Circulating homocysteine levels in patients with radiofrequency catheter ablation for atrial fibrillation.

AIMS: 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. METHODS AND RESULTS: 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). CONCLUSION: 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.

Novel transitional zone index allows more accurate differentiation between idiopathic right ventricular outflow tract and aortic sinus cusp ventricular arrhythmias.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: This novel TZ index can be a more useful marker for differentiating RVOT origin from ASC origin.

Combined assessment of left ventricular dyssynchrony and contractility by speckled tracking strain imaging: a novel index for predicting responders to cardiac resynchronization therapy.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: Forty-seven patients with severe heart failure in New York Heart Association functional class III/IV, left ventricular ejection fraction /=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. RESULTS: 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). CONCLUSION: 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.

Circulating adiponectin levels in patients with atrial fibrillation.

BACKGROUND: 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. METHODS AND RESULTS: 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). CONCLUSIONS: 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.