Pulmonary Hypertension by Bradley A. Maron Roham T. Zamanian & Aaron B. Waxman

Author:Bradley A. Maron, Roham T. Zamanian & Aaron B. Waxman
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

Of note, there a constant of +3 is added if there is notching of the RVOT Doppler envelope (see below). This equation is slightly more accurate than the original approach and is easier to apply in clinical practice [36].

There are several other techniques listed below. While all are reasonable, they require additional calculation and are less useful in a busy clinical practice.

A third method consists of measuring the ratio between sPAP and velocity time integral at the RVOT corrected for heart rate [37]. Compared with the tricuspid regurgitation velocity and the velocity time integral index, this ratio takes into account RAP and heart rate. When evaluated in a population with PHT and high PVR versus invasive measurement of PVR, it was found that a cutoff value of 0.076 had 86 % sensitivity and 82 % specificity in determining indexed PVR > 15 resistance units.

A fourth technique consists of measuring the pre-ejection period (the time between the onset of tricuspid regurgitation and the onset of pulmonary systolic flow), the time interval between the onset of ejection and the time of peak flow velocity, or AcT), and total systolic time (the sum of the pre-ejection period and pulmonary ejection time) [38].

A final method is to estimate each component of PVR (mPAP, PAWP, pulmonary flow) using a set of different validated equations and then calculate PVR. This is appealing, and might be expected to provide more accurate estimates. Given the inaccuracy of TTE PAWP and pulmonary flow estimates, however, the resulting data are disappointing. Because of the labor involved and lack of incremental benefit, this method is of limited clinical relevance.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.