To evaluate the volume and function of left atrium and left atrial appendage in patients with atrial fibrillation by three-dimensional transesophageal echocardiography and transthoracic echocardiography.
 Methods: A total of 112 patients with atrial fibrillation were divided into two groups: a paroxysmal atrial fibrillation (ParAF) group (n=80) and a persistent atrial fibrillation (PerAF) group (n=32). Control group was people without atrial fibrillation (n=40). Clinical data of the participants were collected. Left atrial dimension (LAD), left atrial volume (LAV), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) were measured by transthoracic echocardiography, while left atrial appendage peak emptying flow velocity (LAAeV), left atrial appendage peak filling flow velocity (LAAfV), left atrial appendage maximum volume (LAAVmax) and left atrial appendage minimum volume (LAAVmin) were measured by three-dimensional transesophageal echocardiography. Left atrial volume index (LAVI), left ventricular ejection fraction (LVEF) and left atrial appendage ejection fraction (LAAEF) were calculated. 
 Results: Compared with the control group, LAAEF, LAAeV and LAAfV in the ParAF group were decreased obviously, while LAD, LAV, LAVI, LAAVmax and LAAVmin in the ParAF group were increased obviously (P<0.05). Compared with the ParAF group, LAAEF, LAAeV and LAAfV in the PerAF group were also decreased obviously, and LAD, LAV, LAVI, LAAVmax and LAAVmin in the ParAF group were also increased obviously (P<0.05). There was no statistically significant difference in LVEDV, LVESV, LVEF between the ParAF group and the PerAF group (P<0.05).
 Conclusion: Left atrium and left atrial appendage were enlarged and the function of left atrial appendage was declined in patients with AF, and the changes were more obvious in patients with PerAF compared with patients with ParAF by three-dimensional transesophageal echocardiography and transthoracic echocardiography.
Atrial Appendage ; physiopathology ; Atrial Fibrillation ; physiopathology ; Echocardiography, Transesophageal ; Heart Atria ; physiopathology ; Humans

Acupuncture Therapy ; Aged ; Atrial Fibrillation ; physiopathology ; therapy ; Humans ; Male

Atrial Fibrillation ; physiopathology ; surgery ; Catheter Ablation ; methods ; Humans ; Treatment Outcome

This paper applied the Shannon Entropy based on the cross correlation to analyze the epicardial signals from anterior wall of the canine atria. The result demonstrated that during sinus rhythm, the stability level of the correlation among signals from anterior right atria is much higher than the signals from anterior left atria. All the signals from the anterior wall descended when the rhythm changed from sinus rhythm to atrial fibrillation(AF). However, there were some regions still having a stable correlation during AF. The results will be helpful to enhance understanding of the correlation characteristic of AF.
Animals ; Atrial Fibrillation ; physiopathology ; Dogs ; Entropy ; Heart Atria ; physiopathology ; Pericardium ; physiopathology

OBJECTIVETo investigate how the intra-cardiac activation was translates into the characterized flutter wave in patients with cavatricuspid isthmus-dependent counter-clockwise atrial flutter (CTI-AFL).

METHODSA total of 15 hospitalized CTI-AFL patients (mean age: (60 ± 14) years old, 1 female) from October 2012 to February 2014 were enrolled in the study. The activation map was re-constructed during AFL rhythm for left atrium and right atrium using 3-dimensional mapping system. The flutter wave in surface electrocardiogram was analyzed in combination with the intra-cardiac activation.

RESULTSThe mean left ventricular ejection fraction was (60.8 ± 6.6)%, and the left atrial diameter was (39.0 ± 3.4) mm. The mean tachycardia cycle length was (220 ± 24) ms. The activation map was completed in all cases. In inferior leads, the flutter wave was divided into three parts: slowly downward part, sharp downward part and the terminal positive part. The three parts corresponded to the fixed activation part of the macro-reentry.

CONCLUSIONThe distinctive flutter wave of CTI-AFL was determined by the unique macro-reentry activation in the right atrium. The activation of left atrium contributes to the downward part of the wave.

Aged ; Atrial Appendage ; Atrial Fibrillation ; Atrial Flutter ; Electrocardiography ; Female ; Heart Atria ; physiopathology ; Humans ; Male ; Middle Aged ; Ventricular Function, Left

Arrhythmias, Cardiac ; complications ; genetics ; physiopathology ; Atrial Fibrillation ; complications ; genetics ; physiopathology ; Electrophysiology ; Humans

This paper aims to find a new method of detecting atrial fibrillation (AF) with fast responding speed and high detecting precision by R-R intervals. Probability density function (PDF) of distance between two points in the reconstructed phase space of R-R intervals of normal sinus rhythm (NSR) and AF is studied. It is found that the distribution of PDF between NSR and AF R-R intervals is significantly different; and based on this finding, a characteristic parameter k is defined. k is used for defection among 400 NSR and 400 AF R-R intervals. The results demonstrate that the new algorithm has fast responding speed and high detecting precision (average sensitivity 97.0%, average specificity 95.2%).
Algorithms ; Atrial Fibrillation ; diagnosis ; physiopathology ; Diagnosis, Differential ; Electrocardiography ; Humans ; Signal Processing, Computer-Assisted ; Sinoatrial Node ; physiopathology

This study was aimed to evaluate the relationship between the changes of plasma intermedin (IMD) and atrial fibrosis in hypertensive patients with atrial fibrillation. During the period from 2010 to 2011, appropriate 150 subjects of out-patients (female 50%, male 50%) were selected in West China Hospital, Sichuan University, and were divided into three groups: the hypertension-only group, the hypertension combined with paroxysmal atrial fibrillation group and the hypertension combined with persistent atrial fibrillation group. Firstly, we collected the Physical examination results and medical history records of the patients. We then performed ultrasound cardiogram and blood biochemical tests on the patients. We also detected the plasma IMD and transforming growth factor β1 (TGF-β1) using ELISA. The results showed that compared with the hypertensive group, the plasma level of IMD, TGF-β1 and left atrium director (LAD) in the hypertensive combined with atrial fibrillation group were higher significantly. Compared with the paroxymal atrial fibrillation group, the levels of IMD, TGF-β1 and LAD were higher significantly in persistent atrial fibrillation group. Analysis of correlation and partial correlation showed that IMD was positively correlated with TGF-p1 (r=0.51, P<0. 001), IMD was positively correlated with LAD(r=0.59, P< 0.001), and TGF-β1 was positively correlated with LAD (r = 0.57, P < 0.001). The results suggest that IMD might suppress the pathophysiological process of atrial fibrillation.
Atrial Fibrillation ; physiopathology ; Female ; Humans ; Hypertension ; physiopathology ; Male ; Peptide Hormones ; blood ; Transforming Growth Factor beta1 ; blood

OBJECTIVETo investigate the effects of atrial excitable period (EP) on the stability of atrial fibrillation (AF) in goats.

METHODSTen female goats were instrumented with epicardial electrodes patches on the left atrium (LA) free wall. AF was induced and maintained by a home-made stimulator with frequency of 50 Hz at a 1-second duration and a 2-seconds interval. The stimulator was disconnected regularly. AF-induced duration, average AF cycle length (AFCL), and atrial effective refractory period during AF (ERP(AF)) were measured; EP was calculated by AFCL-ERP(AF).

RESULTSEight goats were studied. Persistent AF (> 24 h) could be induced in all the 8 goats within 6-16 days. When the induced AF lasted for 3-10 min or 24 h, the AFCL was 98.3 ms +/- 11.0 ms and 84.9 ms +/- 5.2 ms (P < 0.05), respectively, ERP(AF) was 90.5 ms +/- 13.2 ms and 63.0 ms +/- 4.8 ms (P < 0.05), respectively, and EP was 7.8 ms +/- 2.4 ms and 21.9 ms +/- 3.5 ms (P < 0.05), respectively.

CONCLUSIONThe decrease in ERP(AF) is more significant than the shortening in AFCL, resulting in the gradually widening of EP which may contribute to the perpetuation of AF.

Animals ; Atrial Fibrillation ; physiopathology ; Disease Models, Animal ; Electrocardiography ; Female ; Goats ; Heart Atria ; physiopathology

OBJECTIVETo observe the maximal heart rate changes, atrioventricular (A-V) conduction block and atrial fibrillation (AF) inducibility in dogs with vagosympathetic trunk exposed to electromagnetic fields (EMFs).

METHODSThe vagosympathetic trunk of adult dogs was separated and exposed to EMFs 0.043 kHz (2.87 microG, n = 5) and to EMFs 2 kHz (0.34 microG, n = 6) for two to three hours. Simultaneously, the vagosympathetic trunk was stimulated with 20 Hz frequency and 1 - 8 V intensity for 0.1 ms. Heart rate, presence of A-V conduction block and AF inducibility were determined.

RESULTSAfter 5-minutes exposure to EMFs 0.043 kHz (2.87 microG), the maximal heart rate decreased 29%, the voltage applied to vagosympathetic trunk required to induce A-V conduction block decreased by 60% in experimental group versus 5% increase in control group. This effect lasted 2 to 3 hours. While vagosympathetic trunk exposure to EMFs 2 kHz (0.34 microG) was associated with significant increase in the incidence of atrial premature beats, atrial tachycardia and AF, these effects could be blocked by propranolol and atropine.

CONCLUSIONSOur results showed that 0.043 kHz (2.87 microG) EMFs exposure might reduce while 2 kHz (0.34 microG) EMFs exposure might increase AF inducibility. Our study thus suggested autonomic nervous system of dogs could be affected by EMFs exposure and 0.043 kHz (2.87 microG) EMFs exposure might be a novel option for AF prevention.

Animals ; Atrial Fibrillation ; etiology ; physiopathology ; Dogs ; Heart Rate ; Magnetics ; Vagus Nerve ; physiopathology