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Biomedical subjects

L Kappenberger

Publications and source records attributed to L Kappenberger.

At least 19 recordsLinked to original sources
PubMed1992

[Complementary information from Doppler echocardiography in the electrocardiogram in the basic assessment of chronic coronary heart disease, especially following a myocardial infarct. Observations from an ambulatory cardiology clinic].

In chronic ischemic heart disease, Doppler echocardiography (DE) at rest permits semiquantitative evaluation of scarring and remodelling processes, global ventricular function and, frequently, regional wall motion state. Late complications are detected, namely infarct expansion, true and false ventricular aneurysm, mitral insufficiency, thrombus formation, and associated valvular and aortic diseases are discovered. We studied 100 patients with known chronic coronary artery disease referred for noninvasive evaluation, including electrocardiogram (ECG) and DE. In all patients, the global left-ventricular function was satisfactorily assessable. In roughly two thirds of the documented infarctions. DE confirmed the ECG diagnosis and permitted a more precise diagnosis in the majority of them in terms of localization and/or dimension of the necrosis. In one third of the patients. DE clarified inconclusive ECG tracings. Thus, the baseline noninvasive investigation with ECG and DE is a potent tool in the management of chronic ischemic heart disease, serving as a guide to further investigation and to treatment adjustments.

Adult↗
PubMed1992

Effects of dual-chamber pacing in hypertrophic obstructive cardiomyopathy.

Although attempts have been made to treat hypertrophic obstructive cardiomyopathy with right ventricular pacing, the usual treatment for those refractory to medical therapy is open heart surgery. To assess in detail the value of non-surgical therapy the effects of acute and long-term dual-chamber pacing were investigated in 13 patients with hypertrophic obstructive cardiomyopathy refractory to medical treatment. In the first part of the study, atrioventricular (AV) sequential pacing was found to reduce peak subaortic pressure gradient in 12 of the 13 patients, from 82 (SD 42) to 47 (34) mm Hg (p less than 0.002), without concomitantly reducing aortic blood pressure or cardiac output. This effect was related to AV interval. In the second part of the study, a dual-chamber pacemaker was implanted in 8 patients and programmed to the optimum AV interval for the individual (50-90 ms). Patients were followed up for up to 62 months. Pacing resulted in a significant and long-lasting reduction in severity of angina pectoris (from NYHA class 3 to 1) and dyspnoea (from NYHA class 3 to 2). Echocardiography showed no significant change in septal thickness or left ventricular contractility but there was a trend to a spontaneous decrease in obstruction. In patients with hypertrophic obstructive cardiomyopathy, synchronised and ventricular pacing at optimum AV interval for the individual reduces the intraventricular pressure gradient and improves functional tolerance. Since the effect is longlasting, such pacing should be deemed an alternative therapy to surgery in selected cases.

Adult↗
PubMed1992

[Value of physiological cardiac stimulation in the treatment of hypertrophic obstructive cardiomyopathy].

Subaortic pressure gradient in hypertrophic obstructive cardiomyopathy (HOCM) is the consequence of a dynamic obstruction of the left ventricular outflow tract linked to the presence of a hypertrophied septum. We tried to induce an altered septal motion electrically by physiologic pacing. We studied 8 patients (6 men, 2 women, mean age 60 +/- 13 years) with symptomatic HOCM, resistant to optimal drug treatment. During a hemodynamic study, dual chamber pacing significantly reduced the preexistent subaortic pressure gradient, from 69 +/- 39 to 34 +/- 26 mm Hg (p less than 0.004), without concomitant reduction of aortic pressure or cardiac output. This reduction was dependent upon a optimized AV interval. A dual chamber pacemaker (PM) was then implanted and programmed to VDD mode and optimized AV delay interval (50-90 ms), warranting full ventricular capture. The follow-up of 3 to 30 months showed a significant reduction of both angina (from NYHA class 3 to 1: p less than 0.009) and dyspnea (from 3 to 2: p less than 0.03). An echo-doppler study in 6 patients proved the persistence of the beneficial effect of the stimulation by showing a significant reappearance of the subaortic pressure gradient after switching off the PM, from 44 +/- 29 in VDD pacing mode to 77 +/- 44 mm Hg (p less than 0.02). We conclude that atrial synchronized ventricular pacing, together with an optimized AV interval, significantly reduces the outflow gradient and improves symptoms in patients with HOCM. An altered ventricular activation sequence with late septal activation is suspected to be the mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Endocavitary ablation: a new therapeutic approach to supraventricular tachycardia].

Nowadays patients suffering from supraventricular tachycardia are first treated with antiarrhythmic drugs. In refractory cases alternative treatment is antitachycardia pacemaker implantation or surgery. Recently new percutaneous catheter techniques have been developed to ablate directly the anatomical substrate responsible for the arrhythmia by delivering energy (high or low energy shock or radiofrequency) at the tip of a catheter. This article summarizes the results of clinical application of these different techniques and briefly presents our experience. The very recent studies with RF in patients with drug-refractory av nodal reentry or accessory pathway related tachycardia (WPW syndrome) report a success rate of 92-99% with a very low complication rate. If the long term success of radiofrequency is confirmed this technique will emerge in the near future as the treatment of choice in patients suffering from symptomatic supraventricular tachycardia, since it avoids expensive, longlasting drug treatment with the permanent risk of side effects.

Atrial Fibrillation↗
PubMed1992

Quantitative angiographic follow-up of the coronary Wallstent in native vessels and bypass grafts (European experience--March 1986 to March 1990).

The coronary stent has been investigated as an adjunct to percutaneous transluminal coronary angioplasty to obviate the problems of early occlusion and late restenosis. From March 1986 to March 1990, 265 patients (308 lesions) were implanted with the coronary Wallstent in 6 European centers. For this study, the patients were analyzed according to date of implantation (group 1, March 1986 to January 1988; group 2, February 1988 to March 1990) and vessel type (native arteries versus bypass grafts). Quantitative angiographic follow-up was performed in 82% of the study patients. The early in-hospital occlusion rate in the overall group was 15%. Group 1 patients had a 20% rate in contrast to 12% rate in group 2 (p = not significant [NS]). The early occlusion rate in native vessels and bypass grafts was 19 and 8%, respectively (p = 0.019). Restenosis was determined by 2 criteria (criterion 1, greater than or equal to 0.72 mm loss in minimal luminal diameter from poststent to follow-up; criterion 2, greater than or equal to 50% diameter stenosis at follow-up) within the stent and in the segments immediately proximal and distal to the stent. The restenosis rate with criterion 1 was 43% in the overall group of patients, 35% in group 1 versus 49% in group 2 (p = NS), and 34% in native vessels versus 54% in bypass grafts (p = 0.016). The second criterion was met by 27% of patients in the overall group, 21% in group 1 versus 32% in group 2 (p = NS), and 18% in native vessel versus 39% in bypass grafts (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1992

Long-term clinical and angiographic follow-up of patients treated with the self-expanding coronary stent for acute occlusion during balloon angioplasty of the right coronary artery.

A self-expanding coronary stent was implanted in 17 patients to treat acute occlusion of the right coronary artery after percutaneous transluminal angioplasty. There were 2 women and 15 men, with a mean age of 59 +/- 8 years. All patients underwent at least one follow-up angiographic examination 4 to 6 months after implantation and six patients had additional follow-up angiography. During a mean follow-up interval of 32 +/- 10 months no patient died or had a myocardial infarction. Restenosis within the stent did not occur. Two patients had a new stenosis adjacent to the stent. Stent occlusion was found on follow-up angiography in one patient who had not been treated with an antiplatelet agent. The mean intraluminal diameter was 2.77 +/- 0.5 mm after implantation and 2.67 +/- 0.5 mm on follow-up angiography. It is concluded that coronary stenting is effective in treating right coronary artery occlusion after balloon angioplasty. Immediate and long-term outcome suggest that the right coronary artery may be a particularly favorable site for stent implantation.

Angioplasty, Balloon, Coronary↗
PubMed1992

[Sudden cardiac death: possibilities of interventional therapy].

There is, at present, no method to prevent sudden cardiac death. However, in patients with documented high risk the implantable automatic cardioverter defibrillator is the only reliable alternative. However, the electrical discharges of high energy may cause discomfort and pain. Antitachycardia pacing is effective for most episodes of ventricular tachycardia and can effectively reduce the number of electrical shocks to be delivered.

Death, Sudden, Cardiac↗
PubMed1991

Long-term follow-up of the first 56 patients treated with intracoronary self-expanding stents (the Lausanne experience).

Fifty-six patients treated with the self-expanding intracoronary stent for acute occlusion during percutaneous transluminal coronary angioplasty (PTCA) or restenosis were followed for 24 to 43 months (mean 34). Successful deployment and positioning were achieved in 55 of 56 patients. Occlusion of the stent was documented in 8 patients, the earliest occurring 30 minutes and the latest 8 months after implantation. Three of the occluded stents were recanalized by PTCA. Coronary artery bypass grafts (CABG) were required in 4 patients: 1 for symptomatic restenosis, 1 for left main stenosis adjacent to the stent and 2 for acute ischemia during the in-hospital stay (less than 7 days). Myocardial infarction occurred in the territory of the stented vessel in 8 patients. Seven patients died between 1 day and 19 months after implantation. Local bleeding complications occurred in 10 patients, with 5 requiring blood transfusion. Restenosis within the stent was angiographically documented in 5 patients (9%). A new lesion in the treated vessel was found in 10 patients, followed by implantation of a second stent in 5 and a third stent in 1 patient. Medical treatment was instituted in the remaining 4 patients. Forty-nine patients (88%) are alive. Twenty-nine patients (51%) remained asymptomatic, and 44 (78%) are in a better functional class than before the implantation. Eleven of 15 (79%) major complications (acute occlusions or deaths) occurred in patients who received a stent in the left anterior descending coronary artery. In conclusion, implantation of the self-expanding intracoronary stent appears to be a new therapeutic option for treating acute occlusion or restenosis after PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1991

[Transesophageal echocardiography. Indications and clinical usefulness].

To optimize the clinical applications of transesophageal echocardiography (TOE), we have compared the contribution of TOE with that of transthoracic echocardiography (TEE). TOE and TTE were performed in 19 outpatients, 17 hospitalized patients and 16 surgical patients (33 males and 19 females, mean age 53.3 +/- 16.8 years). TOE obtained a diagnosis unsuspected from TTE in 12 cases, and additional useful clinical information was obtained by TOE in 15 cases. Surgical treatment was decided on the basis of TOE alone in 8 cases. Patient tolerance of TOE was excellent and no major complications occurred. In conclusion, additional information obtained by TOE was clinically useful in about half of patients (52%), in particular in the diagnosis of cardiogenic embolism and in clinically suspect endocarditis, valvular dysfunction or aortic dissection.

Adult↗
PubMed1991

Angiographic follow-up after placement of a self-expanding coronary-artery stent.

BACKGROUND: The placement of stents in coronary arteries after coronary angioplasty has been investigated as a way of treating abrupt coronary-artery occlusion related to the angioplasty and of reducing the late intimal hyperplasia responsible for gradual restenosis of the dilated lesion. METHODS: From March 1986 to January 1988, we implanted 117 self-expanding, stainless-steel endovascular stents (Wallstent) in the native coronary arteries (94 stents) or saphenous-vein bypass grafts (23 stents) of 105 patients. Angiograms were obtained immediately before and after placement of the stent and at follow-up at least one month later (unless symptoms required angiography sooner). The mortality after one year was 7.6 percent (8 patients). Follow-up angiograms (after a mean [+/- SD] of 5.7 +/- 4.4 months) were obtained in 95 patients with 105 stents and were analyzed quantitatively by a computer-assisted system of cardiovascular angiographic analysis. The 10 patients without follow-up angiograms included 4 who died. RESULTS: Complete occlusion occurred in 27 stents in 25 patients (24 percent); 21 occlusions were documented within the first 14 days after implantation. Overall, immediately after placement of the stent there was a significant increase in the minimal luminal diameter and a significant decrease in the percentage of the diameter with stenosis (changing from a mean [+/- SD] of 1.88 +/- 0.43 to 2.48 +/- 0.51 mm and from 37 +/- 12 to 21 +/- 10 percent, respectively; P less than 0.0001). Later, however, there was a significant decrease in the minimal luminal diameter and a significant increase in the stenosis of the segment with the stent (1.68 +/- 1.78 mm and 48 +/- 34 percent at follow-up). Significant restenosis, as indicated by a reduction of 0.72 mm in the minimal luminal diameter or by an increase in the percentage of stenosis to greater than or equal to 50 percent, occurred in 32 percent and 14 percent of patent stents, respectively. CONCLUSIONS: Early occlusion remains an important limitation of this coronary-artery stent. Even when the early effects are beneficial, there are frequently late occlusions or restenosis. The place of this form of treatment for coronary artery disease remains to be determined.

Angiography↗
PubMed1991

Subjective visual echocardiographic estimate of left ventricular ejection fraction as an alternative to conventional echocardiographic methods: comparison with contrast angiography.

Left ventricular ejection fraction (LVEF) is a measure of ventricular function with clinical and prognostic significance and can be reliably calculated with various M-mode and two-dimensional echocardiographic formulas in selected, good quality echocardiograms. Subjective visual echocardiographic estimate of LVEF is a potentially less time consuming and more widely applicable method. In order to test its reliability, we performed a prospective blind trial in 40 consecutive patients undergoing biplane contrast ventriculography (BCV), to compare the visual estimate of LVEF during a complete echocardiogram of three independent observers with (1) cubed M-mode formula, (2) Teichholz M-mode formula, (3) length-area method from the four-chamber view, and (4) Simpson's single plane formula. BCV was the reference method. The best correlation with BCV was obtained by visual estimate [r of the three observers, respectively = 0.75; 0.84; 0.81] and M-mode measurements [r (1) = 0.8; r (2) = 0.8], but the most sophisticated methods provided the poorest estimate [r (3) = 0.54; r (4) = 0.49]. All correlation coefficients improved when good studies, defined as a definition of the endocardial surface of more than 75%, were selected (n = 23), but the differences persisted. One observer systematically estimated higher values than the other two (Friedman's test, p less than 0.01) and this interobserver variability suggests that each echocardiographer should test himself against BCV in his lab in order to apply the visual estimate method reliably.

Adult↗
PubMed1991

Experience with a new implantable pacer-, cardioverter-defibrillator for the therapy of recurrent sustained ventricular tachyarrhythmias: a step toward a universal ventricular tachyarrhythmia control device.

Ten consecutive patients (mean age 57.9 +/- 7.6 years) were treated with an investigational tachyarrhythmia control device, the implantable Medtronic Pacer-, Cardioverter-, Defibrillator model 7216A or 7217B. All patients had coronary artery disease with old myocardial infarctions and presented hemodynamically significant sustained ventricular tachyarrhythmias not suppressed by antiarrhythmic drug therapy and unrelated to acute myocardial infarction. In two patients a nonthoracotomy lead system was implanted. Lowest effective defibrillation energy ranged from 5 to 18 joules (mean 12.2 +/- 4 joules) for the epicardial bielectrode systems and were 15 and 18 joules for the nonthoracotomy lead system implants. The postoperative periods were unremarkable. Follow-up ranged from 7 to 19 months (mean 13.8 +/- 4.5 months). Spontaneous tachyarrhythmia episodes were detected and treated by the device in six patients, five of them received staged therapies. No deaths occurred and no hospital admissions were necessary for device related or ventricular tachyarrhythmia related complications. In conclusion, this integrated device represents a major step toward the development of a universal ventricular arrhythmia control device.

Aged↗
PubMed1991

Cardiac sources of embolism and cerebral infarction--clinical consequences and vascular concomitants: the Lausanne Stroke Registry.

We studied clinical characteristics and coexisting causes of stroke in 305 patients admitted to a population-based primary care center with an initial ischemic stroke and a potential cardiac source of embolism (PCSE). Using systematic standardized cardiac, arterial, and cerebral investigations and the logistics of the prospective Lausanne Stroke Registry, we found that nonprogressive onset, hemianopia without hemiparesis or hemisensory disturbances, Wernicke's aphasia, ideomotor apraxia, involvement of specific territories (posterior division of middle cerebral artery, anterior cerebral artery, cerebellum, multiple territories), and a hemorrhagic component were associated with the presence of a PCSE, as compared with 1,006 initial ischemic stroke patients without PCSE. Although age and sex did not differ, the frequency of hypertension, diabetes, cigarette smoking, elevated blood cholesterol, and deep hemispheric or brainstem infarcts was higher in the patients without a PCSE. Nearly one-fourth of the patients with a PCSE had a coexisting potential arterial cause of stroke (large artery greater than or equal to 50% stenosis or small-vessel disease). In the majority of patients with a PCSE (76.7%), cardioembolism was the most likely cause of stroke, although a direct source of embolism was uncommon (4.3%) and intracranial embolic occlusions were present in less than one-half of the patients who were angiographed.

Adolescent↗