Sinus node structural changes in patients with long-standing chronic atrial fibrillation.
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Biomedical subjects
Aquilino Hurlé
Publications and source records attributed to Aquilino Hurlé.
Effects of endocardial microwave energy ablation.
Until recently the treatment of atrial fibrillation (AF) consisted primarily of palliation, mostly in the form of pharmacological intervention. However because of recent advances in nonpharmacologic therapies, the current expectation of patients and referring physicians is that AF will be cured, rather than palliated. In recent years there has been a rapid expansion in the availability and variety of energy sources and devices for ablation. One of these energies, microwave, has been applied clinically only in the last few years, and may be a promising technique that is potentially capable of treating a wide range of ventricular and supraventricular arrhythmias. The purpose of this study was to review microwave energy ablation in surgical treatment of AF with special interest in histology and ultrastructure of lesions produced by this endocardial ablation procedure.
Journal Article↗
Early morphologic changes following microwave endocardial ablation for treatment of chronic atrial fibrillation during mitral valve surgery.
INTRODUCTION: The aim of this study was to investigate the early qualitative and quantitative structural changes in the left atrial wall after endocardial microwave ablation in patients with chronic atrial fibrillation (AF) undergoing mitral surgery. METHODS AND RESULTS: Seven patients with chronic AF of for at least 6 months underwent surgical microwave energy ablation. Linear isolation of pulmonary veins was performed in all patients by microwave energy applications to the endocardial surface delivered by catheter at 65-W constant power for 45 seconds. Biopsies were obtained from a selected site (below the right lower pulmonary vein) of the left atrial posterior wall before and after the ablation procedure in all patients. Control tissues from the same sites were obtained at autopsy from patients with noncardiac causes of death. Light and electron microscopy was used to examine qualitative and quantitative changes in tissue morphology. Tissues after endocardial ablation procedure showed significantly increased loss of contractile material. Electron microscopy of atrial tissue demonstrated loss of profile of perinuclear and plasma membranes of myocytes, disruption of the endothelial cells of capillary vessels, and presence of macrophages. CONCLUSION: Lesions created by endocardial microwave energy ablation revealed a transmural effect on the left atrial wall without a significant reduction in thickness but a significant increase in the myolytic areas involving the entire cytosol and occlusion of the small intramyocardial vessels within the ablative lesion.
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Preliminary results with the microwave-modified maze III procedure for the treatment of chronic atrial fibrillation.
Between February 2003 and January 2004 a microwave-modified Maze III procedure was performed as an associated procedure in nine patients in chronic atrial fibrillation undergoing surgery for heart valve disease. Clinical follow-up was carried out in all survivors, and an echocardiographic assessment done in all those in sinus rhythm, during the first week of February 2004. There were six women and three men with a mean age of 60 +/- 9.4 years. Their rhythm at the end of surgery was sinus in 2 patients, nodal in 4, and complete AV block in 3. One patient died in hospital and there patients had no other complications related to the procedure. By the time of hospital discharge, four patients were in sinus rhythm and four were in atrial fibrillation. After a mean follow-up of 5.2 +/- 3.3 months there were no late deaths, 5 patients were in sinus rhythm, 1 required a permanent pacemaker in DDDR mode for persistent sinus bradycardia, and 2 remained in atrial fibrillation. Echocardiographic assessment, performed at a mean of 4.9 +/- 2.5 months after surgery in all patients in sinus rhythm or with a pacemaker, demonstrated biatrial contraction in five patients. The Cox-Maze III procedure can be performed safely and with good results using microwave energy instead of the conventional "cut and sew" technique.
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[A comparative study of the follow-up and hemodynamics in vivo of 21 mm Carpentier-Edwards supra-annular and perimount bioprostheses].
INTRODUCTION AND OBJECTIVES: Analysis and comparison of the clinical performance and hemodynamics in vivo of 21 mm Carpentier-Edwards supra-annular (CESA) and Perimount (CEPM) aortic bioprostheses. METHODS: A follow-up study was made of 40 patients implanted a 21 mm CESA (n = 21) or CEPM (n = 19) prosthesis between October 1992 and September 1997. All eligible survivors (14 CESA, 12 CEPM) were assessed echocardiographically. RESULTS: There were no significant differences between models in the effective orifice area (1.6 cm2 for CESA, 1.44 cm2 for CEPM), peak flow rate (rest: 2.5 m/s for CESA, 2.3 m/s for CEPM; post-dobutamine: 3.4 m/s for CESA, 3.3 m/s for CEPM), mean flow rate (rest: 1.7 m/s for CESA, 1.6 m/s for CEPM; post-dobutamine: 2.5 m/s for CESA, 2.2 m/s for CEPM), peak gradient (rest: 28.3 mmHg for CESA, 21.6 mmHg for CEPM; post-dobutamine: 48.4 mmHg for CESA, 41.6 mmHg for CEPM), and mean gradient (rest: 15.8 mmHg for CESA, 12.0 mmHg for CEPM; post-dobutamine: 28.5 mmHg for CESA, 22.5 mmHg for CEPM). CONCLUSION: In our experience, these two prosthetic models have similar hemodynamic characteristics in small aortic annuli.
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Optimal location for temporary epicardial pacing leads following open heart surgery.
Temporary epicardial pacing wires are routinely placed in patients undergoing cardiac surgery. Eighteen suitable patients undergoing elective surgery were prospectively studied. Their sensing and stimulating characteristics were studied at various locations. Subepicardial pacing leads were applied to the lateral wall of the LV, apex of the LV, anterior wall of the RV, diaphragmatic wall of the RV, and diaphragmatic wall of the LV. Impedance, R wave amplitude, slew rate, and stimulation thresholds were measured on postoperative days 1 and 5. Impedance remained unchanged in time with no significant differences between locations. R waves and slew rates were significantly lower in the anterior RV wall. Stimulation thresholds displayed no differences on day 1, but they increased significantly in all locations on day 5. These thresholds were significantly lower in the lateral and diaphragmatic LV walls on day 5, and the rate of voltage increase was also lower in these two locations. Five patients presented phrenic nerve stimulation when stimulating the lateral LV wall. The authors advocate the diaphragmatic wall of the LV as the best location for placing temporary leads. The anterior wall of the RV is not recommended for pacing purposes.
Adult↗
Nine-year follow up of the omnicarbon prosthesis in the aortic position.
BACKGROUND AND AIM OF THE STUDY: Clinical experience with the Omnicarbon mechanical valve implanted in the aortic position is reported in this retrospective survey. METHODS: A total of 110 patients (mean age 56 years) undergoing isolated aortic valve replacement with Omnicarbon mechanical prostheses at the authors' institution between November 1991 and October 2000 was included. Follow was available in 94.5% of patients (mean follow up 4 years per patient; total follow up was 415 patient-years (pt-yr)). RESULTS: Hospital mortality was 3.6%. There were no instances of valve thrombosis or structural failure. The incidence of valve-related complications (linearized rates in events per 100 pt-yr/actuarial freedom at 9 years, in %) was: valve-related mortality 2.4+/-0.7 / 80.3+/-8.0; non-structural failure 0.7+/-0.4 / 93.8+/-4.2; thromboembolism 0.2+/-0.2 / 99.0+/-1.0; anticoagulant-related hemorrhage 0.9+/-0.5 / 93.7+/-3.3; prosthetic valve endocarditis 0.2+/-0.2 / 99.0+/-1.0; and reoperation 0.7+/-0.4 / 93.8+/-4.2. CONCLUSION: In the authors' experience the Omnicarbon mechanical prosthesis provides a good clinical performance for up to nine years in the aortic position.
Adult↗