Chasing the reflected wave back into the heart: a new hypothesis while the jury is still out

Ion Codreanu1, Matthew D Robson, Oliver J Rider

  • 1Department of Physiology, Anatomy, and Genetics, University of Oxford, UK. codrion@yahoo.com

Insights

The reflected aortic wave influences left ventricular (LV) wall motion, causing a distinct "notch" in velocity graphs. This finding offers new insights into cardiovascular mechanics and arterial stiffness impacts.

Area of Science:

  • Cardiovascular Physiology
  • Biomedical Engineering
  • Cardiac Imaging

Background:

  • Arterial stiffness is a key cardiovascular risk factor impacting cardiac function.
  • The effect of the aortic reflected pulse wave on left ventricular (LV) function remains poorly understood.

Purpose of the Study:

  • To investigate regional LV wall motion patterns related to the aortic reflected wave.
  • To characterize the influence of the reflected wave on specific ventricular segments.

Main Methods:

  • Cardiac magnetic resonance (CMR) navigator-gated tissue phase mapping used in 14 healthy volunteers.
  • LV divided into 16 segments for high-temporal-resolution regional wall motion analysis.

Main Results:

  • A characteristic
  • notch
  • observed in radial, circumferential, and longitudinal myocardial velocity graphs, coinciding with the reflected aortic wave timing.
  • Notches were prominent in septal segments (radial) and anterior/posterior segments (circumferential).
  • Longitudinal graphs showed a diastolic deceleration linked to ventricular recoil.

Conclusions:

  • Reflected aortic waves demonstrably influence regional LV myocardial motion.
  • This novel concept requires further investigation with direct pulse wave recording to confirm the association.
Abstract

Related Concept Videos

Reflection of Waves01:07

Reflection of Waves

When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
Echo01:06

Echo

The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More than this, and they are perceived as separate sources.
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
Propagation of Waves01:07

Propagation of Waves

When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
The Wave Nature of Light02:12

The Wave Nature of Light

The nature of light has been a subject of inquiry since antiquity. In the seventeenth century, Isaac Newton performed experiments with lenses and prisms and was able to demonstrate that white light consists of the individual colors of the rainbow combined together. Newton explained his optics findings in terms of a "corpuscular" view of light, in which light was composed of streams of extremely tiny particles traveling at high speeds according to Newton's laws of motion.
The de Broglie Wavelength02:32

The de Broglie Wavelength

In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
Propagation of Action Potentials01:23

Propagation of Action Potentials

The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...