Late in-stent restenosis in coronary arteries and in grafts.
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Aged↗
Biomedical subjects
L Kappenberger
Publications and source records attributed to L Kappenberger.
Pacing in hypertrophic obstructive cardiomyopathy. A randomized crossover study. PIC Study Group.
BACKGROUND: Uncontrolled studies have shown that short atrioventricular delay dual chamber pacing reduces outflow tract obstruction in hypertrophic obstructive cardiomyopathy. Although the exact mechanism of this beneficial effect is unclear, this seems a promising potential new treatment for hypertrophic obstructive cardiomyopathy. METHOD: In order to evaluate the impact of pacing therapy, were performed a randomized multicentre double-blind cross-over (pacemaker activated vs non activated) study to investigate modification of echocardiography, exercise tolerance, angina, dyspnoea and quality of life in 83 patients with a mean age of 53 (range 22-87) years with symptoms refractory or intolerant to classical drug treatment. RESULTS: After 12 weeks of activated or inactivated pacing, independent of which phase was first, the pressure gradient fell from 59 +/- 36 mmHg to 30 +/- 25 mmHg (P < 0.001) with active pacing. Exercise tolerance improved by 21% in those patients who at baseline tolerated less than 10 min of Bruce protocol; symptoms of dyspnoea and angina also improved significantly from NYHA class 2.4 to 1.4 and 1.0 to 0.4, respectively (P < 0.007). Quality of life assessment with a validated questionnaire objectivated the subjective improvement. CONCLUSION: Pacemaker therapy is of clinical and haemodynamic benefit for patients with hypertrophic obstructive cardiomyopathy, left ventricular outflow gradient at rest over 30 mmHg who are symptomatic despite drug treatment.
Adult↗
Regional wall motion during pacing for hypertrophic obstructive cardiomyopathy.
In order to assess the influence of right ventricular stimulation on LV contraction sequence in hypertrophic obstructive cardiomyopathy (HOCM), we performed a regional wall-motion analysis of the left ventricle by comparing normal His-Purkinje activation to pacing from the right ventricular apex. In 9 patients (5 males and 4 females, mean age 61 +/- 9 years) assessed after a mean pacing period of 12 weeks (range 7-24 weeks), AV sequential pacing induced a 52% reduction in maximal pressure gradient from 76 +/- 36 to 40 +/- 28 mmHg (P < 0.01) as determined by Doppler examination. Regional wall-motion analysis of the left ventricle was computed from digitized two-dimensional echocardiographic images by means of the area shrinking method. Pacing induced a significant reduction of total septal area shrinking from 25% +/- 17% to 12% +/- 17% (P < 0.005). A tendency toward paradoxical septal motion was observed in one patient only. The apex showed no significant variation. A 6% increase in area shrinking was observed at the posterior wall and lateral free wall, from 38% +/- 13% to 43% +/- 10% (P < 0.05). Pacing did not significantly alter the global ejection fraction. A direct correlation between the magnitude of subaortic pressure gradient reduction and that of septal motion changes was found in a majority of patients. In conclusion, dual chamber pacing reduces septal wall motion in patients with HOCM obstructive cardiomyopathy. This might be one of the mechanisms involved in the reduction of LV outflow tract obstruction.
Cardiac Pacing, Artificial↗
Acute hemodynamic effects of atrioventricular pacing at differing sites in the right ventricle individually and simultaneously.
We hypothesized that pacing, which provided a rapid uniform contraction of the ventricles with a narrower QRS, would produce a better stroke volume and cardiac output (CO). We sought to study whether pacing simultaneously at two sites in the right ventricle (right ventricular apex and outflow tract) would provide a narrower QRS and improved CO in 11 patients undergoing elective electrophysiology studies. Patients were studied by transthoracic echocardiography measurement of CO using the Doppler flow velocity method in normal sinus rhythm, AOO pacing (rate 80), DOO pacing in the right ventricular apex (AV delay 100 ms), DOO pacing in the right ventricular outflow tract, and DOO pacing at both right ventricular sites simultaneously in random order. The COs were 5.42 +/- 1.83, 5.61 +/- 1.97, 5.67 +/- 1.6, 5.84 +/- 1.68, and 5.86 +/- 1.52 L/min, respectively (no significant difference by repeated measures analysis of variance [ANOVA]). The QRS durations were 0.09 +/- 0.02, 0.09 +/- 0.02, 0.13 +/- 0.027, 0.13 +/- 0.03, and 0.11 +/- 0.03 secs respectively. Repeated measures ANOVA showed that the QRS duration significantly increased with right ventricular apex or right ventricular outflow tract pacing compared to sinus rhythm and AOO pacing (P < 0.001) but then diminished with pacing at both sites (P < 0.01). QRS duration was not correlated with CO, however the change in QRS duration correlated significantly with the change in CO when pacing was performed at the two right ventricular sites simultaneously. In conclusion, during DOO pacing, there was a trend for pacing in the right ventricular outflow tract or both sites to improve the CO compared to the right ventricular apex. With simultaneous pacing at both ventricular sites, the QRS narrowed. Further studies will be required to see if this approach has value in patients with poor left ventricular function or congestive heart failure.
Adult↗
Dual chamber pacing in hypertrophic obstructive cardiomyopathy: beneficial effect of atrioventricular junction ablation for optimal left ventricular capture and filling.
Clinical improvement with dual chamber pacing has largely been reported in patients suffering from hypertrophic obstructive cardiomyopathy and mainly attributed to the reduction of the subaortic pressure gradient. To be effective, pacing must induce a permanent and complete capture of the LV. In two patients of our collective, symptoms (angina and dyspnea NYHA Class III and/or syncopes) persisted or relapsed despite pacing. This was related to the inability to obtain full LV capture due to a too-short native PR interval. RF ablation of the AV junction was therefore performed in both patients, resulting in permanent AV block in one and prolonged PR interval up 310 ms in the second. Pacing was thereafter associated with an immediate and significant clinical improvement related to permanent LV capture, whatever the patient's activity. After RF ablation, the AV delay was set up to induce the best LV filling, as assessed by Doppler analysis of mitral flow. Our observations suggest that RF ablation or modification of the AV junction can be a successful procedure in some patients with residual or recurrent symptoms, when the latter result from a loss of capture or from the inability to program an AV delay that does not compromise the active component to LV filling. Doppler echocardiography is a simple and effective mean to assess the hemodynamic effect of AV interval modulation in this setting.
Angina Pectoris↗
[Immediate and mid-term clinical and angiographic results after implantation of AVE intracoronary micro-stents in 140 consecutive cases. An experience in Lausanne].
Two hundred AVE (Arterial Vascular Engineering) microstents measuring 4 to 30 mm were implanted in 140 patients aged 62 +/- 10 years with Class II to IV angina of the Canadian Cardiovascular Society Classification. The indications were: de novo lesions (30%), suboptimal angioplasty results (54%), acute occlusion (8%) or restenosis (8%). The stents of 3.0 to 4.0 mm diameter were implanted in the left main coronary artery (1%) the left anterior descending artery (20%), the left circumflex artery (19%), the right coronary artery (44%) or a venous bypass graft (7%) after intravenous injection of 15,000 IU of heparin. Daily treatment with aspirin 100 mg and ticlopidine 500 mg was instituted from the day of the procedure. The success rate was 98.5% with only 3 technical failures. The minimal luminal diameter and percentage stenosis ranged from 0.80 +/- 0.2 mm and 74 +/- 13% before to 2.66 +/- 0.38 mm and 15 +/- 7% after the procedure in vessels with an average reference diameter of 3.05 +/- 0.35 mm. There were 3% of stent-related immediate clinical complications. In February 1996, 97 patients had survived 6 months. With a 97% follow-up rate, the clinical event rate was 18%. The angiographic follow-up rate was 70% and the restenosis rate was 27%. The authors conclude that the AVE microstents are easy to implant and provide excellent immediate angiographic results with a low complication rate.
Aged↗
[Specific percutaneous radiofrequency ablation of atrial flutter].
Radiofrequency catheter ablation has recently been successfully applied to patients suffering from atrial flutter. We report our experience in the ablation of typical atrial flutter in 17 consecutive patients refractory to drug treatment. The procedure was initially successful restoring sinus rhythm in 16 patients (94%). During a mean follow-up of 9 months atrial flutter recurred in 4 patients (23%). A second procedure was successfully performed in 2 patients; the other two patients are presently in sinus rhythm under amiodarone which was formerly ineffective. Finally, 59% of the patients were able to discontinue antiarrhythmic medication. In 4 out of 7 patients with dilated cardiomyopathy, the left ventricular ejection fraction normalized a few weeks after ablation. This successful technique should be considered early in the therapeutic approach to patients suffering from typical atrial flutter, to avoid numerous drug treatments, multiple hospitalizations and possible evolution toward non reversible dilated cardiomyopathy.
Adult↗
[Bicycle exercise echocardiography in the supine position: a simple and effective study method for the detection and localization of myocardial ischemia by the first consulted cardiologist].
Exercise echocardiography is increasingly used as an investigative technique, now that dynamic images can be captured digitally. Its equivalent reliability compared to scintigraphic methods has been demonstrated in a hospital setting. This study is an attempt to analyse its impact in daily practise. Standardized progressive stress was provided by bicycle ergometry in a supine position. Echocardiographic images of complete cardiac cycles were obtained in standard apical and parasternal short axial views before, during and after maximum effort and digitized for simultaneous analysis of synchronized images at rest and during exercise. 279 patients were studied (231 men, 48 women, mean age 61 +/- 10 years). Image quality was suboptimal in four cases. In the remaining 275 cases, ischemia was detected in 125 cases, the test was negative in 141 cases and doubtful in nine cases. Control by selective coronary angiography, as motivated by the clinical situation, was performed in 72 cases. In this particular group, exercise echocardiography showed 89% sensitivity, which is significantly higher than the figure of 63% recorded for conventional exercise testing (p < 0.0001). Exercise echocardiography by bicycle ergometer in a supine position is a valid, noninvasive investigative technique which can be used in an outpatient situation (feasibility 95%), since it is available on the spot. Its value appears greatest in cases where exercise ECG was not conclusive. A negative result enables the first consulted cardiologist to reassure the patient immediately, the favourable prognostic value of such a result having been demonstrated in the literature.
Adult↗
[Lausanne experience in radiofrequency percutaneous ablation of the slow pathway in nodal tachycardia].
Atrioventricular nodal reentrant tachycardia (AVNRT) is the most frequent paroxysmal supraventricular tachycardia and results from reentry in the atrioventricular nodal region via slow and fast pathways. The curative treatment of choice consists of selective radio-frequency catheter ablation of the slow pathway. In this retrospective study we report our experience of 73 consecutive patients suffering from AVNRT treated by selective slow pathway ablation and also review some features of AVNRT. AVNRT appeared for the first time at the age of 29 +/- 15 years and lasted for 17 +/- 13 years. In 37% of the patients AVNRT recurred at least weekly, 10% presented with syncope and 15% were admitted to hospital more than 5 times. On average, 2.5+/-1.6 drugs were prescribed to 66 of the 73 patients and 83% of them were drug-refractory. Selective slow pathway ablation was successfully performed in 65 patients (89%). The procedure, although effective, was complicated by atrioventricular block in 2 patients (2.7%) and failed in 6 patients. In 5 of them, fast pathway ablation was attempted and was successful in 2 cases, resulted in atrioventricular block in one case and failed in 2 cases. The complications, apart from atrioventricular block necessitating a pacemaker in all cases, were one pulmonary embolism and 2 pneumothorax. The mean follow-up for the 70 patients for whom ablation was effective (with or without atrioventricular block) is 12.7+/-7.3 months. AVNRT relapsed in 5 patients (7%); all of them underwent a second ablation with 4 successes (slow pathway) and one atrioventricular block (fast pathway after failed slow pathway ablation). 11 patients (16%) developed palpitations: in one case they were due to atrial fibrillation and in 10 cases they remained of unknown origin. The palpitations were of short duration and well tolerated, and these patients nevertheless felt an improvement after the ablation. Therefore, at medium term, 62 patients (85%) remained free from symptoms or only slightly symptomatic and without a pacemaker, and 51 of them (70%) remained completely asymptomatic and without a pacemaker. AVNRT can result in considerable morbidity and antiarrhythmic drugs are frequently ineffective. Slow pathway ablation is a safe and effective treatment for AVNRT. In our opinion, if AVNRT or medical treatment diminish the quality of life, ablation is indicated. When AVNRT presents with hemodynamic collapse, ablation is mandatory. Fast pathway ablation after failed slow pathway ablation is associated with a high incidence of atrioventricular block and is targeted only at very symptomatic patients who accept the possibility of definitive pacemaker implantation.
Adolescent↗
[Therapeutic electrophysiology].
Due to tremendous technical progress during the last decade, electrophysiology offers now a therapeutic option to patients suffering from cardiac arrhythmias owing to radiofrequency catheter ablation. This article focuses particularly on the different radiofrequency ablation approaches used in the most common encountered supraventricular arrhythmias.
Atrial Flutter↗
[Atrial fibrillation].
Atrial fibrillation is the most common arrhythmia the general practitioner as well as the physician in the hospital has to deal with. Even if it is said to be benign, heart failure and embolism may be deleterious consequences of this arrhythmia. In this article we well discuss the management of this arrhythmia, taking into consideration the etiologic factors, the pathophysiology of atrial fibrillation and therapeutic aspects from cardioversion to prevention of embolism.
Aged↗
[Cardiac pacemaker dysfunction secondary to outside interference: a review].
Electromagnetic signals from various sources may cause interference with pacemakers. The safety systems developed by manufacturers are generally effective. Nevertheless, some electromagnetic sources, particularly those found in the medical environment, can induce transitory or permanent pacemaker dysfunction. This paper presents the various sources of electromagnetic signals to which a pacemaker may be exposed. Taking into account the available literature, it attempts to clarify those which are really deleterious for the pacemaker and how to avoid them.
Biophysical Phenomena↗
Stents for intracoronary placement: current status and future directions.
The technique of intracoronary stenting has achieved remarkable progress over the last few years. Improved stent deployment techniques and optimization of postprocedural management have dramatically improved the safety of intracoronary stent placement. At present, the incidence of early vessel closure after stenting is even lower than that after standard angioplasty and, as most operators no longer prescribe aggressive anticoagulation, bleeding complications are uncommon. Stenting has become an extremely effective treatment for abrupt or threatened vessel closure or for any suboptimal angiographic result during conventional angioplasty. Furthermore, large prospective trials have demonstrated that its efficacy is superior to that of conventional angioplasty for primary restenosis prevention in focal lesions of some native coronary arteries. Ongoing trials tend to extrapolate these conclusions to saphenous vein graft lesions. Mechanical support of the vessel wall explains the sustained angiographic benefit observed after stenting. Future developments may include the use of stents as a vehicle for local drug delivery in an attempt to further reduce the incidence of restenosis. In view of these results, coronary stents should be considered a new standard therapeutic modality in interventional cardiology.
Angioplasty, Balloon, Coronary↗
[Coronary angioplasty in elderly patients].
Percutaneous transluminal coronary angioplasty (PTCA) is a widely accepted treatment of symptomatic coronary heart disease providing prompt and prolonged clinical, improvement in most patients. We have examined the value of this therapy in a group of 91 patients in their eighth decade treated by 133 consecutive angioplasties. Most patients had refractory or instable angor in spite of optimal pharmacotherapy. Multivessel disease was present in 67% and maintained left-ventricular function in 92% of the patients. The angiographic success rate of PTCA was 84%; technical failures occurred in 12% and adverse events in 14%. Two patients died. The rate of symptomatic restenosis was 24%. Survival and patients free of myocardial events were at 89% and 60%, respectively, estimated by Kaplan-Meier analysis. PTCA is an efficient and acceptable treatment for the elderly patient with severe and drug-resistant angina. Two years after PTCA the majority of patients was asymptomatic.
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Comparison of elective Wiktor stent placement with conventional balloon angioplasty for new-onset lesions of the right coronary artery.
This study compared the clinical and angiographic outcome, during a 6-month follow-up period, of 84 patients with new-onset lesions of the right coronary artery randomized to either Wiktor stent implantation (42 patients) or conventional balloon angioplasty (42 patients). At hospital discharge, three patients in each group (7%, p = not significant [NS]) reached a clinical end point. At 6 months, these proportions were 24% (10 patients with stents) and 29% (12 patients with angioplasty) (p = NS). There were no incidents of death or myocardial infarction. Despite a larger minimal luminal diameter after stenting (2.87 mm [95% confidence interval; 2.66 to 2.96 mm] vs 2.37 mm [2.23 to 2.61 mm for angioplasty] [p = 0.001]), no difference was observed at 6 months of follow-up (1.75 mm [1.43 to 2.18 mm] vs 1.74 mm [1.45 to 2.03 mm] [p = NS], respectively). Accordingly, angiographic restenosis rates were 47.5% (19 of 40 patients with stents) and 35% (14 of 40 patients with angioplasty) (p = NS). Elective stenting with the Wiktor stent and conventional balloon angioplasty are safe and immediately effective therapeutic options for symptomatic, obstructive right coronary artery disease. At 6 months of follow-up, clinical and angiographic outcome did not differ. The role of Wiktor stent placement in primary restenosis prevention remains to be determined for lesions of the right coronary artery.
Angioplasty, Balloon, Coronary↗
Impact of the implantable cardioverter-defibrillator on rehospitalizations.
UNLABELLED: Patients who survive out-of-hospital ventricular tachycardia or ventricular fibrillation are at risk of sudden cardiac death and often return to hospital after initial discharge. The frequency and duration of readmittance to hospital are not well known. Thus, the purpose of this study was to evaluate the impact of the implantable cardioverter defibrillator on frequency and duration of hospitalizations. METHODS: Between 1989 and 1993, 38 consecutive patients who had drug-refractory ventricular tachyarrhythmias were selected for the study. A total of 38 patients were implanted with the implantable cardioverter-defibrillator in accordance with the guidelines of the European Society of Cardiology. This analysis includes 35 of the 38 patients (92%). All hospitalizations which occurred one year before and one year after were studied. Clinical information for all patients was obtained by consulting medical records and by interviewing personal general practitioners. RESULTS: The annual number of hospitalizations before and after implantation of the implantable cardioverter-defibrillator was, respectively, 3.28 +/- 2.38 hospitalizations/ patient/year and 0.88 +/- 1.23 hospitalizations/patient/year (P < 0.05). Before implantation of the implantable cardioverter-defibrillator, patients were hospitalized a mean of 32.94 +/- 24.18 days/patient/year and after, 9.31 +/- 32.14 days/patient/year (P < 0.05). The number of hospitalizations for cardiac reasons decreased by 90%. Before implantation, the most frequent cause was ventricular tachyarrhythmia (47 hospitalizations for ventricular tachycardia and eight for ventricular fibrillation), while after implantation, it was as a result of the shock from the implantable cardioverter-defibrillator (11 hospitalizations). The number of hospitalizations for non-cardiac reasons were similar in the two time periods. Of the 35 patients, 26 (74%) had at least one appropriate successful ventricular tachycardia interrupted by the implantable cardioverter-defibrillator, while 17 patients (49%) had their ventricular fibrillation terminated. There is a significant difference in the rate of hospitalizations to intensive care units (ICU) between the two periods. Before implantation, 30% of hospital days were spent in the ICU, with 3% after. CONCLUSIONS: This study documents that the implantable cardioverter-defibrillator not only reduces the frequency and duration of hospital stays, but reduces admissions to the more expensive units in hospital. Taking into account the reduction in hospitalizations, the payback period for the implantation of an implantable cardioverter-defibrillator is 19 months.
Adolescent↗
Bezold-Jarisch-like phenomenon induced by radiofrequency ablation of a left posteroseptal accessory pathway via the coronary sinus.
We report a case of asystole induced by radiofrequency (RF) ablation via the coronary sinus in a 35-year-old man suffering from symptomatic left posteroseptal accessory pathway. RF application provoked progressive slowing of the sinus rhythm, disappearance of the preexcitation, and an 8-second period of asystole followed by atrial fibrillation. The causal mechanism proposed is a strong stimulation of vagal afferent pathways linked with sensory endings of the inferoposterior myocardial wall leading to a Bezold-Jarisch-like phenomenon.
Adult↗
Intracoronary Stenting for Restenosis: Long-Term Follow-up: A Single Center Experience.
One-hundred thirteen stents (78 Wallstents, 29 Palmaz-Schatz and 6 Wiktor) were implanted in 106 patients aged 63 +/- 5 years to treat a restenosis following previous angioplasty in a native coronary artery (86 cases) and in a venous graft (20 cases). Implantation was technically possible in all cases. The native vessels had a mean reference diameter of 3.3 +/- 0.3 mm and their mean minimal lumen diameter increased from 1.2 +/- 0.3 mm before angioplasty to 2.8 +/- 0.8 after stent implantation. The venous grafts mean reference diameter was 4.4 +/- 0.7 mm and their mean minimal lumen diameter increased from 1.3 +/- 0.4 mm before angioplasty to 4.0 +/- 0.7 mm after implantation. Percentage stenosis in the native arteries and in the venous grafts were respectively 78 +/- 13% and 69 +/- 14% before angioplasty and 24 +/- 8% and 22 +/- 8% after stent implantation. Complications at 6 months, presented as a ranking scale with 100% follow-up rate were, overall, of 20% clinical events (4% deaths, 6% myocardial infractions, 2% coronary artery bypass grafting and 8% re-angioplasty). Angiographic complications were of 8% subacute thrombosis and 19% restenosis and chronic occlusions. Long-term, at 65 +/- 9 months, clinical (86% follow-up) and angiographic (74% follow-up) showed that only a further 9% clinical events and 14% restenosis (12% of them between 6 and 12 months) occurred after 6 months. At an estimated follow-up time of 104 months, 70% patients remain event-free and the survival rate is 95%. In conclusion, stent implantation in the treatment of restenosis following conventional balloon angioplasty is a valid strategy with good long-term results.
Journal Article↗