Objective: To assess the ratio of early (E) to late atrial (A) mitral Doppler peak flow velocity (Doppler E/A ratio) before and after adjustment for age in patients with moderate to severe hypertension, in whom left ventricular diastolic dysfunction is an early finding. Mitral flow patterns can be used to assess diastolic filling characteristics, and the Doppler E/A ratio is the parameter most commonly used, although it is known to be strongly age dependent. There are no established normal values for this ratio.
Design: Retrospective data analysis.
Setting: A 2000-bed tertiary-care teaching hospital.
Patients: We studied 190 patients (99 women and 91 men; ages 55 +/- 13 years) with moderate to severe hypertension.
Interventions: The ratio of early (E) to late atrial (A) mitral Doppler peak flow velocity was measured. As this ratio depends on age, a Z score was calculated to control for this influence. The Z score is the standardized normal deviation of the mean, with a normal value of 0 +/- 2.
Main outcome measures: Sensitivities and specificities for detecting an age-dependent reduction in Doppler E/A score (Z score less than -2) with a non-age-dependent Doppler E/A ratio (less than 1) were calculated.
Results: In 106 of the patients (56%) the Doppler E/A ratio was less than 1.0. Only nine patients (4.7%) had a Z score less than -2. The sensitivity of the Doppler E/A ratio threshold of 1.0 for detecting a Z score less than -2 was 0.89 and the specificity was 0.46. A Z score less than -2 was found only in patients younger than 45 years.
Conclusions: The Doppler E/A ratio was reduced in a large proportion of our patients. However, after correction for age it was decreased in only 4.7% of these patients. The use of a single Doppler E/A ratio threshold value has a weak diagnostic power to detect age-independent changes in mitral flow patterns.