Valsalva Maneuver Definition
The Valsalva maneuver (VM) alters the pressure in the chest and abdomen, causing the body to slow the heart in an attempt to compensate for the increased pressure. This is accomplished by forcing fifteen seconds of vigorous breathing against a closed airway, preventing expiratory air from exiting the body via the mouth and nose. The Valsalva manoeuvre is used to identify cardiac abnormalities and autonomic nervous system issues. It may help calm an overly fast pulse.
What is the Valsalva Maneuver?
The Valsalva technique involves breathing in, firmly shutting the lips and squeezing the nose, then aggressively breathing out against a closed airway for fifteen seconds. When you strain during a bowel movement, the glottis shuts as you press down.
Because air is prevented within the body, internal pressure inequalities arise, affecting the heart. In reaction to a brief increase in blood pressure, the autonomic system is activated. The body responds by slowing the heart rate and preventing the heart from contracting as hard.
How Does the Valsalva Maneuver Work?
When you need to know what the Valsalva manoeuvre is for and how it works, you’ll need to know about the circulatory system. A variety of metrics are used to quantify cardiac activity, or the operations of the heart.
- Systole is a contraction of the heart muscle that pumps blood into the arteries.
- Diastole is the relaxation of cardiac muscle that allows blood to flow into the heart.
- The number of times the heart beats each minute is called the heart rate.
- The amount of blood pumped from the left ventricle into the aorta every beat is called stroke volume.
- The quantity of blood pumped into the aorta per minute is known as cardiac output. The heart rate is multiplied by the stroke volume to compute cardiac output.
- Preload refers to the extent to which the heart muscle cells (cardiomyocytes) are stretched before the heart chambers contract, also known as the end-diastolic pressure of the left ventricle (LVEDP).
- The amount of resistance the heart must overcome in order to open the valve in front of the aorta and force blood into it is known as the afterload. When the aorta is stiff, the heart has to work harder, which increases the afterload.
- The movement of blood from the veins into the right atrium is known as venous return. This should closely resemble cardiac output. To put it another way, the quantity of blood pumped into the heart should be equal to the amount pumped out.
The autonomic nervous system—the component of our nervous system that is regulated by the brain rather than our goals—is another issue connected to the Valsalva manoeuvre. The sympathetic and parasympathetic activities of the autonomic nervous system are the fight-or-flight and relax-and-digest reactions, respectively.
In this scenario, the parasympathetic system is largely activated by the vagus nerve (CN X). Pressure sensors in large blood vessels, such as the aorta, activate this crucial neuron. The vagus nerve reduces the heart rate and relaxes the arteries, allowing them to expand and blood pressure to return to normal.
Valsalva Maneuver Phases
There are four stages to the Valsalva manoeuvre:
Phase One: Trying to breathe via a blocked airway raises chest cavity pressure. This increased pressure compresses the main blood arteries, increasing stroke volume and, as a result, systolic and diastolic blood pressure. The pulmonary veins force blood into the left atrium.
Phase Two: The thoracic cavity’s higher pressure for a longer period of time (15 seconds) prevents enough deoxygenated blood from returning to the heart. The vena cava superior and inferior normally drain deoxygenated blood into the right atrium. The right atrium receives less blood because the veins in the thoracic cavity stay squeezed. This lowers the blood pressure by lowering the cardiac output and stroke volume.
The autonomic nervous system attempts to adjust for the fifteen-second rise in intrathoracic pressure and decreased cardiac output. The heart rate rises when the blood vessels constrict. Due to the compressed veins, however, there is inadequate blood flow into the heart.
Phase Three: When the breath is finally expelled, the intrathoracic pressure drops swiftly. Blood may now flow freely into the heart, and cardiac output returns to normal.
Phase Four: The heart receives less blood during phases one and two. This indicates that more blood flows into the heart during phase four. Stroke volume and cardiac output rise above normal for a brief period.
The heart does not need to pump faster when the low blood pressure of phases one and two recovers to normal. The heart rate recovers to its previous level.
What Is the Valsalva Maneuver Used For?
The Valsalva technique may be used for both diagnosis and therapy. When eating is ineffective, it may also be used to relieve pressure in the middle ear during flying. However, unless you know you have a healthy heart and are sitting down, any Valsalva manoeuvre procedures are not recommended while unblocking the ears.
Never attempt the Valsalva technique unless a doctor has recommended it or unless you undergo regular health checkups. In patients with naturally low blood pressure, the quick reduction in heart rate and blood pressure might trigger fainting and overwork the heart. The Valsalva manoeuvre might be harmful if you have an undetected cardiac problem.
Constipation is connected to heart-related fatalities in people with heart disease, and straining while producing a bowel movement has the same impact as the Valsalva manoeuvre. When Elvis Presley’s corpse was discovered in the bathtub in the 1950s and 1960s, it was assumed that he died in this manner. However, his death was ultimately determined to be the consequence of codeine usage. However, codeine is strongly linked to constipation, thus the bowel movement explanation may not be entirely incorrect.
Valsalva Maneuver Uses in Cardiology
The Valsalva technique is used by cardiologists to assess heart function. People with good cardiac function will go through the four stages indicated above. Certain alterations in these stages may occur when the heart is injured.
People with moderate to severe heart valve disease (mitral valve and/or aortic valve) and ventricular failure have abnormal arterial pressure values. Cardiologists may discover cardiac murmurs by listening to the heart during the manoeuvre.
Certain individuals experience short-term racing heartbeats. This is known as supraventricular tachycardia, or SVT. SVT treatment with the Valsalva manoeuvre may bring the heart rate back to normal in up to 50% of patients.
Heart rates exceeding 100 beats per minute are frequently related to SVT. The afflicted individual experiences anxiety, palpitations, and shortness of breath as a result of the symptoms. Because the cardiac output is too low in SVT, the body does not get enough oxygen because the heart does not have enough time to fill between beats.
Patients with supraventricular tachycardia are taught how to do the Valsalva technique to slow down their heart rate. Although the heart beats quicker at first, phase four activation of the vagus nerve causes the heart rate to go down. It’s critical to rule out any cardiac issues that may make this treatment risky.
Other Medical Valsalva Maneuver Uses
The Valsalva technique is used by pulmonologists to assess lung function. During the breath-holding phase, pulmonary hypertension, emphysema, and chronic lung illness may cause the pulse to vanish totally.
The Valsalva technique may also be used to help diagnose spinal injuries. The spinal nerves in this area of the body are compressed by increased intrathoracic pressure. The fifteen seconds of pressure may then be monitored by neurologists and orthopaedic surgeons to see if any symptoms develop.
The technique may also be used to detect soft tissue illness or weakening. It is used to check for testicular enlargement, and it may also reveal inguinal and umbilical hernias when intrathoracic and abdominal pressures rise.
Valsalva Maneuver in Sports
Valsalva techniques are used in sports to stabilise the muscles that surround the pelvis. Squats, deadlifts, bench presses, and push presses are claimed to be more stable with them. Some individuals use it to help them stay balanced during yoga positions. However, if you have an undiscovered cardiac problem, the repercussions might be deadly.
Many how-to videos for the Valsalva technique may be found on YouTube. It is not recommended that you imitate them unless you have received medical clearance. Valsalva manoeuvre forces during a lifting exercise tore his aorta for this weightlifter. The guy died immediately after emergency surgery when doctors discovered pre-existing but undiscovered cardiac issues.
- Foster T, Shen J. (2019). Crash course Cardiology, Fifth Edition. Amsterdam, Elsevier.
- DeTurk W, Cahalin L. (2018). Cardiovascular and Pulmonary Physical Therapy, Third Edition. New York, McGraw Hill Professional.