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Biomedical subjects

L Seipel

Publications and source records attributed to L Seipel.

At least 217 records · Page 12Linked to original sources
PubMed1980

Amiodarone.

Explore the source record for details and available documents.

Amiodarone↗
PubMed1980

[Demonstration of retrograde block in a patient with preexcitation syndrome by intraoperative electrophysiological studies (author's transl)].

In a patient with a WPW syndrome, the electrophysiological investigation revealed a left-sided bypass conducting only in antegrade (A-V) direction. During right ventricular stimulation, there was a complete retrograde (V-A) block. Therefore no reentry tachycardia could be initiated. The patient was operated upon because of an aortic valve lesion. During operation the bypass was localized at the free wall of the mitral annulus by epicardial mapping. Even during direct stimulation at the ventricular insertion of the bypass, no retrograde conduction to the left atrium could be demonstrated. After ablation of the bypass by surgery, intra- and postoperative electrophysiological studies showed a normal antegrade activation pattern of the ventricles. The case reported demonstrates that the "heterodromia" of an accessory bypass can markedly influence the clinical setting in the WPW syndrome.

Action Potentials↗
PubMed1980

[Natural history of patients with severe mitral and double-valve disease under medical therapy (author's transl)].

55 patients with mitral valve disease (MV) and 30 patients with combined aortic and mitral valve lesions (DV) class III or IV (NYHA) were followed up to ten years on medical therapy. In all cases valve replacement was indicated but not done for different reasons. The prediction of late survival was analyzed by anamnestic, clinical and hemodynamic variables. The five-years survival rate in MV was 50% (stenosis 57%, incompetence 25%), in DV 28%. Those patients who refused operation had a high survival rate. Functional class IV, cardiothoracic ratio greater than 60%, mean pulmonary artery pressure greater than 30 mm Hg (MV) or greater than 25 mm Hg (DV), pulmonary vascular resistance greater than 400 dyn/s/cm5 (MV) or 300 dyn/s/cm5 (DV) were significantly negative factors influencing the survival curves. In addition, in patients with MV and incomplete right bundle branch block and a PEP/LVET ratio greater than 0.34 calculated from systolic time intervals indicated a serious prognosis. Comparing the survival curves after mitral valve replacement and conservative therapy, it is evident that in mitral and double valve disease class III or IV the operative therapy leads to life prolongation with the exception of mitral stenosis class III.

Adolescent↗
PubMed1980

[A 17-years follow-up study after closed mitral commissurotomy (author's transl)].

410 patients were operated upon by closed mitral commissurotomy in 1961-62. Of this group, 224 patients were followed up until 1978. The actuarial survival rate after 16 to 17 years postoperatively was 58%. Overall 43 patients were reoperated (second commissurotomy or mitral valve replacement). The cumulative reoperation rate of these patients was 1.5% per year. The mortality rate in patients with reoperation was 1.2% per year, without reoperation 2% per year. 87 patients are still alive 17 years after mitral commissurotomy without reoperation. 59% of this group belong to functional class II or I (NYHA). Most of them have combined mitral valve disease with predominant mitral stenosis. Atrial fibrillation was present in 33% (n = 29) preoperatively and in 58% (n = 50) postoperatively at the end of the study. Only 20% of all patients were on anticoagulant therapy. Nevertheless, the total embolic rate (5.7%) and the cumulative embolic rate (0.2% per year) remained low. The good long-term results show that mitral commissurotomy is an effective therapeutic approach in patients with mitral stenosis.

Adolescent↗
PubMed1980

Further evidence for the site of reentry in so-called sinus node reentrant tachycardia in man.

To provide further evidence for the participation of the sinus node in so-called sinus node reentry in man, right atrial stimulation and endocardial mapping were performed in a case with sustained tachycardias which met the commonly accepted criteria for sinus node reentry. In addition to right atrial mapping, the activation of the high left atrium was depicted from the right pulmonary artery. The results clearly showed that in this patient the high right atrium was indeed the site of origin of the atrial echo beats which could be elicited by programmed premature atrial stimulation. The high left atrial electrogram (from the right pulmonary artery) was activated 35 msec after the high right atrium thus excluding the possibility of reentry in Bachmann's bundle. Atrial mapping during echo beats revealed a right atrial activation pattern which was similar to that observed during spontaneous sinus rhythm. Sinus node reentrant beats could also be evoked by programmed premature stimulation of the low lateral right atrium. In conclusion, activation of the high right atrium prior to the high left atrium is an important additional criterion for defining sinus node reentry in man. Thus, the recording of the left atrial signals from the right pulmonary artery helps to exclude reentry in the high left atrium, e.g. Bachmann's bundle.

Atrial Fibrillation↗
PubMed1980

[The electrophysiological effects of the Ca-antagonists gallopamil (D 600), dimeditiapramine (Ro 11-1781) and verapamil in man (author's transl)].

The electrophysiological effects of D 600 (D) (0.03 mg/kg i.v., 10 pts) and Ro 11-1781 (Ro) (1.0 mg kg i.v., 10 pts) were compared with those of verapamil (V) (0.1 mg/kg i.v., 20 pts). All three Ca-antagonists caused a slight shortening of the cycle length which was only significant after verapamil. There was practically no change in SNRT. As a consequence, the SNRT corrected for heart rate (CNSRT) increased insignificantly in all three groups (control C): 359.7 +/- 174.8 ms, V: 397.1 +/- 204.6 ms; C: 362.5 +/- 125.2 ms, Ro: 420.8 +/- 179.0 ms; C: 339.5 +/- 93.6 ms, D: 407.7 +/- 272.0 ms). In addition, the calculated "sinoatrial conduction time" increased insignificantly (C: 84.3 +/- 23.0 ms, V: 101.3 +/- 39.4 ms; C: 105.2 +/- 35.1 ms, Ro: 114.8 +/- 31.9 ms) or did not change (C: 105.9 +/- +/- 20.6 ms, D: 101.6 +/- 32.2 ms). The conduction time from high-to-low right atrium (HRA-A) as well as the His-ventricle time (HV) and the conduction interval from the septum to the right ventricular apex (V RVA) did not change. In contrast, the conduction time through the AV node (A-H) was significantly prolonged by all three drugs (C: 78.1 +/- 16.0 ms, V: 88,4 +/- 19.5 ms; C: 92.9 +/- 16.2 ms, Ro: 104.3 +/- 19.1 ms; C: 88.5 +/- 20.0 ms, D: 102.5 +/- 22.6 ms). The effective refractory period of the AV node (ERP AVN) was significantly prolonged by verapamil (C: 290.0 +/- 77.6 ms, V: 360.5 +/- 93.3 ms) and by D 600 (C: 266.7 +/- 72.6ms, D: 380.0 +/- 112.7 ms). Ro 11-1781 did not show any effect on this parameter. As a consequence, the Wenckebach point during high rate atrial pacing was significantly lowered by Verapamil and D 600, but only insignificantly by Ro 11-1781. The refractoriness of the right atrium and ventricle was not altered by any of the drugs. The results show that all three Ca-antagonists have similar electrophysiological effects in man after acute i.v. application. In the dose given, D 600 and verapamil are equipotent, whereas Ro 11-1781 is less effective.

Blood Pressure↗
PubMed1980

[Paradoxic response to disopyramide and quinidine (author's transl)].

Until recently, severe paradoxic responses to disopyramide have been believed to occur only, if at all, at extremely high doses. This credo has been shaken by some recent reports on severe ventricular tachyarrhythmias occurring in some patients on disopyramide. A further case (62 years, female, mitral commissurotomy in 1966, combined mitral valve lesion) is presented in whom a normal oral regimen (100 mg disopyramide four times daily) induced syncope due to ventricular tachycardia and flutter. The patient exhibited a long QT time before medication without deafness. Indication for treatment was the preservation of sinus rhythm as intermittent atrial fibrillation or flutter has been documented before. The serum potassium level was in the range of normal. Similar side-effects occurred some days later when the patient received quinidine sulfate. A survey of the most recent literature reveals a total of 20 patients with proven or suspected paradoxic responses to disopyramide. Factors that might favour the occurrence of paradoxic effects were preexisting QT prolongation, hypokaliemia, or massive overdosage. Though the total incidence of these side-effects seems to be relatively low, disopyramide should be given to special subgroups of patients only under careful monitoring.

Adult↗
PubMed1980

[Natural history of patients with severe aortic valve disease under medical therapy (author's transl)].

65 patients out of 420 with aortic valve lesions (class III and IV NYHA) who underwent cardiac catheterization in 1967-1976 were not operated upon for different reasons. The fate of these 65 patients was analyzed retrospectively to elucidate the natural history of severe aortic valve disease. The five years survival rate was 26% (aortic stenosis 17%, aortic incompetence 37%). Patients with angina pectoris and congestive heart failure, ventricular ectopic beats, mean pulmonary artery pressure greater than 30 mm Hg, mean left atrial pressure greater than 16 mm Hg and left ventricular enddiastolic pressure greater than 20 mm Hg had a significant worse prognosis than those without these parameters. Otherwise patients who refused the operation by personal reasons had a high survival rate. The results of the study indicate that patients with aortic valve disease class III or IV (NYHA) have a serious prognosis when treated medically. In comparison with our patients who underwent aortic valve replacement surgery has proven to be a life-prolonging procedure in these highly endangered cases.

Adolescent↗
PubMed1979

[Interaction of quinidine and digoxin in humans (author's transl)].

After full digitalisation, 11 healthy subjects received 0.375 mg digoxin daily as maintenance dose. Under steady-state conditions and determination of serum concentration and renal clearance of digoxin, they were then given 500 or 1000 mg quinidine daily in addition to the digoxin. While serum concentration of digoxin rose significantly from 0.75 +/- 0.2 ng/ml after one week on 500 mg quinidine, and to 1.8 +/- 0.6 ng/ml after 1000 mg of quinidine, renal digoxin clearance fell from 186.2 +/- 67.4 to 125.4 +/- 61.8 ml/min after 500 mg of quinidine. Raising quinidine dosage to 1000 mg daily caused no further digoxin clearance reduction. During the total experimental period endogenous creatinine clearance remained unchanged. The results indicate that the rise in serum digoxin concentration on simultaneous quinidine administration is largely due to reduction in renal digoxin clearance. A clinical observation confirms the considerable practical importance of this interaction.

Digoxin↗