A syringe-targeted, goal-driven valsalva enhances mitral E-wave suppression in a randomized crossover TTE study

Background

Manometer-guided targeted Valsalva (>40 mmHg for 10 s with feedback) increases setup complexity and consumable use. We tested a simplified, goal-driven instruction using a 10-mL syringe plunger as a motivational target (maximal effort encouraged; plunger motion not required).

Methods

In this randomized, within-subject crossover study, 51 patients undergoing transthoracic echocardiography performed two maneuvers in randomized order: (1) conventional manometer-guided targeted Valsalva with real-time pressure feedback and (2) simplified syringe-targeted Valsalva (patients were instructed to “blow as if to push the 10-mL syringe plunger,” while expiratory pressure was recorded simultaneously via a three-way stopcock). Continuous acquisition included transmitral Doppler inflow (E and A waves), ECG, and pressure curves. The primary endpoint was maximal percent reduction in mitral E-wave velocity during strain (Edrop), defined as the maximal E-wave decrease during strain relative to the maximal baseline E-wave. Secondary endpoints were pressure-curve metrics (peak pressure, pressure–time AUC, mean effective pressure, time to peak). In a contrast subset (n=31), complete venous return interruption was assessed by agitated-saline injection after initiation of exhalation and defined as no right atrial/ventricular opacification during the strain phase.

Results

Baseline E-wave velocity prior to the second maneuver was higher than prior to the first (92.77±22.64 vs 89.81±22.32 cm/s; p=0.001). Exploratory period-specific analysis suggested a larger advantage in Period 2 (simplified–conventional difference 8.59 percentage points, p=0.0016). Within-method comparisons showed an Edrop increase from Period 1 to Period 2 for the simplified maneuver (Period 2–Period 1 6.49 percentage points, p=0.0165) but not for the conventional maneuver (p=0.591).

For pressure metrics, the simplified maneuver generated higher peak pressure (58.1 vs 52.5 mmHg; p=0.00013), greater pressure AUC (497.8 vs 442.1 mmHg·s; p=0.0078), and higher mean effective pressure (41.2 vs 36.1 mmHg; p=0.00014), with similar time to peak pressure (3.31 vs 3.19 s; p=0.58). In the contrast subset, complete venous return interruption occurred in 15/31 (48.39%) with the simplified maneuver versus 11/31 (35.48%) with the conventional maneuver (absolute difference 12.91 percentage points). Consumable cost per test was 0.39 RMB (10-mL syringe) for the simplified method versus 2.20 RMB (suction catheter) for the conventional method (−1.81 RMB, ~82.3% lower).

Conclusions

A syringe-targeted, goal-driven Valsalva yields larger mitral E-wave suppression, stronger pressure profiles, higher complete interruption rate, and markedly lower cost, supporting a practical strategy to standardize Valsalva provocation in routine echocardiography.