Superiority of 10% air-10% blood-saline mixture for measuring the velocity of tricuspid regurgitation in patients with severe emphysema.

Background: Severe emphysema frequently is associated with elevated pulmonary artery systolic pressure. However, it is often difficult to obtain adequate tricuspid regurgitation (TR) signals for measurement of pulmonary artery systolic pressure in patients with severe emphysema.

Purpose: This study was conducted to evaluate the usefulness of air-blood-saline mixture in measuring TR velocity in severe emphysema.

Methods: We studied 82 patients with severe emphysema (67.7 +/- 9.2 years, 57 males) who had no or mild TR on color Doppler. Contrast echocardiography studies were performed with agitated 10% air-90% saline and 10% air-10% blood-80% saline mixtures. Tracing quality and peak velocity were assessed on baseline continuous wave signals and contrast continuous wave signals with the 2 mixtures.

Results: With the injection of an air-saline mixture, the quality of TR tracing improved in 45 patients (P <.0001) and a higher peak TR velocity was obtained (2.46 +/- 0.37 m/s vs 2.95 +/- 0.40 m/s, P <.0001) compared with baseline echocardiography. Compared with air-saline mixture, the air-blood-saline mixture further enhanced TR tracing quality in 17 patients (P <.0001) and the peak TR velocity increased to 3.13 +/- 0.42 m/s (P <.0001).

Conclusions: In patients with severe emphysema, an air-blood-saline mixture improves the quantifiable TR signals for more accurate estimation of pulmonary artery systolic pressure, even when there is minimal valve TR.