The long-term follow-up results of the Electrical Cardioversion of Chronic Nonvalvular Atrial Fibrillation / 대한내과학회지

OBJECTIVES:We performed a prospective observation for the patients with chronic nonvalvular atrial fibrillation who underwent electrical cardioversion after failed pharmacological cardioversion with amiodarone. The aim of this study was to look at the immediate sinus conversion rate, the maintenance rate of sinus rhythm at long-term follow-up, and the clinical and echocardiographic parameters that influence on the rate of immediate sinus conversion and maintenance of sinus rhythm. At simultaneously, we intended to evaluate the efficacy of electrical cardioversion for the patients with chronic nonvalvular atrial fibrillation. METHODS: After anticoagulation therapy with coumadine for four weeks before cardioversion, we tried pharmacological cardioversion with amiodarone first. Failed cases included in this study. The direct current cardioversion was performed under transesophageal echocardiography monitoring to exclude the left atrial thrombus and to measure various echocardiographic parameters. After successful sinus cardioversion, we prescribed amiodarone with maintenance doses and coumadine at least 4 weeks. Transthoracic echocardiography was performed before cardioversion and one day, one month, 3 months, 6 months, and 9 months after sinus conversion. The minimum duration of atrial fibrillation was one month before the trial of pharmacological cardioversion. RESULTS: 1) The total number of patients was forty three (male: 28, female: 15, average age: 60+/-9). The initial success rate of sinus conversion was 88 %. 2) The maintenance rate of sinus rhythm with maintenance dose of amiodarone was 52 % after 9 months follow-up. 3) The direct current cardioversion was performed to 10 patients among 17 patients who recurred atrial fibrillation after sinus conversion. Among 10 patients, 5 patients of them were converted to sinus rhythm and maintained sinus rhythm after 9 months follow-up. 4) The initial success rate of sinus conversion was significantly higher in patients with lone atrial fibrillation compared with those patients with other associated heart disease (100 % vs. 83 %, p < 0.05), but the long-term maintenance rate of sinus rhythm was not influenced by the presence of associated disease. 5) The duration of atrial fibrillation before cardioversion was shorter in patients who were naintained sinus rhythm than that of those who were recurred atrial fibrillation. 6) The initial energy requirement at sinus conversion was lower in the patients who were maintained sinus rhythm than that of those who were recurred atrial fibrillation at 9 months follow-up. CONCLUSIONS: Direct current cardioversion was an effective treatment modality for patients with chronic nonvalvular atrial fibrillation after failure of pharmacological cardioversion with amiodarone.

Electrical Cardioversion of Atrial Fibrillation after Successful Percutaneous Balloon Mitral Valvuloplasty

Objectives: There was no previous report about the electrical cardioversion for the patients with atrial fibrillation after successful percutaneous ballon mitral valvuloplasty (PBMV). We performed electrical cardioversion after PBMV to evaluate the effectiveness of this procedure in the view of conversion to and maintenance of the sinus rhythm. METHODS: 28 patients who had persistent atrial fibrillation after successful PBMV were included in this study. All patients were anticoagulated with warfarin. Amiodarone was loaded and maintained before cardioversion. The PBMV procedures were guided by transesophageal echocardiography in all patients. Transthoracic echocardiography was done before and after PBMV and cardioversion, and was followed. RESULTS: The number of patients were 28 (male 9 and female 19) within the mean age of 50.3+/-12.0 years (24-66). Initially 24 patients (86%) succeeded in electrical cardioversion. The energy required for successful conversion was 230+/-75J, on average. There were no complications except for the transient sinus bradycardia in 2 cases. The mean follow-up duration was 357+/-144 days and when followed-up, the sinus rhythm was maintained in 15 patients out of 24 with initial success (63%). No factor was significantly related to the success of cardioversion, but left atrial dimension after 1 month of PBMV was significantly related to the maintenance of the sinus rhythm. CONCLUSIONS: This study suggests that electrical cardioversion of atrial fibrillation after successful PBMV is favorable and recommendable treatment modality of chronic valvular atrial fibrillation with high conversion rate (88%) and good maintenance rate (63%).

Percutaneous Mitral Balloon Valveloplasty after Successful Resolution of Left Atrial Appendage Thrombi by Oral Anticoagulation

OBJECTIVE: Systemic embolism related with left atrial thrombi is a well known complication of percutaneous ballon valveloplasty of the mitral valve stenosis. The presence of left atrial thtombi is believed to be a contraindication to balloon valvuloplasty. The purpose of this study was to determine whether balloon valvuloplasty is possible in mitral stenosis patients with left atrial thrombi after oral anticoagulation therapy. METHODS: We studied 13 consecutive patients(12 : female, 1 : male, mean age : 44+/-11) who had mitral stenosis and left atrial appendage thrombi by serial transesophageal echocardiography before balloon valvuloplasty of the stenotic mitral valve from May 1995 to January 1997. We started oral anticoagulation in those 13 patients with mitral stenosis and left atrial appendage thrombi to keep the INR 2-3. Regular follow up was performed by transesophageal echocardiagraphy to determine whether the left atrial appendage thrombi are resolved. Patients underwent percutaneous balloon valvuloplasty after complete resolution of left atrial appendage thrombi. RESULTS: 9 patients(69.2%) underwent balloon valvuloplasty after complete resolution of left atrial appendage thrombi with oral anticoagulation for average 6 months. Two (15.4%) patients had normal sinus rhythm. Three patients had coronary A-V fistular due to neovascularization to left atrial appendage thrombi. In four patients, oral antiocoagulation failed to resolve the left atrial appendage thrombi and they underwent balloon valvuloplasty under TEE guide with special caution to avoid systemic embolization. There were no complications such as systemic embolization in those 4 patients. CONCLUSION: Left atrial appendage thrombi in mitral stenosis could be resolved in high proportion(69.2%) by oral anticoagulation therapy. Percutaneous mitral balloon valvuloplasty could be a safe and effective treatment modality despite of the presence of left atrial appendage thrombi after adequate oral anticoagulation therapy.

Electrical Cardioversion of Chrome Nonvalvelar Atrial Fibrillation under Transesophageal Echocardiographic Guidance

BACKGROUND: We performed electrical cardioversion for the patients with chormic nonvalvular atrial fibrillation under the transesophageal echocardiographic guidance after anticoagulation to evaluate the safety of this procedure and the effects of electrical cardioversion on the atrial function. METHODS: After anticoagulation therapy with coumadine for three weeks, we tried chemical cardioversion with amiodarone first. Failed cases were included in this study. Pre-cardioversion transesophageal echocardiographic parameters were measured after exclusion of thrombi. After sedation with intravenous midazolam, direct-current cardioversion was done with the transesophageal echocardiographic probe in situ. Immediately after sinus conversion, we measured echocardiographic parameters again. Spontaneous echo contrast(SEC), left atrial appendage flow velocity, pulmonary vein flow velocity and time-velocity-integral(TVI), transmitral flow velocity, TVI and deceleration time were measured. All patients were anticoagulated for at least 4 weeks after cardiovesion. RESULTS: The total number of patients was forty one(24 males, 17 females) with the mean age of 58 years(range : 39-70). Mean duration of atrial fibrillation was 65 months(range : 1-360). Hypertension(12), dilated cardiomyopathy(10), cerebrovascular accidents(6), ischemic heart disease(2) and chronic lung disease(1) were associated. There were no complications. SEC increased or newly appeared in 18(43.9%) patients after sinus conversion. The left atrial appendage emptying velocity decreased(32.8+/-17.4 vs. 22.1+/-11.4cm/sec, p=0.020) and systolic TVI of both upper pulmonic vein increased significantly after sinus conversion. In two cases, early systolic forward flow(S1) of pulmonic vein appeared after sinus conversion. Transmitral E velocity decreased(86.9+/-28.8 vs. 76.3+/-30.6cm/sec, p=0.006) and the deceleration time increased(164+/-49 vs. 206+/-53msec, p=0.000) after sinus conversion. Transmitral A velocity was still low(34.9+/-19.5cm/sec) and E/A ratio was high(2.6+/-1.4) immediately after sinus conversion. CONCLUSION: After appropriate anticoagulation therapy and exclusion of left atrium and left atrial appindage thrombi with TEE we could perform electrical cardioversion safety without complications. The changes in transesophageal echocardiographic parameters after sinus conversion revealed the appearance of atrial mechanical activity in concordance with electrical activity. But these findings suggested atrial stunning or electromechanical dissociation which necessitates extended anticoagulation therapy until the full recovery of atrial mechanical function.