Continuing Education Activity

The Valsalva maneuver involves forceful exhalation against a closed glottis, initially developed to expel fluids and foreign bodies from the middle ear, but has evolved into a critical clinical tool across multiple domains, particularly in cardiology and neurology. The maneuver produces significant hemodynamic changes, primarily increased intrathoracic pressure, reducing preload to the heart. Cardiovascular changes occur during and after this maneuver due to baroreflex and other compensatory reflex mechanisms initiated by decreased preload. Therefore, the Valsalva maneuver can be utilized to assess autonomic function, evaluate heart failure, terminate supraventricular tachycardia, and differentiate cardiac murmurs.

This course explores the physiologic effects of this maneuver, the 4 recognized phases, and its interpretation. The Valsalva maneuver also has technique variants extending its clinical applications in diagnostics, surgical procedures, and labor management. This activity for healthcare professionals is designed to enhance the learner's competence in the optimal performance of the Valsalva maneuver or its variants, its indications and contraindications, diagnostic interpretation, clinical significance, and implementation of an appropriate interprofessional approach when employing this procedure. 

Objectives:

• Interpret physiologic compensatory reflex mechanisms noted after a patient performs the Valsalva maneuver.

• Determine how to perform the Valsalva maneuver optimally.

• Assess the clinical significance of the Valsalva maneuver.

• Apply interprofessional team strategies to improve care coordination and outcomes in patients with autonomic dysfunctions identified by the Valsalva maneuver.

Introduction

The Valsalva maneuver involves forceful exhalation against a closed glottis, producing significant hemodynamic changes that are divided into 4 phases. Individuals frequently perform the Valsalva maneuver during many daily activities, including straining during defecation, lifting heavy weights, or playing the saxophone. The Valsalva maneuver is now utilized to assess autonomic function, evaluate heart failure, terminate supraventricular tachycardia, and differentiate cardiac murmurs.

Variants like the modified Valsalva maneuver (used for supraventricular tachycardia) and reverse Valsalva maneuver (to increase vagal tone) extend its clinical applications. The procedure is also used in diagnostics (eg, heart murmurs, varicocele, liver hemangiomas), surgical procedures (eg, neurosurgery and TEVAR), and labor management. Though generally safe, the Valsalva maneuver should be used cautiously in patients with conditions like coronary artery disease or retinopathy, as it can occasionally induce syncope, arrhythmias, or Valsalva retinopathy. Optimal testing conditions include performing VM at 40 mm Hg for 15 seconds, with patient positioning (eg, supine, sitting, or recumbent) adjusted based on context.

History of the Valsalva Maneuver

Valsalva maneuver was first described in 1704 by Antonio Maria Valsalva, an Italian physician, in his work De Aure Humana Tractatus.[1][2] Antonio Valsalva originally described using this maneuver to effectively drain purulent fluids from the middle ear cavities through perforations and expulsion of foreign bodies from the ear. In 1850, Eduard Friedrich and Ernst Heinrich Weber reported a Valsalva-induced blackout. While performing a Valsalva maneuver on himself, Weber experienced bradycardia and loss of consciousness.

Later, in 1950, Edward Peter Sharpey-Schafer described the cardiovascular effects of the Valsalva maneuver, including a rise in intrathoracic pressure, a decrease in heart-filling pressures, and a decreased stroke volume. His studies of continuous blood pressure showed a drop in blood pressure when the intrathoracic pressure was raised, which was followed by a rise in the diastolic pressure. Sharpey-Schafer described this phenomenon as a baroreceptor response to decreased pulse pressure.[3] Since then, this maneuver has been used in multiple clinical domains, from evaluating autonomic dysfunction to treating arrhythmias and as a marker for heart failure.[3][4][5]

Anatomy and Physiology

The Valsalva maneuver is divided into the following 4 phases based on the characteristic hemodynamic changes:

• Phase I: This phase corresponds to the onset of strain and is associated with a transient rise in blood pressure because some blood empties from the large veins and pulmonary circulation into the aorta due to increasing intrathoracic pressure.

• Phase II: Phase II is divided into early (PII_E) and late (PII_L) phases. Phase PII_E starts when positive intrathoracic pressure reduces venous return to the heart. Because of reduced venous return and thus reduced preload, stroke volume falls; this leads to a fall in blood pressure.[6] This fall in blood pressure activates the baroreceptors in the carotid sinus and aortic arch, marking the beginning of Phase PII_L. The vagal withdrawal, followed by increased sympathetic discharge, ensues, leading to marked tachycardia, increased cardiac output, and vasoconstriction, which leads to the recovery of blood pressure to normal values in healthy individuals.

• Phase III: The transient phase involving the release of strain, which leads to a sudden dip in blood pressure. The release of positive pressure expands the pulmonary vascular bed and reduces the left ventricular cross-sectional area, resulting in a transient fall in blood pressure.[7] This can lead to symptomatic hypotension in patients with autonomic dysfunction.

• Phase IV: This phase is the overshoot of blood pressure above the baseline, which is caused by the resumption of normal venous return to the heart stimulated by the sympathetic nervous system during Phase II. The overshoot of blood pressure stimulates the baroreflex, leading to bradycardia and the return of blood pressure to the baseline.[4][6]

Indications

The Valsalva maneuver is indicated to assess autonomic function as a marker for heart failure, terminate arrhythmias, differentiate murmurs, and be used intraoperatively for different surgeries and other indications.

Contraindications

The Valsalva maneuver is relatively safe and can be performed on all patients. Adverse effects reported are rare. However, since intraocular and intra-abdominal pressure rises, the test must be avoided in patients with retinopathy and intraocular lens implantation. Valsalva retinopathy may result in susceptible patients.[8][9] Also, syncope, chest pain, and arrhythmias have been reported due to the performance of the Valsalva maneuver. Therefore, caution is necessary for patients with preexisting coronary artery disease, valvular disease, or congenital heart disease.[1][10] 

Valsalva maneuver has to be performed with caution in patients with coronary artery disease after having all the emergency equipment available as periods of reduced left ventricular stroke volume during phase PII_E, in addition to the already inefficient autonomic regulation seen in this patient population may contribute to periods of asystole or very rarely sudden cardiac death.[11]

Equipment

This maneuver can be modified in the cardiovascular laboratory or at the bedside using a disposable syringe/mouthpiece connected to a manometer. A small leak is created in the syringe/mouthpiece to ensure sustained effort throughout forced exhalation.[12] Adequacy of the expiratory effort can be gauged by subjective signs, eg, visible strain, flushing, and engorgement of the neck veins.[1] Simultaneous electrocardiogram (ECG) signal acquisition can help us assess autonomic indices, eg, the Valsalva ratio. Measurement of continuous beat-to-beat blood pressure can help in testing baroreflex sensitivity.

Technique or Treatment

Standard Valsalva Maneuver

The patient can perform the maneuver in the sitting, supine, or recumbent position. Some reports advocate a recumbent position, while others report an increased incidence of abnormal blood pressure responses in the supine position.[12][13] While different combinations of pressure and duration have been tried, an optimal combination for autonomic function assessment is 40 mm Hg for 15 seconds. Lower pressures may not be sufficient to elicit the necessary autonomic response, while higher pressures have poor reproducibility, making them less ideal for standardized testing.[12] Valsalva maneuver can be performed using a standard manometer by asking the patient to blow into a tube connected to the manometer while the clinician monitors the pressure.

Modified Valsalva Maneuver

To increase the relaxation phase venous return and vagal stimulation, a modification to the standard Valsalva maneuver has been described in the REVERT trial, which includes supine positioning with leg elevation immediately after the Valsalva strain. The modified Valsalva maneuver is used for the emergency treatment of supraventricular tachycardia.[14] Use of the modified Valsalva maneuver in postoperative management of chronic subdural hematoma is safe and results in reduced rates of recurrence and infection after a burr hole drainage.[15]

Reverse Valsalva Maneuver

The reverse Valsalva maneuver is performed while the patient is sitting. The patient is asked to inhale against resistance for 10 seconds while keeping the nose pinched and the mouth closed tightly. This increases vagal tone and decreases sympathetic activity, leading to bradycardia and arterial hypotension (the Bezold–Jarisch reflex). If effective, a reverse Valsalva maneuver will cause the resolution of supraventricular tachycardia in the next 15 seconds.[16]

Clinical Significance

Autonomic Function Assessment

The Valsalva maneuver is integral to the Ewing battery of tests to evaluate cardiac autonomic neuropathy.[9] This maneuver is a simple, noninvasive bedside test for evaluating autonomic function. Valsalva ratio, the ratio of the longest inter-beat (RR) interval after the expiratory strain and the shortest inter-beat interval during the strain, is an index of parasympathetic function. Also, determination of baroreflex sensitivity (BRS) can be performed using the Valsalva maneuver to assess the integrity of the baroreflex by estimating the slope of a regression plot between RR intervals and systolic blood pressure values during phases II and IV of the maneuver.[12][13]

Assessment of Heart Failure

The Valsalva maneuver is useful in evaluating heart failure. Patients with heart failure show an abnormal blood pressure overshoot in response to the Valsalva maneuver due to impaired ventricular function.[17][18] Baroreflex-related measures like the Valsalva ratio and non-baroreflex-related measures like systolic blood pressure rise in phase IV [ΔSBP_{PHASE_IV}], and pulse amplitude ratio [PAR] are utilized to assess heart failure. Pulse amplitude ratio [PAR] correlates with invasively measured pulmonary capillary wedge pressure in the assessment of heart failure.[19]

Termination of Arrhythmias

The Valsalva maneuver is also useful for terminating paroxysmal supraventricular tachycardia (PSVT) with variable success. Increased vagal activity, leading to increased refractoriness of atrioventricular (AV) nodal tissue, interrupting re-entry, has been proposed as the mechanism for the termination of PSVT.[20] In the management of SVT, applying the modified Valsalva maneuver compared to the standard Valsalva maneuver resulted in a higher conversion rate to sinus rhythm and reduced use of anti-arrhythmic measures and drugs.[21] Some commercially available low-cost Valsalva assist devices have been developed with package instructions on performing modified Valsalva maneuvers (mVM) to aid in the emergency treatment of SVT.[22]

Diagnosis of Murmurs

The Valsalva maneuver may be used to differentiate between different murmurs. Since the maneuver reduces preload and, thus, end-diastolic volume, it can help accentuate some murmurs while diminishing others. The murmur of aortic stenosis is reduced in intensity on the administration of the Valsalva maneuver because reduced end-diastolic volume (EDV) decreases the blood available for ejection through the stenosed aortic orifice.[23] Contrary to aortic stenosis, the murmur of hypertrophic obstructive cardiomyopathy (HOCM) accentuates in response to the Valsalva maneuver because reduced EDV during the Valsalva maneuver worsens the obstruction in hypertrophic obstructive cardiomyopathy.[23][24][25] Valsalva maneuver is also employed in echocardiography as a provocative test for HOCM, especially in patients without significant LVOT obstruction at baseline. Valsalva maneuver decreases venous return and preload secondary to increased intrathoracic pressure, thereby increasing LVOT obstruction.[26]

Additional Applications for the Valsalva Maneuver

The Valsalva maneuver may also be employed in other diagnostic assessments, including detection of bleeding points towards the end of thyroid surgery and for the diagnosis of varicocele assisting in the radiological diagnosis of liver hemangiomas, venous disease, and foramen ovale, and in neurosurgery to detect dural tears following spinal surgery or to confirm venous hemostasis following a craniotomy or transsphenoidal approach surgery.[27][17][20][28] 

Additionally, Valsalva-CT is more specific and accurate in diagnosing inguinal hernias that are equivocal on clinical exams alone.[29] The Valsalva maneuver may also be used to reduce venipuncture pain in pregnant women.[30] When employed during labor and delivery, the Valsalva maneuver increased the anteroposterior diameter of the elevator hiatus compared to rest, decreased the duration of the active second stage of labor, and lowered the incidence of operative delivery.[31]

Munich Valsalva implantation technique (MuVIT), a modified Valsalva maneuver, is employed in Thoracic endovascular aortic repair (TEVAR). This procedure is performed by closing the adjustable pressure-limiting valve to 25 mm Hg during mechanical ventilation, causing the lungs to bloat. The increased intrathoracic pressure reduces backflow and cardiac output, decreasing arterial blood pressure. The stent is safely deployed once the desired pressure is achieved.[32]

Enhancing Healthcare Team Outcomes

To optimize patient-centered care through the use of the Valsalva maneuver, healthcare professionals must collaborate effectively, applying a shared strategy rooted in safety, precision, and interdisciplinary communication. Physicians, particularly neurologists and cardiologists, play a central role in evaluating the diagnostic utility of the maneuver for autonomic dysfunction, heart failure, and arrhythmias. Neurologists can interpret the Valsalva ratio and baroreflex sensitivity to assess autonomic integrity, while cardiologists may use the maneuver to differentiate murmurs, assess cardiac performance, or facilitate procedures like stent deployment in TEVAR. Advanced practitioners and nurses are responsible for proper patient positioning, instruction, and monitoring during the maneuver, ensuring consistent technique and patient comfort. Pharmacists contribute by evaluating medication regimens that could impact autonomic or cardiac responses, helping mitigate risk during testing.

Effective interprofessional communication and care coordination are essential, particularly when preexisting conditions such as retinopathy or ischemic heart disease are present. Prior consultation with ophthalmologists and cardiologists ensures that the maneuver is performed safely. Nurses and advanced practice practitioners should be vigilant for signs of intolerance, eg, syncope or arrhythmias, and be prepared to escalate care if needed. Close teamwork between specialists and frontline clinicians promotes a comprehensive approach, enhancing patient safety and outcomes. By fostering mutual respect, clarity in roles, and shared clinical goals, healthcare teams can fully leverage the diagnostic and therapeutic potential of the Valsalva maneuver while minimizing risk.