scholarly journals Electrophysiological properties of the atrioventricular node and ageing: evidence of a lower incidence of dual nodal pathways in the elderly

EP Europace ◽  
2001 ◽  
Vol 3 (3) ◽  
pp. 216-220 ◽  
Author(s):  
D D'Este
Keyword(s):  
Lower Incidence ◽  
Atrioventricular Node ◽  
The Elderly ◽  
Electrophysiological Properties

Adjusting for Recall Bias with the Proportional Hazards Model

1991 ◽  
Vol 30 (02) ◽  
pp. 108-110 ◽  
Author(s):  
S. Reinsch ◽  
P. G. MacRae ◽  
J. S. Tobis ◽  
P. A. Lachenbruch
Keyword(s):  
Lower Incidence ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
The Elderly ◽  
Recall Bias ◽  
Hazards Model

AbstractIn studying falling frequency in the elderly, we observed that having subjects keep a diary led to a larger number of falls reported than had been noted in a previous study in the same population. The previous study asked subjects to report any falls in the previous three months. We considered two related explanations for the observation of lower incidence reports with a 3-month recall survey. First, there may have been under-reporting of falls due to recall bias. Second, the less severe falls (which did not result in injuries) may not be reported. We suggest that the proportional hazards model may be used to adjust studies in which recall is used to determine incidence and time to falls.

scholarly journals Effect of Atrial Stimulation Site on the Electrophysiological Properties of the Atrioventricular Node in Man

Circulation ◽  
1974 ◽  
Vol 50 (2) ◽  
pp. 283-292 ◽  
Author(s):  
WILLIAM P. BATSFORD ◽  
MASOOD AKHTAR ◽  
ANTONIO R. CARACTA ◽  
MARK E. JOSEPHSON ◽  
STUART F. SEIDES ◽  
...  
Keyword(s):  
Atrioventricular Node ◽  
Stimulation Site ◽  
Electrophysiological Properties ◽  
Atrial Stimulation

scholarly journals Arrhythmia susceptibility in senescent rat hearts

2014 ◽  
Vol 87 (1) ◽  
Author(s):  
Stefano Rossi ◽  
Silvana Baruffi ◽  
Domenico Corradi ◽  
Sergio Callegari ◽  
Ezio Musso ◽  
...  
Keyword(s):  
Cardiac Electrophysiology ◽  
The Elderly ◽  
Detailed Knowledge ◽  
Activation Patterns ◽  
Electrophysiological Properties ◽  
Age Related ◽  
Rat Hearts ◽  
Arrhythmogenic Substrate ◽  
Ventricular Activation

Cardiovascular disease increases with age as well as alterations of cardiac electrophysiological properties, but a detailed knowledge about changes in cardiac electrophysiology relevant to arrhythmogenesis in the elderly is relatively lacking. The aim of this study was to determine specific age-related changes in electrophysiological properties of the ventricles which can be related to a structural-functional arrhythmogenic substrate. Multiple epicardial electrograms were recorded on the ventricular surface of in vivo control and aged rats, while arrhythmia vulnerability was investigated by premature stimulation protocols. Single or multiple ectopic beats and sustained ventricular arrhythmias were frequently induced in aged but not in control hearts. Abnormal ventricular activation patterns during sinus rhythm and unchanged conduction velocity during point stimulation in aged hearts suggest the occurrence of impaired impulse conduction through the distal Purkinje system that might create a potential reentry substrate.

scholarly journals Lower Incidence of Esophagitis in the Elderly Undergoing Definitive Radiation Therapy for Lung Cancer

2017 ◽  
Vol 12 (3) ◽  
pp. 539-546 ◽  
Author(s):  
Payal D. Soni ◽  
Philip S. Boonstra ◽  
Matthew J. Schipper ◽  
Latifa Bazzi ◽  
Robert T. Dess ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Radiation Therapy ◽  
Lower Incidence ◽  
The Elderly

Randomized Study of Propofol Effect On Electrophysiological Properties of the Atrioventricular Node in Patients with Nodal Reentrant Tachycardia

2006 ◽  
Vol 29 (12) ◽  
pp. 1375-1382 ◽  
Author(s):  
PAULO WARPECHOWSKI ◽  
GUSTAVO G. LIMA ◽  
CLÁUDIO M. MEDEIROS ◽  
ARI TADEU L. SANTOS ◽  
MARCELO KRUSE ◽  
...  
Keyword(s):  
Randomized Study ◽  
Atrioventricular Node ◽  
Reentrant Tachycardia ◽  
Electrophysiological Properties

scholarly journals An Image-Based Model of the Whole Human Heart with Detailed Anatomical Structure and Fiber Orientation

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Dongdong Deng ◽  
Peifeng Jiao ◽  
Xuesong Ye ◽  
Ling Xia
Keyword(s):  
Human Heart ◽  
Atrioventricular Node ◽  
Linear Interpolation ◽  
Crista Terminalis ◽  
Electrophysiological Properties ◽  
Computed Tomography Images ◽  
Atrioventricular Ring ◽  
Fibers Orientation ◽  
Whole Heart ◽  
Experimental Findings

Many heart anatomy models have been developed to study the electrophysiological properties of the human heart. However, none of them includes the geometry of the whole human heart. In this study, an anatomically detailed mathematical model of the human heart was firstly reconstructed from the computed tomography images. In the reconstructed model, the atria consisted of atrial muscles, sinoatrial node, crista terminalis, pectinate muscles, Bachmann’s bundle, intercaval bundles, and limbus of the fossa ovalis. The atrioventricular junction included the atrioventricular node and atrioventricular ring, and the ventricles had ventricular muscles, His bundle, bundle branches, and Purkinje network. The epicardial and endocardial myofiber orientations of the ventricles and one layer of atrial myofiber orientation were then measured. They were calculated using linear interpolation technique and minimum distance algorithm, respectively. To the best of our knowledge, this is the first anatomically-detailed human heart model with corresponding experimentally measured fibers orientation. In addition, the whole heart excitation propagation was simulated using a monodomain model. The simulated normal activation sequence agreed well with the published experimental findings.

Lower Incidence of Radiation Induced Esophagitis in the Elderly: Role of Cytokines

2017 ◽  
Vol 99 (2) ◽  
pp. E496-E497
Author(s):  
P.D. Soni ◽  
P.S. Boonstra ◽  
P.G. Hawkins ◽  
S. Hobson ◽  
M. Schipper ◽  
...  
Keyword(s):  
Lower Incidence ◽  
The Elderly ◽  
Radiation Induced

PROGRESS AND GAPS IN UNDERSTANDING THE ELECTROPHYSIOLOGICAL PROPERTIES OF MORPHOLOGICALLY NORMAL CELLS FROM THE CARDIAC ATRIOVENTRICULAR NODE

2003 ◽  
Vol 13 (12) ◽  
pp. 3675-3691 ◽  
Author(s):  
JULES C. HANCOX ◽  
KATHRYN H. YUILL ◽  
JOHN S. MITCHESON ◽  
MARY. K. CONVERY
Keyword(s):  
Potassium Current ◽  
Atrioventricular Node ◽  
Calcium Currents ◽  
Background Current ◽  
Sodium Calcium Exchanger ◽  
Electrophysiological Properties ◽  
Sodium Calcium ◽  
Hyperpolarization Activated Current ◽  
Sustained Inward Current ◽  
Conduction Properties

The atrioventricular node (AVN) is a small but critically important component of the cardiac electrical conduction system and is located at the junction between right atrium and right ventricle of the heart. It plays important roles in normal and abnormal impulse propagation. Mathematical models of the conduction properties of the AVN have been made, but detailed in silico reconstruction of AVN electrophysiology lags behind that of other cardiac regions. One important facet of detailed reconstruction of AVN electrical activity is the development of comprehensive, ionic conductance-based models of single cell electrophysiology. With a view to facilitating the construction of such models, this article reviews progress made regarding single AVN cell electrophysiological data during the last decade, predominantly focusing on that derived from morphologically normal AVN cells. Properties and potential roles of a range of currents are discussed: including L-type and T-type calcium currents (I Ca,L and I Ca,T respectively), background current, hyperpolarization-activated current (I f ), delayed and transient outward potassium currents (I Kr and I to , respectively), sodium–calcium exchanger current (I NaCa ), the sustained inward current (I st ) and acetylcholine-activated potassium current (I KACh ).

Ventricular activation is impaired in aged rat hearts

2008 ◽  
Vol 295 (6) ◽  
pp. H2336-H2347 ◽  
Author(s):  
Stefano Rossi ◽  
Silvana Baruffi ◽  
Andrea Bertuzzi ◽  
Michele Miragoli ◽  
Domenico Corradi ◽  
...  
Keyword(s):  
Ventricular Arrhythmias ◽  
Elderly Population ◽  
The Elderly ◽  
Ventricular Myocardium ◽  
Conduction System ◽  
Aged Rats ◽  
Activation Time ◽  
Activation Patterns ◽  
Electrophysiological Properties ◽  
Ventricular Activation

Ventricular arrhythmias are frequently observed in the elderly population secondary to alterations of electrophysiological properties that occur with the normal aging process of the heart. However, the underlying mechanisms remain poorly understood. The aim of the present study was to determine specific age-related changes in electrophysiological properties and myocardial structure in the ventricles that can be related to a structural-functional arrhythmogenic substrate. Multiple unipolar electrograms were recorded in vivo on the anterior ventricular surface of four control and seven aged rats during normal sinus rhythm and ventricular pacing. Electrical data were related to morphometric and immunohistochemical parameters of the underlying ventricular myocardium. In aged hearts total ventricular activation time was significantly delayed (QRS duration: +69%), while ventricular conduction velocity did not change significantly compared with control hearts. Moreover, ventricular activation patterns displayed variable numbers of epicardial breakthrough points whose appearance could change with time. Morphological analysis in aged rats revealed that heart weight and myocyte transverse diameter increased significantly, scattered microfoci of interstitial fibrosis were mostly present in the ventricular subendocardium, and gap junction connexin expression decreased significantly in ventricular myocardium compared with control rats. Our results show that in aged hearts delayed total ventricular activation time and abnormal activation patterns are not due to delayed myocardial conduction and suggest the occurrence of impaired impulse propagation through the conduction system leading to uncoordinated myocardial excitation. Impaired interaction between the conduction system and ventricular myocardium might create a potential reentry substrate, contributing to a higher incidence of ventricular arrhythmias in the elderly population.

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