RT Journal Article
SR Electronic
T1 58 Speeding up beta-blockade prior to cardiac computed tomography: can we predict the dose of intravenous metoprolol required to achieve target heart rate?
JF Heart
JO Heart
FD BMJ Publishing Group Ltd and British Cardiovascular Society
SP A52
OP A53
DO 10.1136/heartjnl-2018-BCS.58
VO 104
IS Suppl 6
A1 Vitaliy Androshchuk
A1 Nikant Sabharwal
A1 Victoria St Noble
A1 Andrew Kelion
YR 2018
UL http://heart.bmj.com/content/104/Suppl_6/A52.abstract
AB Introduction For most scanners, a low heart rate (HR) is required for optimal image quality with cardiac computed tomography (CCT). Intravenous (IV) metoprolol is commonly given prior to scanning to achieve HR <60 beats per minute (bpm). Local and published protocols often call for small doses to be given incrementally, which can be time-consuming. The ability to predict the minimum dose likely to be required in a given patient would speed up the process and potentially create additional scanner time.Methods Patients undergoing CCT at a tertiary centre Jul 16-Aug 17, with baseline HR 60 bpm requiring IV metoprolol, were retrospectively identified from the Radiology database. Patients with a contraindication to beta-blockade or an indication for CCT other than coronary disease were excluded. HR at baseline and at the time of scanning were recorded, together with the total dose of IV metoprolol administered.Results Of 234 patients identified, 109 (47%) achieved HR <60 with IV metoprolol. Patients who achieved target HR had lower baseline HR. They received a lower radiation exposure due to tight prospective gating and a lower tube voltage (Table 1). Table 2 shows the doses of metoprolol administered, stratified by baseline HR. There were no cases of symptomatic bradycardia/hypotension in the study population.Conclusions Patients with baseline HR 80 could reasonably be given 10–15 mg of metoprolol IV stat, with additional doses as required. Patients with baseline HR 100 could be given 20 mg.View this table:Abstract 58 Table 1 Demographic parameterView this table: Abstract 58 Table 2 Metoprolol dose administered (Median, IQR, min dose max dose).