Lec 26 Cardiology Diagnostics: Basic Non-Invasive

Question 1

Modality to document electrical abnormalities:

Answer 1

ECG

Question 2

Modality to define structural abnormalities:

Answer 2

CXR, 2D Echocardiogram

Question 3

Modality to determine myocardial availability/viability (alive/infarcted) or determine if it’s myocardial ischemia:

Answer 3

Treadmill stress test (ECG), nuclear perfusion scan

Question 4

Important observations in Chest X-ray

Answer 4

1. Cardiothoracic ratio
   > normal: normal: Low density, almost straight edge represents the size of the ascending aorta
2. Double density
   > Abnormal finding indicative of LA enlargement (LAE)
3. Aortic knob
   > Abnormal: > 35 mm (indicative of aortic dissection, aortic aneurysm, tortuosity and dilatation)> Causes of enlargement: Increased pressure, increased flow, changes in the aortic wall
4. Main pulmonary artery
5. Cardiomegaly

Question 5

Most practical test for cardiac perfusion and function

Answer 5

Treadmill Exercise Stress Test

Question 6

Uses ultrasound reflecting off moving red blood cells to measure the velocity of blood flow across the valves, cardiac chambers, and great vessels for assessment of hemodynamics

Answer 6

DOPPLER

> Determines intracardiac pressures, valve gradients, severity of stenosis and regurgitant flows, cardiac output
with the use of the velocity of blood flow

> Can see turbulent flow

> Can estimate severe moderate or mild valve stenosis/regurg

Question 7

a straightening of the cardiac waistline in CXR suggests:

Answer 7

RAE, RVE, LVE, LAE (always)

Question 8

Contraindications to Treadmill Stress Test

Answer 8

1. Unstable angina with recent rest pain
2. Untreated life-threatening cardiac arrhythmias
3. Uncompensated CHF
4. Advanced atrioventricular block
5. Acute myocarditis or pericarditis
6. Critical aortic stenosis (relative contraindication as some could go into cardiac arrest once stressed)
7. Severe hypertrophic obstructive cardiomyopathy
8. Uncontrolled hypertension
9. Acute systemic illness

Question 9

What is the MHR of a 21 y/o patient?

Answer 9

220-21 = 199

 MHR = 220-age (achieve 90% max heart rate for age during stress test)

 Determines how well your patients performed after the test

 Post-test HR should be at least 85% of MHR as long as the patient is not on medicines like beta blockers, digitalis, and calcium channel blockers

Question 10

Exterior carpentry, singles tennis & light-backpacking is equal to how many Metabolic Equivalents (METS)

Answer 10

METS -> Activity

3 – 5 -> Raking leaves, light carpentry, golf, walking 3-4 miles per hour

5 – 7 -> Exterior carpentry, singles tennis, light backpacking

> 9 -> Heavy labor, handball, squash, running at 8 mph\

*It is used to determine at what level the patient undergoes ischemia

Question 11

Echocardiogram uses sound in frequency range of:

Answer 11

Uses sound in frequency range of 2.5-5.0 mHz

2D echo: structural changes
Doppler: blood flow

Question 12

Indications for Echocardiogram

Answer 12

 Assessment of cardiac chamber sizes

 Assessment of LV function and wall motion contractility

 Valve morphology and function
o Stenosis/regurgitation
o Prolapse
o Vegetations

 Pericardial disease
o Pericardial effusions
o Tamponade
o Percicardial construction

 Intracardiac masses
o Thrombus
o Artrial myxoma
o Tumors

 Aortic disease
o Aneurysm
o Dissection
o Atherosclerosis

 Congenital heart disease

Question 13

The multistage protocol of a treadmill stress test consist of ____ minute periods.

Answer 13

Multistage protocol has 3-MINUTE periods to allow achievement of a steady state before workload is increased.

Question 14

Indications for a treadmill stress test:

Answer 14

1. DIAGNOSIS Symptoms or signs of coronary artery disease (CAD) Exercise induced symptoms Chest pain Old or new ECG abnormalities

2.PROGNOSIS

  After recent MI or stable angina 

  To detect for possible recurrence, mild or severe coronary disease

  At risk for myocardial ischemia 

  To determine the possible presence of residual ischemia or vessel that may occlude soon and how much exercise a patient can do.

  Experimental studies show that post-MI patients who can do good is stress test have better prognosis than post-MI patients who perform poorly in the stress test.

3. EXERCISE CAPACITY Congestive heart failure Pulmonary disease Chronic renal failure
4. TREATMENT ASSESSMENT - - Efficacy of treatment Arrhytmia Angina – To determine if medicines work at a higher load Hypertension After revascularization (angioplasty, PTCA, CABG)

Question 15

A small aorta indicates possible:

Answer 15

CHD (e.g., TOF) due to decreased blood flow to Ascending Aorta.

Question 16

Prominent AA denotes

a. aortic aneurysm
b. aortic regurgitation
c. hypertension, or
d. Marfan’s syndrome
e. AOTA

Answer 16

e. AOTA

All conditions lead to dilatation of the Ascending Aorta (due to increase systemic pressure, etc.)

Question 17

Limitations of using Echocardiogram

Answer 17

1. Inability to obtain high quality images in all patients (e.g. obese, COPD, orthopneic patient, patients who cannot lie down)
2. Accuracy is highly dependent on the operator, equipment and interpreter. The technician should be adept in doing the echo. Interpretation should also be done properly.

Question 18

What modality would you use to observe for hypokinetic RV?

Answer 18

2D Echo

• best used to check for structural changes -> rule out possible obstruction such as an embolism

Question 19

Modality to observe for ST elevation or depression.

Answer 19

Electrocardiogram

Question 20

The best modality for checking for an occluded coronary artery

Answer 20

Angiogram

Question 21

ST depression during stress is suggestive of:

Answer 21

Myocardial Ischemia