Related Experiment Video
Updated: Jun 26, 2026
09:17
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Published on: July 29, 2011
Structure specific models of electrical function in the right atrial appendage
Jichao Zhao1, Amir Amiri, Gregory B Sands
1Bioengineering Institute, The University of Auckland, 1142, Auckland, New Zealand. j.zhao@auckland.ac.nz
Summary
Computer models of atrial electrical function aid in understanding arrhythmias like atrial fibrillation. This study developed a detailed, structure-based model of the pig right atrial appendage, revealing uniform electrical activation despite complex anatomy.
Area of Science:
- Computational biology
- Cardiac electrophysiology
- Medical imaging
Background:
- Atrial fibrillation is a common arrhythmia, particularly in the elderly, and a significant contributor to mortality in heart failure.
- Realistic computer models of atrial electrical activation are crucial for understanding reentrant arrhythmias.
- Existing computational and experimental techniques are being extended to create detailed, structure-based atrial models.
Purpose of the Study:
- To develop a detailed, structure-based computational model of atrial electrical function.
- To reconstruct the 3D geometry of atrial structures, including the right atrial appendage (RAA), pectinate muscles (PM), and crista terminalis (CT).
- To simulate electrical activation on this detailed anatomical model to investigate arrhythmia mechanisms.
Main Methods:
- 3D atrial geometry reconstruction using magnetic resonance imaging and extended-volume imaging.
- Serial etching, staining, imaging, and ultramilling to create high-resolution image stacks of the RAA.
- Segmentation and 3D region-growing algorithms to construct RAA geometry.
- Electrical activity modeling using the Courtemanche atrial cell model and a bidomain formulation with a finite element solver.
- Stimulation applied to the crista terminalis to model RAA activation.
Main Results:
- A detailed 3D model of the pig RAA, including PM and CT, was successfully reconstructed.
- Electrical activity was simulated on the reconstructed RAA geometry.
- Despite the complex structure of the pectinate muscles, the simulated right atrial appendage activation was found to be relatively uniform.
Conclusions:
- Detailed, structure-based computational models are feasible for studying atrial electrical function.
- The developed modeling approach can reveal insights into the mechanisms of atrial arrhythmias.
- Simulations suggest that complex atrial structures may not necessarily lead to non-uniform electrical activation patterns.
Related Concept Videos
01:19Electrophysiology of Normal Cardiac Rhythm
The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of...
01:20Conduction System of the Heart
The cardiac conduction system produces and transmits electrical impulses that prompt myocardial contraction, ensuring efficient heart function. This intricate system ensures that the heart beats in a coordinated and efficient manner, beginning with the atria and then the ventricles. The conduction system optimizes cardiac output by maintaining this precise sequence, which is crucial for adequate blood circulation.
This system relies on the unique properties of nodal and Purkinje cells:...
This system relies on the unique properties of nodal and Purkinje cells:...
01:19Conduction System of the Heart
Autorhythmicity is a term that refers to the heart's inherent ability to generate electrical signals and instigate muscle contractions. This self-regulating conduction system within the heart consists of two key components: the pacemaker cells and specialized conducting cells.
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
01:16Chambers of the Heart
The human heart is a complex organ made up of four chambers: the right and left atria and the right and left ventricles. These internal chambers are separated by partitions known as the interatrial and interventricular septa. The exterior of the heart features a groove known as the coronary sulcus that demarcates the atria from the ventricles, while the anterior and posterior interventricular sulci distinguish between the two ventricles.
Deoxygenated blood from the body is received in the right...
Deoxygenated blood from the body is received in the right...
01:28Mechanism of Cardiac Arrhythmias
Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...