PURPOSE: Atrial fibrillation (AF) is one of the major risk factors for ischemic stroke, and 90% of thromboembolisms in these patients arise from the left atrial appendage (LAA). Recently, it has been documented that an LAA occlusion device (OD) is not inferior to warfarin therapy, and that it reduces mortality and risk of stroke in patients with AF. MATERIALS AND METHODS: We implanted LAA-ODs in 5 Korean patients (all male, 59.8+/-7.3 years old) with long-standing persistent AF or permanent AF via a percutaneous trans-septal approach. RESULTS: 1) The major reasons for LAA-OD implantation were high risk of recurrent stroke (80%), labile international neutralizing ratio with hemorrhage (60%), and 3/5 (60%) patients had a past history of failed cardioversion for rhythm control. 2) The mean LA size was 51.3+/-5.0 mm and LAA size was 25.1x30.1 mm. We implanted the LAA-OD (28.8+/-3.4 mm device) successfully in all 5 patients with no complications. 3) After eight weeks of anticoagulation, all patients switched from warfarin to anti-platelet agent after confirmation of successful LAA occlusion by trans-esophageal echocardiography. CONCLUSION: We report on our early experience with LAA-OD deployment in patients with 1) persistent or permanent AF who cannot tolerate anticoagulation despite significant risk of ischemic stroke, or 2) recurrent stroke in patients who are unable to maintain sinus rhythm.
Aged ; Anticoagulants/contraindications ; Atrial Appendage/*physiopathology ; Atrial Fibrillation/epidemiology/*physiopathology/*surgery ; Humans ; Male ; Middle Aged ; Risk Factors ; *Septal Occluder Device ; Stroke/epidemiology/*prevention & control ; Treatment Outcome ; Warfarin/contraindications

OBJECTIVE: To evaluate the electrocardiographic characterizations of atrial contractions(AC) triggering paroxysmal atrial fibrillation(AF), and to explore the effects of AF prevention pacing on their electrocardiographic characterizations. METHODS: Twenty-four patients with the implantation of AF therapy pacemaker(Vitatron 900E) were analyzed by AC triggering paroxysmal AF with Holter monitoring in the study. AC compluing interval, compensatory pause and frequency 2 minutes before the AF or during the AC were compared between the induced paroxysmal AF group and noinduced paroxysmal AF group, and the preventive effect of AF on the post-PAC response program was investigated. RESULTS: There was significant difference in the AC compluing interval [(352.3 +/-30.4) vs (421.8 42.5)ms], compensatory pause [(963 +/-109) vs (733 +/-124) ms], and frequency [(34.8 +/-18.9) vs (12.7 +/-8.7)/min] 2 minutes before the AF or during the AC in the induced paroxysmal AF group, compared with those in the noinduced paroxysmal AF group (all P<0.05). The AF of 7 patients were controlled by atrial overdrive pacing therapy, 17 patients by post-AC-response or/and post-exercise control therapy, 6 patients by the above therapy combining with cordarone (0.2g/d). CONCLUSION AC triggering paroxysmal AF is related to the compluing interval, compensatory pause and frequency 2 minutes before the paroxysmal AF or during the AC, AF prevention pacing may be helpful for the paroxysmal AF induced by AC.
Adult ; Aged ; Atrial Fibrillation ; physiopathology ; prevention & control ; therapy ; Atrial Premature Complexes ; physiopathology ; therapy ; Cardiac Pacing, Artificial ; methods ; Electrocardiography, Ambulatory ; methods ; Female ; Humans ; Male ; Middle Aged

BACKGROUNDP-wave dispersion (PWD) is a useful predictor of paroxysmal atrial fibrillation (AF). The effect of cardiac resynchronization therapy (CRT) on PWD and the prognostic implications of the improvement in PWD remain undefined. The aim of the study was to explore the clinical significance of the improvement of PWD after CRT.

METHODSElectrocardiographic studies were performed before and three months after CRT in 81 patients (57 men and 24 women; age (60.5 ± 11.2) years) with standard CRT indication but no history of AF. A significant improvement of PWD (PWD responder) was defined as a relative decrease ≥ 20% from baseline PWD. The primary endpoints were new-onset AF detected by electrocardiogram (ECG) or CRT.

RESULTSAfter (30.6 ± 7.5) months of follow-up, PWD responders (n = 43) had a significantly lower incidence of AF than did PWD nonresponders, 12% vs. 29% (P < 0.001). In Cox proportional hazard analysis, PWD responders was the only predictor of lower risk of new-onset AF (HR 0.33, 95% confidence interval 0.12 - 0.96, P = 0.033).

CONCLUSIONImprovement of P-wave dispersion after CRT was associated with a lower incidence of AF, which may be related to the significant improvement in left ventricular systolic function and the reverse modeling of the left atrium.

Adult ; Aged ; Atrial Fibrillation ; prevention & control ; Cardiac Resynchronization Therapy ; Echocardiography ; Electrocardiography ; Female ; Heart Failure ; physiopathology ; therapy ; Humans ; Male ; Middle Aged

BACKGROUNDRenin-angiotensin-aldosterone system has been demonstrated to be associated with both congestive heart failure (CHF) and atrial fibrillation (AF). This study investigated the effects of spironolactone, a kind of aldosterone antagonist, on atrial electrical remodeling and fibrosis in CHF dogs induced by chronic rapid ventricular pacing.

METHODSTwenty one dogs were randomly divided into sham-operated group, control group, and spironolactone group. In control group and spironolactone group, dogs were ventricular paced at 220 beats per minute for 6 weeks. Additionally, spironolactone at 15 mg x kg(-1) x d(-1) was given to dogs 1 week before rapid ventricular pacing until pacing stopped. Transthoracic and transoesophageal echocardiographic examinations were performed to detect structural and functional changes of the atrium. Swan2 Ganz floating catheters were used to measure hemadynamics variances. Atrial effective refractory period (AERP), AERP dispersion (AERPd), intra- and inter-atrium conduction time (CT) and intra-atrium conduction velocity (CV) were determined. The inducibility and duration of AF were also measured in all groups. Finally, atrial fibrosis was quantified with Masson staining.

RESULTSAERP did not change significantly after dogs were ventricular paced for 6 weeks. However, AERPd, intra- and inter-atrium CT increased significantly, and CV decreased apparently, which was negatively correlated to the atrial fibrosis (r = -0.74, P < 0.05). Simultaneously, left atriums were enlarged and cardiac hemadynamics worsened in pacing dogs. Although spironolactone could not affect cardiac hemadynamics effectively, it can obviously improve left atrial ejection fraction (P < 0.05). Spironolactone treatment did not alter AERP duration, but this medicine dramatically decreased AERPd (P < 0.05), shortened intra- and inter-atrium conduction time (P < 0.05), and increased atrium CV. Moreover, spironolactone decreased the inducibility and duration of AF (P < 0.05), as well as atrial fibrosis (P < 0.01) induced by chronic rapid ventricular pacing.

CONCLUSIONSpironolactone contributes to AF prevention in congestive heart failure dogs induced by chronic rapid ventricular pacing, which is related to atrial fibrosis reduction and independent of hemadynamics.

Animals ; Atrial Fibrillation ; prevention & control ; Cardiac Volume ; Collagen ; analysis ; Dogs ; Heart Atria ; drug effects ; pathology ; physiopathology ; Heart Failure ; drug therapy ; pathology ; physiopathology ; Hemodynamics ; drug effects ; Spironolactone ; therapeutic use

PURPOSE: Steroids may play a role in preventing the early recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). However, optimal doses and route of steroid delivery have not yet been determined. This study evaluated the effect of two different doses of a single bolus injection of steroids on AF recurrence after RFCA. MATERIALS AND METHODS: Of 448 consecutive AF patients who underwent RFCA, a single steroid bolus was injected into 291 patients. A low-dose steroid group (n=113) received 100 mg of hydrocortisone and a moderate-dose steroid group (n=174) received 125 mg of methylprednisolone. We used propensity-score matching to select patients as follows: control (n=95), low-dose (n=95), and moderate-dose steroid groups (n=97). RESULTS: Pericarditis developed in 1 (1.1%) control patient, 2 (2.1%) low-dose patients and 0 moderate-dose patients. Maximum body temperature and C-reactive protein were significantly decreased in the moderate-dose steroid group compared to the other groups (p<0.01). The number of patients of early AF recurrence (< or =3 months) did not differ among three groups. Early recurrence was 24 (25%) in the control, 24 (25%) in the low-dose and 25 (26%) in the medium-dose groups (p=0.99). Compared with control group, low-dose or moderate-dose steroid treatment did not effectively decrease mid-term (3-12 months) AF recurrence [22 (23%) vs. 23 (24%) vs. 18 (19%); p=0.12]. CONCLUSION: A single injection of moderate-dose steroid decreased inflammation. However, single bolus injections of low-dose or moderate-dose steroids were not effective in preventing immediate, early or midterm AF recurrence after RFCA.
Adult ; Aged ; Anti-Inflammatory Agents/*administration & dosage/adverse effects ; Atrial Fibrillation/physiopathology/*prevention & control ; C-Reactive Protein/drug effects ; *Catheter Ablation ; Female ; Follow-Up Studies ; Humans ; Hydrocortisone/*administration & dosage/adverse effects ; Male ; Middle Aged ; Recurrence ; Secondary Prevention ; Time Factors ; Treatment Outcome