Sang Weon Park

Electrocardiographic and electrophysiological characteristics of premature ventricular complexes associated with left ventricular dysfunction in patients without structural heart disease

AIMSnThe mechanism responsible for premature ventricular complex (PVC)-mediated left ventricular (LV) dysfunction remains unclear. We sought to determine the electrocardiographic and electrophysiological characteristics of PVC-mediated LV dysfunction.nnnMETHODS AND RESULTSnOne hundred and twenty-seven patients who underwent radiofrequency catheter ablation (RFCA) for frequent PVCs (PVCs burden ≥10%/24 h) and had no significant structural heart disease were investigated. Left ventricular dysfunction (ejection fraction < 50%) was present in 28 of 127 patients (22.0%). The mean PVC burden (31 ± 11 vs. 22 ± 10%, P < 0.001), the presence of non-sustained ventricular tachycardia (53.6 vs. 33.3%, P = 0.05), and the presence of a retrograde P-wave following a PVC (64.3 vs. 30.3%, P = 0.001) were significantly greater in those with LV dysfunction than in those with normal LV function. The cut-off PVC burden related to LV dysfunction was 26%/day, with a sensitivity of 70% and a specificity of 78%. The PVC morphology, QRS axis, QRS width, coupling interval, the presence of interpolation, and PVC emergence pattern during exercise electrocardiogram were not significantly different between the two groups. The origin sites of PVCs, the acute success rate, and the recurrence rate during follow-up after RFCA were similar. In a multivariate analysis, the PVC burden (odds ratio 2.94, 95% confidence interval 0.90-3.19, P = 0.006) and the presence of retrograde P-waves (odds ratio 2.79, 95% confidence interval 1.08-7.19, P = 0.034) were independently associated with PVC-mediated LV dysfunction.nnnCONCLUSIONnA higher PVC burden (>26%/day) and the presence of retrograde P-waves were independently associated with PVC-mediated LV dysfunction.

Clinical Significance of Early Recurrences of Atrial Tachycardia After Atrial Fibrillation Ablation

Early Recurrence After AF Ablation.u2002Background: Atrial tachycardia (AT) commonly recurs within 3 months after radiofrequency catheter ablation for atrial fibrillation (AF). However, it remains unclear whether early recurrence of atrial tachycardia (ERAT) predicts late recurrence of AF or AT.

Left atrial appendage: morphology and function in patients with paroxysmal and persistent atrial fibrillation

The anatomical and functional characteristics of the left atrial appendage (LAA) and its relationships with anatomical remodeling and ischemic stroke in patients with atrial fibrillation (AF) have not been clearly established. The purpose of this study was to determine whether functional and morphological features of the LAA independently predict clinical outcome and stroke in patients with AF who underwent catheter ablation (CA). Two hundred sixty-four patients with AF, including 176 with paroxysmal AF (PAF, 54.0xa0±xa011.4xa0years old, M:Fxa0=xa0138:38) and 88 with persistent AF (PeAF, 56.4xa0±xa09.6xa0years old, M:Fxa0=xa074:14) were studied. Of these patients, 31 (11.7xa0%) had a history of stroke/TIA (transient ischemic attack). The LA and LAA volumes were 124.0xa0±xa042.4 and 24.9xa0±xa04.3xa0ml in PeAF, these values were greater than those in PAF (81.2xa0±xa024.8xa0ml and 21.2xa0±xa05.1xa0ml, Pxa0<xa00.001). The AF type (Pxa0=xa00.016) and AF duration (Pxa0=xa00.005), and anti-arrhythmic drugs use (Pxa0<xa00.001) were significant predictors of AF recurrence after CA in all patients. Compared with patients without history of stroke, stroke patients had larger LA volume (106.9xa0±xa023.0 vs. 94.0xa0±xa038.9xa0ml, Pxa0=xa00.004) and had lower LAA EF (50.0xa0±xa011.0 vs. 65.7xa0±xa013.4xa0%, Pxa0<xa00.001). The independent predictors of stroke were age (Pxa0=xa00.002) and LAA EF (Pxa0<xa00.001) in PAF patients and that was only age (Pxa0=xa00.001) in PeAF patients. In anatomical and morphological parameters of the LA and LAA, only depressed systolic function of the LAA was significantly related to stroke/TIA and recurrence of AF after CA in paroxysmal AF patients. Further large scaled prospective study is required for validation.

Prediction of Long‐Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation by Parameters of Preablation DC Cardioversion

Prediction of Long‐Term Outcomes of Catheter Ablation of Persistent Atrial Fibrillation.u2003Aim: It has been demonstrated that atrial fibrillation (AF) frequently recurred after cardioversion (CV) using direct current (DC) or radiofrequency catheter ablation (RFCA) in patients with persistent (PeAF) or longstanding persistent AF (LPAF). We hypothesized that the atrial substrate impeding successful CV would also produce difficulty in catheter ablation, and therefore, the outcomes of RFCA for PeAF and LPAF could be predicted by the parameters determined at the time of DC CV.

Evaluation of quantification methods for left arial late gadolinium enhancement based on different references in patients with atrial fibrillation

By using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging, we compared left atrial late gadolinium enhancement (LA-LGE) quantification methods based on different references to characterize the left atrial wall in patients with atrial fibrillation (AF). Thirty-eight patients who underwent three-dimensional LGE-CMR imaging before catheter ablation for AF were classified into three groups depending on their clinical AF type: (1) paroxysmal AF (PAF; nxa0=xa012); (2) persistent AF (PeAF; nxa0=xa016); and (3) recurrent AF after catheter ablation (RAF; nxa0=xa010). To quantify LA-LGE on LGE-CMR imaging, we used the thresholds of 2 standard deviations (2-SD), 3-SD, 4-SD, 5-SD, or 6-SD above the mean signal from the unenhanced left ventricular myocardium, and we used the full width at half maximum (FWHM) technique, which was based on the maximum signal from the mitral valve with high signal intensity. The 6-SD threshold and FWHM techniques were statistically reproducible with an intraclass correlation coefficient >0.7. On applying the FWHM technique, the normalized LA-LGE volume by LA wall area showed a significant difference between the RAF, PeAF, and PAF groups (0.22xa0±xa00.04, 0.16xa0±xa00.06, and 0.09xa0±xa00.03xa0mL/cm2, respectively) (Pxa0<xa00.05). Furthermore, most of the fibrotic scarring and low-voltage tissue on the electroanatomic map corresponded well with the extent of LA-LGE. The FWHM technique based on the mitral valve can provide a reproducible quantification of LA-LGE related to AF in the thin LA wall.

The Spatial Distribution of Atrial Fibrillation Termination Sites in the Right Atrium During Complex Fractionated Atrial Electrograms-Guided Ablation in Patients with Persistent Atrial Fibrillation

The role of right atrial (RA) ablation guided by complex fractionated atrial electrograms (CFAE) in atrial fibrillation (AF) has been debated. This study evaluated the spatial distribution of RA CFAE, the critical sites, and the predictors of successful termination of longstanding persistent AF during RA ablation.

Clinical significance of induced atrial tachycardia after termination of longstanding persistent atrial fibrillation using a stepwise approach.

Induced Atrial Tachyarrhythmia During Atrial Fibrillation Ablation.u2003Introduction: The utility of inducibility test of atrial tachycardia (AT) in patients with longstanding persistent atrial fibrillation (AF; LPAF) is unclear. This study aimed to evaluate the significance of induced AT and the impact of their ablation on the clinical outcome.

Relation between left atrial wall composition by late gadolinium enhancement and complex fractionated atrial electrograms in patients with persistent atrial fibrillation: influence of non-fibrotic substrate in the left atrium

AbstractnThe complex fractioned atrial electrogram (CFAE) has been considered as the catheter ablation target of left atrium (LA) under persistent atrial fibrillation (PeAF). We evaluated the relation between the LA wall composition by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) and the CFAE in patients with PeAF. Forty-three patients underwent LGE-CMR and CFAE mapping before catheter ablation for PeAF. The LA wall substrates were classified into three: the fibrotic, intermediate, and normal substrates by using two thresholds of 2 standard deviation (2-SD) and 6-SD above the mean signal from the normal myocardium. For each of 12 preselected LA wall regions, the composition ratios (CRs) of fibrotic, indeterminate, and normal substrates were calculated as a percentage to the volume of LA wall region, and compared depending on the CFAE, respectively. The CR of normal substrate was significantly greater at the LA wall region with CFAE (52xa0±xa038xa0% vs. 20xa0±xa028xa0%, Pxa0<xa00.01) than without CFAE. In contrast, the LA wall region with CFAE showed significantly lower CRs of intermediate substrate (39xa0±xa034xa0% vs. 57xa0±xa031xa0%, Pxa0<xa00.01) and fibrotic substrate (7xa0±xa017xa0% vs. 21xa0±xa024xa0%, Pxa0<xa00.01) than did the LA wall region without CFAE, respectively. Thus, the high CR (>18xa0%) of normal substrate predicted the CFAE at the corresponding LA wall region with 71xa0% sensitivity and 62xa0% specificity. In conclusion, the evaluation of LA wall normal substrate by LGE-CMR might be useful to predict the CFAE occurrence before catheter ablation of PeAF.

Idiopathic ventricular arrhythmia originating from the para-Hisian area: Prevalence, electrocardiographic and electrophysiological characteristics

We investigated the prevalence and the electrocardiographic and electrophysiological characteristics of ventricular arrhythmias (VAs) originating from the para‐Hisian area.

Intra-procedural imaging of the left atrium and pulmonary veins with rotational angiography: a comparison of anatomy obtained by pre-procedural cardiac computed tomography and trans-thoracic echocardiography

This study evaluated the feasibility and accuracy of three-dimensional rotational angiography (3DRA) to determine the anatomy of the left atrium (LA) and pulmonary veins (PVs) compared with cardiac computed tomography (CCT) and trans-thoracic echocardiography (TTE). One hundred two patients (56.1xa0±xa09.9xa0years, 86 males) with an indication for atrial fibrillation ablation were prospectively enrolled. Intra-procedural 3DRA was performed with power injected contrast medium (20xa0cc/s for 4xa0s, 240°) in the LA. 3DRA images of the LA and PVs were assessed qualitatively and then compared quantitatively. LA volume measured by 3DRA, CCT and TTE were compared. The majority of 3DRA acquisitions were optimal in delineating the right-side LA–PV (95xa0% for right superior PV and 96xa0% for right inferior PV) and left inferior PV anatomy (91xa0%), whereas it was optimal in only 63xa0% of left superior PV and 73xa0% of the LA appendage. The circumferences of PV ostia identified by 3DRA and CCT were correlated in four PVs (rxa0=xa00.57 for right superior PV, rxa0=xa00.67 for right inferior PV, rxa0=xa00.60 for left superior PV, and rxa0=xa00.52 for left inferior PV, pxa0<xa00.001). The mean LA volume measured by 3DRA (120xa0±xa032xa0mL) was greater than that found by CCT (109xa0±xa035xa0mL) or TTE (64xa0±xa023xa0mL), but the 3DRA LA volume measurements correlated well with those of CCT (rxa0=xa00.83, pxa0<xa00.001) and TTE (rxa0=xa00.69, pxa0<xa00.001). Intra-procedural 3DRA provided anatomical accuracy of LA and PVs comparable to those of CCT. However, optimal delineation of the left superior PV and LA appendage was limited. The LA volume determined by 3DRA was well correlated with those of CCT and TTE, despite different absolute values of each.