OBJECTIVETo map and compare the right atrium in patients with AF to those with atrioventricular nodal reentrant tachycardias (AVNRT, as control group) and to investigate the anatomical and electrophysiological abnormality of the right atrium in AF.

METHODSThe anatomy and electrophysiology of right atrium and cavotricuspid isthmus were evaluated in 20 patients with AF (16 M/4 F, mean age 55.9 +/- 10.68 years) and 26 patients with AVNRT (9 M/17 F, mean age 47.50 +/- 19.56 years) during coronary sinus pacing at 600 ms prior to ablation with electro-anatomical mapping system. Right atrial volume (RAV), the length and width of cavotricuspid isthmus (IsL, IsW), unipolar and bipolar voltage in the right atrium (UniV-RA, BiV-RA) were measured and compared between patients with AF and those with AVNRT.

RESULTSRAV, IsL, IsW, UniV-RA, and BiV-RA were 143.22 +/- 40.72 vs 104.35 +/- 21.06 ml, 39.31 +/- 8.10 vs 32.42 +/- 9.77 mm, 30.54 +/- 7.48 vs 23.15 +/- 6.61 mm, 1.96 +/- 1.24 vs 1.53 +/- 0.91 mv and 1.47 +/- 1.47 vs 1.29 +/- 1.12 mv in AF and AVNRT respectively.

CONCLUSIONThe right atrial volume is larger; both the length and width of cavotricuspid isthmus are greater. Unipolar and bipolar voltages in the right atrium are higher in AF than in AVNRT, suggesting that the enlarged right atrium, increased length and width of cavotricuspid isthmus, and concomitant atrial hypertrophy are important substrates for initiation and perpetuation of typical AF.

Adult ; Aged ; Atrial Flutter ; etiology ; pathology ; physiopathology ; Cardiomegaly ; complications ; Female ; Heart Atria ; pathology ; physiopathology ; Humans ; Male ; Middle Aged ; Tachycardia, Atrioventricular Nodal Reentry ; pathology ; physiopathology

OBJECTIVETo investigate the changes of left ventricular structure and function in patients with liver cirrhosis and their correlation with the model for end-stage liver disease (MELD) score.

METHODSA total of 89 cirrhotic patients admitted between June, 2012 and June, 2014 and 30 healthy control subjects were enrolled in the study. According to MELD score, the cirrhotic patients were divided into 3 groups with MELD scores ≤9, between 10 and 19, and ≥20. The parameters of the left ventricle in resting state were measured using Doppler echocardiography, including left ventricular end systolic diameter (LVESD), left ventricular end diastolic diameter (LVEDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left atrial diameter (LAD), ejection fraction (LVEF), cardiac output (CO), mitral flow velocity, and E wave deceleration time (DT), and evaluated their relationship with MELD score.

RESULTSCompared with the control subjects, the cirrhotic patients showed significantly increased LVESD, LVEDD, IVST, LAD, CO and DT but reduced VE/VA ratio (P<0.05 or 0.01). The values of LVESD, LVEDD, IVST, LAD and DT increased gradually with MELD scores (P<0.05 or 0.01). VE/VA ratio was higher in patients with MELD score of 10-19 than in those with MELD score ≤9, and decreased significantly in those with MELD score ≥20. Of the cirrhotic patients, 55% were found to have left atrial enlargement and 44% had a VE/VA ratio ≤1; left atrial enlargement and a VE/VA ratio below 1 were more common in patients with a MELD score ≥20 than in those with lower MELD scores. The LAD, LVEDD and DT were positively correlated with MELD scores (r=0.208, 0.319 and 0.197, respectively; P<0.05 or 0.01).

CONCLUSIONSThe patients with liver cirrhosis can have cardiac function deficiency manifested mainly by left ventricular diastolic dysfunction in positive correlation with the severity of liver disease.

Cardiac Output ; Case-Control Studies ; End Stage Liver Disease ; physiopathology ; Heart Atria ; pathology ; Heart Ventricles ; physiopathology ; Humans ; Liver Cirrhosis ; physiopathology ; Severity of Illness Index ; Ventricular Function, Left

BACKGROUNDRenin-angiotensin-aldosterone system has been demonstrated to be associated with both congestive heart failure (CHF) and atrial fibrillation (AF). This study investigated the effects of spironolactone, a kind of aldosterone antagonist, on atrial electrical remodeling and fibrosis in CHF dogs induced by chronic rapid ventricular pacing.

METHODSTwenty one dogs were randomly divided into sham-operated group, control group, and spironolactone group. In control group and spironolactone group, dogs were ventricular paced at 220 beats per minute for 6 weeks. Additionally, spironolactone at 15 mg x kg(-1) x d(-1) was given to dogs 1 week before rapid ventricular pacing until pacing stopped. Transthoracic and transoesophageal echocardiographic examinations were performed to detect structural and functional changes of the atrium. Swan2 Ganz floating catheters were used to measure hemadynamics variances. Atrial effective refractory period (AERP), AERP dispersion (AERPd), intra- and inter-atrium conduction time (CT) and intra-atrium conduction velocity (CV) were determined. The inducibility and duration of AF were also measured in all groups. Finally, atrial fibrosis was quantified with Masson staining.

RESULTSAERP did not change significantly after dogs were ventricular paced for 6 weeks. However, AERPd, intra- and inter-atrium CT increased significantly, and CV decreased apparently, which was negatively correlated to the atrial fibrosis (r = -0.74, P < 0.05). Simultaneously, left atriums were enlarged and cardiac hemadynamics worsened in pacing dogs. Although spironolactone could not affect cardiac hemadynamics effectively, it can obviously improve left atrial ejection fraction (P < 0.05). Spironolactone treatment did not alter AERP duration, but this medicine dramatically decreased AERPd (P < 0.05), shortened intra- and inter-atrium conduction time (P < 0.05), and increased atrium CV. Moreover, spironolactone decreased the inducibility and duration of AF (P < 0.05), as well as atrial fibrosis (P < 0.01) induced by chronic rapid ventricular pacing.

CONCLUSIONSpironolactone contributes to AF prevention in congestive heart failure dogs induced by chronic rapid ventricular pacing, which is related to atrial fibrosis reduction and independent of hemadynamics.

Animals ; Atrial Fibrillation ; prevention & control ; Cardiac Volume ; Collagen ; analysis ; Dogs ; Heart Atria ; drug effects ; pathology ; physiopathology ; Heart Failure ; drug therapy ; pathology ; physiopathology ; Hemodynamics ; drug effects ; Spironolactone ; therapeutic use

The purpose of this study is to assess the relationship between left atrial (LA) size and outcome after acute myocardial infarction (AMI) in patients undergoing primary percutaneous coronary intervention (PCI) and to evaluate dynamic changes in LA size during long-term follow-up. Echocardiographic analyses were performed on 253 AMI patients (174 male and 79 female, 65.4 +/- 13.7 yr) undergoing PCI. These subjects were studied at baseline and at 12 months. Clinical follow-up were done at 30.8 +/- 7.5 months. We assessed LA volume index (LAVI) at AMI-onset and at 12-month. Change of LAVI was an independent predictor of new onset of atrial fibrillation or hospitalization for heart failure (P = 0.002). Subjects who survived the 12-month period displayed an increased LAVI mean of 1.86 +/- 4.01 mL/m2 (from 26.1 +/- 8.6 to 28.0 +/- 10.1 mL/m2, P < 0.001). The subject group that displayed an increased LAVI correlated with a low left ventricular ejection fraction, large left ventricle systolic and diastolic dimensions and an enlarged LA size. In conclusion, change of LAVI is useful parameter to predict subsequent adverse cardiac event in AMI patients. Post-AMI echocardiographic evaluation of LAVI provides important prognostic information that is significantly greater than that obtained from clinical and laboratory parameters alone.
Aged ; *Angioplasty, Balloon, Coronary ; Echocardiography ; Female ; Follow-Up Studies ; Heart Atria/pathology/physiopathology/ultrasonography ; Humans ; Male ; Middle Aged ; Myocardial Infarction/*pathology/physiopathology/*therapy/ultrasonography ; Prognosis ; Time Factors

BACKGROUNDBased on the hypothesis that pulmonary vein isolation could result in the damage of the epicardial fat pads, this study aimed to investigated the impact of right upper pulmonary vein (RUPV) isolation on vagal innervation to atria.

METHODSBilateral cervical sympathovagal trunks were decentralized in 6 dogs. Metoprolol was given to block sympathetic effects. Multipolar catheters were placed into the right atrium (RA) and coronary sinus (CS). RUPV isolation was performed via transseptal procedure. Atrial effective refractory period (ERP), vulnerability window (VW) of atrial fibrillation (AF), and sinus rhythm cycle length (SCL) were measured at RA and distal coronary sinus (CSd) at baseline and vagal stimulation before and after RUPV isolation. Serial sections of underlying tissues before and after ablation were stained with haematoxylin and eosin.

RESULTSSCL decreased significantly during vagal stimulation before RUPV isolation (197 +/- 21 vs 13 +/- 32 beats per minute, P < 0.001), but remained unchanged after RUPV isolation (162 +/- 29 vs 140 +/- 39 beats per minute, P > 0.05). ERP increased significantly before RUPV isolation compared with that during vagal stimulation [(85.00 +/- 24.29) ms vs (21.67 +/- 9.83) ms at RA, P < 0.001; (90.00 +/- 15.49) ms vs (33.33 +/- 25.03) ms at CSd P < 0.005], but ERP at baseline hardly changed after RUPV isolation compared with that during vagal stimulation [(103.33 +/- 22.50) vs (95.00 +/- 16.43) ms at RA, P = 0.09; (98.33 +/- 24.83) vs (75.00 +/- 29.50) ms at CSd, P = 0.009]. The ERP shortening during vagal stimulation after RUPV isolation decreased significantly [(63.33 +/- 22.51) ms vs (8.33 +/- 9.83) ms at RA, P < 0.005; (56.67 +/- 20.66) ms vs (23.33 +/- 13.66) ms at CSd, P < 0.05]. AF was rarely induced at baseline before and after RUPV isolation (VW close to 0), while VW of AF to vagal stimulation significantly decreased after RUPV isolation [(40.00 +/- 10.95) vs 0 ms at RA, P < 0.001; (45.00 +/- 32.09) vs (15.00 +/- 23.45) ms at CS, P < 0.05]. The architecture of individual ganglia was significantly altered after ablation.

CONCLUSIONSThe less ERP shortening to vagal stimulation and altered architecture of individual ganglia after right upper pulmonary vein isolation indicate that isolation may result in damage of the epicardial fat pads, thereby attenuating the vagal innervation to atria. The decreased vulnerability window of atrial fibrillation indicates that vagal denervation may contribute to its suppression.

Animals ; Atrial Fibrillation ; etiology ; physiopathology ; surgery ; Dogs ; Female ; Ganglia ; pathology ; Heart Atria ; innervation ; Male ; Pulmonary Veins ; surgery ; Refractory Period, Electrophysiological ; Vagus Nerve ; physiology

PURPOSE: Left ventricular (LV) filling pressure affects atrial fibrillation (AF) recurrence. We investigated the relationship between diastolic dysfunction and AF recurrence after cardioversion, and whether LV filling pressure was predictive of AF recurrence. MATERIALS AND METHODS: Sixty-six patients (mean 58+/-12 years) with newly diagnosed persistent AF were retrospectively enrolled. We excluded patients with left atrial (LA) diameters larger than 50 mm, thereby isolating the effect of LV filling pressure. We evaluated the differences between the patients with (group 1) and without AF recurrence (group 2). RESULTS: Group 1 showed increased LA volume index (LAVI) and E/e' compared to group 2 (p<0.05). During a mean follow-up period of 25+/-19 months, AF recurrence after cardioversion was 60.6% (40/66). The area under the receiver operating characteristics curve of E/e' for AF recurrence was 0.780 [95% confidence interval (CI): 0.657-0.903], and the optimal cut-off value of the E/e' was 9.15 with 75.0% of sensitivity and 73.1% of specificity. A Kaplan-Meier survival curve showed that the cumulative recurrence-free survival rate was significantly lower in patients with higher LV filling pressure (E/e'>9.15) compared with patients with lower LV filling pressure (E/e'< or =9.15) (log rank p=0.008). Cox regression analysis revealed that E/e' [hazards ratio (HR): 1.100, 95% CI: 1.017-1.190] and LAVI (HR: 1.042, 95% CI: 1.002-1.084) were independent predictors for AF recurrence after cardioversion. CONCLUSION: LV filling pressure predicts the risk of AF recurrence in persistent AF patients after cardioversion.
Aged ; Atrial Fibrillation/*physiopathology ; Electric Countershock ; Female ; Follow-Up Studies ; Heart Atria/pathology/physiopathology ; Humans ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Proportional Hazards Models ; ROC Curve ; Recurrence ; Regression Analysis ; Retrospective Studies ; Sensitivity and Specificity ; Survival Rate ; Ventricular Dysfunction, Left/*physiopathology

PURPOSE: Recently, mitochondrial DNA 4977bp deletion (mtDNA4977-mut), a somatic mutation related to oxidative stress, has been shown to be associated with atrial fibrillation (AF). We hypothesized that patient age, as well as electroanatomical characteristics of fibrillating left atrial (LA), vary depending on the presence of mtDNA4977-mut in peripheral blood among patients with non-valvular AF. MATERIALS AND METHODS: Analyzing clinical and electroanatomical characteristics, we investigated the presence of the mtDNA4977-mut in peripheral blood of 212 patients (51.1+/-13.2 years old, 83.5% male) undergoing catheter ablation for non-valvular AF, as well as 212 age-matched control subjects. RESULTS: The overall frequency of peripheral blood mtDNA4977-mut in patients with AF and controls was not significantly different (24.5% vs. 19.3%, p=0.197). When the AF patient group was stratified according to age, mtDNA4977-mut was more common (47.4% vs. 20.0%, p=0.019) in AF patients older than 65 years than their age-matched controls. Among AF patients, those with mtDNA4977-mut were older (58.1+/-11.9 years old vs. 48.8+/-11.9 years old, p<0.001). AF patients positive for the mtDNA mutation had greater LA dimension (p=0.014), higher mitral inflow peak velocity (E)/diastolic mitral annular velocity (Em) ratio (p<0.001), as well as lower endocardial voltage (p=0.035), and slower conduction velocity (p=0.048) in the posterior LA than those without the mutation. In multivariate analysis, E/Em ratio was found to be significantly associated with the presence of mtDNA4977-mut in peripheral blood. CONCLUSION: mtDNA4977-mut, an age-related somatic mutation detected in the peripheral blood, is associated with advanced age and electro-anatomical remodeling of the atrium in non-valvular AF.
Adult ; Aged ; Atrial Fibrillation/blood/*genetics/*physiopathology ; Atrial Remodeling/*genetics ; Base Pairing/*genetics ; Case-Control Studies ; DNA, Mitochondrial/*blood/*genetics ; Female ; Heart Atria/pathology/physiopathology ; Humans ; Kaplan-Meier Estimate ; Logistic Models ; Male ; Middle Aged ; Mutation Rate ; Phenotype ; Sequence Deletion/*genetics

The value of the left atrial volume tracking (LAVT) method in the evaluation of left atrial (LA) function in patients with diabetes mellitus (DM) was examined in this study. Fifty-eight DM patients as DM group and 40 healthy people as normal control group were enrolled in this study. EUB-6500 echocardiographic imaging system with LAVT was applied to display and analyze the LA volume curve imaging on LV apical two and four chamber views. The maximal LA volume at end-systole (LAV(max)), LA volume at the onset of ECG-P wave (LAV(p)), the minimal LA volume at end-diastole (LAV(min)) from the LA volume curve were acquired and recorded. All values above were standardized by body surface area (BSA). Then the passive, active and total LA volume (LAVIpass, LAVIact, LAVItotal) and empting rate (%LAVIpass, %LAVIact, %LAVItotal), effective passive and active empting rate (%eLAVIpass, %eLAVIact), and the proportionality of passive empting volume and active empting volume were calculated. The LAVIp, LAVIact, LAVItotal, %LAVIact, %LAVItotal and %eLAVIact were significantly higher in the DM group than those in the control group, whereas the LAVIpass, %LAVIpass, %eLAVIpass and LAVIpass/act were lower (all P<0.05). For the LA volume change in DM, the active empting volume was enhanced at end-diastole. It was concluded that LAVT is a potentially useful tool to evaluate the function of LA.
Adult ; Aged ; Atrial Function, Left ; physiology ; Case-Control Studies ; Diabetes Mellitus, Type 2 ; physiopathology ; Echocardiography, Doppler ; methods ; Female ; Heart Atria ; diagnostic imaging ; pathology ; Humans ; Male ; Middle Aged ; Organ Size

Prolonged P-wave duration has been observed in diabetes. However, the underlying mechanisms remain unclear. The aim of this study was to elucidate the possible mechanisms. A rat model of type 2 diabetes mellitus (T2DM) was used. P-wave durations were obtained using surface electrocardiography and sizes of the left atrium were determined using echocardiography. Cardiac inward rectifier K+ currents (I(k1)), Na+ currents (I(Na)), and action potentials were recorded from isolated left atrial myocytes using patch clamp techniques. Left atrial tissue specimens were analyzed for total connexin-40 (Cx40) and connexin-43 (Cx43) expression levels on western-blots. Specimens were also analyzed for Cx40 and Cx43 distribution and interstitial fibrosis by immunofluorescent and Masson trichrome staining, respectively. The mean P-wave duration was longer in T2DM rats than in controls; however, the mean left atrial sizes of each group of rats were similar. The densities of I(k1) and I(Na) were unchanged in T2DM rats compared to controls. The action potential duration was longer in T2DM rats, but there was no significant difference in resting membrane potential or action potential amplitude compared to controls. The expression level of Cx40 protein was significantly lower, but Cx43 was unaltered in T2DM rats. However, immunofluorescent labeling of Cx43 showed a significantly enhanced lateralization. Staining showed interstitial fibrosis was greater in T2DM atrial tissue. Prolonged P-wave duration is not dependent on the left atrial size in rats with T2DM. Dysregulation of Cx40 and Cx43 protein expression, as well as fibrosis, might partly account for the prolongation of P-wave duration in T2DM.
Action Potentials ; Animals ; Blotting, Western ; Connexin 43/metabolism ; Connexins/metabolism ; Diabetes Mellitus, Type 2/*physiopathology ; Disease Models, Animal ; Echocardiography ; Electrocardiography ; Fibrosis/pathology ; Heart Atria/*diagnostic imaging/physiopathology ; In Vitro Techniques ; Male ; Membrane Potentials ; Microscopy, Fluorescence ; Patch-Clamp Techniques ; Potassium Channels/metabolism ; Rats ; Rats, Wistar