Relationship between red blood cell distribution width levels and atrial fibrillation in hypertensive patients.

BACKGROUND: Information on the relationship between red blood cell distribution width (RDW) and atrial fibrillation (AF) in patients with essential hypertension are scarce. The study aimed to assess the relationship between AF and RDW in hypertensive patients. METHODS: We enrolled 432 hypertensive patients, including 350 AF patients and 82 patients as controls. Patients' demographic, clinical, laboratory and echocardiographic characteristics were recorded. The AF patients were further divided into the persistent and paroxysmal AF subgroups. Electrocardiograms were monitored to identify the cardiac rhythm during blood sampling, and based on the rhythm, the paroxysmal AF group was categorized into the presence (with AF rhythm during blood sampling) and absence (with sinus rhythm during blood sampling) groups. RESULTS: The AF group had elevated RDW levels than the controls (12.7% ± 0.8% vs. 12.4% ± 0.7%, P = 0.002), and the persistent AF subgroup had higher RDW levels than the paroxysmal AF subgroup (12.9% ± 0.8% vs. 12.6% ± 0.8%, P = 0.007). Furthermore, in the paroxysmal AF group, the presence group had higher RDW levels than the absence group (13.0% ± 0.6% vs. 12.5% ± 0.9%, P = 0.001). There was no significant difference in RDW levels between the persistent AF subgroup and presence group of the paroxysmal AF subgroup (P = 0.533) and between the absence group of the paroxysmal AF subgroup and control group (P = 0.262). In multivariate regression analysis, in hypertensive patients, the presence of AF rhythm is an independent predictor for increased RDW concentration (P = 0.001). CONCLUSIONS: The RDW may be associated with the presence of AF rhythm, which implies the importance of maintaining the sinus rhythm in hypertensive patients.

Correlations between low thyroid function and incidence of atrial fibrillation in hypertrophic obstructive cardiomyopathy.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic obstructive cardiomyopathy (HOCM). Data regarding the correlations of thyroid dysfunction and the incidence of AF in HOCM are quite limited. This study aimed to reveal the correlations between different thyroid status and the corresponding incidence of AF in a large HOCM cohort. METHODS: A total of 806 HOCM patients with complete information on thyroid function tests and comprehensive cardiac evaluations were recruited. The participants were divided into the AF group (n = 159) and non-AF group (n = 647) according to established medical history and results of Holter monitoring. The thyroid status of the study population and the corresponding incidence of AF were assessed and analyzed. RESULTS: Hypothyroidism accounted for the greatest proportion of thyroid dysfunction in HOCM patients. The incidence of AF significantly increased in individuals with both overt (P = 0.022) and subclinical (P = 0.007) hypothyroidism. Compared with participants in the non-AF group, those with positive AF episodes presented with lower free triiodothyronine (FT3) (2.86 ± 0.52 pg/mL vs. 3.01 ± 0.42 pg/mL, P = 0.001), higher free thyroxine (FT4) (1.24 ± 0.25 ng/dL vs. 1.15 ± 0.16 ng/dL, P < 0.001), and remarkably increased levels of thyrotropin (TSH) (12.6% vs. 5.3%, P = 0.001). Multivariable analyses demonstrated that the concentrations of FT3 (odds ratio [OR] = 0.470, 95% confidence interval [CI]: 0.272-0.813, P = 0.007) and FT4 (OR = 17.992, 95% CI: 5.750-56.296, P < 0.001), as well as TSH levels above normal ranges (OR = 2.276, 95% CI: 1.113-4.652, P = 0.024) were independently associated with the occurrence of AF in the large HOCM cohort. CONCLUSIONS: This study indicated a strong link between low thyroid function and the presence of AF in HOCM. Hypothyroidism (both overt and subclinical states) seems to be valuable for assessing the incidence of AF in patients with HOCM.

Association between big endothelin-1 and CHADS2/CHA2DS2-VASc scores in non-valvular atrial fibrillation.

BACKGROUND: Endothelial function, as measured by big endothelin-1 (ET-1), has been demonstrated to be useful in predicting adverse long-term events in patients with cardiovascular disease. Nevertheless, there are little data about the association between big ET-1 and thromboembolism risk in atrial fibrillation (AF). We aimed to investigate the relationship between big ET-1 and CHADS2/CHA2DS2-VASc scores used for evaluating thromboembolic risk in patients with non-valvular AF. METHODS: The study population consisted of 238 consecutive AF patients (67.6% with paroxysmal AF and 32.4% with persistent AF). The patients were divided into two groups (high- or low-intermediate risk group) based on CHADS2 and CHA2DS2-VASc scores (score ≥ 2 or < 2, respectively). Clinical, laboratory, and echocardiographic parameters were evaluated, and the CHADS2/CHA2DS2-VASc scores were compared between groups. The association between big ET-1 levels and CHADS2/CHA2DS2-VASc score was assessed. Multivariate logistic regression analysis was performed to identify independent predictors of CHADS2/CHA2DS2-VASc scores. RESULTS: The high CHADS2/CHA2DS2-VASc score group had older age, higher big ET-1 levels, and enlarged left atrial diameter than the low CHADS2/CHA2DS2-VASc score group (P < 0.05). Multiple logistic regression analysis revealed that big ET-1 level was an independent determinant of high CHADS2/CHA2DS2-VASc scores [odds ratio (OR) = 2.545 and OR = 3.816; both P < 0.05]. CONCLUSIONS: Our study indicates that in non-valvular AF, big ET-1 was significantly correlated with CHADS2/CHA2DS2-VASc scores and an independent predictor of high CHADS2/CHA2DS2-VASc scores. Big ET-1 may serve as a useful marker for risk stratification in this setting.

Aneurysm-related ischemic ventricular tachycardia: safety and efficacy of catheter ablation.

Left ventricular aneurysm (LVA) postmyocardial infarction (MI) might be an arrhythmogenic substrate. We examined the safety and efficacy of catheter ablation of LVA-related ventricular tachycardia (VT).Thirty-three consecutive patients who underwent primary catheter ablation of ischemic VT were divided into LVA group (11 patients, mean age 61.9 years, 10 men) and none LVA group. Acute procedural outcomes, complications, and long-term outcomes were assessed.In LVA group, average number of induced VTs were 3.2 ±â€Š2.6 (range 1-7), clinical VTs were located in the ventricular septum scar zone in 4 (36.4%) patients, acute success was achieved in 7 (63.6%) patients, partial success in 3 (27.3%) and failure in 1 patient, while none LVA group showing a statistically similar distribution of acute procedural outcomes (P = 0.52). There were no major or life-threatening complications. VT-free survival rate at median 19 (1-44) months follow-up was numerically but not significantly lower in LVA versus none LVA group (48.5% vs 62.8%, log-rank P = 0.40).Catheter ablation of ischemic VT in the presence of LVA appears feasible and effective, with about one-third of cases having septal ablation targets. Further studies are warranted.

Fast rate (≥ 250 beats/min) right ventricular burst stimulation is useful for ventricular tachycardia induction in arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: One of the major challenges in arrhythmogenic right ventricular cardiomyopathy (ARVC) ablation is ventricular tachycardia (VT) non-inducibility. The study aimed to assess whether fast rate (≥ 250 beats/min) right ventricular burst stimulation was useful for VT induction in patients with ARVC. METHODS: Ninety-one consecutive ARVC patients with clinical sustained VT that underwent electrophysiological study were enrolled. The stimulation protocol was implemented at both right ventricular apex and outflow tract as follows: Step A, up to double extra-stimuli; Step B, incremental stimulation with low rate (< 250 beats/min); Step C, burst stimulation with fast rate (≥ 250 beats/min); Step D, repeated all steps above with intravenous infusion of isoproterenol. RESULTS: A total of 76 patients had inducible VT (83.5%), among which 49 were induced by Step C, 15 were induced by Step B, 8 and 4 by Step A and D, respectively. Clinical VTs were induced in 60 patients (65.9%). Only two spontaneously ceased ventricular fibrillations were induced by Step C. Multivariate analysis showed that a narrower baseline QRS duration under sinus rhythm was independently associated with VT non-inducibility (OR: 1.1; 95% CI: 1.0-1.1; P = 0.019). CONCLUSION: Fast rate (≥ 250 beats/min) right ventricular burst stimulation provides a useful supplemental method for VT induction in ARVC patients.

Optimized Fluoroscopy Setting and Appropriate Project Position Can Reduce X-ray Radiation Doses Rates during Electrophysiology Procedures.

BACKGROUND: Nonfluoroscopic three-dimensional electroanatomical system is widely used nowadays, but X-ray remains indispensable for complex electrophysiology procedures. This study aimed to evaluate the value of optimized parameter setting and different projection position to reduce X-ray radiation dose rates. METHODS: From June 2013 to October 2013, 105 consecutive patients who underwent complex ablation were enrolled in the study. After the ablation, the radiation dose rates were measured by two different settings (default setting and optimized setting) with three projection positions (posteroanterior [PA] projection; left anterior oblique [LAO] 30° projection; and LAO 45° projection). The parameter of preset voltage, pulse width, critical voltage, peak voltage, noise reduction, edge enhancement, pulse rate, and dose per frame was modified in the optimized setting. RESULTS: The optimized setting reduced radiation dose rates by 87.5% (1.7 Gy/min vs. 13.6 Gy/min, P < 0.001) in PA, 87.3% (2.5 Gy/min vs. 19.7 Gy/min, P < 0.001) in LAO 30°, 85.9% (3.1 Gy/min vs. 22.1 Gy/min, P < 0.001) in LAO 45°. Increase the angle of projection position will increase the radiation dose rate. CONCLUSIONS: We can reduce X-ray radiation dose rates by adjusting the parameter setting of X-ray system. Avoiding oblique projection of large angle is another way to reduce X-ray radiation dose rates.

Relationships of High-sensitive C-reactive Protein and P-wave Dispersion in Lone Atrial Fibrillation.

BACKGROUND: Current evidence links atrial fibrillation (AF) to the inflammation. Inflammatory indexes such as high-sensitive C-reactive protein (hs-CRP) have been related to the development and persistence of AF. However, the role of inflammation in the atrial electrophysiological remodeling indexed by P-wave dispersion (P d ) remains unclear. METHODS: The study consisted of 71 patients with lone paroxysmal AF (AF group) and 71 age- and gender-matched controls of paroxysmal supraventricular tachycardia without history of AF (control group). Electrocardiography, P d , hs-CRP, and other clinical characteristics were compared between the two groups. RESULTS: There was no significant difference between the two groups regarding age, gender, hyperlipidemia, etc. Compared to controls, left atrial diameter (44 ± 7 vs 39 ± 7 mm), P d (49 ± 13 vs 26 ± 8 ms), and hs-CRP (2.17 [1.46-2.89] vs 1.12 [0.74-1.41] mg/L) were increased (P < 0.05), respectively. Linear regression identified hs-CRP as an independent correlation of P d level both in the total population and the AF group (r = 0.464 and 0.313; P < 0.001, respectively). Multiple logistic regression revealed hs-CRP as an independent determinant of AF (odds ratio [OR] =15.430, 95% confidence interval: 6.031-39.476: P <0.001). Further adjusted for P d , both P d and hs-CRP were independent predictors for AF, but the OR for hs-CRP in predicting AF has been attenuated from 15.430 to 6.246. CONCLUSIONS: In lone AF, P d and plasma hs-CRP concentration are inter-associated and related to AF. The interaction between hs-CRP and AF may be mediated by P d , suggesting an important role of inflammation in the atrial electrophysiological remodeling predisposing to AF.

Impact of body mass index on plasma N-terminal ProB-type natriuretic peptides in Chinese atrial fibrillation patients without heart failure.

BACKGROUND: An inverse relationship between body mass index (BMI) and circulating levels of N-terminal proB-type natriuretic peptide (NT-proBNP) has been demonstrated in subjects with and without heart failure. Obesity also has been linked with increased incidence of atrial fibrillation (AF), but its influence on NT-proBNP concentrations in AF patients remains unclear. This study aimed to investigate the effect of BMI on NT-proBNP levels in AF patients without heart failure. METHODS: A total of 239 consecutive patients with AF undergoing catheter ablation were evaluated. Levels of NT-proBNP and clinical characteristics were compared in overweight or obese (BMI≥25 kg/m2) and normal weight (BMI<25 kg/m2) patients. RESULTS: Of 239 patients, 129 (54%) were overweight or obese. Overweight or obese patients were younger, more likely to have a history of nonparoxysmal AF, hypertension, and diabetes mellitus. Levels of NT-proBNP were significantly lower in overweight or obese than in normal weight subjects (P<0.05). The relationship of obesity and decreased NT-proBNP levels persisted in subgroup of hypertension, both gender and both age levels (≥65 yrs and <65 yrs).Multivariate linear regression identified BMI as an independent negative correlate of LogNT-proBNP level. CONCLUSIONS: An inverse relationship between BMI and plasma NT-proBNP concentrations have been demonstrated in AF patients without heart failure. Overweight or obese patients with AF appear to have lower NT-proBNP levels than normal weight patients.

Improved approach to atrial septum puncture: experience in 539 cases.

BACKGROUND: The transseptal puncture technique has been widely used in therapeutic left atrium catheterization. But this technique may lead to some life-threatening complications. It can not be used widely because it is restricted by economy and deferring the transseptal puncture procedure. The aim of this study was to introduce a simple and safe transseptal puncture procedure. METHODS: The distal of coronary sinus (CS) electrode was positioned close to the lateral margin of heart, which was about at 3 o'clock at left anterior oblique (LAO) 30° referred to whole cardiac profile. It was then used as the marker for the level of fossa ovalis at posterior-anterior projection to guide the pull of transseptal needle. The midpoint between the distal CS and the posterior margin of heart at right anterior oblique (RAO) 45° view was considered as the location of fossa ovalis. Once the puncture was succeeded, the guidewire was introduced to the left superior pulmonary vein via puncture sheath after the needle was retrieved. The end of outer sheath was introduced into left atrium with the protection of guidewire. It was applied in 539 patients (316 male, 223 female; (53 ± 16) years old) who underwent catheter ablation of atrial fibrillation or left-sided atrioventricular accessory pathway. RESULTS: This transseptal approach reached 100.0% success and was succeeded in 98.9% with the first attempt. The first attempt puncture was aborted due to greater resistance to needle advancement or smaller needle curve in six patients. However, the second attempts were all succeeded after the needle curve was reshaped. There was no tamponade and embolism occurred. CONCLUSION: The atrial septum puncture approach using the location of distal CS electrode as important marker and the guidewire for protection when sending outer sheath into left atrium is reliable and safe.