Related Experiment Video
Updated: Aug 9, 2026

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice
Published on: September 17, 2015
The metrics of cardiac chronotropism: biometric perspectives
G G Berntson1, J T Cacioppo, K S Quigley
1Department of Psychology, Ohio State University, Columbus 43212, USA.
Abstract:
The selection of heart period versus heart rate as a chronotropic metric has been considered from quantitative and statistical perspectives, which have not yielded a universal preference for either metric. In the present paper, we discuss biometric considerations that bear on the selection of the optimal chronotropic metric. Biometric evidence reveals that the transfer functions relating autonomic nerve traffic to chronotropic effects on the heart are more nearly linear for heart period than for heart rate. This confers considerable advantage on heart period as a chronotropic metric and can facilitate the study of psychophysiological relationships. We further show that heart period offers greater flexibility, because heart period data can be evaluated in cardiac time units (beats) or in real-time units (s), whereas heart rate data can only be analyzed in real time. These considerations suggest clear advantages to heart period as a chronotropic metric.
More Related Videos
Related Concept Videos
Pulse rhythm
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
Pathophysiology of Cardiac Performance
Correlation between ECG and 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...
Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...
Cardiac Output I:Effect of Heart Rate on 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...

