[Fibrinolysis and thrombosis of mechanical valvular prosthesis: risk stratification by transesophageal echocardiography]. / Fibrinolyse et thrombose de prothèse valvulaire mécanique: stratification du risque par échocardiographie transoesophagienne.

The place of fibrinolysis in the treatment of mechanical valvular prostheses is still much discussed. The aim of this work is to define the role of transoesophageal echocardiography in risk stratification. This monocentric study draws on 49 cases of thrombolysis preceded by transoesophageal echocardiography (average age 62.1 years, 37 mitral, 11 aortic, 1 tricuspid, 1 mitro-tricuspid). There were 41 obstructive thromboses (OT) and 8 non-obstructive thromboses (NOT). Clinical events and the effectiveness of fibrinolysis were studied as a function of the obstructive or non-obstructive character of the thrombosis and the size of the thrombus < 10 mm (n = 33) or > or = 10 mm (n = 16). Complete success was observed in 34 patients (69.4%). Follow up revealed 2 early cerebral haemorrhages (4.1%) of which one was in the NOT group, and six systemic emboli (12.2%) of which one was in the NOT group. There was a relationship between the size of the thrombus and embolus at the limit of significance in favour of an increased risk of embolus for a voluminous thrombus. Furthermore, the mobility of the thrombi went in hand with an increased rate of systemic emboli (p < 0.01). The rate of failure of fibrinolysis and/or complications correlated with the size of thrombus (complete success in 88% of the < 10 mm thrombus group, versus 35% in the > or = 10 mm; p < 0.01). This work underlines the significance of trans-oesophageal echocardiography in the therapeutic choice for valvular prosthesis thrombosis and suggests that the existence of a voluminous thrombus especially if mobile is a contra-indication for fibrinolysis.

Right and left atrial radiofrequency catheter therapy of paroxysmal atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF), the most common arrhythmia, is due to multiple simultaneous wavelets of reentry in the atria. The only available curative treatment is surgical, using atriotomies to compartmentalize the atria. Therefore, we investigated a staged anatomical approach using radiofrequency catheter ablation lines to prevent paroxysmal AF. METHODS AND RESULTS: Forty-five patients with frequent symptomatic drug-refractory episodes of paroxysmal AF were studied. Progressively complex linear lesions were created by sequential applications of radiofrequency current in the right atrium and then in the left atrium if required. The outcome of the procedure was considered a success when the episodes of AF were either eliminated or recurred at a rate of no more than one episode (lasting < 6 hours) in 3 months. Patients who had no more than one episode per month were considered "improved." Right atrial ablation organized local electrical activity and led to stable sinus rhythm during the procedure in 18 (40%) of the 45 patients. However, sustained AF remained inducible in 40 of 45 patients, and the lesions failed to produce evidence of a significant linear conduction block/delay in all but four patients. There were no significant complications except for two transient sinus node dysfunctions. The procedure duration and fluoroscopic time were 248 +/- 79 and 53 +/- 22 min, respectively. Additional sessions were required in 19 patients to treat sustained right atrial flutter or arrhythmias linked to ectopic right or left atrial foci. During a mean follow-up of 11 +/- 4 months, right atrial ablation was successful in 15 (33%) patients, 6 without medication and 9 with a previously ineffective drug. Nine (20%) additional patients were improved. Ten patients with an unsuccessful outcome then underwent linear ablation in the left atrium. The procedure duration and fluoroscopy time were 292 +/- 94 and 66 +/- 24 min. A hemopericardium occurred in one patient. Two patients required reablation to treat ectopic atrial foci. Left atrial ablation terminated AF during the procedure in 8 patients, and sustained AF could not be induced in 5. Subsequent success was achieved in 6 (60%) patients, including 4 without medication, and 1 additional patient was improved. CONCLUSIONS: Successful radiofrequency catheter ablation of drug-refractory daily paroxysmal AF is feasible using linear atrial lesions complemented by focal ablation targeted at arrhythmogenic foci. Ablation only in the right atrium is a safe technique providing limited success, whereas linear lesions in the left atrium significantly increase the incidence of stable restoration of sinus rhythm, the inability to induce sustained AF, and the final success rate. The described technique is promising but must be considered preliminary because significant improvements are required to optimize lesion characteristics and shorten total procedure duration.