Heart Rate Variability Flashcards
Define stress
a feeling experienced when a person perceives that demands exceed the personal resources that they are able to handle
What is the stress hormone?
cortisol
Define heart rate variability
the variation in the time interval between heartbeats controlled by the balanced interaction between SNS and PNS
Low HRV vs. High HRV
low HRV = BAD, impairs cardiac function, signs of ventricular arrhythmia after a heart attack
high HRV = GOOD, lowers stress, increased immune function, decreases anxiety and depression
SDRR
shows amplitude of HRV… want this to be big
RMSSD
reflects parasympathetic NS
HR
max - min heart rate during one breath …. also reflects amplitude of HRV
Frequency domain
reflects degree of modulation of sympathetic and/or parasympathetic tone
What are the ranges of frequency domain
VLF, LF, and HF
VLF (very low frequency power)
intrinsic (necessary) rhythm of heart
<0.003-0.04 Hz
LF (low frequency power)
sympathetic AND parasympathetic control, 0.04-0.15 Hz … ideal power at 0.1 Hz
HF (high frequency power)
parasympathetic control, 0.15-0.4 Hz
What is a limitation of HRV
can only be taken on people with normal, sinus rhythm
What is atrial fibrillation?
atrium beat faster than ventricles
How do you optimize HRV?
- 6 breaths per minute
- Respiratory sinus arrhythmia
define respiratory sinus arrhythmia
breathing slow and deep
What happens during inspiration?
heart beats faster bc sympathetic activation and release of parasympathetic break
What happens during expiration?
heart beats slower bc parasympathetic activation
What reflex describes inspiration?
Bainbridge reflex
Bainbridge reflex
breathing in increases chest cavity (more space) –> More blood is returned to the right atrium –> stretches atrium –> INCREASED HR
What response describes expiration?
baroreceptor response
Baroreceptor response
More blood is pumped out of heart and into circulation –> stretches baroreceptors –> tells heart to slow down –> venous return is reduced –> DECREASED HR
Define coherence
simultaneous matching of HRV with respiration
What are Mayer Waves?
the body’s natural BP oscillation at 0.1 Hz
What happens when respiration and Mayer Waves are matched?
RSA and HRV are maximized
