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ABSTRACT: Although several ECG algorithms have been proposed for differentiating the origins of outflow tract ventricular arrhythmia (OT-VA), their accuracy still is limited in cases with cardiac rotation.
The purpose of this study was to assess whether a novel "cardiac rotation-corrected" transitional zone (TZ) index would be a useful marker for differentiating right ventricular outflow tract (RVOT) origin from aortic sinus cusp (ASC) origin.
Surface ECGs of OT-VAs with left bundle branch block morphology and inferior axis in 112 patients who were successfully ablated in the RVOT (n = 87) or the ASC (n = 25) were analyzed. The TZ index was defined according to the site of R-wave transition of sinus beats and OT-VAs.
The TZ index was significantly lower in the ASC origin than in the RVOT origin (-1.2 ± 0.9 vs 0.3 ± 0.7, P <.0001). A cutoff value of the TZ index <0 predicted the ASC origin with 88% sensitivity and 82% specificity. The previously reported R-wave duration index ≥ 50% had a high specificity of 85% but a low sensitivity of 44%, and R/S-wave amplitude index ≥ 30% had 68% sensitivity and 79% specificity. The area under the curve by receiver operating characteristic curve analysis was 0.90 for the TZ index, which was significantly higher than the R-wave duration index and R/S-wave amplitude index of 0.74 and 0.76, respectively.
This novel TZ index can be a more useful marker for differentiating RVOT origin from ASC origin.
Heart rhythm: the official journal of the Heart Rhythm Society 11/2010; 8(3):349-56. · 4.56 Impact Factor
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Yasuya Inden,
Rieko Ito,
Naoki Yoshida,
Hiromi Kamiya,
Kazuhisa Kitamura,
Tomoya Kitamura,
Masayuki Shimano, Tomohiro Uchikawa,
Yukiomi Tsuji,
Rei Shibata,
Makoto Hirai,
Toyoaki Murohara
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ABSTRACT: Mechanical dyssynchrony is an important factor in the response to cardiac resynchronization therapy (CRT). However, no echocardiographic measure can improve prediction of case selection for CRT.
The purpose of this study was to assess the efficacy of a newly combined echocardiographic index for ventricular dyssynchrony and contractility using speckled tracking strain analysis to predict responders to CRT.
Forty-seven patients with severe heart failure in New York Heart Association functional class III/IV, left ventricular ejection fraction </=35%, and QRS duration >/=130 ms were included in the study. Echocardiography was performed, and a novel index (i-Index), the product of radial dyssynchrony and radial strain, was calculated. Responder to CRT was defined as a patient with a >/=15% decrease in left ventricular end-systolic volume at 6-month follow-up.
Thirty-two patients (68%) were classified as responders. The i-Index was significantly higher in responders than in nonresponders (3,450 +/- 1180 vs 1,481 +/- 841, P <.001). The area under receiver operator characteristic curve was 0.92 for the i-Index, which was better than the index of radial dyssynchrony only (0.74). A cutoff value of i-Index >2,000 predicted responders with 94% sensitivity and 80% specificity. The index using only radial dyssynchrony had 81% sensitivity and 53% specificity. Furthermore, i-Index decreased in responders (1,985 +/- 1261, P <.001) but not in nonresponders (1,684 +/- 866, P = .48).
Our findings suggest that a novel combined index by radial strain echocardiography might be a predictor of response to CRT. The value of this novel echocardiographic index requires further assessment in larger studies.
Heart rhythm: the official journal of the Heart Rhythm Society 01/2010; 7(5):655-61. · 4.56 Impact Factor
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ABSTRACT: Identification of arrhythmogenic pulmonary veins (PVs) initiating atrial fibrillation is helpful for catheter ablation. The aim of this study was to examine the possibility to recognize the arrhythmogenic PV using Holter ECG.
In 20 patients, P-wave characteristics were studied during pacing from four PVs. Holter ECG was recorded using two leads: the modified CC5 (Lead 1) and NASA (Lead 2), and the P-wave amplitude and duration were evaluated. In Lead 1, P-waves produced by left PV pacing were significantly lower in amplitude than right PV pacing (-3 +/- 75 vs. 86 +/- 43 microV, P < 0.001). In Lead 2, pacing in superior PVs produced P-waves with higher amplitude than inferior PVs (210 +/- 74 vs. 125 +/- 66 muV, P < 0.001). The criteria proposed by the morphological characteristics of P-waves identified putative arrhythmogenic PVs with an accuracy of 78%.
It might be possible to identify putative arrhythmogenic PVs by modified Holter ECG recording.
Europace 11/2009; 12(1):124-9. · 1.98 Impact Factor
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ABSTRACT: Oxidative stress is associated with atrial fibrillation (AF). However, little is known about the relationship between serum markers of oxidation and electrical activity in patients with AF.
The purpose of this study was to investigate the possible association between serum markers of reactive oxidative metabolism and atrial remodeling in paroxysmal and persistent AF.
Derivatives of reactive oxidative metabolites (DROM), an index of oxidative stress, were measured in 306 consecutive patients with AF (225 paroxysmal, 81 persistent) undergoing radiofrequency (RF) catheter ablation. Filtered P-wave duration by P-wave signal-averaged ECG and levels of high-sensitivity C-reactive protein (CRP) as an inflammatory marker also were measured.
Patients were followed up for 1.2 +/- 0.8 years. DROM levels in patients with persistent AF were significantly higher than in patients with paroxysmal AF (341.6 +/- 85.5 Carratelli [Carr] units vs 305.0 +/- 77.7 Carr units, P <.001). DROM levels showed a tighter, positive correlation with filtered P-wave duration in persistent AF patients (r = 0.56, P <.001) than in all AF patients (r = 0.13, P <.05). DROM levels also showed a weaker but significant correlation with high-sensitivity CRP in patients with AF. Kaplan-Meier analysis revealed that the highest quartile of basal DROM levels exhibited a significantly higher AF recurrence rate after RF catheter ablation in patients with paroxysmal AF (P <.01).
Serum markers of oxidative stress reflect atrial conduction disturbance and predict AF recurrence after RF catheter ablation in paroxysmal AF patients. DROM could serve as a biomarker for predicting risk of AF recurrence after RF catheter ablation.
Heart rhythm: the official journal of the Heart Rhythm Society 07/2009; 6(7):935-40. · 4.56 Impact Factor
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ABSTRACT: Atrial fibrillation (AF) characterized by atrial remodeling occurs with obesity-related conditions. Adiponectin, an adipose tissue-derived hormone exerts beneficial effects on ventricular remodeling, so in the present study the potential association between circulating adiponectin levels and atrial remodeling in patients with AF was investigated.
The levels of plasma adiponectin, serum carboxy-terminal telopeptide of collagen type I (CITP), as a collagen type I degradation marker, and serum type III procollagen-N-peptide (PIIINP), as a collagen type III synthesis marker, were measured in 304 consecutive patients (162 paroxysmal AF, 46 persistent AF, 96 paroxysmal supra-ventricular tachycardia [controls]). Plasma adiponectin levels were significantly higher in patients with persistent AF than in those with paroxysmal AF or the control patients (p<0.05). Serum CITP levels, but not serum PIIINP levels, were higher in patients with persistent AF compared with the paroxysmal AF and control patients (p<0.05). In addition, there was a positive correlation between adiponectin levels and CITP levels in patients with persistent AF (r=0.39, p<0.005).
High plasma adiponectin levels are associated with the presence of persistent AF, which is accompanied by increased CITP levels. Thus, measurement of plasma adiponectin could be useful for assessment of AF.
Circulation Journal 08/2008; 72(7):1120-4. · 3.77 Impact Factor
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ABSTRACT: This study investigated the potential association between homocysteine levels and cardiovascular events or atrial fibrillation (AF) recurrence following radiofrequency catheter ablation (RFCA) in patients with AF.
Blood samples were obtained prior to the RFCA procedure. Levels of homocysteine and carboxy-terminal telopeptide of collagen type I (CITP), a collagen type I degradation marker, were measured in 96 patients receiving RFCA; 62 paroxysmal or persistent AF patients and 34 paroxysmal supra-ventricular tachycardia patients. Patients were followed up for 2.1 +/- 1.5 years. Plasma homocysteine levels were significantly higher in patients with persistent AF (P < 0.05) compared with levels in paroxysmal AF and control patients. Homocysteine levels also positively correlated with left atrial dimension (LAD) (P < 0.01) and CITP levels (P < 0.001). While no significant correlation was found between basal homocysteine levels and recurrent AF after RFCA in AF patients, patients in the high homocysteine group exhibited a significantly higher rate of cardiovascular events without AF recurrence compared with those in the low homocysteine group (P < 0.05).
High homocysteine levels are associated with the presence of persistent AF, which is accompanied by increased CITP levels and LAD. Also confirmed is the role of homocysteine as a risk factor for the pathogenesis of cardiovascular events after RFCA in AF patients. Measurement of homocysteine level may provide useful information for the managing cardiovascular risk in patients with AF.
Europace 06/2008; 10(8):961-6. · 1.98 Impact Factor
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ABSTRACT: The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activator pioglitazone antagonizes angiotensin II actions and possesses anti-inflammatory and antioxidant properties in vitro. There is evidence that pioglitazone improves ventricular remodeling in some experimental models.
The purpose of this study was to assess the effects of pioglitazone on arrhythmogenic atrial structural remodeling versus the effects of the angiotensin II type 1 receptor blocker candesartan in a rabbit model of congestive heart failure.
Rabbits subjected to ventricular tachypacing at 380 to 400 bpm for 4 weeks in the absence and presence of treatment with pioglitazone, candesartan, and combined pioglitazone and candesartan were assessed by electrophysiologic study, atrial fibrosis measurements, and cytokine expression analyses.
Atrial fibrillation (AF) lasting longer than 2 seconds was induced in no nonpaced controls but in all ventricular tachypacing-only rabbits (mean duration of AF: 8.0 +/- 1.4 seconds). Pioglitazone reduced the duration of AF (3.5 +/- 0.2 seconds, P <.05) and attenuated atrial structural remodeling, with significant reductions in interatrial activation time (50 +/- 2 ms vs 41 +/- 2 ms, P <.05) and atrial fibrosis (16.8% +/- 0.8% vs 10.9% +/- 0.7%, P <.05; control 1.6% +/- 0.2%), effects comparable to those of candesartan (duration of AF: 3.0 +/- 0.2 seconds; activation time 44 +/- 2 ms; fibrosis: 9.4% +/- 0.6%). Both pioglitazone and candesartan reduced transforming growth factor-beta1, tumor necrosis factor-alpha, and activated extracellular signal-regulated kinase expression similarly, but neither affected p38-kinase or c-Jun N-terminal kinase activation. The effects of combined pioglitazone and candesartan therapy were not significantly different from the effects of pioglitazone or candesartan alone.
Pioglitazone can attenuate congestive heart failure-induced atrial structural remodeling and AF promotion, with effects similar to those of candesartan. PPAR-gamma may be a potential therapeutic target for human AF.
Heart Rhythm 03/2008; 5(3):451-9. · 4.10 Impact Factor
