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Biomedical subjects

L Kappenberger

Publications and source records attributed to L Kappenberger.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Intravenous withdrawal of infected cardiac pacemaker electrodes. Apropos of 5 cases].

Infection of a cardiac pacemaker and its electrodes is one of the most serious complications after implantation of a pacemaker, as it can be life-threatening and constitutes an absolute indication for complete withdrawal of the implanted material which, up until recently, could only be performed by thoracotomy or sternotomy with or without cardiopulmonary bypass. A new transvenous technique for complete removal of the infected pacemaker system has been recently described. We report 5 cases of infected pacemaker systems in which this technique was used successfully allowing withdrawal of 10 electrodes and thereby avoiding the need for a major surgical operation.

Aged↗
PubMed1996

Doppler echocardiographic assessment of the new ATS medical prosthetic valve in the aortic position.

Advancing The Standard (ATS) Medical (ATS Medical Inc., Minneapolis, MN) is a new mechanical bileaflet valve, composed of pyrolitic carbon. The aim of this study was to define in a blinded manner the Doppler echocardiographic characteristics of normally functioning ATS Medical prostheses with respect to their size. Forty consecutive patients (29 men, mean age 58 +/- 13 years), clinically stable, and without evidence of valve dysfunction, were studied from 1993 to 1995. Doppler echocardiography was performed at least 3 months after valve replacement with ATS Medical valves (5 n degrees 21, 8 n degrees 23, 12 n degrees 25, 10 n degrees 27, 5 n degrees 29). Maximum and mean transprosthetic pressure gradients were calculated by the simplified Bernoulli equation. Functional valve surface area was assessed by the continuity equation using the external diameter of the prostheses to calculate the subaortic surface area. The Doppler velocity index was obtained by the ratio of subaortic and transaortic velocities and the performance index was calculated dividing the effective orifice area by the actual orifice area. For the most commonly used aortic valve (25 mm), the maximum pressure gradient was 17 +/- 8 mmHg, the mean gradient 11 +/- 4 mmHg, the functional surface area 2.2 +/- 0.4 cm2, the Doppler velocity index 0.44 +/- 0.07, and the performance index 0.68 +/- 0.11. This study provides the normal range for Doppler hemodynamic characteristics of the various sizes of the ATS valve.

Adult↗
PubMed1995

[Permanent junctional reciprocating tachycardia: a little-known clinical entity curable with radiofrequency ablation].

We report our experience of 5 patients with the permanent form of junctional reciprocating tachycardia (PJRT), a rare form of supraventricular arrhythmia. PJRT was discovered at a mean age of 31 years (8-60 years) and the mean duration of tachycardia was 13 years (1-40 years). 4 patients had nearly incessant tachycardia and one had paroxysmal attacks. Heart rate varied between 100 and 190 beats/minute and the minimal heart rate was on average 114 beats/minute. Four patients had palpitations, 2 developed tachycardia-induced cardiomyopathy, reversible after control of the arrhythmia, and 4 had asymptomatic episodes of PJRT. ECG showed in all cases a narrow-complex tachycardia with inverted P waves in inferior leads and RP interval greater than PR. All patients presented a posteroseptal accessory pathway. 4 patients received different antiarrhythmic drugs with only partially effective results. Radiofrequency catheter ablation of the accessory pathway was performed in all patients and was successful in 4, who remained free of recurrence after a mean follow-up of 26.5 months (4-37 months). The procedure was partially successful in the 5th patient, who is now asymptomatic under sotalol. Radiofrequency catheter ablation is therefore the treatment of choice of PJRT, a rare arrhythmia which should nevertheless be known in order to treat the patient correctly and avoid progression to cardiac failure, which is not always completely reversible.

Adolescent↗
PubMed1995

[Interventional cardiology].

The evolution of cardiology over the past 25 years has been dominated by the invention and development of interventional techniques. These techniques offer 'surgical treatment' through transvascular access to the heart, avoiding therefore the classic transthoracic surgical approach. Today, coronary artery disease, valvular heart disease and arrhythmias are accessible to interventional treatments. In this article, a review is given about recent developments and results of interventional treatment for coronary artery disease with special consideration of stenting. This article should help the general practitioner or internist to guide and inform their patients suffering from coronary artery disease.

Angioplasty, Balloon, Coronary↗
PubMed1995

[Patient management following cardiac transplantation].

Prognosis of heart transplant patients has dramatically improved in the last decade thanks to the use of cyclosporine as immunosuppressive treatment. Optimal follow-up and early recognition of complications and side effects of treatment lead to longer survival and marked improvement of these patients' quality of life. However, the incidence of complications remains high and their management calls for particular care. We review our experience of heart transplantation in Lausanne and describe in detail the results and complications such as rejection, transplant coronary artery disease, hypertension, renal failure, metabolic disorders, cancer and conduction problems. Cooperation of the medical team (cardiologist, surgeon, anesthetist, general practitioner) is essential to long term success of the transplant program.

Arrhythmias, Cardiac↗
PubMed1995

[Cardiac pacemaker for the treatment of obstructive hypertrophic cardiomyopathy, a concept which is gaining ground].

Pacing reduces the sub-aortic pressure gradient in hypertrophic obstructive cardiomyopathy. This phenomenon was described long ago but only recently, with the development of sophisticated pacemakers, has it become possible to use pacemakers for the long term treatment of this disease. The acute hemodynamic improvement with pacemaker treatment is well documented. The reason for this acute and chronic improvement is of multiple origin. Pacing modulates the activation sequence of the left ventricle, reduces contractility, reduces subaortic flow velocities, influences mitral valve movement and leads to remodeling of the ventricle in the long term. All these factors together explain the clinical and hemodynamic improvement in patients suffering from hypertrophic obstructive cardiomyopathy.

Aorta, Thoracic↗
PubMed1995

Emergency endoluminal stenting for abrupt vessel closure following coronary angioplasty: a randomized comparison of the Wiktor and Palmaz-Schatz stents.

In order to compare the efficacy of two different stent types in case of bailout stenting, 65 patients, with abrupt or threatened vessel closure following coronary angioplasty, were randomly assigned to either Wiktor (Medtronic Inc., Minneapolis, MN, 33 patients) or Palmaz-Schatz (Johnson & Johnson Interventional, Warren, NJ, 32 patients) stent implantation. Stenting was technically feasible in all except one patient and immediately successful in reverting ischemia and vessel closure in 60 patients (92%). At hospital discharge, complication rates were comparable: early vessel closure, 18% (Wiktor) versus 13% (Palmaz-Schatz) (P = 0.53); any clinical event (such as death, myocardial infarction, and surgical revascularization): 18% (Wiktor) versus 22% (Palmaz-Schatz) (P = 0.71). At 6 months follow-up, these complication rates remained equal: restenosis, 38% (Wiktor) versus 27% (Palmaz-Schatz) (P = 0.42); any clinical and angiographic (vessel closure and restenosis) event: 45% (Wiktor) and 41% (Palmaz-Schatz) (P = 0.69). Baseline, direct postprocedural, and follow-up quantitative coronary analysis data were similar, with, however, an exception for the postprocedural residual stenosis [28% (24-32%) (Wiktor) and 21% (18-23%) (Palmaz-Schatz] (means and 95% confidence intervals). In conclusion, despite a discrete postprocedural angiographic benefit observed with the Palmaz-Schatz stent, the long-term clinical and angiographic outcome is similar in both treatment groups. The choice whether to implant a Wiktor or Palmaz-Schatz stent may probably be left to the discretion of the operator and his experience with one particular device.

Aged↗
PubMed1995

Unplanned use of intracoronary stents for the treatment of a suboptimal angiographic result after conventional balloon angioplasty.

This observational single-center trial examines the safety and efficacy of unplanned endoluminal stenting for the treatment of a suboptimal angiographic result (defined as a residual stenosis after angioplasty of 40% to 50% without delayed runoff as estimated by visual assessment) after conventional coronary angioplasty in native, new-onset, coronary artery stenoses. Between October 1991 and April 1994, 101 patients with suboptimal results after coronary angioplasty in new-onset lesions were treated by endoluminal Wiktor (41 patients) and Palmaz-Schatz (60 patients) stent implantation. Stenting was a technical and angiographic success in all cases. In-hospital complications were subacute closure (2%) and vascular complications at puncture site necessitating surgery (12%) or blood transfusion (3%). No myocardial infarction occurred, nor was any urgent bypass surgery performed. At follow-up restenosis was detected in 16 (20%, 80% angiographic follow-up rate) patients requiring repeat angioplasty (8%) and elective bypass grafting (4%). Myocardial infarction was not documented. However, one patient died suddenly at 5 months of follow-up. The unplanned use of intracoronary stents is a safe and effective therapeutic option for the treatment of a suboptimal angiographic result after conventional angioplasty in new-onset lesions. This approach guarantees a high immediate angiographic success but implies a considerable incidence of vascular complications at puncture site.

Aged↗
PubMed1995

Stand-by versus stent-by during percutaneous transluminal coronary angioplasty.

To evaluate the impact of a more liberal use of endoluminal stenting on the incidence of emergency coronary artery by-pass grafting, we analyzed our attitude toward abrupt or threatened closure after percutaneous transluminal coronary angioplasty from 1986 through 1993. In 3083 procedures performed, 204 (6.6%) patients had abrupt or threatened closure. The incidence of closure or threatened closure remained stable during the 8 years, ranging between 5% (1986) and 8% (1987) (p = 0.89). Endoluminal stent implantation was attempted in 92 patients and successfully achieved in 90 (98%), and emergency bypass grafting had to be performed in 41 patients. The proportion without adverse end point (death or myocardial infarction) was higher in the patients treated by endoluminal stenting than in patients treated with bypass grafting (71/90 (79%) patients vs 17/41 (40%) patients, respectively; p < 0.0001). The use of bailout stenting gradually increased from 0.4% (1986) to 5.6% (1993) of all procedures (p = 0.0001), whereas the incidence of emergency bypass grafting decreased from 2.7% (1986) to 0.7% (1993) (p = 0.04). Meanwhile, the incidence of myocardial infarction remained stable between 5.6% (1988) and 1.8% (1992) (p = 0.1), and death rates decreased from 1.4% (1988) to 0.2% (1993) (p = 0.05). It is concluded that "stent-by" is a highly effective therapeutic approach (79% in the present study) toward closure after coronary angioplasty and that, although surgical "stand-by" is certainly mandatory for selected cases, routine stand-by is questionable.

Angioplasty, Balloon, Coronary↗
PubMed1995

Initial experience with the "Big-Skinny" angioplasty catheter.

We describe our initial experience with the "Big Skinny" angioplasty catheter, currently only available as an investigational device and in sizes of 4.5, 5, and 6 mm. Six patients with severe angina pectoris were successfully dilated with this angioplasty catheter and have remained asymptomatic up until a mean follow-up period of 6 months. However, because of the large profile of the catheter, sufficient back-up with an adequate guiding catheter should be obtained and predilation with a smaller angioplasty catheter should be performed. The use of this catheter may be a more simple alternative for the treatment of oversized vessel stenosis than the "hugging balloon" technique or directional atherectomy. Otherwise, it may be considered as an adjunct technique in order to optimize the angiographic result after stenting or directional arthrectomy in this particular indication.

Aged↗
PubMed1995

Mechanisms of AV node modulation in AV node reentry tachycardia.

Atrioventricular nodal reentrant tachycardia has been recognized for many years as a very common cause of supraventricular tachycardia. First curable by surgery, this tachycardia is now successfully approached by selective radiofrequency current application to the slow pathway of the reentrant circuit. Importantly, these curative treatments brought evidence that the reentrant circuit of this arrhythmia was not confined to the compact atrioventricular (AV) node. These findings stimulate anatomists and basic and clinical electrophysiologists to fundamentally reconsider the atrioventricular junction in order to better understand the mysteries of atrioventricular junctional reentrant tachycardia, as we still do not know exactly what we are doing in AV node region procedures. This article will focus on the different hypotheses regarding the effect of selective slow AV pathway ablation in AV junctional reentrant tachycardia.

Atrioventricular Node↗
PubMed1995

Can early closure and restenosis after endoluminal stenting be predicted from clinical, procedural, and angiographic variables at the time of intervention?

OBJECTIVES: To develop a statistical model to assess the risk of early closure and restenosis on the basis of the information available at the time of stent implantation. DESIGN: An exploratory forward, stepwise multivariate logistic regression for each adverse event and multivariate polychotomous analysis for both events. SETTING: Tertiary referral centre for interventional treatment of coronary artery disease. PATIENTS: 243 consecutive, successful stenting procedures between 1986 and 1993 with the Wallstent, the Palmaz-Schatz and Wiktor stents with analysis of clinical, procedural, and angiographic variables. MEAN OUTCOME MEASURES: Early closure was defined as angiographically documented stent thrombosis within the first 3 weeks after implantation and restenosis according to the 50% reference diameter reduction criterion. RESULTS: Overall early closure and restenosis rates were 14.4% (35/243) and 19.2% (40/208, for a 97% repeat angiography rate). The statistical model predicted a worse outcome for male patients, with less restenosis in female patients. The only risk factor in female patients was the presence of collaterals to the target lesion. For male patients the following risk factors for closure and restenosis were retained: multiple stent implantation during the same session, the presence of collaterals to the target lesion, stenting of the left anterior descending artery or of the left circumflex artery, and bailout stenting. Only bailout stenting implied a decreased restenosis risk. CONCLUSIONS: Clinical, procedural and angiographic variables increase the risk for early closure and restenosis after endoluminal stenting. The prediction models described above need to be validated prospectively.

Angina Pectoris↗
PubMed1995

Major dissection during coronary angioplasty: outcome using prolonged balloon inflation versus coronary stenting.

BACKGROUND: Abrupt or threatened closure is the major acute complication following conventional coronary angioplasty with a persistent incidence of 2% to 10%. OBJECTIVES: In order to evaluate the safety and efficacy of endoluminal stenting and autoperfusion balloon angioplasty in the setting of abrupt or threatened closure following coronary angioplasty, the short- and long-term clinical and angiographic follow-up of respectively 45 and 51 patients treated by either method were compared. METHODS: From August 1986 through August 1992, consecutive patients treated by either endoluminal stenting or autoperfusion balloon angioplasty for abrupt closure following coronary angioplasty, were entered into an observational trial that requested clinical follow-up and repeat angiography at 6 months. RESULTS: Except for vessel localization, baseline clinical, angiographic and procedural characteristics were comparable. The in-hospital clinical and angiographic outcome was similar (p = 0.85) with 69% event-free patients in both treatment groups. The postprocedural minimal luminal diameter was larger following stenting: 2.67 +/- 0.76mm versus 2.07 +/- 0.70mm (autoperfusion balloon) (p = 0.0002). At follow-up, there were less events in the stent group: 11% versus 34% for the autoperfusion balloon angioplasty group, (p = 0.03). Restenosis rates were 5% (2/37 patients, stent) versus 27% (11/41 patients, autoperfusion balloon) (p = 0.02). CONCLUSIONS: Autoperfusion balloon angioplasty and endoluminal stenting are effective and safe therapeutic options for abrupt or threatened closure following coronary angioplasty with a comparable short-term clinical and angiographic outcome. However, during follow-up, more complications occur following autoperfusion balloon angioplasty. This is explained by a higher restenosis rate in this treatment group.

Adult↗
PubMed1995

[Balloon angioplasty for restenosis of coronary endoprostheses].

Between March 1991 and June 1994, the authors treated restenosis (> or = 50%) of coronary endoprostheses in 17 men aged 39 to 72 years by balloon angioplasty. The stents had been implanted for de novo stenosis in 14 patients, restenosis in 1 patient and for acute occlusion in 2 patients. The vessels treated were the left anterior descending artery (1 case), the left circumflex artery (2 cases), the right coronary artery (7 cases) and venous bypass grafts (7 cases). The endoprostheses used were 5 Wallstents in 4 patients, 13 Wiktor stents in 11 patients and 2 Palmaz-Schatz in 2 patients. Clinically, the patients with restenosis presented with class II angina (6 patients), class III (8 patients) and class IV (3 patients) of the Canadian Cardiovascular Society Classification. Conventional balloon angioplasty was performed 17 months (range: 3 to 87 months) after stent implantation and resulted in immediate clinical and angiographic success (residual stenosis < or = 50% on quantitative analysis) in all patients. In particular, there were no dissections. The minimal lumenal diameter (MLD) and percentage stenosis changed from 1.04 mm (range: 0.87 to 1.20) and 72% (range: 68 to 76) respectively before stent implantation to 2.83 mm (range: 2.46 to 3.20) and 23% (range: 20 to 27) after stent implantation. Restenosis resulted in a MLD and percentage stenosis of 0.89 mm (range: 0.77 to 1.01) and 73% (range: 69 to 78) respectively. After angioplasty of the stent, they returned to 2.68 mm (range: 2.29 to 3.06) and 27% (range: 23 to 30) respectively. The patients were not anticoagulated after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗