Ablation of pulmonary vein foci for the treatment of atrial fibrillation; percutaneous electroanatomical guided approach.

AIMS: To evaluate the usefulness of three-dimensional (3D) electroanatomical mapping of the pulmonary veins (PV) for guiding radiofrequency (RF) ablation of focal atrial fibrillation (AF) in a single session and to correlate the electrophysiological results with the six month clinical outcome. METHODS AND RESULTS: Sixteen consecutive patients with idiopathic paroxysmal AF (more than 1 episode/month) were studied. A non-fluoroscopic mapping system was used to generate 3D electroanatomic maps of the left atrium and deliver RF energy. In patients with frequent ectopies, mapping was performed using the 'hot-cold' approach (looking for the earliest electrogram in the 3D reconstruction). In patients with infrequent/no ectopies, double/ multiple potentials recorded at the PV were tagged. Pacing at these sites to test for inducibility of ectopy or atrial fibrillation was used to define PV foci. The therapeutic endpoint was defined as suppression of premature beats, dissociation of PV potentials and inability to induce AF. Twenty-five foci were identified (multiple foci in 38%). In the 4 pts with frequent ectopies, Group A, these were suppressed by 4 +/- 4.7 applications. In the 12 pts with infrequent/no ectopies, Group B, an average 4.7 +/- 1.8 applications were delivered per focus; the endpoint was achieved in eight of the patients (13 of 21 foci). By 180 days follow-up, 11 patients were free of symptoms and in sinus rhythm, two had paroxysmal AF episodes and 3 have symptomatic ectopies and are receiving antiarrhythmic drugs. The overall success rate at six months was thus 69%, 100% for group A and 58% for group B. CONCLUSION: Electroanatomic guided RF ablation of paroxysmal AF was highly successful in patients with frequent ectopies. The use of electroanatomical mapping for precise anatomical localization of multiple potentials and for guiding the PV ostia isolation allowed successful RF ablation in 50% of pts with infrequent/no ectopies.

[Primary mesothelioma of the pericardium: a clinical case]. / Mesotelioma primário do pericárdio: um caso clínico.

We describe a 33-years-old male patient, presenting with progressive right heart failure. After evaluation, the hypothesis of effusive-constrictive pericarditis was considered. Medical therapy was initiated with no clinical benefit. On the 15th day after admission he was proposed for surgical intervention. The intraoperatory examination revealed a thick pericardium adhering to the epicardium without a clear separation between them. Complete resection was technically impossible. The postoperative course evolved with worsening heart failure and development of renal failure requiring hemodialysis. A diagnosis of primary pericardial mesothelioma was made after histological evaluation. The patient died 8 days after surgery despite all efforts at hemodynamic compensation. Despite its rarity, this diagnosis should be considered in cases with rapid evolution of constrictive or effusive-constrictive pericarditis. The prognosis for pericardial mesothelioma is poor due to its late diagnosis, the difficulty of surgical excision and poor response to radio- or chemotherapy.

Endocardial and epicardial radiofrequency ablation in the treatment of atrial fibrillation with a new intra-operative device.

OBJECTIVE: Atrial fibrillation has been a difficult problem to solve in many surgical patients, especially in those with mitral valve pathology. This study evaluates the results of endocardial and epicardial radiofrequency ablation with a new intra-operative device in the treatment of atrial fibrillation. METHODS: We operated on 65 patients with atrial fibrillation, 58 of which had concomitant mitral surgery. Atrial fibrillation was chronic (over 1 year) in 46 patients (group A) and paroxysmal or recent onset in 12 (group B). Group C had lone atrial fibrillation (two), concomitant coronary artery disease (four) or a sarcoma (one). Bilateral pulmonary vein isolation with a new intra-operative device was performed through multiple dry lesions in all patients. Groups A and B had endocardial applications at 70 degrees C during 60 s and group C had epicardial applications at 75 degrees C. Three group C patients had epicardial applications off pump. Atrial wall biopsies were performed in nine patients from groups A and B. RESULTS: There were no serious post-operative complications. At 1 month follow-up 54% of all patients were out of atrial fibrillation and 34% were in normal sinus rhythm with bilateral atrial contraction (Santa Crus Score 4). At 6 months follow-up, in spite of some crossover of patients among groups, similar results were obtained. The success of the procedure was 69% (Santa Crus scores 3 and 4) in mitral patients with a left atrial volume smaller than 200 cm(3). Preliminary data on the transmurality of the lesions is presented. The patients submitted to epicardial radiofrequency ablation (group C) have satisfactory results at 1 month (six out of seven were out of AF). CONCLUSIONS: Both endocardial and epicardial RF applications are simple and quick to perform and do not pose an additional risk for most patients. Furthermore we believe that it is possible to perform bilateral epicardial radiofrequency ablation of the pulmonary veins without cardiopulmonary bypass. Further refinements of the technique are needed to assure transmurality of all lesions and better results.

Operative risks of the maze procedure associated with mitral valve surgery.

Twelve patients were operated on for mitral valve disease with concomitant chronic atrial fibrillation. Valve repair was performed in five patients and replacement in seven. Maze I and maze III procedures were applied in eight and four patients, respectively, and are compared. There was a regular rhythm in all maze I patients with a constant junctional rhythm in three and an alternating sinus and junctional rhythm in the remainder. In one case, part of the left atrium was in atrial fibrillation with the remaining atria in sinus rhythm. In the maze III group, one patient was always on a regular rhythm, two had episodes of atrial fibrillation and one was in atrial fibrillation with controlled ventricular rate. Echocardiography showed atrial contraction in two maze I patients, but systolic atrial flow across both atrioventricular valves could only be demonstrated in two patients in the maze III group.

When and how to report results of surgery on atrial fibrillation.

OBJECTIVE: Several medical, interventional and surgical techniques are used to treat atrial fibrillation, aimed at different goals and having variable success rates. To be able to assess and compare all these techniques a methodology of study and a classification is proposed. METHODS: We developed a five grade score, named the Santa Crus Score, based upon the post-operative atrial rhythm and the effective atrial contraction. Score 0 corresponds to a persistence of atrial fibrillation, the presence of a regular rhythm is grade 1, 2 or 3 if there is no atrial contraction; right atrial contraction; or bilateral atrial contraction, respectively. Score 4 corresponds to sinus rhythm and bilateral atrial contraction. Surgery for atrial fibrillation was performed on 51 patients since 1992. All patients but two had associated mitrial surgery. Three different maze techniques were performed on 17 patients and the pulmonary veins isolation procedure on 34 patients. Patients were reassessed at 1, 6, 12, 24 and 36 months. RESULTS: After the maze I procedure atrial fibrillation eradication was achieved in 88% of patients but none scored 4. Three patients changed score during the first year. All maze III patients scored 0 initially and one changed to score 3 in the first year. Sixty percent of the maze IIIA patients scored 4, but one evolved to score 0 at 6 months. The pulmonary veins isolation technique eliminated atrial fibrillation in 71% of the patients initially, and in 60% after 1 year, and achieved a score of 4 in a third of the patients. CONCLUSION: This classification considers the intermediate grades of success that can occur with absence of atrial fibrillation and is applicable to all forms of therapy.

What are the limits for the Ross operation?

The Ross operation is physiologically the best approach for aortic valve replacement. At the Hospital de Santa Cruz 22 consecutive pulmonary autograft operations have been performed in patients with a mean age of 49 (range 17-65) years. Six patients had mitral valve disease, two had aortic aneurysms and one had a ventricular septal defect. Subcoronary implantation of the autograft was performed in 20 patients. A partial inclusion aortic root replacement technique was used in one and the aortic root was replaced in another. There were no hospital or late deaths. Two patients required autograft replacement at 3 and 9 months postoperatively because of regurgitation. One of these cases was caused by an abnormality of the pulmonary valve and since then echocardiographic assessments of this valve have been performed routinely and have detected significant pulmonary incompetence in four patients who otherwise would have been operated on using the Ross procedure.

[Clinical and echocardiographic assessment of surgical replacement of the aortic valve with lung autograft: results after 2 years]. / Avaliacão clínca e ecocardiográfica da cirurgia de substituicão da válvula aórtica com auto-enxerto pulmonar: resultados aos 2 anos.

OBJECTIVE: The goal of this study was to evaluate the clinical and echocardiographic results of a cohort of patients subjected to aortic valve replacement with pulmonary autograft (Ross procedure). DESIGN: We studied prospectively with clinical and echocardiographic evaluation all patients subjected to this type of aortic valve surgery, before operation, intraoperatively, before hospital discharge and at the end of this study in September 1994 and we analysed the evolution of the results during the follow-up period. PATIENTS: 22 consecutive patients 12 men and 10 women mean age 48 +/- 14 years subjected to Ross operation between April 1992 and June 1994. METHODS: Patients were studied with transesophageal echocardiography intraoperatively and transthoracic echocardiography. Two-dimensional and M-mode evaluation, continuous and pulsed wave Doppler and color coded Doppler were performed, with assessment of the morphology and Doppler profile of both the autograft and the homograft in pulmonary position. RESULTS: No early or late mortality was registered, and apart two patients who were reoperated, all patients were asymptomatic in the last medical visit. There was no incidence of thromboembolic events even though no anticoagulation has been used. Aortic regurgitation was present in 14 patients, grade 1 in 11 patients and grade 2 in three. In the last echocardiogram performed the analysis of aortic flow, demonstrated absence of significant transvalvular gradient (maximal aortic gradient of 5.6 +/- 0.4 mmHg and mean aortic gradient of 1.8 +/- 0.08 mmHg). Pulmonary regurgitation was absent in nine patients, and present in 13, considered trivial in all cases. CONCLUSIONS: These data suggest that this type of surgery has a low operative risk, with absence of thromboembolic complications and excellent clinical and echocardiographic results.

[Anomalous insertion of mitral papillary muscles in obstructive hypertrophic myocardiopathy. Report of 2 cases]. / Insercão anómala de músculos papilares mitrais na miocardiopatia hipertrófica obstrutiva. A propósito de dois casos.

Hypertrophic obstructive cardiomyopathy is a pathologic entity whose features are complex and diverse. Its surgical treatment generally requires myectomy. When the left ventricle outflow gradient is also due to mitral valve abnormalities, mitral valve replacement has been considered as the treatment of choice for the relief of the obstruction. We report two cases in which transesophageal echocardiography has allowed a good definition of this complex area of the heart and a better diagnosis and treatment of its components. Its use led to the diagnosis of abnormal papillary muscles inserted directly in the anterior leaflet of the mitral valve, with severe left ventricle outflow obstruction. Surgical treatment consisted of septal myectomy and excision of the muscles, thus preventing the need for mitral replacement. Systolic anterior motion of the mitral valve subsided and the outflow gradients became negligible. This new approach for the treatment of hypertrophic obstructive cardiomyopathy will be of benefit for patients in whom the anomalous insertion of the papillary muscles are recognized before surgery, thus preventing mitral valve replacement.

Atrioventricular valve repair using externally adjustable flexible rings.

Initial results obtained with a new flexible ring, adjustable from outside of the heart after interruption of extracorporeal circulation, are presented. Twenty-five rings have been inserted in 20 patients, 14 in the mitral position and 11 in the tricuspid position. In 8 of the 14 patients receiving mitral annuloplasty, other standard mitral valve repair techniques were used. Adjustment, assisted by intraoperative transesophageal color Doppler echocardiography, was done for 10 (71%) of the mitral rings and for 8 (73%) of the tricuspid rings. Residual mitral regurgitation disappeared or became minimal in 9 (90%) patients, and a mild regurgitation remained in 1. In all patients who received tricuspid rings regurgitation was abolished after the adjustment. There was no hospital or late mortality. After a maximum follow-up of 6 months results are comparable in the tricuspid and mitral positions and echocardiographic evaluation revealed stable competent valves in all patients but one, who underwent reoperation because of failure of a mitral valve chordae shortening procedure. The use of externally adjustable rings for the mitral and tricuspid valves is a safe alternative for atrioventricular valve annuloplasty and has the additional advantage of reducing postrepair regurgitation.