Anastomosis & Quasi Vagal Manoeuvres

An anastomosis is a connection between tubular structures, such as loops of intestine or blood vessels, as in the Circle of Willis pictured above. This clever continuity provides collateral blood flow between the anterior and posterior circulations of the brain, which protects against ischemia in the event of vessel disease or damage.

That's Nature hedging her bets!

Our bodies have evolved in response to the constant motion and connectedness that survivorship requires. What circulation needs to stay in good service is, you guessed it... circulation!

Inversions like Headstand and Downward Dog may well pop to mind as popular ways to play with circulation. But there's more! You may not have been aware that manipulating circulation also profoundly affects the nervous system. 

The vagus nerve, responsible for keeping us calm, sated and well, is sensitive to changes in pressure. Vagal maneuver/manoeuvres (VMs) are medical techniques used to increase vagal parasympathetic tone, which is useful for treating various arrhythmias. VMs such as the Valsalva and Handstand (surprised?) are a first-line (first choice) treatment for supraventricular tachycardia (SVT) (fast heart rate) and general stress because they’re relatively low-risk, low-cost ways to slow down a heart rate that’s too fast.¹

So how does it work?

Performing the Valsalva manoeuvre, for example, increases intrathoracic pressure, reducing the heart's preload. Baroreflex and other compensatory reflex mechanisms initiated by this decreased preload lead to a rebalancing of cardiovascular effects via vagus regulation.² Read more about this technique's history, clinical applications and contraindications here.

The Valsalva is but one of the many VMs that use physical actions to trigger the vagus nerve to act on your heart’s natural pacemaker by slowing down its electrical impulses. From the brainstem to the belly, the vagus nerve largely orchestrates the parasympathetic nervous system, slowing down the heart rate, stimulating digestion, and fostering intimacy. We might consider the vagus a kind of oar for changing the trajectory and decelerating our behavioural canoe.

I argue that VMs, defined as such, can be reimagined as yogic interventions. Further, I'm going to say that postural yoga practice, with its pranayama and bandha techniques, amounts to vagal manoeuvring toward the tandem goals of physical self-regulation and behavioural self-mastery.

Indeed, yoga offers a wealth of low-risk, creative ways to manually override the stress response in medically stable practitioners. It is always worth stating for the record that your health choices are your own responsibility. If you're concerned, please check with your healthcare professional before undertaking any new physical practice.

What can you do right now to promote vascular health and rebalance stress response levels? Here are 3 "quasi" vagal manoeuvres, ideas for coaxing circulation and staving off the stress when you can't get upside down.

Swan Circles

• Using the tip of your nose, draw an imaginary circle as you flex/extend/protract/retract your head and neck, work up to 10 - 20 rounds.
• Try drawing the circles in various planes, e.g., using the "clock face" and "swan" techniques. 

Bhramari 

• Breathe in normally through the nose and audibly hum/buzz your exhalation.
• The Bhramari Pranayama is thought to relieve hypertension by lowering blood pressure and cerebral tension with repeated practice.  

Kite Compression 

• Bring your fingertips to the sides of your neck, about halfway between your shoulders and ears.
• Applying gentle compression, begin turning your head left and right responsively as you pull the 'kite strings' of the sternocleidomastoid. 
• Not to be confused with carotid massage, which should never be administered casually!

Join my Group Mentorship program to explore these techniques in practice, with discussion around building a safe context for exploring the parasympathetic-rebalancing power of spiral motion.

Here are some publications to explore the overlap between vagal science and yoga sadhana:

Gerritsen RJS, Band GPH. Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity. Front Hum Neurosci. 2018 Oct 9;12:397. doi: 10.3389/fnhum.2018.00397. PMID: 30356789; PMCID: PMC6189422.

Rao, B, Gowlikar, V, Vooturi, S. et al. “Tadasana” Yoga Maneuver for Preventing Vasovagal Syncope Recurrences: A Pilot Study. J Am Coll Cardiol EP. 2022 Feb, 8 (2) 253–254.
https://doi.org/10.1016/j.jacep.2021.12.007

Resources

1. https://my.clevelandclinic.org/health/treatments/22227-vagal-maneuvers

2. Srivastav S, Jamil RT, Zeltser R. Valsalva Maneuver. [Updated 2023 Aug 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537248/