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B Lüderitz

Publications and source records attributed to B Lüderitz.

At least 343 records · Page 19Linked to original sources
PubMed1989

[Arrhythmogenic effect of flecainide--treatment with i.v. magnesium].

We report on a 46-year-old woman with ventricular tachycardia and ventricular fibrillation after starting antiarrhythmic drug therapy with flecainide. The flecainide acetate plasma levels were always in the normal range. A successful therapeutical intervention was induced with two i.v. applications of 1,000 mg magnesium glutamate. A persistent suppression of ventricular rhythm disturbance was accomplished by continuous i.v. application of 4 mg magnesium glutamate/min.

Electrocardiography↗
PubMed1989

[Assessment of the severity of mitral valve insufficiency using color Doppler echocardiography].

UNLABELLED: To evaluate different methods for quantification, 55 adult patients with mitral insufficiency were investigated by Doppler color flow mapping (CFM). The maximal area, length and width of the regurgitant jet were determined using apical windows and these were then related to the angiographic findings (Sellers I-IV). In 11/55 patients reliable tracing of the regurgitant flow was not possible because of drop-outs and impaired signal-to-noise ratio. With none of the three systems was a reliable differentiation of moderate to severe forms of mitral incompetence possible because of wide overlapping of the CFM-values in the four angiographic classes. Relating the CFM-values to the diameter or area of the left atrium did not improve the correlations with the angiographic data. At best, the measurement of the maximal area allowed an approximate estimation of the degree of insufficiency: values greater than 6.5 cm2 were not found in patients with Sellers class I or II. Results below this limit could be found in all four angiographic classes. The variability for the estimation of the maximum area (linear regression analysis) was r = 0.96, SEE = 0.07 (intraobserver) and r = 0.94, SEE = 0.08 (interobserver). CONCLUSION: CFM is not a reliable method for classification of mitral regurgitation.

Blood Flow Velocity↗
PubMed1989

[Cibenzoline: electrophysiologic effects of a new class I anti-arrhythmia agents in supraventricular tachycardia].

Cibenzoline, an imidazoline derivate, is a new class 1 antiarrhythmic agent. The electrophysiologic effects and antiarrhythmic properties of cibenzoline (100 mg i.v.) were evaluated in 22 patients with paroxysmal supraventricular tachycardia: 12x Wolff-Parkinson-White Syndrome, 9x AV nodal reentrant tachycardia, 1x atrial tachycardia. Cibenzoline shortened the sinus cycle length from 742 +/- 103 ms to 661 +/- 87 ms (p less than 0.001) and the sinus node recovery time from 1026 +/- 106 ms to 926 +/- 135 ms (p less than 0.001). The substance lengthened the AH interval from 93 +/- 19 ms to 112 +/- 24 ms (p less than 0.001) and the HV interval from 42 +/- 12 ms to 61 +/- 14 ms (p less than 0.001). The effective refractory periods of the atrium and right ventricle did not change significantly, but the effective refractory period of the AV node in antegrade (269 +/- 42 ms vs 278 +/- 46 ms; p less than 0.05) and retrograde direction (281 +/- 57 ms vs 413 +/- 124 ms; p less than 0.001) increased markedly. Cibenzoline prolonged the effective refractory period of the accessory pathway in retrograde direction from 263 +/- 41 ms to 428 +/- 101 ms (p less than 0.001). The effective refractory period of the antegrade accessory pathway did not change. During atrial stimulation inducibility of the reentrant tachycardia was suppressed in 14 of 22 patients and the inducibility of atrial fibrillation in 7 of 12 patients. The RR interval of the reentrant tachycardia was prolonged from 353 +/- 57 ms to 420 +/- 57 ms (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Inhibition of the heparin effect by nitroglycerin].

The interaction of intravenous (i.v.) nitroglycerin (glyceryl trinitrate) on the anticoagulant effect of heparin was studied in 27 patients. The heparin dose was adjusted (800-1400 IU/h) to achieve partial thromboplastin time (PTT) of more than 100 s (130 +/- 28 s). While the heparin infusion was continued at the same dosage, the patients received 2-5 mg/h nitroglycerin i.v. (Perlinganit without propylene glycol [15 patients] or Gilustenon with propylene glycol [12 patients]). During combined heparin and nitroglycerin (NG) administration PTT decreased significantly (60 +/- 23 s; P less than 0.01). After withdrawal of NG, PTT increased to the initial levels (126 +/- 30 s). The drug interaction was seen in both groups--with or without propylene glycol. In nine of the 27 patients plasma heparin levels were measured; they remained unchanged during NG administration. The results indicate that i.v. NG induces heparin resistance. After NG is withdrawn, a rebound increase in PTT may occur. Adequate monitoring of PTT and heparin dosage adjustment are thus required during combined heparin and NG administration.

Adult↗
PubMed1988

[Emergency therapy of ventricular tachycardias: lidocaine versus ajmaline].

The efficacy of ajmaline (50-75 mg i.v.) or lidocaine (100-200 mg i.v.) in terminating persistent, haemodynamically stable ventricular tachycardia (VT) was compared in a prospective, randomized trial of 31 patients. There were no significant differences as to age, underlying heart disease, ejection fraction and rate of ventricular tachycardia between the two treatment groups. Ajmaline terminated VT in 10 of the 15 patients receiving it, lidocaine in only 2 of 16 (P less than 0.01). The frequency of VT was not significantly changed by lidocaine, while mean cycle length during VT changed under ajmaline from 369 +/- 82 ms to 452 +/- 11 ms (P less than 0.01). In contrast to lidocaine, QRS duration under ajmaline lengthened from 166 +/- 18 ms to 200 ms +/- 28 ms (P less than 0.01), but return cycles after tachycardia termination were similar (ajmaline, 863 +/- 296 ms; lidocaine, 917 +/- 367 ms). Both drugs were equally well tolerated, but in this series ajmaline was more effective in the acute treatment of persistent VT.

Ajmaline↗
PubMed1988

[Diagnostic and prognostic value of plasma ANP determination after myocardial infarction].

In the present study the prognostic value of ANP measurement was investigated in 52 patients undergoing coronary angiography. 22 normotensive and 30 hypertensive subjects were included. A significant inverse correlation between left ventricular ejection fraction (EF) and plasma ANP was found in normotensives, but not in hypertensives. In patients with chronic myocardial infarction, there was no difference in ANP levels compared to patients without infarction in either group, provided that EF was normal. However, hypertensives showed a 35% increase in ANP compared to normotensives. This was true for subjects with and without myocardial infarction. These results show that in normotensives ANP levels have a prognostic value on a statistical rather than an individual basis. This does not apply to hypertensives, whose ANP level is increased by factors other than impaired ejection fraction.

Angiocardiography↗
PubMed1988

[Elevated levels of atrial natriuretic peptide and plasma catecholamines in arterial hypertension--indications for an interaction].

In this study plasma levels of atrial natriuretic peptide and of the catecholamines epinephrine and norepinephrine were investigated in hypertensive patients (HT) (n = 30). 22 normotensive patients (NT) served as controls. Hypertensives showed an elevated ANP-level in comparison with controls (46.8 +/- 3.3 vs. 36.8 +/- 3.3 pg/ml, M +/- SEM, p less than 0.01). When patients with myocardial infarction or with reduced ejection fraction were excluded, the same relation was demonstrated (49.3 +/- 3.2 vs. 33.6 +/- 2.0 pg/ml, p less than 0.01). Plasma norepinephrine was 230.8 +/- 52.3 pg/ml in HT compared with 138.0 +/- 19.6 pg/ml in NT (p less than 0.05). Epinephrine was 70.8 +/- 10.5 vs. 54.8 +/- 9.7 pg/ml in HT and NT. To exclude an increased left ventricular enddiastolic - and hence left atrial - pressure as the cause for the elevation of ANP and norepinephrine, HT and NT were matched for the same levels of enddiastolic pressure (LVEDP) (n = 18). For each level of LVEDP ANP was higher in HT than in NT (p less than 0.01). The same held true for norepinephrine (p less than 0.05) and to a lesser extent for epinephrine (p = 0.09). Our results demonstrate that patients with essential hypertension exhibit markedly elevated levels for ANP and catecholamines which is not due to myocardial failure. We propose that the increased secretion of the vasodilatory hormone ANP serves as counterregulation against the vasoconstrictor norepinephrine. The endocrine function of the heart may play a pivotal role in the modulation of sympathetic activity.

Aged↗
PubMed1988

[Hemodynamics in ventricular arrhythmias and in their treatment].

The hemodynamic consequences of ventricular tachyarrhythmias are influenced by age, underlying cardiac disease, left ventricular ejection fraction, and possibly by atrial natriuretic peptide. Severity and frequency of the rhythm disorder play, of course, a major role, e.g., monomorphic or polymorphic ventricular premature complexes (VPC), rare or frequent VPC, ventricular tachycardia, ventricular flutter or fibrillation, torsade de pointes, and tachycardia, etc. The therapeutic approach with antiarrhythmic drugs or cardiac pacemakers in cases of conduction disturbances have an additional impact on cardiac performance. Compared to ventricular pacing, a significant higher cardiac output was observed during AV sequential (so called "physiological") pacing evaluated by radionuclide ventriculography. Especially in patients with a reduced left ventricular ejection fraction, the negative inotropic effects of antiarrhythmic drugs are of major importance. A decrease of cardiac output may occur under beta-blocking agents, propafenone, flecainide and particularly disopyramide. On the other hand, amiodarone does not impair cardiac output significantly during acute high dose loading and longterm therapy. In general, negative inotropic effects of antiarrhythmic substances are overestimated; they may even be neglected as long as the antiarrhythmic agent leads to effective suppression of the symptomatic ventricular tachyarrhythmia.

Amiodarone↗
PubMed1988

[Concentrations of amiodarone and flecainide in plasma and saliva--indications for the active transport of flecainide].

UNLABELLED: Only the free protein-unbound drug concentration in plasma is pharmacologically active. The concentration of some drugs in saliva is equal to the free drug level. We compared concentrations (in plasma before, 30 and 60 min after the morning dose, in saliva before, 30, 60, 90 and 120 min after the morning dose) of amiodarone (n = 8, 2 x 200 mg orally per day) and flecainide (n = 16, 2 x 100 mg) administered as chronic antiarrhythmic treatment. Drug levels were measured by "high performance liquid chromatography". RESULTS: Just prior to the first morning dose, amiodarone concentrations in plasma were 1.0-2.9 (2.0 +/- 0.6) micrograms/ml, in saliva 0.02-0.25 micrograms/ml; flecainide in plasma 80-560 (316 +/- 163) ng/ml, in saliva 630-3700 (1749 +/- 963) ng/ml. After the morning dose we found maximal flecainide plasma levels of 462 +/- 203 and saliva levels of 3218 +/- 2857 ng/ml. The highest flecainide concentrations in the saliva (13,400 and 11,300 ng/ml) were found in two patients 30 and 60 min after the morning dose. Flecainide, but not amiodarone, is excreted actively in the saliva, probably indicating an enteroenteric circulation. This should be considered to reduce life-threatening flecainide intoxications by gastric and intestinal lavage and suction. The concentration of flecainide in the saliva does not represent the non-protein-bound free drug level in the plasma.

Adult↗
PubMed1988

[Supraventricular tachycardia: therapy with a variable antitachycardia stimulation program].

Modern, microprocessor-controlled antitachycardia pacemakers are available with extended detection and termination programs for the treatment of supraventricular tachycardias. Using the "InterTach 262-12" we examined a universal antitachycardia pacing mode in the chronic state. Based on the individual electrophysiologic parameters, a defined burst stimulation mode was used for the first intervention and, consecutively, a determined scanning mode. The InterTach device was implanted in 17 patients with a mean age of 50 +/- 15 years: 10 with AV-nodal reentrant tachycardia, 6 with Wolff-Parkinson-White syndrome, 1 with reentrant tachycardia with Mahaim fibers. The mean tachycardia rate was 178 +/- 23/min and the follow-up 10 +/- 4 months. Every 3 months the efficacy of the termination mode was tested by programmed stimulation in supine and upright body position or during physical activity. In these tests, a rate of 95-100% successful terminations was observed. In the chronic state, 26 persistent tachycardias in 11 patients were noted; 21 episodes could be referred to an insufficient tachycardia detection. Only four persistent tachycardias were due to ineffective antitachycardia pacing. The introduction of extended variable termination programs, including consecutive, flexible pacing modes, can be considered as a marked advancement in the antitachycardia pacemaker therapy for supraventricular tachycardias.

Adult↗
PubMed1988

[Intraoperative measurement of velocity and volume of coronary circulation using the Duplex system].

A high frequency ultrasound system processor was used for an intraoperative evaluation of coronary blood flow velocity and volume. In 12 patients with symptomatic coronary heart disease, morphology and hemodynamic parameters of the coronary artery system were examined intraoperatively. Optimal imaging was possible by keeping the ultrasound transducer at a constant distance of a few millimeters from the surface of the heart and the pericardial space between them filled with saline solution. Using this technique, large areas of the cardiovascular system were reproducible up to a peripheral vascular diameter of 2-3 mm. Blood flow velocity (20 to 33 cm/s) and blood volumes (33 to 94 ml/min) provide quantitative information on the degree of stenosis intraoperatively after coronary anastomosis during bypass surgery. All images were of outstanding quality and precision. This method is highly valuable for the intraoperative determination of blood flow parameters.

Adult↗
PubMed1988

[Improving color Doppler echocardiography of the right heart chambers following intravenous injection of SHU 454].

The echocardiographic contrast agent SHU 454 provides microbubbles of defined size (median 3 micron) in a solution of galactose and is available in different reproducible concentrations. In 22 patients with suspected tricuspid regurgitation, color flow mapping (CFM) Doppler echocardiography was performed before and after intravenous injection of 2-4 ml SHU 454. Without SHU 454 the diastolic blood flow was imaged on 13.6 +/- 7.5% (mean value + standard deviation) of the cross sectional area of the right ventricle (four-chamber view) in comparison to 39.0 +/- 15.0% with SHU 454 (p less than 0.001). For the right atrium, the area analyzed by CFM increased from 9.4 +/- 12.9% to 62.4 +/- 25.3% (p less than 0.001). The interindividual variability of measurements after injection of SHU 454 was 5.9 +/- 4.0% as compared to 10.7 +/- 6.9% without SHU 454 (p less than 0.05). These findings demonstrate that intravenous SHU 454 administration increases the detection of blood flow by CFM within the right heart.

Adult↗
PubMed1988

[Noninvasive diagnosis of bilocular left atrial and right ventricular myxoma of the heart].

Bilateral cardiac myxomas are very rare and therefore mostly overlooked. In most cases the diagnosis has been made intraoperatively or at postmortem examination. We report on a 60-year-old woman with a left atrial and right ventricular myxoma where diagnosis was made by echocardiography and computer tomography, and confirmed histologically after successful surgical and therapeutic aspects are discussed.

Echocardiography↗
PubMed1987

[Elevated plasma flecainide concentrations in heart failure].

In 42 patients with heart failure who were on long-term treatment with flecainide (2 X 100 mg daily by mouth) plasma concentration of flecainide was measured before the morning dose and compared with the clinical grade of heart failure or left ventricular ejection fraction (in the levo-angiogram). Mean plasma flecainide concentration was 415 +/- 244 ng/ml (110-1035 ng/ml), mean ejection fraction 55 +/- 17.7% (24-84%) (r = -0.60). In seven patients with plasma concentrations over 700 ng/ml (870 +/- 150 ng/ml) in clinical grade III or IV, ejection fractions were 24, 25, 25, 30, 33, 37 and 44%, respectively. In two patients (ejection fraction of 24 and 25%, respectively) the morning plasma concentration was around 1000 ng/ml. The results point to possible high plasma flecainide concentrations--at times in the toxic range--in patients who are in heart failure. In patients with marked reduction in left ventricular pumping function who are on long-term flecainide treatment, a reduction in dosage or monitoring of plasma flecainide concentration is indicated.

Adult↗