G Barletta1, R Del Bene, F Fantini. 1. Department of Cardiology, Careggi Hospital, University of Florence, Italy. g.barletta@dfc.unifi.it
Abstract
OBJECTIVE: To study the sequence of atrial activation and the interatrial electromechanical delay (IEmD) noninvasively in healthy subjects during sinus rhythm (SR). METHODS AND RESULTS: In 66 SR healthy subjects P-wave activation was analyzed by means of vectorcardiography. The timing of atrial contractions was measured as the intervals between the P-wave and the A-wave of the Doppler right and left ventricular inflows (P-A(t) and P-A(m)), and IEmD was calculated as the algebraic difference P-A(m)- P-A(t). In the horizontal plane the vectorcardiographic P-loop was anteroposterior ("typical", 41 subjects), anterior (18), or posterior (7). IEmD (mean +/- SE 17 +/- 8 ms) was directly related to R-R and P-R intervals. IEmD was significantly shorter in anterior and posterior P loops than in the typical (6.5 +/- 5.3 and 8.1 +/- 10.1, respectively, vs 24.2 +/- 3.1 ms). In the posterior P-loop group, who exhibited longer P-A(t), mitral E-wave velocity and E/A ratio were reduced, and left atrial booster function was increased. CONCLUSION: IEmD was widely variable in SR, reflecting the origin site of sinus impulse, which independently influenced ventricular filling dynamics.
OBJECTIVE: To study the sequence of atrial activation and the interatrial electromechanical delay (IEmD) noninvasively in healthy subjects during sinus rhythm (SR). METHODS AND RESULTS: In 66 SR healthy subjects P-wave activation was analyzed by means of vectorcardiography. The timing of atrial contractions was measured as the intervals between the P-wave and the A-wave of the Doppler right and left ventricular inflows (P-A(t) and P-A(m)), and IEmD was calculated as the algebraic difference P-A(m)- P-A(t). In the horizontal plane the vectorcardiographic P-loop was anteroposterior ("typical", 41 subjects), anterior (18), or posterior (7). IEmD (mean +/- SE 17 +/- 8 ms) was directly related to R-R and P-R intervals. IEmD was significantly shorter in anterior and posterior P loops than in the typical (6.5 +/- 5.3 and 8.1 +/- 10.1, respectively, vs 24.2 +/- 3.1 ms). In the posterior P-loop group, who exhibited longer P-A(t), mitral E-wave velocity and E/A ratio were reduced, and left atrial booster function was increased. CONCLUSION: IEmD was widely variable in SR, reflecting the origin site of sinus impulse, which independently influenced ventricular filling dynamics.
Authors: D W Sohn; I H Chai; D J Lee; H C Kim; H S Kim; B H Oh; M M Lee; Y B Park; Y S Choi; J D Seo; Y W Lee Journal: J Am Coll Cardiol Date: 1997-08 Impact factor: 24.094