Abstract

Objective—To investigate the effects of heart rate on the Doppler measurements of left ventricular function and to determine the normal pattern of rate dependency.

Setting—University hospital specialising in internal medicine.

Participants—14 healthy male volunteers 10 of whom were studied.

Intervention: Transoesophageal atrial pacing.

Main outcome measures—At paced rates of 70, 80, and 90 ppm the ratio of early to late peak transmitral flow velocity (E/A) was 1·97 (0·28), 1·49 (0·21), and 0·95 (0·11) respectively; the ratio of early to late time-velocity integrals of transmitral flow (Ei/Ai) was 3·03 (0·51), 2·11 (0·24), and 1·14 (0·30) respectively; and the atrial filling fraction (AFF) was 0·17 (0·03), 0·21, (0·04), and 0·24 (0·04) (mean (SD)).

Results—Heart rate showed a linear correlation with E/A (r² = 0·806), Ei/Ai (r² = 0·838), and AFF (r² = 0·343). Neither the peak aortic flow velocity or the mean aortic flow acceleration showed significant changes during pacing at rates of 70, 80, 90, and 100 ppm.

Conclusions—E/A and Ei/Ai can be expected to decrease by 0·5 and 0·9 for each increase of 10 beats/min in heart rate.

Knowledge of this relation may be useful for the development of algorithms to correct for heart rate when diastolic function is assessed.