Effect of ethnicity and hypertension on atrial conduction: Evaluation withhigh-resolution P-wave signal averaging

Background: Measurements by P-wave signal-averaged electrocardiogram (P-SAE CG) of P-wave duration and P-wave voltage integral are higher in patients w ith atrial fibrillation (AF) than in those with sinus rhythm. Hypertension is perhaps the most common cardiovascular antecedent cause of AF, and parti cularly a disproportionate cause of morbidity and mortality among blacks. T he purpose of this study was to examine the effect of hypertension and ethn icity on P-SAECG parameters in patients without AR Hypothesis: It was hypothesized that P-SAECG parameters can identify hypert ensives, and are disproportionately higher in hypertensive blacks. Methods: In all, 234 normotensives and 84 hypertensives underwent P-SAECG a nalysis. In an ancillary study group of 34 hypertensive black men, the rela tionship between severity of hypertension and measured parameters of P-SAEC G was evaluated. Results: Mean filtered P-wave duration and total P-wave voltage integral fo r 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 m uV-ms; p <0.001) than white hypertensives. Filtered P-wave duration and tot al P-wave voltage integral increased with severity of hypertension. Conclusions: Patients at very early stages of hypertension have demonstrabl e evidence of prolonged atrial conduction by P-SAECG and, thus, cardiac ele ctrical remodeling. P-wave duration and total P-wave voltage integral incre ase with severity of hypertension. Hypertensive blacks manifest a greater i ncrease in P-SAECG parameters than whites. This may portend an increased ca rdiovascular risk for black patients with hypertension.