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S Willems

Publications and source records attributed to S Willems.

At least 73 records · Page 4Linked to original sources
PubMed1993

Unexpected emergence of manifest preexcitation following transcatheter ablation of concealed accessory pathways.

INTRODUCTION: The basis for anterograde or retrograde unidirectional block of accessory pathways still remains a controversial issue. METHODS AND RESULTS: Four of 19 consecutive patients (1 male, 3 female; ages 27 to 34 years) who underwent transcatheter ablation of concealed accessory pathways developed manifest preexcitation after the ablation. The location of the concealed accessory pathways in these four patients were right lateral, left posteroseptal, left posterolateral, and left lateral. Radiofrequency current was used in three of the four patients and high energy direct current in one patient. After ablation, manifest preexcitation was observed in these four patients for the first time. Manifest preexcitation developed immediately after ablation in two of the four patients and after 4 and 14 days in the other two. Detailed endocardial mapping revealed that the manifest preexcitation originated from the same location as the concealed pathways. Subsequently, catheter ablation was successfully performed in three of the four patients using radiofrequency current. One patient underwent successful surgical ablation. No recurrence of preexcitation was observed during a follow-up period of 9 to 38 months. All patients remained free of arrhythmias. CONCLUSION: The basis for this unexpected emergence of preexcitation in these patients with only retrograde conducting accessory pathways deserves further investigation. Although not compared in the present study, this phenomenon has not been reported in patients who underwent surgical interruption of accessory pathways. We postulate that a lesion at the site of insertion of the accessory pathway had modified the anterograde conduction capacity.

Adult↗
PubMed1993

[Torsade de pointes].

Torsade de pointes (TDP) is a polymorphic ventricular tachycardia with a particular electrocardiographic pattern of continuously changing ("twisting") morphology of the QRS complex occurring in the setting of delayed myocardial repolarization (i.e., prolongation of the QT interval). TDP may develop in the setting of an idiopathic disorder (Jervell/Lange-Nielsen syndrome, Romano-Ward syndrome, sporadic long QT syndrome) or may be induced by pharmacologic agents which prolong the QT interval, as well as by other clinical circumstances under which repolarization is delayed (e.g., hypokalemia, hypomagnesemia, bradycardia) (acquired long QT syndrome). Since the treatment of TDP strongly differs from that of conventional ventricular tachycardia, correct diagnosis is critical as it guides the treating physician in selecting the appropriate mode of therapy. In this paper mainly the electrocardiographic criteria presently used for the correct identification of this unusual form of ventricular arrhythmia are presented. Additionally, the potential mechanisms and therapeutic modalities of TDP are discussed.

Anti-Arrhythmia Agents↗
PubMed1993

[Oral anticoagulation for prevention of thromboembolism in non-rheumatic atrial fibrillation: indications, effectiveness and risk].

Oral anticoagulation in patients with rheumatic heart disease for prevention of systemic thromboembolism is accepted clinical practice. The incidence of stroke in patients with nonrheumatic atrial fibrillation is about five times the rate of patients in sinus rhythm. However, contradictory findings in several small retrospective studies have precluded determination of a gold standard for patients with nonrheumatic atrial fibrillation so far. Recently, the results of five prospective, placebo-controlled studies in patients with nonrheumatic atrial fibrillation treated with anticoagulation have been published. A consistent risk reduction of thromboembolism ranging from 37 to 87% in patients treated with warfarin was reported. This risk reduction occurred in excess of a relatively low incidence of intracerebral and/or fatal bleeding complications. The efficacy of prevention of thromboembolism was comparable for high intensity anticoagulation (International Normalized Ratio (INR) 2.8-4.2) and low dose anticoagulation (INR 1.5-2.7). However, fatal and/or intracerebral bleedings only occurred with INR > or = 2.6. In subgroup analysis, recent congestive heart failure, arterial hypertension, and previous apoplex or arterial thromboembolism were independent clinical predictors of increased risk for thromboembolism, whereas results in patients with chronic and intermittent atrial fibrillation were comparable. In 69 patients with lone atrial fibrillation, no single event occurred in the follow-up period. Thus, lone atrial fibrillation does not seem to carry an increased risk for stroke when strict criteria for diagnosis of lone atrial fibrillation are applied. In two of the five studies, aspirin was additionally randomized. Since contradictory findings resulted, the role of aspirin for prophylaxis of stroke still needs to be determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

[Initial presentation of ventricular pre-excitation after catheter ablation of concealed retrograde conducting accessory atrioventricular pathways].

Catheter ablation using radiofrequency or direct current energy was performed in 19 consecutive patients with concealed accessory pathways. Four patients developed manifest preexcitation for the first time following ablation. The concealed accessory pathways of these four patients were localized at right lateral, left posteroseptal, left posterolateral, and left lateral sites, respectively. In two patients, manifest preexcitation developed immediately after attempted ablation. In the other two patients, preexcitation occurred after 4 and 14 days. Electrophysiologic testing revealed in all four patients that the origin of manifest preexcitation corresponded to the site of the concealed pathway. Successful catheter ablation using radiofrequency current was performed in three patients. One patient preferred surgical interruption of the accessory pathway. The reason for this sudden emergence of preexcitation of these patients with only retrograde conducting pathways remains to be investigated. The anterograde conduction capacity might have been modified by damaging the site of the accessory pathway insertion.

Adult↗
PubMed1992

[Percutaneous high frequency current catheter ablation in permanent ventricular tachycardia of the "bundle-branch reentry" type after implantation of an automatic cardioverter-defibrillator].

A 65-year-old female patient with a history of recurrent sustained ventricular tachycardia presented with an incessant ventricular tachycardia (cycle length 360-400 ms) following implantation of a cardioverter-defibrillator (ICD). The tachycardia could not be terminated by antiarrhythmic drug treatment, antitachycardia pacing or internal defibrillation via the ICD. An invasive electrophysiologic study revealed that the mechanism of this newly occurring tachycardia was bundle branch reentry. The patient underwent emergency catheter ablation using radiofrequency (RF) current. Endocardial mapping of the right bundle branch and of the distal His bundle was performed and a bundle branch reentry tachycardia was diagnosed. After delivery of the fifth RF-impulse, the tachycardia terminated and complete AV block was induced. No malfunction of the ICD was observed following RF-ablation. The patient was hemodynamically stable with a junctional escape rhythm and antibradycardia pacing back-up of the ICD (VVI-mode). This case report demonstrates the feasibility of RF catheter ablation in the treatment of incessant bundle branch reentry tachycardia as a complementary option after implantation of an ICD.

Aged↗
PubMed1992

Transcatheter ablation of cardiac tissue: advantages and disadvantages of different ablative techniques.

Transcatheter ablation techniques are emerging as an alternative therapeutical tool in the management of cardiac arrhythmias. Catheter ablation was initially introduced as the last resort to ablate the atrioventricular nodal conduction in patients with atrial fibrillation and uncontrolled ventricular response and in patients with drug refractory ventricular tachycardias. Direct current energy was used as the sole source of energy, but because of potential significant complications and early and late mortality, presumably mostly due to ventricular tachyarrhythmias, other sources of energy were sought. Radiofrequency current which does not produce barotrauma and does not require general anesthesia rapidly replaced direct current ablation in many centers. Early results with radiofrequency current ablation of the atrioventricular node and accessory atrioventricular pathways are very encouraging. The results of radiofrequency as well as direct current ablation for atrial flutter, atrial tachycardia and ventricular tachycardia, where the components of reentry circuit are less defined, are not as favorable as those of AV junctional tachycardias. However, improvement of catheter and generatory technology and better understanding of the mechanisms of ventricular tachycardias and characteristics of the target site will enhance the results of catheter ablation in ventricular tachcardias. The procedures are still considered investigational, and mostly done by very experienced groups at tertiary referral hospitals with surgical teams available in case of serious complications. Larger patient populations and longer follow-up periods are required before these techniques expand to community hospitals and to patients with minimal symptoms or asymptomatic individuals as a prophylaxis therapy.

Cardiac Catheterization↗
PubMed1992

Catheter ablation of ventricular tachycardia using radiofrequency current.

Catheter ablation techniques have evolved as an alternative to map-guided surgery and proven effective in a variety of supraventricular tachyarrhythmias. Direct current catheter ablation has been shown to be effective in about 50 to 70% of cases. Approximately, 60% of patients with structural heart disease and monomorphic ventricular tachycardia were successfully treated using direct current ablation techniques. This overall success rate and possible risks associated with the use of direct current have stimulated the search for other energy sources appropriate for catheter ablation. Presently, only a few preliminary reports on the clinical efficacy of radiofrequency energy for the treatment of ventricular tachyarrhythmias in man exist. 23 patients with identifiable heart disease at a mean age of 52 +/- 17 years underwent radiofrequency catheter ablation. 16 patients had coronary artery disease, one patient dilative cardiomyopathy and six patients had arrhythmogenic right ventricular disease. All patients presented with chronic current sustained ventricular tachycardia. After detailed endocardial catheter mapping radiofrequency energy was applied at the site of earliest ventricular activation during ventricular tachycardia which could be entrained during fixed rate ventricular pacing at the site of origin of ventricular tachycardia. At all ablation sites a long latency between the stimulus and QRS complex was noted. Of 23 patients 18 were treated with radiofrequency alone whereas in five patients a second ablation procedure using direct current was performed. Following the ablation procedures, 14 patients (61%) remained free of ventricular tachycardia. One patient died due to congestive heart failure 21 months following ablation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1991

Regression of left ventricular hypertrophy in hypertensive heart transplant recipients treated with enalapril, furosemide, and verapamil.

BACKGROUND: This prospective study was designed to examine whether left ventricular (LV) hypertrophy of the denervated transplanted heart may be reversed by medical therapy and, if so, to investigate the time course of this process and its effect on exercise capacity, myocardial function, and cardiac hemodynamics. METHODS AND RESULTS: Ten hypertensive heart transplant recipients with LV hypertrophy were evaluated before therapy with enalapril plus furosemide alone or combined with verapamil, at initial blood pressure (BP) control and after 3, 6, 9, and 12 months, using 24-hour noninvasive ambulatory BP monitoring, M-mode and two-dimensional echocardiography, and supine bicycle ergometry. Average 24-hour systolic and diastolic BP declined from 158 +/- 10 and 104 +/- 7 mm Hg to 129 +/- 9 and 84 +/- 10 mm Hg at initial BP control (p less than 0.005 and p less than 0.025, respectively) and total peripheral resistance from 1,687 +/- 177 to 1,376 +/- 122 dyne.sec.cm-5 (p less than 0.025), remaining normal thereafter. Exercise capacity remained unchanged during the study. LV mass, mass-to-volume ratio, and end-diastolic septal plus posterior wall thickness decreased progressively from 211 +/- 30 g, 2.49 +/- 0.62 g/ml, and 25.7 +/- 2.6 mm to 184 +/- 26 g, 2.22 +/- 0.46 g/ml, and 22.5 +/- 1.9 mm after 3 months (all p less than 0.025) and to 174 +/- 25 g, 2.07 +/- 0.38 g/ml, and 21.5 +/- 1.5 mm after 6 months (all p less than 0.005), remaining unaltered at 9 and 12 months. A correlation was found between the decrease in average 24-hour mean BP and LV mass after 3 months of antihypertensive therapy (r = 0.71, p less than 0.05). Systolic meridional wall stress, LV end-diastolic and stroke volume, ejection fraction, and cardiac output remained unchanged throughout the observation period. CONCLUSIONS: The results indicate that regression of LV hypertrophy is induced by effective antihypertensive therapy in the denervated transplanted heart. The extent of decrease in average 24-hour BP appears to be the main determinant for the extent of reduction in LV mass. LV afterload as characterized by systolic meridional wall stress, LV size and pump function, and physical exercise capacity of the transplant patients are not influenced by the therapeutic regimen chosen in this study.

Adult↗
PubMed1990

[Coxa vara. Isolated growth of the greater trochanter. Prevention-treatment].

Prevention of avascular complications is a primary aim. The ischemic insult to the femoral head provokes different types of morphologic deformities depending on its location. When the lateral part of the growth plate is affected, the head will be in valgus with a short neck, on the contrary, when the medial part is affected, a coxa vara occurs. The sooner the growth is stopped, the shorter the neck will be. Nevertheless, the greater trochanter will continue its growth and under certain conditions, will extend beyond the head. The Articulo-Trochanteric Distance is a measurement of the deformity which may be checked regularly. Early recognition permits prevention and adequate treatment. Treatment options include epiphysiodesis of the greater trochanter before the age of 8 to 10 years, trochanteric repositioning with osteotomy, and valgus osteotomy (Pauwels' Y-osteotomy).

Bone Diseases, Developmental↗
PubMed1989

[Circadian behavior of blood pressure and heart rate following orthotopic heart transplantation. Studies before and during antihypertensive therapy].

The de novo hypertension, which develops in most cardiac transplant recipients within the first postoperative months, is multicausal, though toxic side-effects of cyclosporin A seem to play a key role. In order to analyze the circadian behavior of arterial blood pressure and heart rate after cardiac transplantation (HTX) and to evaluate the effect of an antihypertensive regimen on these parameters, 24-h noninvasive ambulatory blood pressure and heart rate monitoring was performed in 10 hypertensive cardiac transplant recipients on cyclosporin A (mean age 42.3 +/- 11.2 years, 14.3 +/- 8.3 months after HTX) before antihypertensive therapy and after introduction of an antihypertensive regimen with the ACE-inhibitor enalapril plus furosemide alone or combined with verapamil. The study demonstrated a complete loss of the usual nocturnal decline in blood pressure in cardiac transplant recipients (mean systolic and diastolic blood pressure 149 +/- 8 and 102 +/- 7 mm Hg during daytime and 152 +/- 8 and 104 +/- 9 mmHg at night). Antihypertensive therapy lowered the blood pressure level effectively, but did not influence the circadian pattern (mean systolic and diastolic blood pressure 121 +/- 8 and 81 +/- 4 mmHg during daytime and 121 +/- 9 and 83 +/- 3 mmHg at night, all p less than or equal to 0.001). Heart rate, in contrast, showed a significant, though in comparison to normal, a blunted decrease at night (mean heart rate 94 +/- 6 beats per min during daytime and 84 +/- 8 beats per min at night, p less than or equal to 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Comparative study of a series of normal knees and a series of knees with patellar instability].

In studying the long-term follow-up of 39 cases of patellofemoral instability operated in our department for recurrent dislocation, we also analyzed their morphological appearance on X-ray. We compared the data given by Maldague and Malghem, Dejour and Walch for the pathological conditions of our cases with the same number of normal knees. This comparative analysis showed that measuring the bulging of the upper part of the trochlea and the depth of its groove on a lateral view is a reliable method to evaluate patellar instability. The classical axial view gives less useful information to quantify the instability. However, this axial view shows a particular aspect in the cases of severe instability: the fulcrum of the trochlea is displaced inwards while the inner trochlear facet is smaller or even absent. This precise radiological examination and the complete clinical examination with an analysis of the "morphotype" (Lerat) are necessary in the screening, diagnosis and treatment of severe patellofemoral instability.

Follow-Up Studies↗
PubMed1989

[Treatment of major patellar instability. Results of the Fèvre-Dupuis operation].

In the treatment of recurrent subluxation and dislocation of the patella in adolescents and young adults, the authors describe a method consisting of: --a modified Roux procedure for internal transposition and advancement of the anterior tibial tuberosity; --the Lecène technic for over-the-top reinsertion of the vastus medialis on the lateral aspect of the patella. All the patients had a plaster cast for 10 days followed by rehabilitation until normal knee function was achieved. Stiff knees were mobilized under general anesthesia. Normal activity was progressively resumed 6 weeks after surgery. Out of the 31 patients (41 knees) available for objective follow-up evaluation, 26 were women and 5 men, with an average age of 19 years. The mean follow-up period was 9 and a half years with a minimum of 2 years and a maximum of 23. End results in terms of relief of pain, patellar stability and knee function were gratifying. Thirty knees were rated good, 8 fair and 3 poor. No recurrence of subluxation or dislocation was found.

Adolescent↗
PubMed1989

[Pathology of the anterior peroneus tendon and that of the intermetatarsal bone].

The inconstant peroneus tertius is the fourth muscle in the antero-lateral aspect of the leg. Its tendon crosses the fourth tendon of the extensor hallucis brevis on the dorsal aspect of the cuboïdo-metatarsal joint. If an impingement occurs it may provoke a painful condition and a typical synovial cyst. The anatomy and the pathology of the condition are described. The treatment is very simple: the inconstant tendon should be removed when it produces symptoms. An accessory bone, the intermetatarsal bone, located at the proximal part of the first intermetatarsal or intercuneiform space, may have various shapes. It can provoke pain in the first space when pressure is exerted on capsulo-ligamentous structures or on neuro-vascular elements. The treatment is excision of the accessory bone.

Foot Diseases↗
PubMedDate not supplied

SLAP lesions: a retrospective multicenter study.

A retrospective analysis of 530 glenohumeral arthroscopies performed by three independent Belgian arthroscopists revealed the presence of 32 SLAP lesions, which represents an incidence of 6%. Since this is exactly the same percentage as found by Snyder et al., we report our data in this article. We classified 23 of the SLAP lesions using Snyder's classification, 7 needed the additional classification of Maffet et al., and 2 lesions were considered to be anatomic variations; 53% of the lesions were of type II. Concerning the mechanism of injury, we found comparable percentages of traction (22%) and compression (28%) injury as reported by Snyder, but also a high number (25%) of overhead sports activities as described by Andrews et al. Associated lesions were in close accordance with Snyder's data, but a relatively low incidence of rotator cuff injuries (10%) was present. Comparison of treatment regimens showed that the same percentage of lesions (34%) was fixed arthroscopically in both series. Only SLAP II, IV, and V lesions must be considered as unstable and in need of fixation. We confirm that patients' complaints and clinical symptoms are vague and inconsistent. Imaging, using computed tomographic arthrography or magnetic resonance, was performed in a minority of cases. Advantages and pitfalls of both techniques are discussed. Anatomic variations causing an extra-large sublabral hole are shown, and we warn about potential diagnostic and therapeutic errors in these cases.

Adolescent↗
PubMedDate not supplied

Heterotopic heart transplantation in 1988--recent selective indications and outcome.

Considering a worldwide average 1-year survival rate of nearly 90% after orthotopic heart transplantation, the question arises as to whether there is still an indication for heterotopic heart transplantation. Since 1967, 132 heart transplantations have been performed at our institution. From 1974 to 1983 only heterotopic transplantations were performed. Since 1985, quadruple-drug therapy has been used for immunosuppression. This consists of low dose cyclosporine in combination with azathioprine, methylprednisolone (in lower dosages), and rabbit antithymocyte globulin (for the first 4 to 6 days after operation and as rescue therapy for severe rejections). Fifty-five transplantations have been performed with this therapy (44 orthotopic and 11 heterotopic). The indications for heterotopic transplantations were either elevated pulmonary vascular resistance (4 to 6 Wood units, n = 6), or a gross donor and recipient weight mismatch (more than 20%) in candidates who showed signs of severe cardiac decompensation (n = 6). One patient had both indications. The 1-year survival rate for those patients was 83%. Currently seven of the 11 patients are alive with life spans ranging from 6 months to 2.5 years after operation. Causes of deaths were infections (n = 3) and chronic graft rejection (n = 1). The recipients were restudied with right-sided heart catheterizations performed from 2 months to 2 years after transplantation. In all patients the cardiac output increased significantly from a mean of 4.0 to 5.8 L/min (p less than 0.0005). In patients with elevated pulmonary vascular resistance, this value decreased after heterotopic transplantation from a mean of 4.9 to 2.4 Wood units.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗