TY - JOUR
T1 - P wave changes during exercise in normal subjects and in patients with hemodynamic evidence of left atrial overload
AU - Ahmad, Masood
AU - Blomqvist, C. Gunnar
N1 - Funding Information:
From the Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research of the Department of Internal Medicine, University of Texas Health Science Center at Dallas, Southwestern Medical School, Dallas, Texas 75235. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. w solely to indicate this fact. Supported by NASA Grant NSG-9026, NIH Program-Project Grant HL 06296, and the Moss Heart Fund. Reprint requests to: C. Gunnar Blomqvist, M.D., Division of Cardiology, H8.122, University of Texas Health Science Center, Southwestern Medical School, 5323 Harry Hines Boulevard, Dallas, Texas 75235.
PY - 1978
Y1 - 1978
N2 - P wave characteristics at rest and during exercise in normal subjects and patients with hemodynamic evidence of left atrial overload were compared. Three groups were studied, including 48 normal subjects, 15 patients with mitral stenosis, and 24 patients with left ventricular dysfunction. Frank lead electrocardiograms were recorded on magnetic tape at rest sitting and during upright bicycle exercise. Digital computer techniques were used to derive P wave area vectors. The initial 3/8 of the P wave were regarded as representing primarily right atrial, and the terminal 5/8 primarily left atrial activity. The P wave response to exercise in normal subjects include a small but significant (p<0.005) increase of the vertical component of the initial or right atrial vector and a significant (p<0.001) increase of the posterior terminal P vector component from 0.5 to 1.1 μV-sec. Analysis of area vectors in the abnormal groups at rest increased the recognition rate of left atrial overload over that obtained with standard 12-lead criteria, from 38 to 82% (P<0.005) at a specificity of 92%. The recognition rate during exercise was 67%, slightly lower than that at rest, due to increased inter-individual variation and exercise-induced changes in the normal group in the direction of the left atrial overload.
AB - P wave characteristics at rest and during exercise in normal subjects and patients with hemodynamic evidence of left atrial overload were compared. Three groups were studied, including 48 normal subjects, 15 patients with mitral stenosis, and 24 patients with left ventricular dysfunction. Frank lead electrocardiograms were recorded on magnetic tape at rest sitting and during upright bicycle exercise. Digital computer techniques were used to derive P wave area vectors. The initial 3/8 of the P wave were regarded as representing primarily right atrial, and the terminal 5/8 primarily left atrial activity. The P wave response to exercise in normal subjects include a small but significant (p<0.005) increase of the vertical component of the initial or right atrial vector and a significant (p<0.001) increase of the posterior terminal P vector component from 0.5 to 1.1 μV-sec. Analysis of area vectors in the abnormal groups at rest increased the recognition rate of left atrial overload over that obtained with standard 12-lead criteria, from 38 to 82% (P<0.005) at a specificity of 92%. The recognition rate during exercise was 67%, slightly lower than that at rest, due to increased inter-individual variation and exercise-induced changes in the normal group in the direction of the left atrial overload.
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U2 - 10.1016/S0022-0736(78)80142-3
DO - 10.1016/S0022-0736(78)80142-3
M3 - Article
C2 - 712286
AN - SCOPUS:0018084319
SN - 0022-0736
VL - 11
SP - 361
EP - 368
JO - Journal of Electrocardiology
JF - Journal of Electrocardiology
IS - 4
ER -