P wave morphology during atrial pacing along the atrioventricular ring (original) (raw)
Related papers
Use of P wave configuration during atrial tachycardia to predict site of origin
Journal of the American College of Cardiology, 1995
Objectives. This study sought to construct an algorithm to differentiate left atrial from right atrial tachycardia foci on the basis of surface electrocardiograms (ECGs). Background. Atrial tachycardia is an uncommon form of supraventricular tachycardia, often resistant to drug therapy. Methods. A total of 31 consecutive patients with atrial tachycardia due to either abnormal automaticity or triggered rhythm underwent detailed atrial endocardial mapping and successful radiofreqnency catheter ablation of a single atrial focus. P wave configuration was analyzed from 12-lead ECGs during tachycardia during either spontaneous or pharmacologically induced atrioventricular block. P waves inscribed above the isoelectric line (TP interval) were classified as positive, below as negative, above and below (or conversely, below and above) as biphasic and flat P waves as isoelectric (0). In 17 patients the tachycardia was located in the right atrium: crista terminalis (n = 4); right atrial appendage (n = 4); lateral wall (n = 4); posteroinferior right atrium (n = 3); tricuspid annulus (n = 1); and near the coronary sinus (n = 1). In 14 patients, atrial tachycardia was located in the left atrium: at the entrance of the right (n = 6) or left (n = 4) superior pulmonary veins; left inferior pulmonary vein (n = 1); inferior left atrium (n = 1); base of left atrial appendage (n = 1); and high lateral left atrium (n = 1). Results. There were no differences in P wave vectors between sites at the right atrial lateral wall versus the right atrial appendage or between sites at the entrance of right versus left superior pulmonary veins. However, analysis of P wave configuration showed that leads aVL and V1 were most helpful in distinguishing right atrial from left atrial foci. The sensitivity and specificity of using a positive or biphasic P wave in lead aVL to predict a right atrial focus was 88% and 79%, respectively. The sensitivity and specificity of a positive P wave in lead V 1 in predicting a left atrial focus was 93% and 88%, respectively. Conclusions. 1) Analyses of surface P wave configuration proved to be reasonably good in differentiating right atrial from left atrial tachycardia foci. 2) Leads II, III and aVF were helpful in providing clues for differentiating superior from inferior foci.
Time sequence of right and left atrial depolarization as a guide to the origin of the P waves
American Journal of Cardiology, 1969
1. The time sequence of right atria1 and left atria1 depolarization as a guide to the origin of ectopic atria1 beats was studied in 46 patients with heart disease: in 36 patients after electrical stimulation of known areas of the two atria and in 10 patients with ectopic atria1 rhythms. A direct right atria1 and a bipolar esophageal lead were recorded simultaneously with one or more limb and chest leads on a photographic recorder. A catheter-pacemaker assembly was used for electrical stimulation of the atria.
Proceedings of the First International Conference on Bio-inspired Systems and Signal Processing, 2008
Aim of this study is to perform the principal component analysis (PCA) of the P-wave in patients prone to atrial fibrillation (AF). Eighteen patients affected by paroxysmal AF and implanted with dual chamber pacemakers were studied. Two 5-minute ECG recordings were performed: during spontaneous (SR) and paced rhythm (PR). ECG signals were acquired using a 32-lead mapping system (2048 Hz, 24 bit, 0-400 Hz bandwidth). For each patient, PCA of the averaged P-waves extracted in any of the 32 leads has been performed. We extracted PCA parameters related to the dipolar (using the first 3 PCs) and not dipolar (from the 4 th to the 32 nd PCs) components of the P-wave. The number of PCs according to the latent root criterion ranges between 2 and 3 during SR and between 2 and 4 during PR. PCA parameters related to the 3 largest PCs, and describing the dipolar component of the P-wave, did not significantly differ during SR and PR. The not dipolar components during SR were significantly lower than during PR (PCAres%: 0.03±0.06 vs 0.12±0.21, p=0.001; PCAres [mV 4 ]: 0.10±0.14 vs 0.49±0.73, p=0.001). Factor analysis showed that on average all leads contributes to the first principal component.
Journal of the American College of Cardiology, 2006
The purpose of this study was to perform a detailed analysis of the P-wave morphology (PWM) in focal atrial tachycardia (AT) and construct and prospectively evaluate an algorithm for identification of the anatomic site of origin. Although smaller studies have described the PWM from particular anatomic locations, a detailed algorithm characterizing the likely location of a tachycardia associated with a P-wave of unknown origin has been lacking. The PWMs for 126 consecutive patients undergoing successful radiofrequency ablation of 130 ATs are reported. P waves were included only when the onset was preceded by a discernible isoelectric segment. P waves were classified as positive (+), negative (-), isoelectric, or biphasic. Sensitivity, specificity, and predictive values were calculated. On the basis of these results, an algorithm was constructed and prospectively evaluated in 30 new consecutive ATs. The distribution of ATs was right atrial (RA) in 82 of 130 (63%) and left atrial (LA) ...
Annali dell'Istituto Superiore di Sanità, 2012
orIgInAl ArtIcles And reVIews INTRODUCTION Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. It is defined by the absence of coordinated atrial systole, since it results from multiple re-entrant electrical wavelets that move randomly around the atria. Although it is not a lethal disease, AF may increase mortality up to 2-fold, primarily due to embolic stroke. Indeed, the lack of coordinated atrial contraction leads to unusual fluid flow states through the atrium that could favour the formation of thrombus at risk to embolize, especially after return to normal sinus rhythm. The incidence of atrial fibrillation increases significantly with advancing age. When a patient spontaneously alternates between AF and normal rhythm,
Annals of Noninvasive Electrocardiology, 2016
Background: It has previously been demonstrated that orthogonal P-wave morphology in healthy athletes does not depend on atrial size, but the possible impact of left atrial orientation on P-wave morphology remains unknown. In this study, we investigated if left atrial transverse orientation affects P-wave morphology in different populations. Methods: Forty-seven patients with atrial fibrillation, 21 patients with arrhythmogenic right ventricular cardiomyopathy, 67 healthy athletes, and 56 healthy volunteers were included. All underwent cardiac magnetic resonance imaging or computed tomography and the orientation of the left atrium was determined. All had 12-lead electrocardiographic recordings, which were transformed into orthogonal leads and orthogonal P-wave morphology was obtained. Results: The median left atrial transverse orientation was 87 (83, 91) degrees (lower and upper quartiles) in the total study population. There was no difference in left atrial transverse orientation between individuals with different orthogonal P-wave morphologies. Conclusions: The physiological variation in left atrial orientation was small within as well as between the different populations. There was no difference in left atrial transverse orientation between subjects with type 1 and type 2 P-wave morphology, implying that in this setting the P-wave morphology was more dependent on atrial conduction than orientation.
Circulation, 1978
In studies to ascertain the basis of dynamic changes in the P wave, bipolar epicardial potentials were recorded from multiple atrial electrodes in dogs. One hundred to 120 activation times were displayed by a digital computer and used to construct atrial isotemporal activation sequence maps. Changes in heart rate or beat-to-beat cycle length were induced by vagal stimulation or infusion of autonomic mediating drugs. Changes in cycle length were associated with dynamic changes in the atrial activation sequence and surface P-wave. A conspicuous finding was that epicardial atrial depolarization began at three widely separated locations. These three points were consistently present in all animals and were generally located at the 12, 3, and 6 o'clock positions of the superior vena cava-right atrial junction. The dynamic changes in P waves and atrial activation sequence which accompanied the changes in cycle length were due to sudden shifts in the point of earliest activity between t...
Pace-pacing and Clinical Electrophysiology, 1993
The detection of atrial activation from a standard ventricular pacing lead with standard ventricular electrodes would provide patients with VVI and VVIR pacing systems atrial rate response and atrial synchrony. In addition to potentially increasing cardiac output appropriately in these patients at rest and during moderate exercise, P wave sensing with such a device could help reduce pacemaker syndrome. In this study, unipolar signals from distal and proximal intraventricular electrodes were recorded from the right ventricular apex in 20 patients. Unipolar eJectrograms from 16 patients were recorded using temporary electrophysiology catheters and in four patients using permanent pacemaker leads. Approximately 3 minutes of data per patient were acquired and analyzed. After selection of a P wave template, the difference in baseline normalized area between the template and signal was calculated on a point-by-point basis. The percent of atrial depolarizations correctly detected was determined for each patient and lead configuration at the optimal threshold. Far-field P wave accuracy was better at the proximal electrode (74 ± 25%) than at the distal electrode (57 ± 34%) (P < 0.025). At the proximal electrode, 15/20 (75%) patients had > 70% accuracy and 11/20 (55%) patients had > 80% accuracy. At the distal electrode, 10/21 (48%) patients had > 70% accuracy and 7/21 (33%) patients had > 80% accuracy. In conclusion, far-field detection of atrial activation at the ventricular proximal electrode appears possible with sufficient accuracy to provide periods of atrial rate response and synchrony in patients with a single standard lead.
Orthogonal P-wave morphology is affected by intra-atrial pressures
BMC Cardiovascular Disorders
Background: It has previously been shown that the morphology of the P-wave neither depends on atrial size in healthy subjects with physiologically enlarged atria nor on the physiological anatomical variation in transverse orientation of the left atrium. The present study aimed to investigate if different pressures in the left and right atrium are associated with different P-wave morphologies. Methods: 38 patients with isolated, increased left atrial pressure, 51 patients with isolated, increased right atrial pressure and 76 patients with biatrially increased pressure were studied. All had undergone right heart catheterization and had 12-lead electrocardiographic recordings, which were transformed into vectorcardiograms for detailed P-wave morphology analysis. Results: Normal P-wave morphology (type 1) was more common in patients with isolated increased pressure in the right atrium while abnormal P-wave morphology (type 2) was more common in the groups with increased left atrial pressure (P = 0.032). Moreover, patients with increased left atrial pressure, either isolated or in conjunction with increased right atrial pressure, had significantly more often a P-wave morphology with a positive deflection in the sagittal plane (P = 0.004). Conclusion: Isolated elevated right atrial pressure was associated with normal P-wave morphology while left-sided atrial pressure elevation, either isolated or in combination with right atrial pressure elevation, was associated with abnormal P-wave morphology.