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Biomedical subjects

B Lüderitz

Publications and source records attributed to B Lüderitz.

At least 19 recordsLinked to original sources
PubMed1997

Left atrial chamber and appendage function after internal atrial defibrillation: a prospective and serial transesophageal echocardiographic study.

OBJECTIVES: The purpose of this prospective study was to assess left atrial chamber and appendage function after internal atrial defibrillation of atrial fibrillation and to evaluate the time course of recovery. BACKGROUND: External cardioversion of atrial fibrillation may result in left atrial appendage dysfunction ("stunning") and may promote thrombus formation. In contrast to external cardioversion, internal atrial defibrillation utilizes lower energies; however, it is unknown whether the use of lower energies may avoid stunning of the left atrial appendage. METHODS: Transesophageal and transthoracic echocardiography were performed in 20 patients 24 h before and 1 and 7 days after internal atrial defibrillation to assess both left atrial chamber and appendage function. Transthoracic echocardiography was again performed 28 days after internal atrial defibrillation to assess left atrial function. The incidence and degree of spontaneous echo contrast accumulation (range 1+ to 4+) was noted, and peak emptying velocities of the left atrial appendage were measured before and after internal atrial defibrillation. To determine left atrial mechanical function, peak A wave velocities were obtained from transmitral flow velocity profiles. RESULTS: Sinus rhythm was restored in all patients. The mean +/- SD peak A wave velocities increased gradually after cardioversion, from 0.47 +/- 0.16 m/s at 24 h to 0.61 +/- 0.13 m/s after 7 days (p < 0.05) and 0.63 +/- 0.13 m/s after 4 weeks. Peak emptying velocities of the left atrial appendage were 0.37 +/- 0.16 m/s before internal atrial defibrillation, decreased significantly after internal atrial defibrillation to 0.23 +/- 0.1 m/s at 24 h (p < 0.01) and then recovered to 0.49 +/- 0.23 m/s (p < 0.01) after 7 days. The corresponding values for the degree of spontaneous echo contrast were 1.2 +/- 1.2 before internal atrial defibrillation versus 2.0 +/- 1.0 (p < 0.01) and 1.1 +/- 1.3 (p < 0.01) 1 and 7 days after cardioversion, respectively. One patient developed a new thrombus in the left atrial appendage, and another had a thromboembolic event after internal atrial defibrillation. CONCLUSIONS: Internal atrial defibrillation causes depressed left atrial chamber and appendage function and may result in the subacute accumulation of spontaneous echo contrast and development of new thrombi after cardioversion. These findings have important clinical implications for anticoagulation therapy before and after low energy internal atrial defibrillation in patients with atrial fibrillation.

Anticoagulants↗
PubMed1996

Epicardial neodymium. YAG laser photocoagulation of ventricular tachycardia without ventriculotomy in patients after myocardial infarction.

BACKGROUND: Surgical ablation of ventricular tachycardia (VT) after myocardial infarction has been reported by different endocardial approaches. The ventriculotomy may increase mortality of the procedure. METHODS AND RESULTS: We report on nine patients who suffered from recurrent VT in the late post-myocardial infarction period. Significant stenoses were detected in all patients. The mean left ventricular ejection fraction was 43.1 +/- 8.3%. Left ventricular scar (n = 9) was seen. The mean NYHA class was 2.2 +/- 0.4. Sustained VT (mean cycle length, 293 +/- 52 ms) occurred spontaneously (n = 9) and could be induced reproducibly. Catheter mapping detected a prematurity of -42 +/- 13 ms in six patients. Clinical VT was inducible during surgery in seven patients. Middiastolic potentials were detected from the epicardial surface (n = 3), and premature potentials were found (n = 8 with prematurity of -108 +/- 46 ms). Application of neodymium/yttrium/argon/ garnet (Nd:YAG) laser energy to early epicardial activation terminated the arrhythmia (n = 7). Ventriculotomy was not performed. Seven patients have been free of VT for a mean follow-up period of 17 +/- 11 months; one patient relapsed and was treated with an implantable cardioverter-defibrillator, as was a second patient with inducible VT after surgery. CONCLUSIONS: Surgical Nd:YAG laser photocoagulation of VT on the epicardial surface of the heart in post-myocardial infarction patients without ventriculotomy is safe and has a high success rate. At the present time, this method is recommended in patients with sustained and tolerated VT who need bypass surgery. This is the first report on epicardial laser ablation of VT in post-myocardial infarction VT.

Adult↗
PubMed1996

Quality of life and driving in recipients of the implantable cardioverter-defibrillator.

UNLABELLED: The efficacy of a treatment is primarily based on objective criteria, such as mortality and morbidity. Besides these criteria, the interest in measuring quality of life (QOL) in relation to health care has increased in recent years. Although the concept of patients' QOL is inherently subjective, and definitions vary, it can be assessed on a basis of 3 major components: physical condition, psychological well-being, and social activities. The basic requirements of QOL assessments are: multidimensional construct, reliability, validity, sensitivity, responsiveness, appropriateness to question or use, and practical utility. The instruments to assess QOL can be disease specific or generic, depending on the context. In 1991 a prospective and systematic evaluation of QOL in implantable cardioverter-defibrillator (ICD) recipients was started at the University of Bonn: psychological profile and patient acceptance were assessed in 57 consecutive patients using a specifically designed questionnaire. The results of this pilot study demonstrated that the acceptance of the ICD was remarkably high. Restrictions on driving a vehicle may have a substantial impact on QOL in patients with ICDs. A specifically designed questionnaire was addressed to 47 European national delegates in order to determine their present practices and criteria utilized when advising driving restrictions to patients after ICD implantation. Of the 39 (83%) respondents, 22 (56%) cardiologists advised all patients to abstain from driving--13 (33%) advising permanent abstinence, while 26 (67%) recommended temporary driving abstinence for periods of 3-18 months (mean 9 +/- 4 months). Despite medical advice not to drive, one third of the patients resume driving; half of the patients resumed driving after 6 months, with the vast majority driving within 12 months after ICD surgery. Two patients experienced ICD discharges while driving, but no motor vehicle accident occurred. Another patient had a motor vehicle collision with a fatal outcome, which was not caused by loss of consciousness or ICD discharge. CONCLUSIONS: (1) Fatal accidents or ICD discharges while driving are a rare finding in ICD patients. (2) About half of the physicians always advise their patients to cease driving for a period of 9 +/- 4 months. Despite this medical advice, the majority of the patients resume driving within 6 months of ICD implantation. (3) Criteria used in advising driving abstinence are not uniform among physicians.

Attitude↗
PubMed1996

[Driving of a motor vehicle after implantation of a cardioverter-defibrillator in malignant heart rhythm disorders. Criteria for the medical assessment of driving fitness in Europe].

AIM OF STUDY: To investigate how medical permission to drive in patients with a cardioverter defibrillator is handled in various European countries. METHODS: A specially developed questionnaire was sent to all 46 delegates of the pacemaker groups of the European Society of Cardiology. They were asked to provide information on the procedures and criteria used in the various countries regarding a driving ban after cardioverter defibrillator implantation (ICD). RESULTS: 39 answers (83%) were received from representatives of 24 countries. 22 (56%) of those replying advised their patients not to drive. A permanent driving ban was recommended by 13 (33%), a temporary one of 3-18 (mean 9 +/- 4) months by 26 (67%). Presyncope was named as a criterion for a ban by 15 (38%), syncope by 13 (33%) and multiple defibrillator shocks by two (5%). Contrary to medical advice not to drive about one third of patients resumed driving, half of them after 6 months. 12 months after implantation most of the patients were again driving. Defibrillator discharges occurred in 2 patients, without consequence. One patient had a fatal car accident, unrelated to loss of consciousness or defibrillator shock. CONCLUSIONS: 1. ICD discharges are an extremely rare cause of driving accidents. 2. About half of the cardiologists recommended a driving ban for a mean of 9 months after ICD. 3. Despite medical ban about half of the patients resumed driving after 6 months. 4. There are as yet no uniform criteria in Europe for judging fitness to drive.

Accidents, Traffic↗
PubMed1996

[HIV-associated Pneumocystis carinii pneumonia, primary pentamidine inhalation prophylaxis notwithstanding. Are there differences with Pneumocystis carinii pneumonia without prophylaxis?].

OBJECTIVE: To study the effect of pentamidine aerosol inhalation, known to be effective and well tolerated in the primary prevention of HIV-associated Pneumocystis carinii pneumonia (PCP), on the severity, on clinical and radiological findings and prognosis of break-through PCP. PATIENTS AND METHODS: Data were obtained from the case notes of 17 men (mean age 36 [23-55] years) with HIV-associated PCP, treated between 1989 and 1994, who had received primary prophylaxis with pentamidine aerosol. During the same period 42 patients with HIV-associated PCP but no pentamidine prophylaxis (39 men, three women; mean age 36 [21-67] years) were also treated. Bronchoalveolar lavage of the most affected segment was performed. Diagnostic measures and treatment remained constant during the period of observation. RESULTS: The clinical presentation was the same in the two groups. There was also no difference between them regarding sensitivity to the lavage (94 and 98%). However, infiltration of the upper segments was significantly more common in the prophylaxis group (90 and 43%; P < 0.02). There was no statistically significant difference between the two groups in death rate (13 and 7%) and the long-term prognosis after PCP (survival time 18 and 24 months, respectively). CONCLUSION: Primary prophylaxis of PCP had no significant effect other than altering the distribution pattern of the pneumonic infiltrates towards the apical segments.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Nonpharmacologic strategies for treating atrial fibrillation.

Nonpharmacologic tools to treat atrial fibrillation (AF) are direct current cardioversion, radiofrequency (RF) current catheter ablation, antiarrhythmic surgery, pacing, and atrial defibrillation. In patients with sustained AF, when no cause can be found for AF or when the associated disease is mild, an attempt should be made to restore sinus rhythm. Electrical cardioversion by synchronized direct current shock can be attempted when drugs have failed and is the first choice in acutely ill patients. Virtually all patients should be anticoagulated. Temporary pacing should be available in patients with evidence of previous bradycardia. Although efficacy may be improved in patients pretreated with antiarrhythmic drugs, there is a considerable risk of adverse events. In AF and sinus node dysfunction, both pacing and antiarrhythmic drugs may be necessary. Pacing should be atrial or dual chamber, since ventricular pacing provokes AF. Failure to control the ventricular rate in AF can be treated by RF: atrioventricular (AV) node ablation, ablation of accessory pathways in preexcitation syndrome with AF, modulation of AV node, or ablation of AF. Antiarrhythmic surgery is a major procedure and may be the therapy of last resort in AF: the so-called corridor procedure isolates the fibrillating atria from a strip of tissue connecting the sinus and AV nodes. The maze procedure attempts to abolish AF by channeling the atrial activation between a series of incisions. In patients with chronic AF, internal cardioversion should be attempted if conventional transthoracic electrical cardioversion is ineffective. Several studies demonstrated the feasibility and efficacy of internal atrial defibrillation in selected patients with recent onset, as well as with chronic, AF. An implantable atrial defibrillator--as a stand-alone device or as part of a whole heart cardioverter--might be an option in the future. Nonpharmacologic tools play only a minor role in the management of paroxysmal and chronic AF. If symptoms persist despite pharmacologic therapy and other causes of persisting symptoms are excluded, consideration should be given to cardiac pacing, RF catheter treatment, or surgery. in some cases nonpharmacologic therapy of the AV node must be followed by implantation of a permanent pacemaker (due to complete AV block) and anticoagulation (due to persistence of underlying AF.

Adolescent↗
PubMed1996

Influence of captopril on nitroglycerin-mediated vasodilation and development of nitrate tolerance in arterial and venous circulation.

We investigated whether captopril is able to potentiate vasodilation and prevent tolerance to a 48-hour infusion of nitroglycerin (NTG). Twenty-six patients were randomly assigned to a 7-day regimen of captopril (50 mg/day) or placebo. The hemodynamic response to a 0.8 mg sublingual NTG dose was assessed by measuring mean arterial pressure (MAP), mean pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), and cardiac output (CO), and calculating systemic (SVR) and pulmonary vascular resistances (PVR). The parameters were obtained serially at baseline and 1 to 10 minutes after the sublingual NTG application (day 1). Then intravenous NTG was started and maintained for 48 hours (1.5 micrograms/kg/min), and the hemodynamic study was repeated (day 3). There was no difference between the captopril and the placebo groups at day 1 (baseline values and response to sublingual NTG). After the 48-hour infusion, there was a complete loss of the NTG effects in the placebo group (day 1 vs day 3: PAP, 20 +/- 5 mm Hg vs 21 +/- 8 mm Hg; MAP, 86 +/- 11 mm Hg vs 90 +/- 9 mm Hg; SVR, 1295 +/- 330 mm Hg vs 1380 +/- 465 dyne.sec.cm-5) whereas there was still evidence of a persistent vasodilation in the captopril group (day 1 vs day 3: PAP, 19 +/- 4 mm Hg vs 13 +/- 4 mm Hg; MAP, 84 +/- 9 mm Hg vs 74 +/- 10 mm Hg; SVR, 1265 +/- 280 mm Hg vs 1140 +/- 425 dyne.sec.cm-5). The response to sublingual NTG on day 3 was markedly attenuated in the placebo group only. We conclude that captopril does not increase the vasodilatory response to nitroglycerin but is able to prevent developing nitrate tolerance in arterial and venous circulation.

Administration, Sublingual↗
PubMed1996

Bronchopulmonary infection with Mycobacterium malmoense presenting as a bronchoesophageal fistula.

We report a bronchopulmonary infection with Mycobacterium malmoense in a patient with severe immunosuppression due to insulin-dependent diabetes mellitus, humoral immunodeficiency after thymoma (Good's syndrome) and prolonged immunosuppressive treatment after myasthenic crisis. It presented as non-resolving pneumonia of the left lower lobe. Bronchoscopically, a bronchoesophageal fistula was detected. Numerous acid-fast organisms were found in the sputum specimen and in the bronchial biopsy around the fistula. M. malmoense was isolated from sputum, bronchoalveolar lavage and bronchial biopsy. Whereas conventional in vitro susceptibility testing revealed susceptibility only to ethambutol, multi-drug susceptibility testing confirmed susceptibility to rifampicin, ethambutol, clarithromycin and prothionamide. The clinical outcome after 12 months of therapy resulted in a stable remission and considerable suppression of the mycobacterial load, but not in complete eradication.

Aged↗
PubMed1996

Direct angiography of the coronary sinus: impact on left posteroseptal accessory pathway ablation.

The purpose of this study was to determine the incidence and types of venous branches and anomalies in posteroseptal accessory pathways (APs) and whether these findings are indicative for successful ablation sites. Some posteroseptal APs may be located epicardially, or may be associated with venous anomalies or related to the middle cardiac vein. These APs account for many of the failures encountered during endocardial ablation. Direct coronary sinus (CS) angiography was performed in 43 consecutive patients with left posteroseptal APs (n = 23) and in 20 patients with AV nodal reentrant tachycardia prior to catheter ablation. In 14 (61%) of 23 APs, a venous branch or an anomaly of the CS was found in the posteroseptal region (6 with middle cardiac vein, 2 with other ventricular venous branches, and 6 had a diverticulum). Eleven (48%) of 23 APs were successfully abolished from within that demonstrated venous system, with a median of four radiofrequency impulses. In the remaining 12 (52%) patients, ablation was attempted from the endocardial site of the mitral annulus. Repeat angiography after energy delivery revealed no major complications in any patient. One (5%) patient with AV nodal reentrant tachycardia had evidence of a CS anomaly (P < 0.01). Various types of venous branches and anomalies are associated with the majority of patients with left posteroseptal APs. The APs are directly related to these complex findings, and AP conduction can easily be eliminated from within the venous branches. CS angiography is suggested prior to catheter ablation of left posteroseptal APs to facilitate the ablation procedure.

Adult↗
PubMed1996

Relation between symptoms and profiles of coronary artery blood flow velocities in patients with aortic valve stenosis: a study using transoesophageal Doppler echocardiography.

OBJECTIVE: To analyse profiles of coronary artery flow velocity at rest in patients with aortic stenosis and to determine whether changes of the coronary artery flow velocities are related to symptoms in patients with aortic stenosis. DESIGN: A prospective study investigating the significance of aortic valve area, pressure gradient across the aortic valve, systolic left ventricular wall stress index, ejection fraction, and left ventricular mass index in the coronary flow velocity profile of aortic stenosis; and comparing flow velocity profiles between symptomatic and asymptomatic patients with aortic stenosis using transoesophageal Doppler echocardiography to obtain coronary artery flow velocities of the left anterior descending coronary artery. SETTING: Tertiary referral cardiac centre. PATIENTS: Fifty eight patients with aortic stenosis and 15 controls with normal coronary arteries. RESULTS: Adequate recordings of the profile of coronary artery flow velocities were obtained in 46 patients (79%). Left ventricular wall stress was the only significant haemodynamic variable for determining peak systolic velocity (r = -0.83, F = 88.5, P < 0.001). The pressure gradient across the aortic valve was the only contributor for explaining peak diastolic velocity (r = 0.56, F = 20.9, P < 0.001). Controls and asymptomatic patients with aortic stenosis (n = 12) did not differ for peak systolic velocity [32.8 (SEM 9.7) v 27.0 (8.7) cm/s, NS] and peak diastolic velocity [58.3 (18.7) v 61.9 (13.5) cm/s, NS]. In contrast, patients with angina (n = 12) or syncope (n = 8) had lower peak systolic velocities and higher peak diastolic velocities than asymptomatic patients (P < 0.01). Peak systolic and diastolic velocities were -7.7 (22.5) cm/s and 81.7 (17.6) cm/s for patients with angina, and -19.5 (22.3) cm/s and 94.0 (20.9) cm/s for patients with syncope. Asymptomatic patients and patients with dyspnoea (n = 14) did not differ. CONCLUSIONS: Increased pressure gradient across the aortic valve and enhanced systolic wall stress result in characteristic changes of the profile of coronary flow velocities in patients with aortic stenosis. Decreased or reversed systolic flow velocities are compensated by enhanced diastolic flow velocities, particularly in patients with angina and syncope. This characteristic pattern of the profile of coronary artery flow velocities in patients with angina or syncope may be useful for differentiating those patients from asymptomatic patients.

Aged↗
PubMed1996

Value of routine microbial investigation in community-acquired pneumonia treated in a tertiary care center.

The study was conducted at a tertiary care and teaching hospital with about 200 beds for internal medicine. The objective was to determine the diagnostic yield and value in directing antibiotic therapy of a routine microbial approach in patients with community-acquired pneumonia referred to a tertiary care center. We studied 93 episodes in a retrospective study. 69/93 (74%) cases were treated with at least one empirical antibiotic therapy prior to admission. Microbial investigation was performed in 83/93 cases (89%). An etiological agent was established in 19/83 (23%) cases including 7/50 (14%) by blood culture and 12/52 (23%) by serology. Bronchoscopy with 18 protected specimen brush and 20 bronchoalveolar lavage examinations was definitely diagnostic in only 1/25 (4%) cases, and this case was also identified by blood culture. 5/25 (20%) were probably diagnostic. Three pathogens, Streptococcus pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila, accounted for 15/19 (79%) of the identified agents. The diagnostic results directed a change in antibiotic therapy in 6/19 (32%) of cases with definitely proven pathogens. 4/19 (21%) of cases would have been treated with an inappropriate regimen without diagnostic results. The diagnostic yield of routine microbial investigation in pretreated patients is low. The routine approach reveals its limited value especially in patients with severe courses. The role of bronchoscopy remains to be defined for patients with severe (and pretreated) community-acquired pneumonia.

Adolescent↗
PubMed1996

Effect of long-term primary aerosolized pentamidine prophylaxis on breakthrough Pneumocystis carinii pneumonia.

Aerosolized pentamide is a well-tolerated primary prophylaxis regimen for Pneumocystis carinii pneumonia (PCP) in human immunodeficiency virus (HIV)-infected patients. It is now commonly administered for prolonged periods. We therefore studied the effect of long-term inhalation on breakthrough PCP. We recorded clinical, immunological, radiological and microbiological data, as well as therapy and clinical course of all episodes with confirmed PCP diagnosed at our institution between January 1, 1990 and June 30, 1995. Furthermore, data of all patients on primary aerosolized pentamidine since May 1, 1989 were retrieved. Prophylaxis failures were subdivided into "early" (< or = 12 months of inhalation time) and "late" (> 12 months of inhalation time) failures and were compared with episodes without any prophylaxis. Thirty patients without any prophylaxis, six with early and 14 with late failures represented the study population. Mean +/- SD inhalation times were 4.9 +/- 4.8 and 26.3 +/- 14.1 months, respectively. No significant differences could be detected with regard to clinical presentation, severity of PCP, and in-hospital as well as long term outcome. Early as well as late prophylaxis failures had a higher incidence of upper lobe infiltrates on chest radiography (50% without prophylaxis versus 100% with early and 83% with late failure, respectively; p < 0.05). No extrapulmonary or disseminated pneumocystosis was observed in either group. The sensitivity of site-directed bronchoalveolar lavage was conserved after long-term inhalation (86% versus 100% without prophylaxis and 97% in early failure; p = NS). The severity and outcome of Pneumocystis carinii pneumonia is not altered by long-term primary aerosolized pentamidine prophylaxis. Presentation with upper lobe infiltrates is a radiographic pattern also of late failures. Bronchoalveolar lavage should, therefore, be performed using the site-directed technique in this setting.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Clinical experiences with pectoral defibrillator implantation].

UNLABELLED: The pectoral approach to implantation of cardioverter/defibrillators has the aim to further simplify the implantation of transvenous defibrillation systems. The PCD 7219 D/C is a device of the fourth generation which makes the pectoral implantation feasible due to a weight of 132 g, a size of 89 x 64 x 18 mm, a volume of 83 cm3 and a surface of 108 cm2. The use of the "active-can"-system (PCD 7219 C) requires the implantation of only one right ventricular lead. The PCD 7219 D/C was implanted in 75 patients with ventricular tachyarrhythmias, the follow-up period was 12 +/- 4 (1-24) months. Subpectoral implantation was feasible in 59 patients (79%), in 55 with a left pectoral, in 4 with a right pectoral approach due to previous left-sided operation or thrombosis of the left subclavian vein. Male sex (p < 0.005), body weight (p < 0.005) and body surface (p < 0.05) were predictors of pectoral implantation. In the 45 patients (60%) with a unipolar defibrillation system ("active can") the defibrillation threshold was significantly lower compared to those with a dual lead system (9.9 +/- 6.5, 2.5-24 Joule vs. 19 +/- 4.5, 6-24 Joule p < 0.0001). In one patient with pectoral and in one patient with abdominal implantation a dislodgement of the right ventricular lead was diagnosed and an operative revision was indicated. CONCLUSION: The down-sized implantable cardioverter/defibrillator PCD 7219 D/C makes the pectoral implantation feasible in the majority of patients. The use of the "active-can"-system requires the implantation of only one right ventricular lead with significantly lower defibrillation thresholds.

Adolescent↗