Pulmonary Artery

Finally, it should be noted that although PA acceleration time is useful for the evaluation of pulmonary hypertension, this Doppler measurement is affected not only by PA pressure, but also by pulmonary blood flow and pathologic changes in the pulmonary vascular bed. For example, patients with an atrial septal defect who exhibit high PA pressure […]

However, this and other studies relating PA acceleration time to PA pressure have been performed primarily in patients not exhibiting tachycardia. Since it might be expected that increased heart rate would shorten time-based measurements such as acceleration time and ejection time, we evaluated the use of the PA AT/ET ratio as a technique for correcting […]

Table 1 summarizes the data for Doppler PA peak flow velocity, acceleration time, ejection time, AT/ET ratio, and PA pressure in seven pigs at atrially paced heart rates of 100 and 140 beats per minute. Mean PA pressure (14 ±5 mm Hg) remained constant over the entire range of paced heart rates. As shown in […]

Doppler measurements of acceleration time (AT) in the pulmonary artery (PA) or right ventricular outflow tract have been used clinically to estimate PA pressure. We and others have previously shown that in the range of PA AT less than 100 ms, there is a linear inverse relationship between PA AT and (mean) PA pressure. However, […]