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Biomedical subjects

L Seipel

Publications and source records attributed to L Seipel.

At least 199 records · Page 11Linked to original sources
PubMed1982

[Clinical-electrophysiological findings in patients following ventricular fibrillation].

30 patients, successfully resuscitated from ventricular fibrillation outside acute myocardial infarction, were studied by programmed right-ventricular stimulation. The stimulation studies were carried out one week up to 1.5 years after the event (median two months). Mean age of the patients was 50.2 +/- 8.8 years, 27 were male. The majority of patients had coronary heart disease and/or localized or diffuse ventricular contraction abnormalities. In 26 patients the stimulation protocol included the application of premature single and double ventricular stimuli during sinus rhythm and a paced ventricular rhythm at cycle lengths of 500, 430, 370 and 330 msec until ventricular tachycardia, ventricular flutter or ventricular fibrillation were induced. 4 patients were studied only at a cycle length of 500 msec. Using this stimulation protocol, in 7 patients (26.9%) sustained ventricular tachycardia, in 5 patients (19.2%) ventricular flutter and in 7 patients (26.9%) ventricular fibrillation were induced. These arrhythmias were induced at a basic cycle length of 500 ms in 10 patients, at 430 ms in 3 patients, at 370 ms in 4 patients and at 330 ms in 2 patients. In the remaining patients, only ventricular echo beats (one to six) of the intra-ventricular reentry type were induced. Thus these results show a persistent increase in ventricular vulnerability in a high percentage of patients (73%), provided that appropriate stimulation techniques are used. These observations may have great importance for the management of these patients.

Arrhythmias, Cardiac↗
PubMed1982

[The effect of disopyramide, mexiletine and propafenon after intravenous and oral administration on left ventricular function in the M-mode echocardiogram].

The effects of the antiarrhythmic drugs disopyramide (D), mexiletine (M), and propafenone (P) on left ventricular function after intravenous injection and after oral therapy of at least 48 hours, and of the combined oral application of D and M, were studied by M-mode echocardiography in patients with ventricular arrhythmias in whom antiarrhythmic therapy was indicated. The drugs were given in doses comparable in terms of clinical efficacy. The results showed that the three drugs had varying negative inotropic power. The intravenous injection resulted in a more pronounced cardiac depression than the oral therapy. The most significant decrease in left ventricular wall motion after intravenous and oral application was seen after D, the smallest negative inotropic effect after M. P caused a cardiac depression between these extremes. After the combined oral application of D and M the impairment of left ventricular function was more pronounced than after therapy with the single drugs.

Administration, Oral↗
PubMed1981

Preliminary clinical and hemodynamic results after mitral valve replacement using St. Jude Medical prostheses in comparison with the Björk-Shiley valve.

The clinical improvement and the hemodynamic performance at rest and during bicycle exercise in 12 patients one year after St. Jude Medical mitral valve (SJMM) replacement were compared to the results of 40 patients after Björk-Shiley mitral valve (BSM) implantation. In both groups subjective and functional improvement was significant. In the SJMM-group no thromboembolic event had occurred, while 5 patients suffered from embolism during the first postoperative year after BSM (12.5%). Hemolysis was significantly lower in BSM but remained subclinical in SJMM. This may be explained by a premature backward movement of the posterior leaflet of the SJMM-prosthesis in late diastole resulting in a change of flow pattern. Low resistance to blood flow in the SJMM-prosthesis could be verified by a smaller diastolic transvalvular gradient (SJMM: 2.8 +/- 1.1; BSM: 5.3 +/- 2.6 mmHg). In valves with equal tissue annulus diameters (29 mm) the calculated effective valve orifices were significantly different (SJMM: 2.83 +/- 1.3 cm2; BSM: 1.85 +/- 0.53 cm2). In both groups the mean pulmonary artery pressure was significantly reduced at the time of reinvestigation but increased under exercise. Durability may become a problem because of the 2 moving parts of SJMM but until now we have observed no malfunction. St. Jude Medical mitral valve seems to be a good alternative in heart valve replacement with prostheses of small sizes, both for the mitral and tricuspid valve.

Adolescent↗
PubMed1981

[Bundle of His extrasystoles as a cause for A-V block and junctional tachycardia (author's transl)].

The electrophysiological findings in two cases with premature beats arising from the bundle of His are presented. In the first case, the nonconducted impulses led to a functional first and second degree A-V block of the following sinus beats due to retrograde concealed conduction. In addition, very early premature beats from the bundle of His were conducted retrogradely to the atrium simulating blocked premature atrial beats. In the second patient, the premature beats appeared as bigeminy after each sinus beat. As the sinus beats and the extrasystoles from the bundle of His showed a left bundle branch block pattern, a ventricular tachycardia was suspected from the findings in the surface ECG. The reported cases demonstrate the clinical value of the His bundle electrography in patients with bradycardic and tachycardic rhythm disturbances.

Adult↗
PubMed1981

[Atrial arrhythmias after surgical repair of an atrial septal defect (secundum-type). Six years follow-up in adults (author's transl)].

Atrial arrhythmias before and after repair of an atrial septal defect (secundum-type) were analyzed in 100 patients. The mean postoperative follow-up was 5.8 years, the mean age at the last check-up was 33.4 years. Preoperatively, 10 patients showed atrial arrhythmias (6 pts atrial flutter or fibrillation [AF], 3 pts sinus node [SN] dysfunction, 1 pt atrial tachycardia). About 6 years after operation, 29 patients showed atrial arrhythmias (16 pts AF, 10 pts SN dysfunction, 3 pts atrial tachycardias). The 26 patients with AF and SN dysfunction were 10 years older and had a 3 years longer follow-up period postoperatively than those with sinus rhythm. In addition, they had a higher pulmonary artery pressure preoperatively. Especially the occurrence of AF after operation was strongly related to the age and the pulmonary artery pressure. All other factors had no significance. The data show that closure of an atrial septal defect cannot prevent the occurrence of AF in the following period. In addition, SN dysfunction is found postoperatively in a significant number of patients probably due to the intraoperative injury to the sinus node. However, it cannot be excluded that the unfavorable results may in part be due to the selection of the patients.

Adolescent↗
PubMed1981

[Non-invasive recording of late ventricular potentials--methodology and first clinical experiences (author's transl)].

Late potentials occurring after the QRS complex were searched for from the body surface using high-gain amplification and signal-averaging techniques with filter settings between 100 and 300 hz at a sampling rate of 10 khz. The number of repetitions of the averaging process ranged between 150 and 300. 52 patients were studied. In 11 control subjects, no late potentials were detected within the ST segment. Late potentials were observed in 3/27 patients without previously documented ventricular tachycardia, all having left ventricular aneurysms. All three patients had evidence of increased ventricular vulnerability (one dying from ventricular tachycardia, one with stimulus-inducible ventricular tachycardia, one with multiple episodes of ventricular fibrillation after surgery). In patients with previously documented ventricular tachycardia and/or fibrillation, late potentials occurred in 7/14 cases (50%), mainly in those with aneurysms (6/8 pts = 75%). Mean onset of late potentials after the QRS complex was 38 +/- 20.1 ms, mean amplitude was 3.9 +/- 2.0 uV, and mean duration was 17.1 +/- 5.4 ms. We conclude that late potentials, which represent late depolarization of a mass of ventricular tissue after slow conduction, herald increased susceptibility to ventricular tachycardia mainly in patients with ventricular aneurysms.

Adult↗
PubMed1981

Preliminary results in mitral valve replacement with St. Jude medical prosthesis: comparison with the Björk-Shiley valve.

The clinical improvement and the hemodynamic performance at rest and during bicycle exercise in 22 patients 1 year after implantation of a St. Jude Medical mitral valve (SJMM) were compared with the results of 40 patients after implantation of a Björk-Shiley mitral valve (BSM). In both subjective and functional improvement were significant. In the SJMM group no thromboembolic event occurred, while five patients in the BSM group suffered from embolism during the first year postoperative year (12.5%). Hemolysis was significantly lower in the BSM group but remained subclinical in the SJMM group. This may be explained by a premature backward movement of the posterior leaflet of the SJMM prosthesis in the late diastole, which resulted in a change of flow pattern. Low resistance to blood flow in the SJMM prosthesis could be verified by a small diastolic transvalvular gradient. In valves with equal tissue annulus diameters (29 mm), the calculated effective valve orifices were significantly different (3.07 +/- 1.36 cm2 in SJMM, 1.85 +/- 0.53 cm2 in BSM). In both groups, the mean pulmonary artery pressure was significantly reduced at the time of reinvestigation but increased during exercise. Durability may become a problem because of the two moving parts of SJMM, but we have observed no malfunction. The SJMM appears to be a good alternative in mitral valve replacement.

Adult↗
PubMed1981

[Prognostic significance of ventricular echo beats induced during programmed ventricular stimulation (author's transl)].

To determine the incidence and prognostic significance of the repetitive ventricular response, the present retrospective study was done in 123 patients (75 male, 48 female, mean age +/- S.D. 49 +/- 14 years) with a variety of cardiac rhythm disorders. Programmed right ventricular stimulation was done at a basic pacing rate of 120 b.p.m. using one (S2) and two (S2,S3) premature stimuli. The data were analysed as to the presence ro absence of a repetitive ventricular response and the outcome of the patients ((1) sudden death less than or equal to 1 h or documented ventricular fibrilllation without myocardial infaction without myocardial infarction; (2) survivors or patients dying from non-cardiac or non-suddenly). A repetitive ventricular response was observed in 45/123 patients (36.6%) after one and in 51/120 patients (42.5%) after two premature stimuli. It occurred in 9/9 patients with ventricular fibrilation and in 20/23 patients (87%) with ventricular tachycardia. Mean follow-up period was 84 +/- 37.1 weeks (+/- S.D.). Five patients were lost to follow-up. 17/123 patients were classified as sudden death patients, the remaining patients were regarded as surviving (or dying non-suddenly). After one premature stimulus, a repetitive ventricular response was observed in 34.9% of survivors and in 47.1% of non-survivors (n.s.). After two premature stimuli, the incidence of a repetitive ventricular response increased from 36.8% in survivors to 70.6% in non-survivors (p less than 0.005). 12/106 of patients (11.3%) surviving and 10/17 patients (58.8%) non-surviving had more than three ventricular echo beats (p less than 0.005). All patients non-surviving who demonstrated a repetitive ventricular response has intraventricular reentry. Depending on the regidity of the criteria used (i.e. number of echo beats), the sensitivity of the test ranged between 47 to 88%, whereas the specificity ranged between 44 to 94%. The number of false-positives was high (43 to 80%); however, the number of false-negatives was low (4 to 8%). Concluding, this retrospective study has shown a correlation between sudden death and the incidence and number of repetitive ventricular response (depending on the number of premature stimuli) and the type of reentrant beats (bundle branch reentry or intraventricular reentry).

Adult↗
PubMed1981

[Electrophysiological effects of the new antiarrhythmic drug flecainide (R 818) in man (author's transl)].

The electrophysiological effects of the new antiarrhythmic drug Flecainide (R 818) was tested in altogether 27 patients with and without disturbances of sinus node function and intraventricular conduction. Flecainide was given intravenously in a dose of 1 mg/kg and 2 mg/kg. Constant "therapeutic" plasma levels were reached by application of 1 mg/kg as a bolus and an additional infusion of 1 mg/kg during the test period of 20 min. The drug had no significant effects on sinus node function even in patients with sinus node dysfunction tested so far. Intracardiac conduction time was prolonged within all compartments of the heart in a dose-dependent manner. After bolus injection of 1 mg/kg, the HRA-A interval lengthened by 10.4%, the A-H interval by 13.5%, the H-V time by 15.7% and the V-RVA interval by 29.1% of the control value. In addition, the QRS complex widened by 8.1%. After 2 mg/kg Flecainide the HRA-A interval was prolonged by 9.0%, the A-H interval by 24.4%, the H-V time by 40.2%, and the V-RVA interval by 16.5% of the control value. The QRS complex widened by 24.2%. In contrast, there was only a small and often insignificant increase in the refractoriness of the different compartments of the heart (5-15% increase of the control value). In two patients with bundle branch block, a higher degree A-V block distal the H potential occurred after 2 mg/kg Flecainide. These electrophysiological effects may explain some antiarrhythmic actions of Flecainide. In addition, possible side effects of the drug can be assessed. In patients with intraventricular conduction defects the drug should be used with caution especially when given iv in higher doses.

Adult↗
PubMed1981

[Clinical-electrophysiological study of the effect of lorcainide on induction of ventricular tachycardia (author's transl)].

11 patients (mean age 52 +/- 16.3 years) with recurrent ventricular tachycardia (VT), in whom VT could be initiated by programmed ventricular stimulation, were studied before and after lorcainide, a new antiarrhythmic agent. Lorcainide was either injected intravenously at a dose of 2 mg/kg within five to ten minutes (n = 3) or infused at a rate of 0.1 mg/kg/min up to the same total dose. After intravenous administration, there was no change in inducibility of VT in three patients, whereas in seven patients VT was either more difficult to induce requiring two instead of one premature beat (n = 2) or a higher rate of basic pacing (n = 2) or VT was no longer inducible (n = 3). In one case, VT was easier to induce. In patients with still inducible VT, the rate of VT decreased from 220 +/- 33 b.p.m. to 186 +/- 49.1 b.p.m. (non-significant). The echo zone for initiation of VT did not show any consistent change. The coupling interval between the last stimulated complex and the first beat of VT increased from 327 +/- 66.8 ms to 390 +/- 98.6 ms (p less than 0.05). The effective refractory period of the right ventricle increased slightly though not significantly. In three cases paradoxical side effects, probably due to lorcainide, were observed. The blood level of lorcainide at the end of injection or infusion immediately before right ventricular stimulation was 0.69 +/- 0.48 micrograms/ml (range 0.11 to 1.74 micrograms/ml). No N-dealkylated metabolite of lorcainide was detected after intravenous injection. Thus far, lorcainide is effective in preventing initiation of VT in some patients making it more difficult to induce in others. However, long-term efficacy and tolerance to the drug cannot be predicted from the data of this study though the data suggest that the drug might be effective on the long-term run against ventricular tachyarrhythmias.

Benzeneacetamides↗