Showing papers by "Hui Nam Pak published in 2012"

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: Recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

Abstract: During the past decade, catheter ablation of atrial fibrillation (AF) has evolved rapidly from an investigational procedure to its current status as a commonly performed ablation procedure in many major hospitals throughout the world. Surgical ablation of AF, using either standard or minimally invasive techniques, is also performed in many major hospitals throughout the world. In 2007, an initial Consensus Statement on Catheter and Surgical AF Ablation was developed as a joint effort of the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society.1 The 2007 document was also developed in collaboration with the Society of Thoracic Surgeons and the American College of Cardiology. Since the publication of the 2007 document, there has been much learned about AF ablation, and the indications for these procedures have changed. Therefore the purpose of this 2012 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a Task Force, convened by the Heart Rhythm Society, the European Heart Rhythm Association, and the European Cardiac Arrhythmia Society and charged with defining the indications, techniques, and outcomes of this procedure. Included within this document are recommendations pertinent to the design of clinical trials in the field of AF ablation, including definitions relevant to this topic. This statement summarizes the opinion of the Task Force members based on an extensive literature review as well as their own experience. It is directed to all health care professionals who are involved in the care of patients with AF, particularly those who are undergoing, or are being considered for, catheter or surgical ablation procedures for AF. This statement is not intended to recommend or promote catheter ablation of AF. Rather the ultimate judgment regarding care of a particular patient …

Does additional linear ablation after circumferential pulmonary vein isolation improve clinical outcome in patients with paroxysmal atrial fibrillation? Prospective randomised study

Abstract: Objective Circumferential pulmonary vein isolation (CPVI) has been considered the cornerstone of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). However, it is unclear whether linear ablation in addition to CPVI improves clinical outcome. Design Prospective randomised study to compare the efficacy of CPVI and CPVI with additional linear ablation in patients with paroxysmal AF (PAF). Setting University hospital. Patients This study enrolled 156 patients (male 76.3%, 55.8±11.5 years old (mean±SD)) who underwent RFCA for PAF. Interventions CPVI (n=52), CPVI+roof line (CPVI+RL; n=52) and CPVI+RL+posterior inferior line (CPVI+PostBox; n=52). Main outcome measures Procedure time, ablation time and clinical outcome. Results (1) The CPVI group showed shorter total procedure time (180.4±39.5 min vs 189.6±29.0 min and 201.7±51.7 min, respectively (mean±SD); p=0.035) and ablation time (4085.5±1384.1 s vs 5253.5±1010.9 s and 5495.0±1316.0 s, respectively; p Conclusion In patients with PAF, linear ablation in addition to CPVI did not improve clinical outcome, regardless of bidirectional block achievement, while it prolonged the total procedure and ablation time.

Right atrial anatomical remodeling affects early outcomes of nonvalvular atrial fibrillation after radiofrequency ablation.

Abstract: Background: The impact of the right atrial (RA) anatomical remodeling on outcomes of atrial fibrillation (AF) after radiofrequency ablation (RFA) is unclear. Methods and Results: Sixty-three patients (50 men, 57±10 years, 23 persistent AF [PeAF]) who underwent RFA for AF were enrolled. Both RA and left atrial (LA) volumes, measured with multidetector computed tomography, as well as echocardiographic parameters were compared between subjects with early (<3 months, n=13) or 1-year (n=19) recurrence after RFA and without recurrence. The RA volume index (RAVI) was larger (98±21 vs. 77±22ml/m2) and PeAF was more common (62% vs. 30%) in the early recurrence group (P<0.05 for all), whereas the LA volume index (LAVI) was similar between the 2 groups (78±15 vs. 72±19ml/m2, P=0.23). Notably, RAVI was the only independent predictor of early recurrence (for each 10ml/m2 increase, OR: 1.650, 95%CI: 1.017-2.677, P=0.04). PeAF was the only independent predictor of 1-year recurrence after RFA (OR: 4.496, 95%CI: 1.110-18.211, P=0.04), whereas RAVI and LAVI were not. Conclusions: RA anatomical remodeling might affect the early recurrence of AF after RFA. However, the chronicity of AF, rather than RA and LA anatomical remodeling, is a determinant of 1-year recurrence of AF after RFA. (Circ J 2012; 76: 860-867)

Significant reduction of atrial defibrillation threshold and inducibility by catheter ablation of atrial fibrillation

Abstract: Background: Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) has antiarrhythmic effects by multiple mechanisms. We hypothesized that RFCA curtails atrial defibrillation threshold (A-DFT) and postablation induction pacing cycle length (iPCL), making critical mass reduction one potential mechanism by which antiarrhythmic effect is achieved. Methods: We included 289 patients with AF (male 77.9%, 55.7 ± 10.8 years old; 197 paroxysmal AF: 92 persistent AF) who underwent RFCA. A-DFT (serial internal cardioversion 2, 3, 5, 7, and 10 J) and iPCL (serial 10 mA 10-second atrial pacing with pacing cycle length 250, 200, 190, 180, 170, 160, and 150 ms) were evaluated before and after RFCA. Results: (1) RFCA of AF reduced the A-DFT from 6.7 ± 3.7 J to 3.0 ± 3.0 J (P < 0.001). (2) AF ablation reduced AF inducibility from 95.4% before the procedure to 56.3% after the procedure (P < 0.001), and the iPCL from 194.8 ± 32.6 to 160.9 ± 26.2 ms (P < 0.001). (3) In patients who underwent a greater number of ablation lines, the post-RFCA A-DFT (P < 0.001) was lower, and %ΔA-DFT (P = 0.003) and proportion of atrial tachycardia (P = 0.022) were higher than those with a lower number of ablation lines. Conclusion: AF ablation significantly reduced A-DFT, AF inducibility, and iPCL, and the degree of their reduction was related to the number of ablation lines. (PACE 2012;35:1428–1435)

Safety of capsule endoscopy using human body communication in patients with cardiac devices

Abstract: Background The MiroCam (IntroMedic, Ltd., Seoul, Korea) is a small-bowel capsule endoscope that uses human body communication to transmit data. The potential interactions between cardiac devices and the capsule endoscope are causes for concern, but no data are available for this matter.

Bleeding Risk and Major Adverse Events in Patients With Previous Ulcer on Oral Anticoagulation Therapy

Abstract: Bleeding is the major concern for patients receiving oral anticoagulation therapy (OAT), especially those with histories of gastrointestinal ulcer. The aim of this study was to evaluate the efficacy and safety of OAT in patients with nonvalvular atrial fibrillation with histories of ulcer. A composite end point, including major adverse cardiac events or major bleeding, was compared between patients with AF with previous ulcers who were (OAT+; n = 200) and were not (OAT- n = 230) receiving OAT. During the follow-up period of 3.3 ± 2.7 years, 28 (14%) and 66 (29%) OAT+ and OAT- patients, respectively, had major adverse cardiac events (p = 0.001). Major bleeding occurred in 46 OAT+ patients (23%) and 25 OAT- patients (11%) (p = 0.001). There was no significant difference in the composite end point between OAT+ and OAT- patients (29% vs 36%, p = 0.08). The incidence of major bleeding was significantly lower, decreasing from 30% to 14%, when OAT began after endoscopic confirmation of ulcer healing (p = 0.02). OAT+ patients who achieved time in the therapeutic range ≥60% for international normalized ratio (2.0 to 3.0) demonstrated better cumulative survival free from the composite end point than OAT- patients (p = 0.01). In conclusion, OAT in patients with nonvalvular AF with histories of gastrointestinal ulcer made no difference in the composite end point compared to absence of OAT. In OAT+ patients, maintaining an optimal international normalized ratio reduced the composite end point, and the confirmation of ulcer healing reduced the incidence of bleeding.

Importance of tachycardia cycle length for differentiating typical atrial flutter from scar-related in adult congenital heart disease

Abstract: Background: Radiofrequency catheter ablation (RFCA) for intraatrial reentrant tachycardia (IART) in congenital heart disease (CHD) remains difficult. Methods: Thirty-four consecutive adult patients (age, 37.6 ± 12.8 years; male, 21) with previously repaired CHD and IART underwent an electrophysiological study and RFCA. CHD included atrial septal defect (ASD, n = 14), tetralogy of Fallot (n = 11), ventricular septal defect (n = 4), pulmonary atresia (n = 2), atrioventricular septal defect (n = 1), transposition of the great arteries (n = 1), and double-outlet right ventricle (n = 1). Results: Duration of CHD repair to IART onset was 19.1 ± 8.5 years. Thirty and four patients had single- and double-loop reentrant tachycardia, respectively. Among the total of 38 IARTs, which were mapped, 22 (57.9%) and 13 (34.2%) IARTs were cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) and scar-related AFL, respectively. Typical AFL electrocardiography findings including definite sawtooth appearance in inferior leads and positive F wave in lead V1 were observed in only 12 of 21 patients (57.1%) with CTI-dependent AFL. CTI-dependent AFL had a significantly longer tachycardia cycle length (TCL) than scar-related AFL (267.6 ± 34.4 ms and 235.9 ± 37.0 ms, respectively; P = 0.031). TCL > 250 ms had 79% sensitivity as the cutoff value for differentiating CTI-dependent from scar-related AFL. The acute success rates of RFCA in CTI-dependent and scar-related AFLs were 85.7% and 90.0%, respectively. The recurrence rates in CTI-dependent and scar-related AFLs were 11.1% and 11.1%, respectively, during a follow-up of 21.2 ± 28.3 months. Conclusions: CTI-dependent AFL was the most common IART in adult patients with repaired CHD and was easily manageable by RFCA. TCL might help to differentiate CTI-dependent AFL from other IARTs. (PACE 2012;35:1338–1347)

Early Experience Using a Left Atrial Appendage Occlusion Device in Patients with Atrial Fibrillation

Abstract: 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.

Electroanatomical Characteristics of Idiopathic Left Ventricular Tachycardia and Optimal Ablation Target during Sinus Rhythm: Significance of Preferential Conduction through Purkinje Fibers

Abstract: Purpose: We hypothesized that Purkinje potential and their preferential conduction to the left ventricle (LV) posteroseptum during sinus rhythm (SR) are part of reentrant circuits of idiopathic left ventricular tachycardia (ILVT) and reentry anchors to papillary muscle. Materials and Methods: In 14 patients with ILVT (11 men, mean age 31.5±11.1 years), we compared Purkinje potential and preferential conduction during SR with VT by non-contact mapping (NCM). If clear Purkinje potential(SR) was observed in the LV posteroseptum and the earliest activation site (EA) of preferential conduction at SR (EASR) was well matched with that of VT (EAVT), EASR was targeted for radiofrequency catheter ablation (RFCA). Also, the anatomical locations of successful ablation sites were evaluated by echocardiography in five additional patients. Results: 1) All induced VTs exhibited clear Purkinje potential(VT) and preferential conduction in the LV posteroseptum. The Purkinje potential(VT) and EAVT was within 5.8±8.2 mm of EASR. However, the breakout sites of VT were separated by 30.2±12.6 mm from EAVT to the apical side. 2) Purkinje potential(SR) demonstrated a reversed polarity to Purkinje potential(VT), and the interval of Purkinje potential(SR)-QRS was longer than the interval of Purkinje potential(VT)-QRS (p<0.02) 3) RFCA targeting EASR eliminated VT in all patients without recurrence within 23.3±7.5 months, and the successful ablation site was discovered at the base of papillary muscle in the five additional (100%) patients. Conclusion: NCM-guided localization of EASR with Purkinje potential(SR) matches well with EAVT with Purkinje potential(VT) and provides an effective target for RFCA, potentially at the base of papillary muscle in patients with ILVT.

Mid-septal hypertrophy and apical ballooning; potential mechanism of ventricular tachycardia storm in patients with hypertrophic cardiomyopathy

Abstract: Medically refractory ventricular tachycardia (VT) storm can be controlled with radiofrequency catheter ablation (RFCA), however, it may be difficult to control in some patients with hemodynamic overload. We experienced a patient with intractable VT storm controlled by hemodynamic unloading. The patient had mid-septal hypertrophic cardiomyopathy with an implantable cardioverter defibrillator (ICD) back-up. Because of the severe mid-septal hypertrophy, his left ventricle (LV) had an hourglass-like morphology and showed apical ballooning; the focus of VT was at the border of apical ballooning. Although we performed VT ablation because of electrical storm with multiple ICD shocks, VT recurred 1 hour after procedure. As the post-RFCA monomorphic VT was refractory to anti-tachycardia pacing or ICD shock, we reduced the hemodynamic overload of LV with β-blockade, hydration, and sedation. VT spontaneously stopped 1.5 hours later and the patient has remained free of VT for 24 months with β-blockade alone. In patients with VT storm refractory to antiarrhythmic drugs or RFCA, the mechanism of mechano-electrical feedback should be considered and hemodynamic unloading may be an essential component of treatment.

Male Pseudohermaphroditism Presented with Sudden Cardiac Arrest

Abstract: Torsades de Pointes is a life-threatening arrhythmia associated with a number of causes, but is very rare among endocrinologic disorders. We report a case of male pseudohermaphroditism with hyperaldosteronism due to a 17α-hydroxylase defi ciency presented with sudden cardiac arrest.