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Biomedical subjects

G M Guiraudon

Publications and source records attributed to G M Guiraudon.

At least 19 recordsLinked to original sources
PubMed2000

Pacing in right ventricular dysplasia after disconnection surgery.

This report describes a 33-year-old patient with arrhythmogenic right ventricular (RV) dysplasia who had a dual chamber pacemaker implanted at age 23 years for drug-induced bradycardia. Pacing was continued after right ventricular free-wall disconnection (RVFWD) at age 24 years. Her pacemaker was not replaced after battery depletion 7 years later. She presented the following year in severe right-sided heart failure. Her old pacemaker generator was replaced. This was followed by rapid resolution of her clinical failure and return to a full, active, physical lifestyle. This observation suggests the potential benefit of dual chamber pacing in patients with RV dysplasia after RVFWD.

Adult↗
PubMed1999

Living anatomy of the atrioventricular junctions. A guide to electrophysiologic mapping. A Consensus Statement from the Cardiac Nomenclature Study Group, Working Group of Arrhythmias, European Society of Cardiology, and the Task Force on Cardiac Nomenclature from NASPE.

Current nomenclature for the atrioventricular (AV) junctions derives from a surgically distorted view, placing the valvar rings and the triangle of Koch in a single plane with antero-posterior and right-left lateral coordinates. Within this convention, the aorta is considered to occupy an anterior position, although the mouth of the coronary sinus is shown as being posterior. Although this nomenclature has served its purpose for the description and treatment of arrhythmias dependent on accessory pathways and atrioventricular nodal reentry, it is less than satisfactory for the description of atrial and ventricular mapping. To correct these deficiencies, a consensus document has been prepared by experts from the Working Group of Arrhythmias of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. It proposes a new anatomically sound nomenclature that will be applicable to all chambers of the heart. In this report, we discuss its value for description of the AV junctions, establishing the principles of this new nomenclature.

Atrioventricular Node↗
PubMed1999

Comparison of late results of surgical or radiofrequency catheter modification of the atrioventricular node for atrioventricular nodal reentrant tachycardia.

AIMS: Although arrhythmia surgery and radiofrequency catheter ablation to cure atrioventricular nodal reentrant tachycardia differ in technical concept, the late results of both methods, in terms of elimination of the arrhythmogenic substrate and procedure-related new and different arrhythmias, have never been compared. This constituted the purpose of this prospective follow-up study. METHODS AND RESULTS: Between 1988 and 1992, 26 patients were surgically treated using perinodal dissection or 'skeletonization', and from 1991 up to 1995, 120 patients underwent radiofrequency modification of the atrioventricular node for atrioventricular nodal reentrant tachycardia. The acute success rates of surgery and radiofrequency catheter ablation were 96% and 92%, respectively. Late recurrence, rate in the surgical and radiofrequency catheter ablation groups was 12% and 17%, respectively. Mean follow-up was 53 months in the surgical group and 28 months in the radiofrequency catheter ablation group. The final success rate after repeat intervention was 100% in the surgical group and 98% in the radiofrequency catheter ablation group. Comparison of the initial and recent series of radiofrequency catheter ablated patients showed an increased initial success rate with fewer applications. In the radiofrequency catheter ablation group, a second- or third-degree block developed in three patients (2%), requiring permanent pacing, whereas in the surgical group no complete atrioventricular block was observed. Inappropriate sinus tachycardia needing drug treatment was observed in 13 patients (11%), mostly after fast pathway ablation, but was never observed after surgery. New and different supraventricular tachyarrhythmias arose in 27% of the patients in the surgical group and in 11% of the radiofrequency catheter ablation group, but did not clearly differ. CONCLUSION: This one-institutional follow-up study demonstrated comparable initial and late success rates as well as incidence of new and different supraventricular arrhythmias following arrhythmia surgery and radiofrequency catheter ablation for atrioventricular nodal reentrant tachycardia. Today radiofrequency catheter ablation has replaced arrhythmia surgery for various reasons, but the late arrhythmic side-effects warrant refinement of technique.

Adult↗
PubMed1999

Living anatomy of the atrioventricular junctions. A guide to electrophysiological mapping. A Consensus Statement from the Cardiac Nomenclature Study Group, Working Group of Arrythmias, European Society of Cardiology, and the Task Force on Cardiac Nomenclature from NASPE. North American Society of Pacing and Electrophysiology.

Current nomenclature for atrioventricular junctions derives from a surgically distorted view, placing the valvar rings and the triangle of Koch in a single plane with antero-posterior and right-left lateral coordinates. Within this convention, the aorta is considered to occupy an anterior position, while the mouth of the coronary sinus is shown as being posterior. While this nomenclature has served its purpose for the description and treatment of arrhythmias dependent on accessory pathways and atrioventricular nodal re-entry, it is less than satisfactory for the description of atrial and ventricular mapping. To correct these deficiencies, a consensus document has been prepared by experts from the Working Group of Arrhythmias of the European Society of Cardiology, and the North American Society of Pacing and Electrophysiology. It proposes a new, anatomically sound, nomenclature that will be applicable to all chambers of the heart. In this report, we discuss its value as regards the description of the atrioventricular junctions, establishing the principles of this new nomenclature.

Atrioventricular Node↗
PubMed1999

ESCWGA/NASPE/P experts consensus statement: living anatomy of the atrioventricular junctions. A guide to electrophysiologic mapping. Working Group of Arrhythmias of the European Society of Cardiology. North American Society of Pacing and Electrophysiology.

Current nomenclature for the AV junctions derives from a surgically distorted view, placing the valvar rings and the triangle of Koch in a single plane with anteroposterior and right-left lateral coordinates. Within this convention, the aorta is considered to occupy an anterior position, whereas the mouth of the coronary sinus is shown as being posterior. Although this nomenclature has served its purpose for the description and treatment of arrhythmias dependent on accessory pathways and AV nodal reentry, it is less than satisfactory for the description of atrial and ventricular mapping. To correct these deficiencies, a consensus document has been prepared by experts from the Working Group of Arrhythmias of the European Society of Cardiology and from the North American Society of Pacing and Electrophysiology. It proposes a new, anatomically sound, nomenclature that will be applicable to all chambers of the heart. In this report, we discuss its value for description of the AV junctions and establish the principles of this new nomenclature.

Atrioventricular Node↗
PubMed1998

Surgery without interventions?

Cardiac surgeons took to the heart and claimed an exclusive privilege to intervene. The task of cardiologists was to identify "candidates" and feed the Great Surgical Machine. Recently catheter surgery has developed and fell into the hands of cardiologists, who became interventionists. Cardiac surgeons are concerned about losing interventions and their identify. The analysis of the current situation implies a revisitation of old concepts: surgery, intervention, therapy, patients, invasiveness etc ... etc ... and a review of our therapeutic philosophy. Therapeutic plans comprise three interrelated components: the target, the bullet (therapeutic agent), and the gun (the way of delivering the bullet on target). This description characterizes surgery as a way of delivering. If side effects are effects that do not affect the target, surgical procedures are mostly side effects, with significant morbidity. Future surgical rationales should reconcile target-specific therapy and minimal collateral damages: Minimal Surgery! or to use a new buzz, less invasiveness. Cardiac surgery has focused too much on surgical practice and neglected the rest of cardiology, missing opportunities for new researches, new rationales, and new techniques. Surgeons must become again Renaissance Men, involved in the entire field of cardiology, with a special skill in surgical techniques. Cardiac surgeons should no longer confine their practice to the delivering end. This end does not, any more, justify the means.

Attitude of Health Personnel↗
PubMed1998

Musing while cutting.

Cardiac surgeons took to the heart and claimed an exclusive privilege to intervene. The task of cardiologists was to identify "candidates" and feed the great surgical machine. Recently, catheter surgery was developed and has fallen into the hands of cardiologists who became interventionists. Cardiac surgeons are concerned about shrinking domain, identity, and the future. The analysis of the current situation requires another look at old concepts: surgery, intervention, therapy, patients, invasiveness, etc., and a revision of the philosophy of the entire profession. Therapeutic plans comprise three interrelated components: the target, the bullet (therapeutic agent), and the gun (the way of delivering the bullet on target ). This description characterizes surgery as a way of delivering. If side effects are effects that do not affect the target, surgical procedures are mostly side effects, with significant morbidity. Future surgical rationales should reconcile target-specific therapy and minimal collateral damages: "minimal surgery!" or to use a new buzzword, "less invasive surgery." Cardiac surgery has focused on surgical practice and neglected the science of cardiology, missing opportunities for new research, new rationales, new techniques, and new territories. Surgeons must again become Renaissance men, involved in the entire field of cardiology, with a special skill in surgical techniques. Cardiac surgeons should no longer confine their practice to the delivering end. This end does not, any more, justify the means.

Cardiac Surgical Procedures↗
PubMed1997

Intraaortic balloon counterpulsation improves right ventricular failure resulting from pressure overload.

BACKGROUND: Right ventricular (RV) dysfunction is common after heart transplantation, and myocardial ischemia is considered to be a significant contributor. We studied whether intraaortic balloon counterpulsation would improve cardiac function using a model of acute RV pressure overload. METHODS: In 10 anesthetized sheep, RV failure was induced using a pulmonary artery constrictor. Baseline measurements included mean systemic blood pressure, RV peak systolic pressure, cardiac index, and RV ejection fraction. Myocardial and organ perfusion were measured using radioactive microspheres. RESULTS: After pulmonary artery constriction, there was an increase in RV peak systolic pressure (32 +/- 2 to 60 +/- 3 mm Hg; p < 0.01) and a decrease in mean systemic blood pressure (68 +/- 4 to 49 +/- 2 mm Hg; p < 0.01), RV ejection fraction (0.51 +/- 0.04 to 0.16 +/- 0.02; p < 0.01), and cardiac index (2.48 +/- 0.04 to 1.02 +/- 0.11; p < 0.01). Blood flow to the RV did not change significantly, but there was a significant reduction in blood flow to the left ventricle. The initiation of intraaortic balloon counterpulsation (1:1) using a 40-mL intraaortic balloon inserted through the left femoral artery resulted in an increase in mean systemic blood pressure (49 +/- 2 to 61 +/- 3 mm Hg; p < 0.01), cardiac index (1.02 +/- 0.11 to 1.45 +/- 0.14; p < 0.05), RV ejection fraction (0.16 +/- 0.02 to 0.23 +/- 0.02; p < 0.01), and blood flow to the left ventricle. CONCLUSIONS: In a model of right heart failure, the institution of intraaortic balloon counterpulsation caused a significant improvement in cardiac function. Although RV ischemia was not demonstrated, the augmentation of left coronary artery blood flow by intraaortic balloon counterpulsation and subsequent improvement in left ventricular function suggest that left ventricular ischemia contributes to RV dysfunction, presumably through a ventricular interdependence mechanism. Therefore, study of the safety and efficacy of intraaortic balloon counterpulsation in the management of patients with acute right heart dysfunction is warranted.

Animals↗
PubMed1997

Long-term follow-up of corridor operation for lone atrial fibrillation: evidence for progression of disease?

INTRODUCTION: Currently, surgery- and catheter-mediated ablation is applied when drug refractoriness of atrial fibrillation is evident, although little is known about the long-term incidence of new atrial arrhythmia and the preservation of sinus node function. METHODS AND RESULTS: To address this issue, 30 patients with successful corridor surgery for lone paroxysmal atrial fibrillation and normal preoperative sinus node function were followed in a single outpatient department. Five years after surgery, the actuarial proportion of patients with recurrence of atrial fibrillation arising in the corridor was 8% +/- 5%, with new atrial arrhythmias consisting of atrial flutter and atrial tachycardia in the corridor 27% +/- 8%, and with incompetent sinus node requiring pacing therapy 13% +/- 6%. Right atrial transport was preserved in 69% of the patients without recurrence of atrial fibrillation and normal sinus node function. Stroke was documented in two patients. CONCLUSIONS: Corridor surgery for atrial fibrillation is a transient or palliative treatment instead of a definitive therapy for drug refractory atrial fibrillation. This observation strongly affects patient selection for this intervention and constitutes a word of caution for other, nonpharmacologic interventions for drug refractory atrial fibrillation.

Adult↗
PubMed1996

Atrial flutter: lessons from surgical interventions (musing on atrial flutter mechanism).

We report our experience with seven patients who underwent direct surgical ablation of problematic common flutter. Intraoperative mapping was obtained in four patients. Surgical techniques varied over time. A circular incision of the right atrium was performed in the first patient. Two patients had epicardial cryoablation of the isthmus between the inferior vena cava and the tricuspid valve annulus. Four patients had extensive endocardial cryoablation of the isthmus. There were no immediate postoperative complications. One patient had atrial fibrillation 2 months postoperatively and underwent a corridor operation 1 year later. The other six patients are free of arrhythmias without antiarrhythmic drugs. Surgical ablation confirmed that the common form of atrial flutter is associated with a right atrial macroreentrant circuit. One of our intraoperative endocardial maps suggested that variant reentrant circuits can be associated with variant forms of flutter.

Adult↗
PubMed1996

Surgery for supraventricular tachycardia.

1995 is the fifth anniversary of the advent of catheter ablation for the treatment of supraventricular tachycardia. Surgery has established the principles of the interventional approaches: 1) identification of the mechanism; 2) localization of the site of the mechanism; 3) identification of the anatomical arrhythmogenic substrate and its localization using preoperative and intraoperative electrophysiological cardiac mapping; 4) ablation of the arrhythmogenic substrate using "surgical" dissection or excision or various forms of energy to neutralize the substrate: cryoablation, laser, etc. Surgical approaches also established the EP interventions as the first line of therapy because they are curative. Currently, surgery for supraventricular tachycardia is essentially confined to atrial fibrillation, and after attempted catheter ablation for the Wolff-Parkinson-White syndrome. Atrial fibrillation is a complex arrhythmia, commonly associated with structural heart disease. To understand atrial fibrillation, a number of premises should be reviewed: atrial functional anatomy, atrial pathology, atrial fibrillation mechanism (s) and clinical presentation. The role of atrial fibrillation in terms of symptoms, morbidity and mortality is not clear because it is difficult to determine if atrial fibrillation is a symptom, a marker, an autonomous disease albeit it is in most cases an aggravating factor. Surgical rationales for atrial fibrillation are based on three concepts: exclusion, fragmentation and channelling. The Corridor operation was the first used direct surgical approach. The Maze operation and other techniques (fragmentation, spiral) have been reported. All surgical techniques have been reported with good results in terms of sinus node function and exercise tolerance, and to various degrees, in terms of atrial contraction. Currently, there is a trend to combine direct atrial fibrillation surgery with surgery for mitral valve albeit beneficial effects are not documented.

Atrial Fibrillation↗
PubMed1995

Latissimus dorsi dynamic cardiomyoplasty: role of combined ICD implantation.

Latissimus dorsi cardiomyoplasty is a promising surgical therapy in some patients with congestive heart failure. Although the mortality in heart failure patients is attributable primarily to heart failure and ventricular arrhythmias, the mechanism of death after cardiomyoplasty is not well characterized. We describe the clinical course of a patient undergoing cardiomyoplasty and discuss the role of combined use with an implantable cardioverter defibrillator. A 39-year-old man with congestive heart failure due to a massive anterior wall myocardial infarction was evaluated for latissimus dorsi cardiomyoplasty. The patient was in NYHA Functional Class III due to heart failure. He did not have any significant exertional or rest angina. During a Naughton stress test, the patient could exercise for 10 minutes, achieving 4 METS. Pulmonary function study showed a peak V O2 of 22.1 mL/min per kg. Radionuclide angiography demonstrated that the anterior wall was akinetic with a left ventricular ejection fraction of 22%. Cardiac hemodynamic studies suggested moderate pulmonary hypertension, elevated wedge pressure, and suboptimal response to exercise. A Holter recording showed frequent ventricular extrasystoles. Cardiomyoplasty was preferred to heart transplantation because the patient did not have end-stage heart failure. Postoperatively, the patient required low doses of dopamine. He developed recurrent, sustained, and hemodynamically significant episodes of ventricular tachycardia. He was treated with a combination of amiodarone and procainamide. He died 2 days postoperatively with ventricular fibrillation. Ventricular arrhythmias are a major cause of death in patients with heart failure. Latissimus dorsi cardiomyoplasty appears to be a promising but unproven therapy in such patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Encircling endocardial cryoablation for ventricular tachycardia after myocardial infarction: experience with 33 patients.

Encircling endocardial cryoablation, consisting of circumferential cryoablation of the infarct scar, can be curative in selected patients with ventricular tachycardia (VT). We describe our experience with and long-term outcome in 33 patients undergoing this procedure. The interval between myocardial infarction and the onset of tachycardia varied from 2 weeks to 22 years (mean 38 +/- 63 months and median 3 months). All patients had a left ventricular aneurysm (anterior in 20, posterior in 12, and lateral in 1) and significant coronary artery disease. Fourteen patients had clinical evidence of heart failure preoperatively. Twenty-eight patients had sustained monomorphic VT (incessant in 3); 3 had polymorphic or nonsustained tachycardia; 2 had primary ventricular fibrillation; and 1 had associated Wolff-Parkinson-White syndrome. Surgery was undertaken after failed drug therapy and consideration of left ventricular anatomy and function. At surgery, 32 patients had encircling endocardial cryoablation, and 1 patient had partial right ventricular free-wall disconnection (right ventricular infarct). Thirteen patients underwent concomitant coronary artery bypass grafting. An implantable cardioverter defibrillator (ICD) was implanted in 2 patients and prophylactic ICD patches in 1. One patient died postoperatively; 3 had recurrent VT perioperatively; 1 was treated with amiodarone; and 2 had ICD implantation. During long-term follow-up (mean 5 years), all patients who were free of tachycardia at discharge remained alive and free of arrhythmias or syncope. The patient receiving amiodarone sustained a cardiac arrest subsequently and received an ICD implant. One patient with an ICD continued to receive appropriate shocks frequently and died 2 years after surgery. Nine patients had congestive heart failure postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

Surgical treatment of Wolff-Parkinson-White syndrome: a "retrospectroscopic" view.

The surgical treatment of the Wolff-Parkinson-White syndrome made its appearance in 1968 when Dr W. C. Sealy performed the first direct surgical intervention for ablating an accessory connection in a patient with incessant atrioventricular reentrant tachycardia. The surgical approach fell into disfavor in 1990 when catheter ablation using radiofrequency energy was adopted into widespread use. In this presentation, I will attempt to assess the scientific value of the surgical experience using the scholarly tool, the "retrospectroscope," and also to answer the questions, Was it worth it? What was learned? and What was achieved? We conclude that a large body of scientific knowledge and skill was brought to light by this experience and, of even more importance, passed on for best use to the catheter surgeons.

Catheter Ablation↗
PubMed1994

Operation for the Wolff-Parkinson-White syndrome in the catheter ablation era.

Catheter ablation has greatly altered surgical referral patterns for the Wolff-Parkinson-White syndrome. We describe 51 patients (aged 9 to 63 years; 35 male, 16 female) referred for operation from our institution and elsewhere between August 1990 and August 1993, coincident with the inception of our ablation program. During the same period, 375 patients with problematic Wolff-Parkinson-White syndrome had ablation procedures. Operation was the initial therapy in 26 patients, due to physician preference in 23 and the need for a concomitant cardiac operation in 3. Operation was related to ablation failure in 22 patients and was urgent in 3 patients. Previous ablation was not associated with added surgical difficulties, and all pathways were ablated intraoperatively on the first attempt using the epicardial approach. Visible epicardial lesions were observed in 8 patients at the site of the accessory pathway. In 2 patients, the lesions were remote to the atrioventricular ring. There was a striking significant increase in proportion of right free wall pathways after attempted ablation (27% versus 8%) as compared with the preablation era. We conclude that previous attempted ablation does not impair efficacy and safety of operative therapy. Operation remains a useful alternative for ablation failure and as a back-up for acute complications.

Adolescent↗
PubMed1994

Intraoperative mapping is not necessary for VT surgery.

Surgical ablation of ventricular tachycardia is generally guided by the results of pre- and intraoperative cardiac mapping. However, in certain situations intraoperative cardiac mapping may not be possible and, therefore, surgery has to be based on information obtained preoperatively. This raises the question whether intraoperative mapping is necessary for the success of this approach. We describe our experience with encircling endocardial cryoablation for ischemic VT and examine the contribution of intraoperative mapping for this procedure. Thirty-three patients with inducible VT refractory to medical therapy and a well defined anatomic scar were considered for surgery. All patients underwent baseline electrophysiology study and intraoperative mapping was attempted during normothermic cardiopulmonary bypass. In 14 patients, VT was inducible intraoperatively (Group 1) and surgical ablation was guided by this information, whereas in 19 patients, VT could not be mapped for various reasons (Group 2). Reasons for failure to obtain intraoperative map included noninducibility (3), nonsustained VT (8), polymorphic VT (4), VF (3), and incessant VT with hemodynamic collapse and cardiac arrest (1). The two groups did not differ with respect to age, location of myocardial infarction, or preoperative left ventricular ejection fraction. The operative procedures were similar in the two groups with respect to aortic cross clamp time, cardiopulmonary bypass time, number of cryoablation lesions, concomitant revascularization, aneurysmectomy, and ICD implantation. Encircling endocardial cryoablation was performed in 32 patients and one patient underwent partial right ventricular free wall disconnection (RV infarct). Thirteen patients underwent concomitant coronary artery bypass grafting (5 in Group 1 and 8 in group 2). One patient had prophylactic ICD patches (Group 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗