Noninvasive Recording of Sinus Node Activity by P-Wave-Triggered Signal-Averaged Electrocardiogram: Validation Using Direct Intra-Atrial Recording of Sinus Node Electrogram

1993 ◽  
Vol 7 (3) ◽  
pp. 132-137 ◽  
Author(s):  
Anna Toso ◽  
Alessandro Mezzani ◽  
Luigi Padeletti ◽  
Mohamed Bamoshmoosh ◽  
Simone Salvi ◽  
...  
Keyword(s):  
Sinus Node ◽  
P Wave ◽  
Node Activity ◽  
Sinus Node Activity

THE BEHAVIOR OF ATRIO–VENTRICULAR NODAL RHYTHM FOLLOWING DIRECT PERFUSION OF THE SINUS NODE

1966 ◽  
Vol 44 (2) ◽  
pp. 317-324 ◽  
Author(s):  
R. A. Nadeau ◽  
T. N. James
Keyword(s):  
Sinus Node ◽  
Gradual Transition ◽  
Sinus Arrest ◽  
P Waves ◽  
Pharmacological Agents ◽  
Node Activity ◽  
Relaxation Oscillators ◽  
Sinus Node Artery ◽  
Chronotropic Effects ◽  
Sinus Node Activity

Direct perfusion of the canine sinus node with various pharmacological agents having negative chronotropic effects commonly leads either to abrupt sinus arrest or to a gradual transition from sinus to atrio–ventricular (A–V) nodal rhythm with progressive shortening of the P–R interval. The reappearance of sinus rhythm is usually preceded by a change in A–V nodal rate and a progressive lengthening of the P–R interval to a stable value. During A–V nodal rhythm, changes in heart rate are observed following injections into the sinus node artery. As perfusion of the sinus node is selective, these cannot be attributed to a direct pharmacological effect of the perfusates on the A–V node. Deliberate suppression of A–V nodal pacemaking dominance reveals the persistence of slow sinus node activity which is unapparent electrocardiographically during A–V nodal rhythm. It would seem that even in the absence of P waves, the sinus node may still influence the rate of the A–V node. These observations are consistent with the hypothesis that the sinus and A–V nodes behave as a system of coupled relaxation oscillators.

Rate-Responsive Cardiac Pacemakers

1991 ◽  
Vol 2 (1) ◽  
pp. 140-149 ◽  
Author(s):  
Patricia Gonce Morton
Keyword(s):  
Clinical Experience ◽  
Sinus Node ◽  
Cardiac Pacing ◽  
Cardiac Pacemakers ◽  
Node Activity ◽  
Advantages And Disadvantages ◽  
New Form ◽  
Sinus Node Activity ◽  
Rate Responsive ◽  
The Ideal

Pacemaker technology continues to advance in the direction of restoring a normal hemodynamic response under varying physiologic conditions. Rate-responsive pacemakers meet this challenge by adjusting the pacing rate in response to a sensed physiologic variable other than sinus node activity. In an effort to design the ideal rate-responsive system, various physiologic cues have been tested. To translate shifts in the sensed physiologic indicator into an appropriate pacing rate, specialized sensor systems also have been developed and include mechanical, chemical, thermal, and electrical sensors. Although each sensor system offers advantages and disadvantages, continued research and clinical experience will determine the future of this exciting new form of cardiac pacing

SIMULATION OF SINUS NODE ACTIVITY BY AN ELECTRONIC RELAXATION OSCILLATOR

1966 ◽  
Vol 44 (2) ◽  
pp. 301-315 ◽  
Author(s):  
F. A. Roberge ◽  
R. A. Nadeau
Keyword(s):  
Sinus Node ◽  
Relaxation Oscillator ◽  
Rhythmic Activity ◽  
Electronic Relaxation ◽  
Node Activity ◽  
Relaxation Oscillators ◽  
Ventricular Response ◽  
Sinus Node Activity ◽  
The Right ◽  
Intact Heart

After the sinus node was destroyed, its rhythmic activity was simulated by an electronic relaxation oscillator coupled to the beating heart. The output of the oscillator was used to stimulate the right atrium, and the ventricular response was returned to the input of the relaxation oscillator. By manually varying the frequency of this artificial pacemaker it was possible to produce changes in the rate of the atrio–ventricular (A–V) node similar to those obtained by perfusion of the intact sinus node with chronotropic agents. Particular attention was paid to the transitions from "oscillator" rhythm to A–V nodal rhythm, and vice versa. The results provide support for the following hypotheses relative to the intact heart: (i) some form of sinus node activity persists during A–V nodal rhythm, and (ii) the principal pacemakers of the heart, the sinus and A–V nodes, behave as a system of coupled relaxation oscillators.

Widespread distribution and rate differentiation of the atrial pacemaker complex

1980 ◽  
Vol 239 (3) ◽  
pp. H406-H415 ◽  
Author(s):  
J. P. Boineau ◽  
R. B. Schuessler ◽  
D. B. Hackel ◽  
C. B. Miller ◽  
C. W. Brockus ◽  
...  
Keyword(s):  
Superior Vena ◽  
Sinus Node ◽  
P Wave ◽  
Right Atrial ◽  
Superior Vena Caval ◽  
Heart Rates ◽  
Widespread Distribution ◽  
Depolarization Wave ◽  
Lower Limits ◽  
Origin Point

In a study to examine the basis of rate-related changes in the electrocardiographic P wave we found a multicentric rather than unifocal origin of the atrial depolarization wave in dogs. Three to five pacemakers, or origin points, were distributed over a 30- to 40-mm area compared to the 11-mm size of the sinus node. Two or three of the sites could excite simultaneously, or one specific site would dominate excitation. Each separate origin point dominated excitation within a specific range of heart rates, and on reaching either the upper or lower limits of this range, a new focus abruptly dominated and initiated the atrial wave front. We have obtained evidence to suggest that these findings may be explained by a widely distributed atrial pacemaker complex. The spatial distribution of this system exceeded the dimensions of the canine sinus node by a factor of three to four times. The pacemaker centers, although distributed, were consistently located at specific positions along the superior vena caval-right atrial junction. Also, each separate pacemaker site appeared functionally differentiated to generate a specific range of heart rates. We propose that in addition to the sinus node there are other specialized atrial pacemaker centers, and that this specialization, including the differentiated response and coordination, is conferred by focal receptor characteristics and their inputs.

scholarly journals Prolonged Sinus Pauses upon Termination of Paroxysmal Atrial Fibrillation: Abnormal Right Atrial Electrophysiologic and Electroanatomic Findings

2017 ◽  
Vol 44 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Zhengyu Bao ◽  
Hongwu Chen ◽  
Bing Yang ◽  
Michael Shehata ◽  
Weizhu Ju ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Node ◽  
P Wave ◽  
Right Atrial ◽  
Control Group ◽  
Paroxysmal Supraventricular Tachycardia ◽  
Group A ◽  
Group B ◽  
Activation Times ◽  
The Right

The efficacy of pulmonary vein antral isolation for patients with prolonged sinus pauses (PSP) on termination of atrial fibrillation has been reported. We studied the right atrial (RA) electrophysiologic and electroanatomic characteristics in such patients. Forty patients underwent electroanatomic mapping of the RA: 13 had PSP (group A), 13 had no PSP (group B), and 14 had paroxysmal supraventricular tachycardia (control group C). Group A had longer P-wave durations in lead II than did groups B and C (115.5 ± 15.4 vs 99.5 ± 10.9 vs 96.5 ± 10.4 ms; P=0.001), and RA activation times (106.8 ± 13.8 vs 99 ± 8.7 vs 94.5 ± 9.1 s; P=0.02). Group A's PP intervals were longer during adenosine triphosphate testing before ablation (4.6 ± 2.3 vs 1.7 ± 0.6 vs 1.5 ± 1 s; P <0.001) and after ablation (4.7 ± 2.5 vs 2.2 ± 1.4 vs 1.6 ± 0.8 s; P <0.001), and group A had more complex electrograms (11.4% ± 5.4% vs 9.3% ± 1.6% vs 5.8% ± 1.6%; P <0.001). Compared with group C, group A had significantly longer corrected sinus node recovery times at a 400-ms pacing cycle length after ablation, larger RA volumes (100.1 ± 23.1 vs 83 ± 22.1 mL; P=0.04), and lower conduction velocities in the high posterior (0.87 ± 0.13 vs 1.02 ± 0.21 mm/ms; P=0.02) and high lateral RA (0.89 ± 0.2 vs 1.1 ± 0.35 mm/ms; P=0.04). We found that patients with PSP upon termination of atrial fibrillation have RA electrophysiologic and electroanatomic abnormalities that warrant post-ablation monitoring.

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