Compute transvalvular and vascular gradients from measured pressures. Choose Doppler velocity or distance-based gradients instantly. Clear outputs, downloads, and examples help every clinical workflow.
Visualize the pressure gradient curve and your calculated point.
Graphs are educational visual aids and may not reflect complex physiologic conditions.
Sample rows to demonstrate inputs and exported outputs.
| Case | Method | Inputs | ΔP (mmHg) | Distance (cm) | ΔP/cm (mmHg/cm) |
|---|---|---|---|---|---|
| 1 | Doppler | V2 = 3.2 m/s | 40.960 | — | — |
| 2 | Modified Doppler | V2 = 4.0 m/s, V1 = 1.0 m/s | 60.000 | — | — |
| 3 | Catheter | Pup = 120 mmHg, Pdown = 90 mmHg | 30.000 | — | — |
| 4 | Distance-based | P A = 110 mmHg, P B = 95 mmHg | 15.000 | 5 | 3.0000 |
Note: Example values are illustrative only and not patient-specific.
Using ΔP = 4·V², a jet velocity of 2.5 m/s corresponds to about 25 mmHg, 3.0 m/s to about 36 mmHg, and 4.0 m/s to about 64 mmHg. These reference points help communicate peak gradients during echocardiography and support serial comparison when acquisition technique is consistent.
If proximal flow is not negligible, the modified relationship ΔP = 4·(V2² − V1²) can prevent overestimation. For example, V2 = 4.0 m/s with V1 = 1.5 m/s yields about 55 mmHg instead of 64 mmHg. Consider V1 when there is marked acceleration proximal to the obstruction or high-output physiology.
Direct measurement uses ΔP = Pup − Pdown. A 120 and 90 mmHg pair produces 30 mmHg. Differences between instantaneous and peak‑to‑peak reporting, damping, zeroing, and transducer leveling can shift results by several mmHg. Document timing, site, and waveform quality alongside the number.
For long lesions or grafts, ΔP per cm helps compare segments. A 15 mmHg drop over 5 cm equals 3.0 mmHg/cm. Small length errors can meaningfully change the normalized value, so report both absolute ΔP and the assumed distance when the segment length is estimated.
This calculator converts mmHg, kPa, and cmH₂O using standard factors. As a quick audit, 1 kPa ≈ 7.50 mmHg and 10 cmH₂O ≈ 7.36 mmHg. Consistent unit discipline prevents errors when mixing pressure sources from monitors, reports, or research datasets.
Compare gradients only under similar physiologic conditions: resting versus stress, heart rate, afterload, and support devices can change values. Record whether the value is peak or mean, and note image alignment or catheter position. Use the CSV export to track serial values and the PDF export for chart-ready documentation. If a value looks implausible, recheck units, calibration, and measurement location before reporting. In research settings, store paired measurements with the same cardiac cycle label and sampling location. For bedside checks, repeat the measurement and compare the median of three beats, especially with atrial fibrillation. If you export data, include device type and operator initials to support traceability and quality improvement. Small documentation habits reduce errors and improve team communication.
ΔP is the pressure difference between two points, commonly across a valve or along a vessel segment. It supports severity discussions alongside symptoms, imaging, and overall hemodynamics.
The simplified Bernoulli relationship links velocity to pressure drop under common assumptions. The factor 4 scales the equation so velocity in m/s yields pressure in mmHg.
Use V1 when proximal acceleration is not small compared with the jet velocity, such as high‑output states or subvalvular narrowing. Including V1 can reduce overestimation in selected cases.
They can reflect different definitions (instantaneous vs peak‑to‑peak), sites, alignment, pressure recovery, or technical issues like damping and timing. Verify acquisition quality before interpretation.
It normalizes pressure drop by distance to compare lesions or segments of different lengths. It is most useful when length is reliably measured and the segment behaves relatively uniformly.
This tool is for education and structured reporting support. Do not use it as the sole basis for diagnosis or therapy. Integrate patient status, imaging, and expert clinical judgment.
Use the buttons near the result to export your latest calculation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.