Metoprolol Protocol

Protocol:  Beta-Blocker Use for Cardiac CTA (CCTA) – Metropolol


Purpose:  To decrease patient's heart rate and reduce r-r interval variability for improved image quality of coronary artery CTA. 
 

Goal:  Achieve a heart rate of 50-60 beats per minute.


Contraindications

·         2nd degree or greater A-V block, sick sinus syndrome

·         Decompensated Congestive heart failure (CHF)

·         Asthma or COPD with severe bronchospasm

·         Severe aortic stenosis

·         Prior allergic or severe adverse reaction to beta-blockers

 

Relative contraindications:

·         1st degree AV block with PR interval >/= 0.24sec

·         Systolic blood pressure less than 100 mm Hg

·         Heart rate less than 60 bpm

·         Left ventricular systolic dysfunction


I.          Oral Metropolol Administration
1. Obtain baseline resting heart rate and blood pressure.  For all patients consider anxiety level, BMI, clinical and medical history in selecting doses and consult with physician if there are questions/concerns.


             If HR is 60-64 bpm give metropolol 50 mg orally.

 

             If HR is 65-69 bpm give metropolol 75 mg orally.

             If HR is 70-79 bpm give metropolol 100 mg orally.

 

 If HR is 80-90 bpm give metropolol 100 mg orally and contact MD.

 

            If HR<60 or >90 bpm contact MD.

 

2. Check and document heart rate and blood pressure every 15 minutes x 1 hour after oral metoprolol is given.

II.        Intravenous Metroprolol

If heart rate > 60 bpm and blood pressure is >100 systolic 60 minutes after oral Metropolol then:

 

1. Give intravenous Metoprolol 5mg IV slowly over two minutes.

2. Monitor and record patient's heart rate every one (1) minute and blood pressure every 3 minutes x 6 minutes

 

3.  Wait 3 minutes in between each dose.


4. Continue to administer Metropolol 5mg IV every one (1) minute until heart rate <60 or cumulative IV dose equals 15mg or blood pressure is <100 systolic.