RT Journal Article
SR Electronic
T1 Diastolic-systolic velocity ratio to detect coronary stenoses under physiological resting conditions: a mechanistic study
JF Open Heart
JO Open Heart
FD British Cardiovascular Society
SP e000968
DO 10.1136/openhrt-2018-000968
VO 6
IS 1
A1 Guus A de Waard
A1 Christopher J Broyd
A1 Christopher M Cook
A1 Nina W van der Hoeven
A1 Ricardo Petraco
A1 Sukhjinder S Nijjer
A1 Tim P van de Hoef
A1 Mauro Echavarria-Pinto
A1 Martijn Meuwissen
A1 Sayan Sen
A1 Paul Knaapen
A1 Javier Escaned
A1 Jan J Piek
A1 Niels van Royen
A1 Justin E Davies
YR 2019
UL http://openheart.bmj.com/content/6/1/e000968.abstract
AB Objective Diastolic-systolic velocity ratio (DSVR) is a resting index to assess stenoses in the left anterior descending artery (LAD). DSVR can be measured by echocardiographic or intracoronary Doppler flow velocity. The objective of this cohort study was to elucidate the fundamental rationale underlying the decreased DSVR in coronary stenoses.Methods In cohort 1, simultaneous measurements of intracoronary Doppler flow velocity and pressure were acquired in the LAD of 228 stable patients. Phasic stenosis resistance, microvascular resistance and total vascular resistance (defined as stenosis and microvascular resistance combined) were studied during physiological resting conditions. Stenoses were classified according to severity by strata of 0.10 fractional flow reserve (FFR) units.Results DSVR was decreased in stenoses with lower FFR. Stenosis resistance was equal in systole and diastole for every FFR stratum. Microvascular resistance was consistently higher during systole than diastole. In lower FFR strata, stenosis resistance as a percentage of the total vascular resistance increases both during systole and diastole. The difference between the stenosis resistance as a percentage of total vascular resistance during systole and diastole increases for lower FFR strata, with an accompanying rise in diastolic-systolic resistance ratio. A significant inverse correlation was observed between DSVR and the diastolic-systolic resistance ratio (r=0.91, p<0.001). In cohort 2 (n=23), DSVR was measured both invasively and non-invasively by transthoracic echocardiography, yielding a good correlation (r=0.82, p<0.001).Conclusions The rationale by which DSVR is decreased distal to coronary stenoses is dependent on a comparatively higher influence of the increased stenosis resistance on total vascular resistance during diastole than systole.