TY - JOUR
T1 - Consequences of increasing heart rate on deceleration time, the velocity-time integral, and E/A
AU - Chung, Charles S.
AU - Kovács, Sándor J.
N1 - Funding Information:
This study was supported in part by the Whitaker Foundation; the National Institutes of Health, Bethesda, Maryland (Grants HL54179 and HL04023); the American Heart Association, Dallas, Texas; the Alan A. and Edith L. Wolff Charitable Trust; and the Barnes-Jewish Hospital Foundation.
PY - 2006/1/1
Y1 - 2006/1/1
N2 - The ascendancy of diastolic heart failure to "epidemic" proportions has increased the use of and reliance on Doppler echocardiography as a source for diagnosis and as the preferred method for determining indexes of diastolic function (DF). Current indexes are primarily derived from shape-based features of Doppler E and A waves, such as their amplitudes, slopes, durations, and areas. Load dependence and pathologic correlates of these indexes have been considered, but DF indexes are not routinely corrected for heart rate (HR). To determine the dependence of selected Doppler-derived indexes of DF on HR, transmitral Doppler flow velocities and electrocardiograms were simultaneously recorded during supine bicycle exercise in 21 young, healthy volunteers. Standard E- and A-wave shape-based indexes (acceleration time, deceleration time [DT], peak E, peak A) were measured using triangle approximation. Velocity-time integrals (VTIs) were calculated by trapezoidal and triangular approximations. A-wave peak velocity (A) was measured conventionally, relative to baseline, and also using 2 alternative methods: A*, measured relative to the E@A velocity, and Ac, relative to the E-wave deceleration value at peak A-wave velocity. E/A was calculated conventionally and by using A* and Ac. The results showed that DF indexes derived from individual E waves are essentially HR independent. DT showed a mere 20% decrease for a 100% increase in HR. A triangular approximation for the E-wave VTI and the corrected E/Ac were found to be nearly HR independent. In conclusion, on the basis of the established continuity of cardiac output as a function of increasing HR and the observed data, Doppler-derived indexes of DF (DT, VTIs, E/Ac) can be treated as essentially HR independent only if the VTI and A-wave peak are corrected for HR as described.
AB - The ascendancy of diastolic heart failure to "epidemic" proportions has increased the use of and reliance on Doppler echocardiography as a source for diagnosis and as the preferred method for determining indexes of diastolic function (DF). Current indexes are primarily derived from shape-based features of Doppler E and A waves, such as their amplitudes, slopes, durations, and areas. Load dependence and pathologic correlates of these indexes have been considered, but DF indexes are not routinely corrected for heart rate (HR). To determine the dependence of selected Doppler-derived indexes of DF on HR, transmitral Doppler flow velocities and electrocardiograms were simultaneously recorded during supine bicycle exercise in 21 young, healthy volunteers. Standard E- and A-wave shape-based indexes (acceleration time, deceleration time [DT], peak E, peak A) were measured using triangle approximation. Velocity-time integrals (VTIs) were calculated by trapezoidal and triangular approximations. A-wave peak velocity (A) was measured conventionally, relative to baseline, and also using 2 alternative methods: A*, measured relative to the E@A velocity, and Ac, relative to the E-wave deceleration value at peak A-wave velocity. E/A was calculated conventionally and by using A* and Ac. The results showed that DF indexes derived from individual E waves are essentially HR independent. DT showed a mere 20% decrease for a 100% increase in HR. A triangular approximation for the E-wave VTI and the corrected E/Ac were found to be nearly HR independent. In conclusion, on the basis of the established continuity of cardiac output as a function of increasing HR and the observed data, Doppler-derived indexes of DF (DT, VTIs, E/Ac) can be treated as essentially HR independent only if the VTI and A-wave peak are corrected for HR as described.
UR - http://www.scopus.com/inward/record.url?scp=29244482753&partnerID=8YFLogxK
U2 - 10.1016/j.amjcard.2005.07.116
DO - 10.1016/j.amjcard.2005.07.116
M3 - Article
C2 - 16377298
AN - SCOPUS:29244482753
VL - 97
SP - 130
EP - 136
JO - American Journal of Cardiology
JF - American Journal of Cardiology
SN - 0002-9149
IS - 1
ER -