Should we pay more attention to the ‘HR’ in ‘HRV’?

One of the more common questions I get when presenting my research relates to difference between heart rate (HR) and heart rate variability (HRV). HR is incredibly easy to collect (in comparison to HRV) so if this is a similar to HRV why not just measure that instead?

The simple answer is that average HR represents both parasympathetic (PNS) and sympathetic (SNS) input to the sinoatrial node (plus a few other factors) so it’s difficult to pin down what fluctuations in HR really represent. If PNS modulation can be approximated via HRV why even bother with HR?

While I usually only give HR a ‘hat tip’ in the demographics section of my papers (we have this data, why not present it?) it’s looking like that HR is really worth paying attention to due to its important influence on HRV.

Memorable paper titles

I came across a paper using a ‘breaking bad’ pun in the title and began to wonder how much popular culture influences the stodgy domain of paper titles.

Using this handy Pubmed trend tool I plugged in “breaking bad’ to see if the above paper was an isolated case. Sure enough, there was a uptick in papers with ‘breaking bad’ from 2009 - a year after the show’s first season.

Once I tried using a pun for a paper title (can’t for the life of me remember what it was though) but the editor asked me to change the title “to appeal to a wider audience”. Even though I ended up changing the title (I was under time pressure to get publications for my PhD thesis and wasn’t that attached to the pun from memory) I still disagreed with this sentiment as papers with memorable titles are much more likely to be cited. 

Paper titles are often an afterthought but I think there’s a certain art to choosing the right title that not only conveys what the paper is about but also catches the reader’s eye and sticks in their mind.

For instance, one of my collaborators recently wrote a review paper on issues in frequency domain measures of cardiac autonomic outflow with the title: “Everything Hertz: methodological issues in short-term frequency-domain HRV”. 

Clever, huh?

As well clearly stating what the paper was about, I’ll always remember the paper whenever I need cite something related to common issues in frequency domain HRV measures. 

Why do we sigh?

What’s the point of sighing? Just think about it. Why do we occasionally have an isolated breath with increased tidal volume?

It’s well established that sighing resets cardiorespiratory variability, which is important considering an oscillating cardiorespiratory system promotes dynamic homeostasis. For instance, sighing restores blood gas exchange and parasympathetic activity.

Sighs are also associated with worry in popular culture (check out this supercut of 301 sighs from movies), which is actually a pretty accurate reflection of sigh frequency in anxiety disorders. Stressing people with difficult arithmetic and sustained attention tasks in the lab also increases rates of sighing. Moreover, sighing is also an expression of relief with sighing related decreasing muscle tension and perceived restlessness

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I recently came across an excellent program of research from Vlemincx and colleagues suggesting that these physiological and psychological relationships with sighing are themselves related, with sighing acting as a psychophysiological “reset button”.

New publication: Considerations in the assessment of heart ate variability in biobehavioral research

New paper I wrote with James Heathers has just been published in Frontiers in Psychology. 

You can read the open access paper here.

Reference:

Quintana DS and Heathers JAJ (2014). Considerations in the assessment of heart rate variability in biobehavioral research. Front. Psychol. 5:805. doi: 10.3389/ fpsyg.2014.00805

New publication: Reduced heart rate variability in anxiety disorders

New paper I co-authored has been published in Frontiers in Psychiatry.

You can read this open access paper here.

Reference:

Chalmers JA, Quintana DS, Abbott MJ-A and Kemp AH (2014) Anxiety disorders are associated with reduced heart rate variability: a meta-analysis. Front. Psychiatry 5:80. doi: 10.3389/fpsyt.2014.00080

New publication: Cytokine aberrations in autism spectrum disorder

A new paper I co-authored has just been published in Molecular Psychiatry.

The paper can be accessed from the journal website here or you can download the preprint of the article if you don’t have access to the journal.

Reference:

Masi, A., Quintana, D.S., Glozier, N., Lloyd, A., Hickie, I.B., Guastella, A.J. (2014). Cytokine aberrations in Autism Spectrum Disorder: A systematic review and meta-analysis. Molecular Psychiatry, doi: 10.1038/mp.2014.59

New publication: Heart rate variability during social interactions in children with and without psychopathology

A paper I co-authored has just been published in the Journal of Child Psychology and Psychiatry.

You can access the article from the journal website here or you can download the preprint

Reference:

Shahrestani, S., Stewart, E. M., Quintana, D. S., Hickie, I. B. and Guastella, A. J. (2014), Heart rate variability during social interactions in children with and without psychopathology: a meta-analysis. Journal of Child Psychology and Psychiatry. doi: 10.1111/jcpp.12226

Low frequency HRV is associated with psychological pain but what does this really mean?

The idea of psychological pain is an interesting one as it feels just as real as physical pain for the individual but it’s a lot harder to conceptualise. Considering how real psychological pain feels, it’s no surprise that both types of pain share similar neural circuitry.

Psychological pain is a commonly reported symptom in depression. While it’s not related with depression severity, it is associated with an increased risk of suicide. Despite the prevalence of “psychache” in depression, the relationship between this and physiological measures, beyond brain imaging, is not well known.

Oxytocin probably reaches the brain directly but it’s not necessary to influence social behavior and cognition

There are a myriad of studies indicating that intranasal oxytocin (OT) influences social behaviour and cognition. For instance, OT has been reported to improve emotion recognition, trust, social memory, altruism, generosity, and approachability. While not all of the reported improvements are “positive” (e.g., increasing schadenfraude1), there’s no doubt that OT modulates social behavior and cognition.

Most of these OT studies operate under the assumption that these observed effects are due to intranasally administered OT reaching the brain via pathways from the nasal cavity. As evidence, a cerebrospinal fluid (CSF) study by Jan Born and team2 is often cited. The idea here is that if a molecule can be detected in CSF, it’s also in the brain. However, this study didn’t actually use OT, instead reporting on vasopressin (neuropeptide that is structurally similar to OT).

Listen to your heart: cardiac biofeedback improves heart rate control during emotional reactions

Like it or not, the experience of negative emotions are a fact of life. Most people are able to effectively regulate their emotional responses but sometimes this can be hard, particularly for people with anxiety disorders. 

One element of emotional reactions is the physiological response. For instance, when you’re speaking publicly your heart may begin to race. People with anxiety are particularly sensitive to these physiological cues, which leads to a vicious cycle as anxiety begets a physiological response, which begets anxiety, and so forth.

But what if you were better able to regulate your accelerating heart rate?