BACKGROUND AND OBJECTIVES: We undertook this study to assess the initiation and maintenance mechanisms of atrial fibrillation (AF) and their relationships with the anatomical structures of the left atrium (LA) and pulmonary veins (PVs). SUBJECTS AND METHODS: Thirty-seven patients (33 men, mean age 50, range 25-68 years) with paroxysmal AF (n=29) and persistent AF (n=8) who underwent mapping of the LA and PV using 3D non-contact endocardial mapping system (EnSite 3000) were enrolled. The multielectrode array and ablation catheter were positioned in the LA via the double transseptal approach. Atrial premature beats (APBs) which triggered initiation of AF that lasted longer than 1 min were mapped and the activation sequence was analyzed on isopotential color maps. Wave front dynamics and the relationship with the underlying structures were assessed. RESULTS: More than half, 56.4%, of APBs from PV were related to the initiation of AF, but not related to the maintenance of AF. A quarter, 25.6%, of APBs from PV not only initiated AF, but also maintained AF without continuous triggering. Mixed type and indeterminate type of AF was 5.0% and 12.8%, respectively. During AF, the mean number of wavelets was 1.45 (maximum 3 in 76.5%). Anatomical structures showing slow conduction and wavebreaks were mostly located at the septopulmonary bundle (86.5%) and the posterior roof of the LA between the left superior PV and right superior PV (54.1%). CONCLUSION: Focal repetitive activity from PV played an important role in both the initiation and maintenance of AF. Specific anatomical structures such as septopulmonary bundle or posterior roof of the LA were related to the heterogeneous conduction delay and spontaneous wavebreak, which was also important in the maintenance of AF.
Atrial Fibrillation* ; Atrial Premature Complexes ; Cardiac Complexes, Premature ; Catheters ; Heart Atria ; Humans ; Male ; Pulmonary Veins ; Structure-Activity Relationship

Cardiac arrhythmias are a common problem in the neurological intensive care unit and represent a major cause of ischemic stroke. Significant arrhythmias are most likely to occur in elderly patients. In this review, we focus on three arrhythmias: premature beats, atrial fibrillation, and QT prolongation. The goal of this review is to provide a current concept of diagnosis and acute management of arrhythmias in the neurological intensive care unit.
Aged ; Arrhythmias, Cardiac ; Atrial Fibrillation ; Atrial Premature Complexes ; Cardiac Complexes, Premature ; Critical Care ; Diagnosis ; Humans ; Intensive Care Units ; Stroke ; Ventricular Premature Complexes

In this paper, the multifractal detrended fluctuation analysis method was used to study the multifractal characteristics of atrial premature beat (APB) signals, of premature ventricular contraction (PVC) signals and of normal ECG signals. By analyses of Hurst index, Renyi index and multifractal spectrum, three kinds of signals were noted to have different degrees of long-range correlation and multifractal characteristics. Normal ECG signals had the strongest fractality, the PVC beats had stronger fractality and the APB beats had the weakest fractality. When the fluctuations function order was positive, the three kinds of signals showed distinct long-range correlation properties. These findings are of good reference to diagnosing and distinguishing between PVC and APB signals in clinical medicine.
Atrial Premature Complexes ; diagnosis ; physiopathology ; Diagnosis, Differential ; Electrocardiography ; methods ; Humans ; Signal Processing, Computer-Assisted ; Ventricular Premature Complexes ; diagnosis ; physiopathology

In this paper, wavelet moudulus maxima based multifractal analysis was used to study the multifractal characteristics of the atrial premature beat (APB) signal, the premature ventricular contraction (PVC) signal and normal ECG signal. By analyzing the multifractal spectrum, it was obtained that three kinds of signals had different multifractal strengths. Normal ECG signals had the strongest singularity strength. The PVC beats had the second stronger singularity strength. And the APB beats had the weakest singularity strength. The T test indicated that above-mentioned analysis could disclose significant differences among these three signals. It has meaningful reference for clinical diagnosing and distinguishing with PVC and APB signals.
Atrial Premature Complexes ; diagnosis ; physiopathology ; Electrocardiography ; methods ; Humans ; Signal Processing, Computer-Assisted ; Ventricular Premature Complexes ; diagnosis ; physiopathology ; Wavelet Analysis

BACKGROUND AND OBJECTIVES: The mechanism by which atrial fibrillation (AF) electrically converts to sinus rhythm remains undefined. The purpose of this study was to assess in detail the electrograms recorded during cardioversion using direct current (DC) shock. SUBJECTS AND METHODS: In 23 patients with AF (chronic n=20, paroxysmal n=3, M:F=15:8, 50 - 70 years old), electrograms were recorded simultaneously from a 20-pole electrode catheters (Duo-deca, DAIG) in the right atrial free wall and the coronary sinus immediately after DC shock given transthoracically. The activation patterns following 45 trials consisting of 23 successful and 22 unsuccessful cardioversion were analyzed. RESULTS: Two distinct patterns following successful cardioversion were observed; either immediate resumption of normal sinus rhythm (n=5, 21%), or one or two activations immediately after shock preceded normal sinus rhythm (n=18, 79%). The energy levels of the two patterns were not significantly different (260 J, 250 J, respectively). Four patterns following unsuccessful cardioversion were noted; unchanged (n=10, 45%), converted to atrial flutter (n=4, 18%), production of three or four beats of more coordinated complexes and reverted to AF (n=5, 22%), and converted to sinus rhythm transiently and reinitiated AF by one or two atrial premature beats (n=3, 13%). The magnitude of the DC shock applied at these 4 different patterns was 196 J, 240 J, 264 J, and 340 J, respectively in which low energy levels made a simultaneous depolarization of the entire atria unlikely. CONCLUSION: Distinct activation patterns were identified following successful and unsuccessful cardioversion using DC shock for AF. These observations suggest that total depolarization of the entire atria is not a prerequisite for the conversion of AF into sinus rhythm.
Atrial Fibrillation* ; Atrial Flutter ; Cardiac Complexes, Premature ; Catheters ; Coronary Sinus ; Electric Countershock* ; Electrodes ; Humans ; Shock

We report the case of a 17-year-old girl who presented with an indentation in the right ventricle caused by an incomplete pericardium on preoperative 3-dimensional reconstructed computed tomography. She was to undergo surgery for a partial atrioventricular septal defect and secundum atrial septal defect. Preoperative electrocardiography revealed occasional premature ventricular beats. We found the absence of the left side of the pericardium intraoperatively, and this absence caused strangulation of the diaphragmatic surface of the right ventricle. After correcting the lesion, the patient’s rhythm disturbances improved.
Adolescent ; Electrocardiography ; Female ; Heart Septal Defects, Atrial ; Heart Ventricles* ; Humans ; Pericardium* ; Ventricular Premature Complexes

In order to observe the arrhythmia which occured in early convalescent phase of acute myocardial infarction, a 24 hour ambulartory ECG monitiring was performed in 15 patients who is admitted at dept of Int Medicine, Ewha Womans University hospital from Aug. 1985 to Sept. 1986. during 7.5+/-3.4 days after admission. In all cases one or more of the following arrhythmias were observed;atrial premature beat, ventricular premature beat(VPB), transient paroxysmal ventricular thchycardia, atrial fibrillation, sinus arrest and junctional beat. Of 15 cases, 11(77.3%) had VPB's:Simple VPB's in 4 cases(26.7%) and complex VPB's(6.52+/-2.52)(P<0.05). But there were no difference of premature and abberancy index between complex VPB's and simple VPB's(P>0.1). In addition, we compaired the arrhythmias in CCU with those of early convalescent phase of acute myocardial infarction. But there was no correlation between them.
Arrhythmias, Cardiac* ; Atrial Fibrillation ; Cardiac Complexes, Premature ; Electrocardiography* ; Female ; Humans ; Myocardial Infarction*

The esophageal electrocardiogram is of increasing significance in the study and diagnosis of cardiac arrhythmia and of posterior myocardial disease. We used both bipolar and unipolar esophageal recording leads and standard electrocardiogram equipment, and compared the effectiveness of esophageal electrocardiogram with co nventional electrocardiogram. The effectiveness of esophageal electrocardiogram were as follows: 1) Differentiation of sinus, atrial, junctional, or ventricular rhythm. 2) Differentiation of origin of premature beats. 3) Differentiation of atrial flutter and fibrillation. 4) Detection of retrograde atrial conduction of extraventricular systole. 5) Detection of electrical alternance of QRS amplitude. 6) Diagnosis of posterior myocardial infarction. The results reported here indicate that the esophageal electrocardiogrm seems to be a valid method in the diagnosis of cardiac arrhythmias without invasiveness.
Arrhythmias, Cardiac ; Atrial Flutter ; Cardiac Complexes, Premature ; Cardiomyopathies ; Diagnosis ; Electrocardiography* ; Myocardial Infarction ; Systole

In this paper, an algorithm for atrial premature beat classification with abnormal ECG rhythm analysis is presented. The classification algorithm identifies QRS morphology by template matching and recognizes abnormal ECG rhythm by the features of heart rate and ECG. Algorithm has been evaluated by the MIT-BIH arrhythmia database and the results show that the specificity and the sensitivity for atrial premature beat are 99.5% and 96.9% respectively. atrial premature, arrhythmia, beat classification
Algorithms ; Arrhythmias, Cardiac ; physiopathology ; Atrial Premature Complexes ; physiopathology ; Electrocardiography ; methods ; Signal Processing, Computer-Assisted

BACKGROUND: Paroxysmal atrial fibrillation (PAF) causes not only severe symptoms and hemodynamic changes, but may progress to chronic atrial fibrillation. Autonomic nervous system or atrial premature beat (APB) has been suggested to contribute to the spontaneous initiation of PAF, but the exact mechanism has been largely unknown. METHODS: One hundred and twenty nine episodes of PAF lasting longer than 5 sec were analyzed in 18 patients (M:F=11:?). Two minutes of normal sinus rhythm before the onset of PAF, and the initial one minute of PAF were printed and analyzed. RESULTS: Most of PAFs were initiated by APBs (38%) or rapid atrial tachycardias (AT, 59%). The frequency of APBs tended to increase immediately before PAF onset (p=0.08). The coupling intervals and coupling indices were not significantly different between PAF-producing APBs and benign APBs. More than half of PAF episodes were initiated by rapid ATs (rate, 357+/-50 bpm). After the onset, they accelerated over several seconds and then degenerated into AF. In some cases, transition from AF to atrial flutter and vice versa were observed. Heart rate, measured at 60-second intervals during 2 minutes before PAF onset, did not change significantly (p=0.44). CONCLUSION: Most of PAFs were initiated by APBs or rapid ATs. Heart rate did not change significantly but the frequency of APBs tended to increase immediately before PAF onset. Rapid ATs frequently accelerated and degenerated into AF. In this regard, Holter monitoring could be useful in identifying patients with PAF triggered by rapid ATs.
Atrial Fibrillation* ; Atrial Flutter ; Autonomic Nervous System ; Cardiac Complexes, Premature ; Electrocardiography, Ambulatory* ; Heart Rate ; Hemodynamics ; Humans ; Tachycardia