolution ECG was obtained from the body surface, high-gain amplified and filtered. With the averaging technique, the improved signal-to-noise ratio was able to detect low-amplitude cardiac activity. The incidence of late potentials detected with the four averaging systems, whose characteristics are described, ranged between 12% and 21%. Corresponding positive results were obtained in 5.5%, corresponding negative results in 68.8%. The reasons for differing results were mainly due to differences in visual or automatic interpretation of the registered fractionated electrical cardiac activity. Additionally, the determination of the end of QRS using the QRS width, obtained from reference leads, may influence the specificity of the methods.

Cardiac Complexes, Premature↗
PubMed1986

[Combined use of thrombolysis and PTCA in myocardial infarct. Effect on global and regional ventricular function].

The study was performed to evaluate the combined effect of thrombolysis therapy and percutaneous coronary transluminal angioplasty (PTCA) on global and regional left ventricular function. In 127 patients with acute transmural myocardial infarction combined intravenous (250 000 U) and intracoronary (50 000 U) streptokinase therapy was started. When the infarct related vessel was occluded mechanical recanalization was performed with recanalization by Gruentzig balloon catheters. Patients were randomized in two groups, group I, n = 64, thrombolysis without PTCA; group II, n = 63, thrombolysis with PTCA. Both groups demonstrated no difference in relation to sex, age, infarct location, as well as CPK levels and time between onset of symptoms and start of treatment. First coronary angiography showed an open vessel in 23/64 patients (36%) of group I and in 12/63 patients (19%) of group II (p less than 0.001). Mechanical recanalization with 3 F catheters could be achieved in 27/41 patients (66%) of group I and with 4 F catheters in 26/51 patients (51%) of group II. In 9/41 patients (22%) of group I and in 18/51 patients (35%) in group II reperfusion took place before mechanical recanalization could be performed or occurred during superselective thrombolysis therapy, when mechanical recanalization failed. Thus, reperfusion rate in group I was 59/64 patients (92%) and in group II 56/63 patients (89%). PTCA was attempted in 55/56 patients in group II with a success rate of 65% and reocclusion rate of 4%. During hospital stay, reocclusion occurred in 10/59 patients in group I (17%) and in group II in 9/55 patients (16%). The patients were divided in those with and without successful angioplasty. Reocclusion was found in 3/36 patients (8%) and 6/17 patients (35%), respectively. Improvement with PTCA of regional and global left ventricular function was observed in patients with anterior myocardial infarction. With combined medical-mechanical recanalization, reperfusion rate can be increased and infarct time shortened, thus, providing the possibility of full revascularization by PTCA, improving coronary blood flow as well as improving global and regional left ventricular function.

Angioplasty, Balloon↗
PubMed1986

The serum selenium concentration of patients with acute myocardial infarction.

Serum selenium concentration was determined in 49 patients with acute myocardial infarction within 4 hours after the beginning of the symptoms. The mean serum selenium concentration of the patients was significantly lower than that of healthy controls (55 +/- 15 micrograms/l vs. 78 +/- 11 micrograms/l). Among the 49 patients with acute myocardial infarction 20 (41%) had serum selenium concentration below the 95% percentile of the healthy control group. It is concluded that the low serum selenium concentration was present in these patients before the acute event and was not a consequence of the myocardial infarction. No relationship was found in this study between the serum selenium concentration and the severity of myocardial infarction if the number of coronary vessels occluded is taken as the criterion of severity. Serum selenium concentration was similar in patients with 1 or more coronary vessels occluded. Patients with anterior or posterior myocardial infarction had similar serum selenium concentrations. A positive correlation was observed between serum selenium concentration and total serum creatine kinase (CK) activity and serum myoglobin (MB). The serum selenium concentration correlated negatively with the ratio CK-MB/total CK activity, which can be interpreted as minor injury of mitochondria during infarction in patients with normal serum selenium concentration.

Aged↗
PubMed1986

[Diagnosis of thoracic aortic aneurysms and dissections using transesophageal echocardiography].

Transesophageal echocardiography was performed in 25 patients with the clinical suspicion of an aneurysm or dissection of the thoracic aorta. The results obtained were compared to those of conventional transthoracic echocardiography. An aortic dissection was found in 11 patients, an aortic aneurysm in 9 patients, and an aneurysm of the left subclavian artery, an abscess of the aortic ring and a perforated aortic sinus in one patient each. In 2 patients no abnormalities of the thoracic aorta could be found. The intimal flap was detected in 11 patients with transesophageal imaging and in 9 patients with the transthoracic approach. Aortic dissection was suspected in another 5 patients with transthoracic echocardiography which could be excluded by transesophageal echocardiography. In 13 patients (52%) imaging of the descending thoracic aorta was not possible with transthoracic echocardiography but in all patients it was possible from the transesophageal approach. Transesophageal echocardiography seems to be a useful diagnostic approach when diseases of the thoracic aorta were clinically suspected.

Abscess↗