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Clin. Cardiol. 24, 597–602 (2001)
Ernest C. Madu, M.D., FACC, Dainia S. Baugh, M.D.,* T. David Gbadebo, M.D., M.S., Anwer Dhala, M.D., FACC,† Sergio Cardoso, M.D., Ph.D.,‡ for the Phi-Res Multi-Study Group
Vanderbilt University Medical Center, Division of Cardiovascular Medicine, and *Division of Internal Medicine, Nashville, Tennessee; †The University of Wisconsin, Milwaukee, Wisconsin; ‡The University of Tennessee, Memphis, Tennessee, USA
Summary
Background: Measurements by P-wave signal-averaged electrocardiogram (P-SAECG) of P-wave duration and P-wave voltage integral are higher in patients with atrial fibrillation (AF) than in those with sinus rhythm. Hypertension is perhaps the most common cardiovascular antecedent cause of AF, and particularly a disproportionate cause of morbidity and mortality among blacks. The purpose of this study was to examine the effect of hypertension and ethnicity on P-SAECG parameters in patients without AF.
Hypothesis: It was hypothesized that P-SAECG parameters can identify hypertensives, and are disproportionately higher in hypertensive blacks.
Methods: In all, 234 normotensives and 84 hypertensives underwent P-SAECG analysis. In an ancillary study group of 34 hypertensive black men, the relationship between severity of hypertension and measured parameters of P-SAECG was evaluated.
Results: Mean filtered P-wave duration and total P-wave voltage integral for normotensives of both ethnic groups were similar. Hypertensive blacks had greater increase in P-wave duration (138 ± 16 vs. 132 ± 12 ms; p<0.01, N 42:42) and total P-wave voltage integral (922 ± 285 vs. 764 ± 198 µV-ms; p<0.001) than white hypertensives. Filtered P-wave duration and total P-wave voltage integral increased with severity of hypertension.
Conclusions: Patients at very early stages of hypertension have demonstrable evidence of prolonged atrial conduction by P-SAECG and, thus, cardiac electrical remodeling. P- wave duration and total P-wave voltage integral increase with severity of hypertension. Hypertensive blacks manifest a greater increase in P-SAECG parameters than whites. This may portend an increased cardiovascular risk for black patients with hypertension.
Key words: hypertension, hypertrophy, ethnic, high resolution, atrial conduction, left ventricular hypertrophy
This work was supported in part by a grant from GE-Marquette Medical Systems, Wisconsin
Address for reprints:
Ernest C. Madu, M.D., FACC
Vanderbilt University Medical Center
Division of Cardiovascular Medicine
315 MRB II
2220 Pierce Avenue
Nashville, TN 37232-6300, USA
e-mail: ernest.madu@mcmail.vanderbilt.edu
Received: August 2, 2000
Accepted with revision: December 1, 2000