Assessing Cardiac function

Question 1

What is MET?

Answer 1

Metabolic Equivalent of Task, a physiological measure expressing the energy cost of the physical task. Reference rate is set by convention at 3.5ml

Question 2

What are the average METs for a day and what is a safe level?

Answer 2

Daily functions = 2
Doing tasks/walking = 4
Safe level = 10

Question 3

How can you determine a patients MET?

Answer 3

Ask them what the max amount of physical exercise they can do

Question 4

How can you test for ischemia?

Answer 4

use a treadmill to work out their fitness, increase the slope to get to 5 MET. Can be used before surgery to assess their level of care afterwards

Question 5

What can ECG traces be used for?

Answer 5

Can compare exercise and recovery periods to see that the issue is, Inverted T wave can show ischemia

Question 6

What makes a test more likely to be a FP?

Answer 6

if it is unlikely the patient has the disease in the first place. therefore should only be done in high risk grous

Question 7

What does infusion of dobutimine (B agonist for b1) do?

Answer 7

Raises blood pressure
Increases cardiac contractility
Increases demand of heart muscle for blood supply
Induces ischemia, where flow is inadequate to meet needs

Question 8

What does infusion of vasodilator do?

Answer 8

Relative ischemia: where vasodilation not possible because of fixes stenosis >75% lumen area

Question 9

How can exercise make a patient become systematic?

Answer 9

1. exercise causes stress
2. manifests as reduced blood supply to the heart
3. heart stops contracting well
4. change inrelaxation pattern
5. change next in systolic function
6. may then globally stop contracting
7. ECG begins to change
8. patient becomes systematic

Question 10

What is the myocardial perfusion scan?

Answer 10

Useful in patients with intermediate probability of coronary disease, if mobility limits treadmill use or if resting ECG is abnormal.
Thallium is taken up by myocardium in proportion to blood
Detected by gamma camera
Images under stress or at rest

Question 11

What is a disadvantages to the gamma camera?

Answer 11

You have to be lying down, therefore can’t be on a treadmill

Question 12

What can echocardiology show?

Answer 12

Chamber size, muscle contractility, valve function

Question 13

What is Focus Assessed Transthoracic Echo (FATE)?

Answer 13

Ultrasound test that creates a fan line band of echo impulses which shines between the ribs and slices the heart at real time.
Difficult in fat people

Question 14

What can doppler visualise?

Answer 14

Blood flow

Question 15

What does a stress echo cardiology show?

Answer 15

Significant narrowing of the arteries which stops the heart contracting. When stimulated the heart contracts quicker, if you have a coronary artery stenosis it would not be able to contract quicker

Question 16

When is a Transesophageal echocardiology (TOE/TEE) used and what has to be done?

Answer 16

• Anesthetic has to be put on the back of the throat to stop retching, and a mouth guard to stop from biting down on the tube.
• Used when TTE view is poor, when a clear view of the valves, inter-atrial septum and atrial appendages is needed

Question 17

What is a CT and what is it good for?

Answer 17

Radiation- adds to risk of cancer in the future. But it is great for getting a clear view of the heart and vessels. Can do 3D reconstructions.

Question 18

What can a CT coronary angioplasty be used for?

Answer 18

Look at level of calcification and estimate the level of blood supply. can visualise stens and bypasses

Question 19

What is a cardiac MRI and why is it good?

Answer 19

Excellent for structure and muscle fucntion. Great detailed muscle structure. No radiation so is repeatable.

Question 20

What is the process for a CMRI?

Answer 20

Lie in a tunnel in the dark and a loud banging sound is the magnet going back and forth. Image made showing blood supply in the heart

Question 21

What is a Holter ECG?

Answer 21

24hr monitoring, automatic detection. Usually after a patient has palpitations, dizzy spells and/or blackouts

Question 22

What may happen if a patient has ventricular tachycardia?

Answer 22

May fall unconcious

Question 23

What are implantable loop recorders?

Answer 23

Super small needles in anaesthetised chest, device slid through into chest. Records all data, and rerecords every 20 mins. It connects to the telephone so it can contact the hospital if it picks up anything wrong and the hospital can contact the patient to come in.