Tickling Ears to Correct Vagal Heart Tone

By Unsa Shafi

The annual death rate due to cardiac failure in the United States is 600,000, and that number increases every year. The amount of deaths due to heart disease make finding effective treatment plans crucial. The discovery that vagal withdrawals are correlated with heart failure has propelled a new range of initiatives. Scientists are now researching the stimulation of the parasympathetic and sympathetic nervous system by the vagal pathway.  It is common knowledge that the vagus nerve, a major cranial nerve, regulates the heart and many other internal organs.

In 2013 Sayers et. al published a study in which different locations along the cardiac vagal pathway were stimulated in anesthetized canines to test the correlation of vagal pathway stimulation to cardiac vagal tone.  These scientists not only tested the vagus nerve, but also other ganglionic neurons that regulated the heart’s conduction system. Different combinations of electrodes were placed in these systems of canines. With the stimulation of the vagus nerve, the heart rates of the test subjects were seen to increase and parasympathetic effects were observed. In all of their studies, it was evident that heart rate and blood pressure increased after stimulation of the different nerves ceased. Sayers et. al found that stimulation of the vagus nerve could be of use to heart failure patients. However, the researchers recognized that using micro-electrode arrays for more targeted stimulation was essential in yielding better results.

Coming from the discovery that vagus nerve stimulation is beneficial in studying for heart failure treatments, Dr. Jennifer Clancy innovatively tested how “tickling” the ears can correct vagal heart tone. Transcutaneous Electrical Nerve Stimulation (TENS) machines are commonly used to stimulate the release of endorphins throughout the body, relieving pain in patients with chronic pain or many other diseases. This TENS machine stimulates a sensory branch of the vagus nerve, located in the outer ear. The small shocks the machine sends out have a tickling sensation, but also yield many positive results for the heart. Like Sayers et. al suggested with using micro-electrode arrays for targeted stimulation, Dr. Clancy and her team were able to manipulate a chronic pain machine to improve health.  

Dr. Clancy went beyond merely improving cardiac vagal tone, but was also able to maintain heart rate variability.  This is essential to the overall health of an individual because every second, our heart rate is changing. It increases when we inhale to allow for more oxygen input, and decreases when we exhale. By stimulating the branch of the vagus nerve present in the ear, the stimulation can still be manipulated as it travels to the heart. This increases heart rate variability by twenty percent. Because of the same reason, using the TENS machine not only improves parasympathetic effects, but also improves components of the sympathetic nervous system.

Works Cited

Iyer, S. (2014, August 20). Tickle Your Way To A Healthy Heart. Retrieved from
            http://www.medicaldaily.com/heart-healthy-tip-tickling-ears-nerve-impulses-can-help-

            stabilize-overworking-heart-298828

Sayers, S., Thomas, D., Walter, J., Scheiner, A., Dieter, R., Hsieh, A., & Singh, S. (2013). Stimulation Along the Vagal Pre and Postganglionic Pathway to Selectively Enhance Vagal Tone to the Heart. The Open Cardiovascular and Thoracic Surgery Journal. 6. 1-9. Retrieved from  https://luc.app.box.com/s/4c031c26bsh2bj3619si/1/2366698397/20298964193/1