Elevated Doppler-estimated right ventricular systolic pressure in complete atrioventricular block and its response to atrioventricular-synchronous pacing

Background Complete atrioventricular block causes both bradycardia and loss of atrioventricular synchrony. Case reports have described marked elevations in Doppler-estimated right ventricular systolic pressure that fall after pacing, but the prevalence and consistency of this phenotype have not been examined in a cohort. Methods We retrospectively studied consecutive patients in sinus rhythm with complete atrioventricular block and a left ventricular ejection fraction of at least 50%, identified from 142 permanent pacemaker implantations at one center between 2021 and 2026. Right atrial pressure was estimated using current guideline categories. The prespecified primary endpoint was the paired change in Doppler-estimated right ventricular systolic pressure between the native state and the first study within 72 h of atrioventricular-synchronous pacing. Tricuspid regurgitant signal quality was graded on envelope completeness and analyzed alongside it. Results Thirty patients formed the native cohort and 14 had paired studies. Doppler-estimated right ventricular systolic pressure was 44.0 mmHg (interquartile range 32.4–50.3) during native block and was 35 mmHg or greater in 21 patients. In the paired cohort it fell from 46.6 to 25.0 mmHg in all 14 patients (median relative change −51.4%; P < 0.001), and the proportion with values of 35 mmHg or greater fell from 11 to 3 ( P = 0.008). Both the tricuspid regurgitant gradient and the estimated right atrial pressure decreased, and tricuspid regurgitation grade fell in 7 patients and increased in none. Paced QRS duration increased, and the heart-rate change was not correlated with the change in Doppler-estimated right ventricular systolic pressure. Signal quality tended to decline after pacing; in a post hoc analysis restricted to the 7 patients in whom it was unchanged or improved, the reduction persisted (median relative change −33.8%; P = 0.016). In four catheterized patients, Doppler estimates diverged from invasive pressures in both directions. Conclusion Elevated Doppler-estimated right ventricular systolic pressure was common during complete atrioventricular block and fell consistently after atrioventricular-synchronous pacing. Because signal quality changed concurrently and invasive pressure did not invariably track the estimate, the magnitude of the observed Doppler reduction, and whether pulmonary artery pressure itself falls, remain uncertain.