Do you know that your heart rate can be an indicator of an underlying health issue? The normal resting heartbeat of an adult is between 60 and 100 beats per minute If you have an Increased heart rate, it could be a warning sign of an illness. Before you reach for your medication or undergo surgery, there are non-invasive techniques you can try to normalize your heart rate. One such simple yet unique technique is vagal maneuvers. It stimulates the vagus nerve and slows down the heart rate.
Whether you are dealing with a fast heartbeat or a complex arrhythmia, vagal maneuvers can be a quick, non-invasive technique to stabilize your condition and buy more valuable time for further treatment. Read on to learn more about the Vagal Maneuvers in detail to get your heart rhythm back on track!
What is Vagal Maneuvers?
Vagal maneuvers are simple techniques for managing particular types of arrhythmias in patients. They are ideal for use in emergency settings, thereby increasing the victim’s survival chances by stimulating the vagus nerve, which controls heart rate. Vagal maneuvers are particularly effective in treating SVT (Supraventricular Tachycardia), a rapid heart rhythm that occurs above the ventricles.
Studies show that these treatments have a 40% success rate in restoring the patient to normal sinus rhythm. You can stabilize the victim’s condition by learning how to slow down your heart rate through vagal nerve stimulation. Moreover, these maneuvers are a highly effective, non-pharmacological approach to emergency care that can be performed quickly on the patient without the need for any medication.
Read More: Ventricular Fibrillation: Causes and Treatments
The Role of Vagal Maneuvers in SVT Treatment
SVT (Supraventricular Tachycardia) is a type of arrhythmia characterized by an irregular heartbeat where your heart beats fast. The condition affects the upper chambers of the heart hence the name supraventricular tachycardia.
The vagus nerve, also known as the tenth cranial nerve (CN X), is a critical part of your body’s parasympathetic nervous system. It represents the ‘rest and digest’ aspect of the nervous system that facilitates relaxation. The vagus nerve travels from the brainstem to the abdomen and assists in various functions, including digestion, mood regulation, and immune response.
Vagal maneuvers stimulate the vagus nerve, which in turn slows down the electrical activity in a structure in the heart known as the AV node. Vagal nerve stimulation also plays a critical role in managing SVT, thereby preventing further complications.
Read More: Synchronized Cardioversion: Everything You Need to Know
Examples of Vagal Maneuvers
The stimulation of the vagus nerve modifies the electrical conduction through the atrioventricular node of the heart, which is important in synchronized heartbeat. The stimulated vagus nerve ensures the slowdown of the rate and frequency of electrical impulses in the heart. Let us explore the different types of techniques in maneuvers to know how to lower heart rate.
Valsalva Maneuvers
Performing Valsalva maneuvers creates increased pressure within the chest cavity and stimulates the vagus nerve, which leads to a slower heart rate. Most people perform this technique in everyday life when they are lifting something heavy or straining to defecate. In general, the technique involves forceful exhalation against a closed airway.
Though generally considered safe, make sure to consult your healthcare professional before trying it yourself. In clinical settings, Valsalva maneuvers are performed using the following steps:
- Step 1: The patient should lie down in a semi-recumbent (partially reclined) position.
- Step 2: They should forcefully exhale against resistance into a pressure-measuring device known as a manometer (or a large syringe) for around 15 seconds, creating a pressure of 40 mmHg.
- Step 3: The patient will lie flat, and the healthcare provider will passively raise their legs to around 45 degrees.
- Step 4: After 15 seconds, the patient can return to the semi-recumbent position. During the technique, the patient’s heart rate, blood pressure, and other vital signs should be monitored closely.
Phases of Valsalva Maneuver
While performing a Valsalva maneuver, the technique is expected to create physiological responses, which can be categorized into four distinct phases. The phases are as follows:
Phase I
When you hold your breath and strain, you create pressure inside the chest cavity, including your lungs, heart, and blood vessels. As the pressure on your blood vessels increases, it squeezes some blood out of your chest and into the rest of your body, causing a temporary rise in your blood pressure.
Phase II
The pressure on the blood vessels inside your chest decreases the amount of blood that flows back to your heart. This means there will be less blood for your heart to pump out with each beat. As a result, your blood pressure drops, which in turn increases your heart rate. This triggers the activation of your sympathetic nervous system, or a ‘fight or flight’ response. Then, the brain sends a signal through the nerves to release adrenaline, causing all of the blood vessels outside the chest to contract, elevating the blood pressure.
Phase III
The next phase begins when you stop straining and release your breath. Your contracted blood vessels will expand again, and blood will return to your chest, filling the blood vessels. This will cause a further drop in your blood pressure level.
Phase IV
Once everything normalizes in your chest, the heart will begin to pump a normal amount of blood again. However, the blood vessels outside your chest will remain contracted, as it will take an extended period for them to recover. As your blood moves toward the blood vessels, your blood pressure will rise once more. In this final phase, the blood pressure will shoot up, which will send a signal to the vagus nerve in an attempt to slow down your heart rate.
In the end, the technique will cause a sudden increase in the activity of the vagus nerve and bring the blood pressure down. The increase in vagal tone will also be transmitted to the AV node, which can impede the connection and slow down the arrhythmia.
Modified Valsalva Maneuver
The modified Valsalva maneuver is more effective than the standard version at slowing down a fast heart rate. Studies show it works twice as well, increasing the success rate by 40%. Below are the steps you can follow to perform a modified Vasalva maneuver:
- Start by sitting upright.
- Take a syringe (or similar object) and blow into it as hard as you can for 10 to 20 seconds, like you’re trying to inflate a balloon.
- Right after, you’ll lie down flat on your back, and your legs will be lifted up at an angle (about 45 to 90 degrees).
- Stay in this position, with your legs held up, for 40 to 60 seconds.
This technique helps improve blood flow and triggers your vagus nerve to slow your heart rate. If it doesn’t work the first time, you can repeat it. Always make sure to do this under medical guidance or if a healthcare professional has recommended it.
Carotid Sinus Massage
Carotid sinus massage should be performed only by a trained medical professional. This maneuver aids in the SVT treatment by stimulating the nerve endings in the carotid sinus, which slows down the heart rate. This occurs because the carotid sinus has arterial baroreceptors that relay signals corresponding to blood pressure differences to the autonomic nervous system during the massage. The steps for performing carotid sinus massage include:
- Step 1: Have the patient lie down with their head slightly turned away from the side where you will be massaging.
- Step 2: Gently apply pressure to the carotid artery located in the neck, just below the jawline.
- Step 3: Massage the area for about 5-10 seconds while monitoring the patient’s heart rate.
- Step 4: Repeat the massage steps on the other side if necessary. However, refrain from massaging both sides simultaneously.
Ice Water Facial Immersion
The doctor often advises people to immerse their heads in ice water to lower their heart rate. Cold water increases vagal nerve activity and induces bradycardia. This technique is used in the treatment of SVT in hospital settings. Here are the steps for the ice water facial immersion technique:
- Step 1: Prepare a basin filled with ice-cold water.
- Step 2: Ask the patient to hold their breath.
- Step 3: Submerge their face in the cold water of the basin for a few seconds.
- Step 4: Monitor their heart rate after performing this maneuver.
Gag Reflex
Applying or performing the gag reflex can also stimulate the vagus nerve, further slowing down the heart rate. The gag reflex sends nerve signals up to the medulla oblongata and also triggers the vagus nerves. The easiest way to perform the gag reflex is by inserting your fingers into the throat.
Risks for Vagal Maneuvers
Vagal maneuvers are simple and generally effective, but there still are a few risks associated with this technique. Hence, you should not attempt the technique without the supervision of a medical professional. For instance, carotid massage is complicated in anyone with a history of ventricular fibrillation or ventricular tachycardia. It is also contraindicated in patients who have SVT along with:
- An acute heart attack
- Unstable blood pressure
- Worsening of Arrhythmia
- Syncope
- Bradycardia
- Carotid artery stenosis
- Certain eye disorders, such as glaucoma or retinopathy
Bring your Heart Rate Back to Normal!
Vagal maneuvers are a valuable treatment to treat abnormally elevated heart rates as you can perform them quickly without any specialized equipment. This creates a window of opportunity for medical professionals for further evaluation and comprehensive treatment when seconds matter. You should also learn to perform these maneuvers with proper ACLS training, as this will not only be for treating the symptoms of your heart condition. It targets the underlying cause of the condition and offers a more holistic approach to improve patient outcomes.
