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B Letac

Publications and source records attributed to B Letac.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Coronary involvement in systemic lupus erythematosus].

BACKGROUND: Coronary artery disease is an uncommon event in lupus erythematosus. The mechanisms responsible for coronary occlusion are probably complex and intermixed. We report three patients with lupus erythematosus and antiphospholipid antibodies who had coronary artery disease diagnosed with coronary angiogram. OBSERVATION: Coronary artery disease occurred in three young patients aged from 21 to 35 years 3 to 11 years after the onset of lupus. They all had antiphospholipid antibodies. They had been treated with corticosteroids for 6 to 36 months. Two of them were smokers. Angiograms showed coronary occlusion two patients while the third one had probable myocardial microvasculopathy. The lupus was quiescent in all cases when coronary artery disease occurred. DISCUSSION: Antiphospholipid antibodies associated with smoking may be involved in the pathogenesis of coronary artery disease in these 3 patients.

Adrenal Cortex Hormones↗
PubMed1996

Radiofrequency catheter ablation of atrial flutter. Further insights into the various types of isthmus block: application to ablation during sinus rhythm.

BACKGROUND: Radiofrequency ablation of type 1 atrial flutter (AF1) has recently evolved toward an anatomically guided procedure directed to isthmuses at the lower part of the right atrium (RA). However, different types of block at these isthmuses may be observed and potentially correlated with different late outcomes. In addition, because the ablation is anatomically guided, ablation should be possible during sinus rhythm. METHODS AND RESULTS: Forty-four patients underwent ablation of type 1 AF1 performed during ongoing tachycardia (33 patients) or sinus rhythm (11 patients). Evidence of inferior vena cava-tricuspid annulus isthmus block was assessed by changes in RA impulse propagation while pacing from both sides of the ablation site. Apparent complete isthmus block was achieved in 43 of 44 patients with 9 +/- 7 pulses. However, incomplete block mimicking complete block because of intra-atrial conduction delay but leading to a different low RA activation pattern was individualized. At the end of the procedure, isthmus block was complete in 35 patients and incomplete in 8, but since AF1 reinduction was no longer possible, patients were discharged. During a follow-up period of 12.1 +/- 5.5 months, 4 patients experienced AF1 recurrence; all had shown incomplete or no block. CONCLUSIONS: Detailed multiple-point low RA mapping is necessary to differentiate incomplete from complete isthmus block. Complete block is the best marker for long-term success of AF1 ablation, although incomplete block may be sufficient to prevent recurrence in a significant number of cases. Isthmus block is achievable during sinus rhythm, and AF1 induction is not mandatory.

Atrial Flutter↗
PubMed1996

Effects of prolonged sequential balloon inflations on results of coronary angioplasty.

In percutaneous transluminal coronary angioplasty (PTCA), prolonged balloon inflations using perfusion balloon catheters have shown a higher procedural success rate and fewer in-hospital complications than short balloon inflations. However, perfusion balloons have well-recognized limits for routine use. This study assessed the effects of a prolonged cumulative occlusion time obtained with sequential balloon inflations using a routine balloon catheter, applicable to all lesions, and compared these results with those obtained with standard short balloon inflations. Three hundred ten lesions (in 289 patients) were randomized to either standard (3 to 5 inflations < or = 1 minute each; n = 161) or prolonged (3 to 5 inflations of 3 to 5 minutes each; n = 149) balloon inflations. Angiographic success (residual stenosis <50% and no dissection > or = D1) was assessed at the end of this "protocol" phase. Further dilatation was performed if required ("adjunctive" phase). Systematic repeat catheterization was scheduled 4 to 6 months later. Cumulative inflation time was 198 +/- 58 seconds in the "standard" group versus 782 +/- 303 seconds in the "prolonged" group. At the end of the protocol phase, the success rate was higher after prolonged than after standard dilatation (92% vs 80%; p <0.002), with less frequent dissections (14% vs 30%; p = 0.0009). At the end of the adjunctive phase, required for 12 patients in the prolonged group and 32 patients in the standard group (p = 0.003), results were comparable in the 2 groups and the restenosis rate was similar at 6 months. The prolonged cumulative occlusion time achieved with sequential balloon inflations using a routine balloon catheter improves the immediate results of PTCA. Repeat catheterization shows no effect of prolonged sequential inflations on the restenosis rate.

Aged↗
PubMed1996

Radiofrequency catheter ablation of atrial tachycardias.

Atrial tachycardias are frequently unresponsive to medical therapy. His bundle ablation has been proposed as a palliative treatment to treat symptoms and prevent development of tachycardia-mediated cardiomyopathy. Experience with catheter ablation directed at the atrial origin of the tachycardia remains limited. We reviewed the initial success rate and long-term follow-up of radiofrequency ablation of atrial tachycardias. Thirty-six patients underwent electrophysiologic study and radiofrequency ablation of atrial tachycardias, excluding atrial flutter. The suspected mechanism of the clinical arrhythmia was automatic in 16 patients, intraatrial reentrant in 15, sinoatrial reentrant in 3, and unknown in 2. One or two ablation catheters with a 4 mm distal electrode were used to find (1) the earliest local atrial activation time compared to P-wave onset in the bipolar recording mode and (2) a QS pattern in the unipolar mode. When two ablation catheters were used, an encircling approach was taken. Pace-mapping during sinus rhythm and entrainment techniques were occasionally used for mapping. Tachycardia rose from the right atrium in 33 of 36 patients and from the left atrium in the remaining three. Three patients showed multiple foci during the procedure. Successful ablation was obtained in 31 (86%) of 36 patients, with a median of two radiofrequency applications (range 1 to 32) at 10 to 50 W for 10 to 60 seconds. Failure occurred in 5 patients (including the 3 patients with multiple atrial foci). Late follow-up (18 +/- 15 months) showed recurrence of atrial tachycardia in 2 patients, each of whom underwent a successful second ablation. Emergence of another atrial tachycardia was noted in 2 other patients, and an uncommon atrial flutter was noted in 1 patient with repaired atrial septal defect. No late sinus or atrioventricular nodal dysfunction were observed. In conclusion, radiofrequency catheter ablation is a safe and reasonable alternative for atrial tachycardias that do not respond to drugs. However, as previously suggested by the surgical experience, the success rate of ablation appears less satisfactory in patients with multiple sites of origin of ectopic atrial tachycardia.

Adult↗
PubMed1996

Mitral valve reconstruction: long-term results of 120 cases.

Between January 1977 and December 1992, 120 patients underwent mitral valve reconstruction for pure mitral valve regurgitation (n = 88), or associated with mitral stenosis (n = 32). The mean age was 57.6 years. Some 89 patients were in New York Heart Association (NYHA) class III and IV; 61% were in atrial fibrillation. Four mechanisms of mitral regurgitation were assessed: dilatation of the annulus (group I: n = 10); increased amplitude of valve motion (group II: n = 62); restriction of valve motion (group III: n = 23), and mixed lesions (group IV: n = 25). Mitral valve repair was carried out using techniques described by Carpentier. Ring annuloplasty was performed in all patients. There were two operative deaths, and six late deaths. Mean patient follow-up was 41 (range 2-142) months. The actuarial survival rate, excluding hospital deaths, was 91.7% at 5 years and 89.1% at 8 years. Actuarial freedom from reoperation at 8 years was 95(2)%. Freedom from all thromboembolic complications was 89.1% at 8 years. Most survivors had improved to NYHA class I or II and postoperative Doppler echocardiography revealed satisfactory mitral valve competence in 83 patients. Mitral valve reconstruction for mitral regurgitation using Carpentier techniques provides excellent long-term functional results and should be considered as the procedure of choice in patients referred for mitral regurgitation.

Adolescent↗
PubMed1996

Aortic valve replacement after aortic valvuloplasty for calcified aortic stenosis.

OBJECTIVE: This study concerns patients who underwent one or several aortic balloon valvuloplasties at our institution and subsequently required cardiac surgery, either on an emergency basis after aortic valvuloplasty or due to the development of aortic stenosis. METHODS: Between February 1987 and December 1993, 137 patients (73 male, 64 female, mean age 72 +/- 9 years) underwent aortic valve replacement for calcified aortic stenosis after several percutaneous balloon aortic valvuloplasties. Thirty-one patients were in NYHA stage II, 70 in stage III and 36 in stage IV. Seventy patients had angina (23 stage I or II, 47 stage III or IV) and 24 patients presented syncope or lipothymia. Twenty-three percent had at least two of these three symptoms. The indications for balloon dilatation were non-definitive surgical contraindication or high surgical risk (73), personal choice (49), refusal of surgery (9) and emergency (5:2 massive aortic regurgitation, 1 left ventricle perforation, 1 cardiogenic shock, 1 endocarditis in cardiogenic shock). Seven patients received preoperative aortic valvuloplasty due to a very high operative risk. The average time between dilatation and surgery was 472 days and there was clinical improvement for an average period of 261 days. The aortic valve replacements consisted of 58 mechanical prostheses and 79 xenografts with 22 concomitant procedures. RESULTS: Operative mortality was eight patients (5.8%). During the follow-up (17.4 +/- 9.2 months), four patients died (3.6%), 91.2% of the patients were in class I and II and 95% were without angina. The actuarial survival rate was 90.5 +/- 6.6% including hospital mortality. CONCLUSIONS: Both our experience and the literature show that balloon aortic valvuloplasty is followed by an immediate improvement in hemodynamic status with a decrease in valve gradient and an increase in valve area. However, the hemodynamic benefit is typically short-lived with a very high restenosis rate. Balloon aortic valvuloplasty is not an alternative to aortic valve replacement, which remains the best treatment for calcified aortic stenosis; the benefits and long-term results of aortic valve replacement are well established, even in the elderly.

Adult↗
PubMed1996

Electrocardiographic patterns and results of radiofrequency catheter ablation of clockwise type I atrial flutter.

INTRODUCTION: Counterclockwise right atrial propagation is usually observed in common atrial flutter, but little is known regarding flutter with clockwise right atrial rotation. The aim of this study is to describe the ECG characteristics and results of catheter ablation of atrial flutter with clockwise right atrial rotation. METHODS AND RESULTS: Among the 38 patients with type I atrial flutter in this study population, right atrial impulse propagation was counterclockwise in 20 and clockwise in 8. In the remaining 10 patients, both clockwise and counterclockwise patterns were seen. Clinical and ECG parameters associated with clockwise flutter were compared to those of 28 cases of counterclockwise atrial flutter. Ablation was performed in 11 of 18 cases using a technique identical to that used for counterclockwise flutter. A classical "sawtooth" pattern of the flutter wave was observed in 28 of 28 counterclockwise and 14 of 18 clockwise flutter. A shorter plateau phase, a widening of the negative component of the F wave in the inferior leads, and a negative F wave in V1 were the most consistent findings in clockwise flutter. Coronary sinus recording always showed septal to lateral left atrial impulse propagation. Ablation was successful in 11 of 11 cases of clockwise flutter in whom this procedure was performed, with 9.5 +/- 11.6 radiofrequency pulses delivered between the tricuspid valve and the coronary sinus ostium (n = 5) or the inferior vena cava (n = 5), and in the proximal coronary sinus (n = 1). After a follow-up of 46.6 weeks, two recurrences of clockwise flutter were encountered, which were successfully treated with a second session. CONCLUSION: Contrary to commonly accepted concepts, clockwise rotation of atrial flutter is not an infrequent phenomenon and can mimic counterclockwise rotation. It can also be successfully ablated by radiofrequency pulses.

Atrial Flutter↗
PubMed1996

[Value of dobutamine echocardiography in the detection of coronary disease in heart transplant patient. Groupe de Recherche VACOMED].

The value of Dobutamine stress echocardiography in the detection of coronary artery disease in heart transplant patients was studied in 64 patients at control coronary angiography 39 +/- 14 months after transplantation. Dobutamine was infused at progressively increasing doses (5 to 40 micrograms/kg/min) at 5 minute intervals, in order to reach 85% of the theoretical maximal heart rate or an ischaemic event. Echocardiography was analysed in the 4 standard views which were digitised allowing calculation of a regional wall motion score under basal conditions and at peak dosage in 16 left ventricular segments. Coronary angiography identified three groups: group I: 29 patients with normal coronary arteries; group II: 17 patients with non-significant coronary disease (diffuse or localised stenosis < 50%); group III: 9 patients with significant (> 50%) coronary disease. Dobutamine stress echocardiography showed regional wall motion abnormalities in 2/29 patients in group I, 13/17 patients in group II and all patients in group III (global sensitivity: 85%; specificity: 97%). The contractility score was significantly higher under basal conditions in group III (1.45 +/- 0.54) than in group I (1) and group II (1.17 +/- 0.23). At peak dose, the contractility score was unchanged in group I and increased significantly (p < 0.01) in the other two groups. The authors conclude that Dobutamine echocardiography is a reliable, non-invasive method of detecting coronary disease in cardiac transplant patients, and is particularly valuable for demonstrating myocardial ischaemia related to coronary lesions judged to be not significant at coronary angiography.

Adult↗
PubMed1996

[Myocardial adaptation to ischemia. A study during repeated prolonged coronary occlusions in angioplasty].

Coronary angioplasty provides an ideal model for studying ischemic preconditioning in humans. Four coronary occlusions, each lasting 5.2 +/- 1.3 min, separated by 3 min of reperfusion, were performed during angioplasty of isolated stenosis of the left anterior descending artery of 18 patients with stable angina and normal left ventricular function. The ischaemia was evaluated and compared during the first and fourth coronary occlusion with the aid of clinical, electrocardiographic, echocardiographic and metabolic parameters. We analysed: 1) interval to chest pain and its intensity; 2) degree of ST change on the intracoronary electrocardiogram; 3) regional wall motion abnormalities on 2D echocardiography; 4) coefficient of myocardial lactate extraction. The results showed that during the fourth occlusion: chest pain occurred later (93 +/- 57 vs 60 +/- 49 s; p < 0.05) and ST elevation was less (0.69 +/- 0.5 vs 1.03 +/- 0.8; p < 0.05). During the fourth occlusion, there was a delay in appearance and a decrease in the regional wall motion abnormalities: anterior wall hypokinesia occurred later: 26 +/- 15 vs 19 +/- 19 s (p = 0.08). Akinesia observed in 10 patients out of 13 (77%) during the first occlusion, was only observed in 8 patients (62%) and dyskinesia, observed in 5 patients out of 13 (38%) during the first occlusion was not observed thereafter in any patient. The production lactate was less important during the fourth occlusion than during the first one: -3 +/- 17% vs -12 +/- 19% (p < 0.05). This study confirms that, in man, preconditioning allows myocardial adaptation to successive episodes of acute ischaemia.

Adaptation, Physiological↗
PubMed1996

[Determination of cardiac troponin I on Stratus analyzer: prospective evaluation in unstable angina].

Cardiac troponin I (troponin lc) has been measured on the Dade Stratus analyzer. Cardiac specificity has been studied in patients presenting a rhabdomyolysis syndrome. The obtained results clearly demonstrated that this parameter may be used as a specific marker of myocardial injury, in contrast to total creatine kinase- or mass CK-MB measurements. In unstable angina, two groups of patients may be defined: one group with elevated troponin lc (> 0.60 microgram/L; 31 patients, group I), one other with normal troponin lc (< 0.35 microgram/L; 49 patients; group II). Quantitative angiographic analysis was performed on 50 patients including 18 patients from group I. Group I showed a more severe culprit lesion than group II. All the results suggested that troponin Ic might be an indicator of severity in unstable angina.

Adult↗
PubMed1995

Standard orthotopic heart transplantation versus total orthotopic heart transplantation. A transesophageal echocardiography study of the incidence of left atrial thrombosis.

BACKGROUND: After standard orthotopic heart transplantation (Sd HT), the enlarged resultant atria may promote atrial thrombosis. The purpose of this study was to compare the incidence of spontaneous echo contrast and left atrial thrombosis after Sd HT and total orthotopic (Tot HT) heart transplantation. METHODS AND RESULTS: Transesophageal echocardiography (TEE) was performed in 75 patients with Sd HT and in 20 patients with Tot HT. Despite the use of antiplatelet therapy, an acute arterial embolism occurred in 11 (15%) of the 75 patients with Sd HT but in none of the 20 Tot HT patients. All patients were in sinus rhythm. Left ventricular ejection fraction was similar in Sd HT and Tot HT patients. Left atrial diameter was smaller in Tot HT patients than in Sd HT patients (41 +/- 4 versus 58 +/- 6 mm, P < .001). In Sd HT patients, spontaneous echo contrast was present in 43 patients (57%) and was associated with left atrial thrombus in 20 patients (on the left atrial appendage in 12 patients, on the posterior wall in 6, and on the suture in 2). No thrombus was detected by transthoracic echocardiography; all thrombi were detected by TEE. On the other hand, no left atrial thrombus was observed in Tot HT patients, and only 1 patient had spontaneous echo contrast. Of the 11 Sd HT patients who experienced an arterial embolism, 5 had both spontaneous echo contrast and left atrial thrombus and 5 had only spontaneous echo contrast. CONCLUSIONS: This study demonstrates a high rate of left atrial thrombus after Sd HT and emphasizes the role of TEE in the follow-up of these patients. The therapeutic implications are the need for a preventive anticoagulant therapy in the high-risk population receiving Sd HT diagnosed with TEE and the consideration of Tot HT as a better surgical approach as far as thrombotic complications are concerned.

Adult↗
PubMed1995

Radiofrequency catheter ablation of type 1 atrial flutter. Prediction of late success by electrophysiological criteria.

BACKGROUND: Radiofrequency energy has demonstrated its efficacy in catheter ablation of atrial flutter (AFl). However, long-term recurrences of AFl have been reported frequently after initial, apparently successful ablation. To date, criteria for prediction of late recurrences are lacking. METHODS AND RESULTS: Twelve patients (10 men; mean age, 53.6 years; range, 26 to 69 years) were referred for AFl ablation. Duodecapolar and decapolar catheters were used for detailed mapping of the tricuspid ring, the inferior vena cavatricuspid annulus (IVC-TA) isthmus, and the coronary sinus ostium (CSOs) area. Additional multipolar catheters were used for recording activation of the coronary sinus and the CSOs-TA isthmus. AFl was present at baseline in 9 patients and was induced by proximal coronary sinus (PCS) pacing in 3. Counterclockwise right atrial activation was recorded in all patients. Primary success of ablation was defined as when AFl was no longer inducible even during isoproterenol infusion. AFl was successfully ablated in all 12 patients, with a median of 4 pulses delivered at the IVC-TA isthmus. In the 3 patients in whom AFl was induced, during PCS pacing in sinus rhythm before ablation, a collision of descending and ascending wave fronts was observed at the middle lateral right atrium (LRA). This activation pattern of the LRA also was noted after unsuccessful radiofrequency applications. Noninducibility of AFl after radiofrequency applications was associated with a change of activation pattern at the LRA and with an inversion of the activation sequence of the IVC-TA isthmus (from clockwise to counterclockwise) in 9 patients when pacing from the PCS. In 2 of 3 patients, despite noninducibility of atrial flutter, ablation was pursued to obtain evidence of permanent block of conduction at the IVC-TA isthmus. Finally, a completely descending LRA wave front was observed when pacing from the PCS in all patients except one. Low LRA pacing was also performed in 4 patients and showed evidence for block in the counterclockwise direction at the isthmus. During a follow-up of 9 +/- 3 months, AFl recurred in 1 patient; this was the only patient who showed no conduction block at the isthmus after the procedure. CONCLUSIONS: Direction of impulse propagation at LRA and block of propagation at the IVC-TA isthmus during PCS and low LRA pacing appear to be of interest in predicting long-term success of AFl ablation.

Adult↗
PubMed1995

Dobutamine stress echocardiography in orthotopic heart transplant recipients. VACOMED Research Group.

OBJECTIVES: This study sought to determine whether dobutamine stress echocardiography could accurately identify coronary artery disease after heart transplantation. BACKGROUND: After heart transplantation, coronary artery disease is related to either diffuse concentric intimal thickening or focal stenosis and may be underdiagnosed by coronary angiography. METHODS: We enrolled 41 patients, a mean (+/- SD) of 40 +/- 20 months after heart transplantation, at the time of their routine control coronary angiogram. Three patients were excluded because of poor echogenicity on the angiogram and one because of ventricular premature beats. Standard echocardiographic views were acquired at baseline and at incremental dobutamine infusion levels (from 5 to a maximal dose of 40 micrograms/kg body weight per min at 3-min intervals). Regional wall motion score was calculated from a 16-segment model, and each segment was graded from 1 (normal) to 4 (dyskinesia). Coronary angiography was performed 24 h after dobutamine stress echocardiography, and angiograms were analyzed in blinded manner. RESULTS: Twenty-three (62%) of 37 patients had normal coronary angiographic findings. Dobutamine stress echocardiography showed abnormalities in only 2 of 23 patients. Fourteen patients (38%) had abnormal angiographic findings, seven of whom had stenoses > 50%. Dobutamine stress echocardiography correctly identified the corresponding hypoperfused segments in these seven patients. More of interest were the other seven patients, of whom three had angiographic nonsignificant stenoses (< 50%), and four had minor diffuse coronary irregularities. Dobutamine stress echocardiography showed hypokinesia in five of these seven patients despite nonsignificant lesions at coronary angiography. The respective overall sensitivity and specificity of dobutamine stress echocardiography were 86% and 91%. At follow-up, 2 of the 37 patients had an acute myocardial infarction. Both had abnormal findings on dobutamine stress echocardiography: One had normal coronary angiographic results, and one had significant coronary lesions. CONCLUSIONS: Dobutamine stress echocardiography is a useful technique for the diagnosis of coronary artery disease after heart transplantation. These preliminary results indicate that dobutamine stress echocardiography may have a predictive value for further ischemic events in heart transplant recipients.

Cardiac Catheterization↗
PubMed1995

High incidence of left atrial thrombus detected by transoesophageal echocardiography in heart transplant recipients.

The aim of the study was the detection of spontaneous echo contrast (SEC) and left atrial thrombus by transoesophageal echocardiography (TEE) in patients who had undergone orthotopic heart transplantation. TEE was prospectively performed in 64 heart transplant recipients (53 males, 11 females, mean age 51 years). Since surgery (mean time: 31 months), all heart transplant recipients had received either aspirin (39), or dipyridamole (22), or both (3). Despite the antiplatelet treatment, an acute arterial embolism (two strokes, one popliteal and one mesenteric ischaemia) occurred in four patients who subsequently received an oral anticoagulant therapy. TEE was performed with a biplane high-frequency transducer after lidocaine pharyngeal anaesthesia, midazolam intravenous injection and antibiotic prophylaxis. Mean ejection fraction was 63 +/- 10%. None had evidence of rejection at endomyocardial biopsy performed on the same day as TEE and analysed in a blinded fashion. All were in sinus rhythm. Left atrial SEC was found in 35 patients (55%) and was associated with left atrial thrombus in 18 patients (28%). These thrombi were localized in the donor left atrial appendage in 10 cases, on the posterior wall of the left atrium in six cases, on the donor part of inter-atrial septum in one case and on the suture line in one case. They were not detected by transthoracic echocardiography (TTE). When compared with patients without thrombus, no difference was found concerning left atrial size, left ventricular ejection fraction, pulmonary artery pressure and number of previous episodes of rejection. However, cardiac index was significantly lower in patients with left atrial thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Function, Left↗