Related Experiment Video
Updated: Jul 30, 2026
12:09
Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations
Published on: January 8, 2013
Stochastic model for heart-rate fluctuations
Tom Kuusela1, Tony Shepherd, Jarmo Hietarinta
1Department of Physics, University of Turku, Finland. tom.kuusela@utu.fi
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 26, 2005
Summary
A new model accurately describes human heart rate fluctuations using a simple stochastic difference equation. This reveals the underlying dynamics of the heart rate control mechanism over minutes to hours.
Area of Science:
- Physiology
- Nonlinear dynamics
- Statistical modeling
Background:
- Human heart rate exhibits complex, unpredictable fluctuations due to multiple feedback control loops.
- These fluctuations display fractal dynamics, long-term correlations, and 1/f noise, but their detailed time evolution remains less understood.
Purpose of the Study:
- To develop and validate a model for the detailed time evolution of heart rate fluctuations.
- To investigate the underlying dynamics of the heart rate control mechanism.
Main Methods:
- A one-dimensional Langevin-type stochastic difference equation was employed to model heart rate fluctuations.
- The model incorporates both deterministic nonlinear and stochastic Gaussian noise components, determined from measured heart rate data.
- Data from 27 healthy subjects were analyzed.
Main Results:
- The proposed stochastic difference equation accurately models heart rate fluctuations on time scales from minutes to hours.
- The deterministic component of the model, in most subjects, exhibits characteristics of bistable systems with two stable and one unstable fixed point.
Conclusions:
- A simple stochastic model can effectively capture the complex dynamics of human heart rate variability.
- The findings suggest that the heart rate control mechanism may operate based on bistable dynamics.
Related Concept Videos
01:30Factors Influencing Heart Rate
The heart rate, or pulse rate, is a vital indicator of cardiovascular health. It reflects the number of times the heart beats per minute. Various physiological and environmental factors influence heart rate, increasing or decreasing cardiac output. Understanding these factors is crucial for assessing heart function and identifying potential health issues.
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
01:25Correlation between ECG and Cardiac Cycle
The electrical signals recorded on an electrocardiogram (ECG) occur before the mechanical processes of contraction and relaxation during the cardiac cycle.
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:29Disturbances in Heart Rhythm
Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
01:31Regulation of Heart Rates
The regulation of heart rate is a complex process controlled by the autonomic nervous system (ANS), hormonal influences, and intrinsic cardiac mechanisms. The ANS has two main components: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
01:29Dysrhythmias III: Characteristics of Dysrhythmias
Dysrhythmias, also known as arrhythmias, are irregular heart rhythms that result from abnormal electrical activity in the heart, affecting its ability to circulate blood efficiently. Tachyarrhythmias, a subset of dysrhythmias, are characterized by abnormally fast heart rates exceeding 100 beats per minute. Here are some types of tachyarrhythmias with their distinct ECG features:Sinus Tachycardia:Sinus tachycardia presents a regular heart rhythm with an increased rate of 101-180 beats per minute.