Heart failurePurpose

When differentiating a normal left ventricular inflow velocity waveform from a pseudonormal pattern is difficult, the Valsalva maneuver should be performed to facilitate the diagnosis [10, 11]. The Valsalva maneuver may also be performed to evaluate the reversibility of restrictive filling pattern of the left ventricular inflow [10, 11]. These are performed in phase II of the Valsalva maneuver to determine E-wave reduction via decreased left ventricular filling pressure caused by decreased venous return.

Inage acquisition during the Valsalva maneuver

A left ventricular inflow waveform is observed during the Valsalva maneuver. The sweep speed on pulsed-wave Doppler images should be decreased to ≤ 50 mm/s, and the left ventricular inflow waveform should be recorded for 10 to 12 s in phase II of the maneuver where straining was started (Fig. 3) [11]. An annotation to show the application of the Valsalva maneuver is preferred to be indicated in the recorded image.

Fig. 3

Change in left ventricular inflow velocity waveform during the Valsalva maneuver. Owing to the Valsalva maneuver, the E wave decreased and the A wave increased, with an E/A ratio of < 1. The left ventricular inflow velocity waveform was classified as pseudonormal pattern from these findings

Evaluation items

Changes in the E/A ratio and A-wave peak velocity owing to the Valsalva maneuver.

Interpretation of the test

The pseudonormal filling pattern is diagnosed by assessing positivity when the E/A ratio becomes < 1 or the A-wave peak velocity increases during the Valsalva maneuver [11]. In the normal filling pattern, both E and A waves show decreased velocities during the maneuver [10, 12]. In the case of a restrictive filling pattern, if the E/A ratio becomes < 1 during the Valsalva maneuver, it is considered reversible, and if it remains restrictive, it is assessed as an irreversible restrictive pattern [10].

Impact on treatment

If a pseudonormal or irreversible restrictive filling pattern is determined by the Valsalva maneuver, increased left ventricular filling pressure is suspected. The attending physician will evaluate the results and prevent the exacerbation of heart failure by optimizing volume status.

HOCM, left ventricular outflow tract obstructionPurpose

In patients with hypertrophic cardiomyopathy or sigmoid interventricular septum, the Valsalva maneuver is performed to induce left ventricular outflow tract obstruction when (1) the patient complains shortness of breath, but no significant left ventricular outflow tract obstruction or (2) systolic anterior motion (SAM) of the mitral valve is observed whereas no significant pressure gradient is detected in the left ventricular outflow tract [13]. Since left ventricular outflow tract obstruction is enhanced by reduced preload, [14] the decrease in venous return in phase II of the Valsalva maneuver induces or further enhance the obstruction.

Image acquisition during the Valsalva maneuver

First, the left ventricular outflow tract is monitored in the apical long-axis view or apical five-chamber view during the Valsalva maneuver. Changes in SAM on two-dimensional images and mosaic blood flow in the left ventricular outflow tract and mitral regurgitation associated with SAM on color Doppler images are also observed. Continuous-wave Doppler images of the left ventricular outflow tract are then recorded during the same maneuver. In patients with concomitant mitral regurgitation due to SAM, continuous wave Doppler imaging at the site of left ventricular outflow tract obstruction should be securely recorded to avoid mitral regurgitation [15]. If it is difficult to distinguish whether the blood flow velocity is that of the left ventricular outflow tract or of mitral regurgitation, continuous wave Doppler images should be recorded after ensuring that the beam is directed to the left ventricular ejection flow on color Doppler images during the Valsalva maneuver. Continuous wave Doppler waveforms of mitral regurgitation are faster and longer in duration than left ventricular outflow tract obstruction and are characterized by a peak at mid-systole, which is used for differentiating between mitral regurgitation and left ventricular outflow tract obstruction [15]. In addition, when mitral regurgitation is directed posteriorly, the left ventricular ejection flow moving toward the probe can be separated from the continuous wave Doppler waveform of mitral regurgitation that is moving away, as observed from the parasternal long-axis view.

Evaluation items

The presence or absence of SAM appearance or enhancement during the Valsalva maneuver, appearance of mosaic blood flow in the left ventricular outflow tract, and the maximum pressure gradient of the left ventricular ejection flow (Fig. 4).

Fig. 4

Valsalva maneuver for latent left ventricular outflow tract obstruction. Apical long-axis color Doppler image (top) and a continuous-wave Doppler image of the left ventricular outflow tract (bottom). The Valsalva maneuver causes mitral regurgitation associated with the systolic anterior motion of the mitral valve, increasing the mosaic flow in the left ventricular outflow tract. Continuous-wave Doppler imaging, which avoids mitral regurgitation, showed a pressure gradient of 112 mmHg, indicating outflow tract obstruction

Interpretation of the test

A peak left ventricular outflow tract pressure gradient ≥ 30 mmHg during Valsalva maneuver is considered positive and indicates latent left ventricular outflow tract obstruction [13, 14]. A left ventricular outflow tract pressure gradient of 50 mmHg is generally used as the threshold for therapeutic intervention in patients with HOCM [13, 14].

Description of test results

If the result was positive, the examiner reports that a significant left ventricular outflow gradient was induced using the Valsalva maneuver. If it was negative, it is reported that an outflow obstruction was not induced while induction was performed. Since multiple factors are associated with the enhancement of left ventricular outflow tract obstruction, some outflow tract obstructions are not induced by the Valsalva maneuver. Therefore, in patients in whom left ventricular outflow tract obstruction is strongly suspected clinically but significant outflow tract obstruction is not induced, other stress methods such as exercise stress, standing stress, and sitting stress should be considered.

Patent foramen ovale (PFO)Purpose

Echocardiography during the Valsalva maneuver with saline contrast should be performed in patients with embolic stroke of undetermined source with suspected paradoxical embolism involving PFO to induce a right-to-left shunt via PFO [16,17,18]. A right-to-left atrial shunt is induced by transiently increasing the right atrial pressure through increased venous return during phase III of the Valsalva maneuver.

Image acquisition during the Valsalva maneuver

The contrast agent is prepared by mixing 1 mL of air and 8–9 mL of normal saline [16, 19]. The method of mixing 1 mL of blood aspirated from a patient, 1 mL of air, and 8 mL of normal saline reportedly produces better contrast effects than the method using air alone [20] and has been widely used. If blood aspiration is technically impossible, one drop of diazepam may be added instead of blood. However, this is an off-label use. Although no such cases have been reported to date, there is concern that the use of blood may be associated with embolism due to the formation of small thrombi. However, to prevent air contamination due to insufficient agitation, using > 1 mL of air should be avoided, and care should be taken to avoid injecting coagulated blood outside the body for prolonged periods.

A cut plane that allows simultaneous visualization of all four cardiac chambers, such as apical four-chamber or parasternal four-chamber view, should be obtained, and the patient should then be instructed to perform a forceful straining maneuver [21]. At that time, an imaging plane should be selected in which the right ventricle is placed as little as possible in front of the left ventricle, so as to minimize artifacts caused by bubbles. The strength of stress can be maintained if it is applied while compressing the abdomen. Therefore, abdominal compression should be performed as concomitantly as possible. Agitated saline is rapidly administered intravenously at the onset of straining and release of straining when the entire right heart is imaged, and the appearance or absence of contrast in the left heart system is assessed.

Evaluation items

A positive result is defined as contrast appearing in the left heart within 3 heartbeats after release of the Valsalva maneuver, with grading of severity.

Interpretation of the test

Images are considered negative when no contrast is observed in the left heart. When contrast appears in the left heart, it is classified into four grades according to the degree, although the cutoff value varies among reports [16,17,18]. The cutoff values described in the guidelines of the Japan Stroke Society are introduced in this guidance (Fig. 5).

Fig. 5

Grading of the right to left shunt in microbubble test. LV, left ventricle; RV, right ventricle

Description of results

The presence or absence of contrast in the left heart system and its degree is described in the report. If the patient has an intrapulmonary shunt, contrast appears in the left heart without Valsalva maneuver a few seconds after the appearance of contrast in the right heart. Therefore, the results of the observations during normal respiration might also be described.

All authors are members of the Echocardiogram Guideline Committee of the Japanese Society of Echocardiography in 2026.