8/3- How to Msr Cardiac Fct at the Bedside

Question 1

Pulmonary artery pressure? (mmHg)

Answer 1

15-30/3-12

Question 2

Right ventricular pressure? (mmHg)

Answer 2

15-30/0-8

Question 3

Aortic pressure? (mmHg)

Answer 3

100-140/60-90

Question 4

Left ventricular pressure? (mmHg)

Answer 4

100-140/5-12

Question 5

Pulmonary capillary wedge pressure? (mmHg)

Answer 5

5-`1

Question 6

The right atrial pressure waveform has:

• _(#)_ positive waves (examples)
• _(#)_ negative deflations (examples)

Answer 6

Three positive waves:

- a wave: atrial systole (follows ECG “P” wave)

- c wave: TV closure

- v wave: atrial filling (followed by TV opening)

Two negative deflations:

- x-descent: atrial relaxation

- y-descent: rapid atrial emptying

Question 7

Right ventricular pressure has:

• ______ peak pressure
• ______ pressure phases (examples)

Answer 7

Systolic Peak Pressure

Diastolic Pressure Phases

• Rapid filling phase
• Slow filling phase
• Atrial contraction

Question 8

What is this? Label?

Answer 8

a wave- atrial kick

c wave- closure of AV valve

x descent- atrial relaxation

v wave- atrial filling from jugular vein (peaks when AV valve closes)

y descent- rapid early emptying of atrium (atrial counterpart of rapid early filling phase of ventricle) Which descent(s) is/are clinically useful?

**Change in y descent is very important sign of abnormality!! Critical!

** x descent abnormality (steeper/shallower) has no specificity for cardiac disease

Question 9

Measurements of systolic function (4)?

Answer 9

• Hemodynamic measurements (4)
• Regional ventricular function
• Left ventricular mass
• Ventricular response to stress

Question 10

What are hemodynamic measurements of cardiac function?

Answer 10

• Ventricular volume
• Ejection fraction
• Cardiac output
• Vascular resistance

Question 11

How do we measure ventricular volumes?

Answer 11

Systolic and diastolic volumes can be measured by echocardiography or angiography (nuclear or contrast dye)

Question 12

What is typical LV end-diastolic volume?

(don’t need to memorize)

Answer 12

79 +/- 11 mL/m2

Question 13

What is typical LV end-systolic volume?

(don’t need to memorize)

Answer 13

28 +/- 6 mL/m2

Question 14

Equation for stroke volume?

Answer 14

EDV - ESV

(Typically LV: 79 - 28 ~ 51 mL/m2)

Question 15

What is left ventricular ejection fraction?

What does it indicate?

What increases/decreases it?

Answer 15

Ratio of stroke volume to end-diastolic volume: SV/EDV

• Measure of cardiac performance
• Increases with increase in preload and contractility or decrease in afterload

Question 16

What is normal LVEF?

Answer 16

67 +/- 7% (> 50%)

Question 17

What is cardiac output?

Answer 17

Blood flow to systemic circulation in every minute

CO = SV x HR

(SV: blood ejected per beat)

Question 18

What is cardiac index?

Answer 18

Cardiac output/body surface area

CI = CO/BSA

Question 19

How can we measure CO? (2 main methods)

Which is used more often?

Answer 19

• Thermodilution method using a Swan Ganz catheter** more common
• Doppler echocardiography (complicated)

Question 20

Method behind measuring CO by Swan Ganz catheterization?

Answer 20

Thermodilution method using a Swan Ganz catheter:

• Balloon-tipped catheter floated into the pulmonary artery from a systemic vein
• 10 mL saline injected into the RA and resultant change in PA blood temperature (detected by a thermal sensor) is used to compute the cardiac output
• Then we infer left side CO from right side (they are equal!!!)

Question 21

T/F: Left sided cardiac output can be estimated from the right side (via Swan Ganz catheterization)?

Answer 21

True

Right side cardiac output approximates the left

Question 22

What can we measure by Swan Ganz catheterization?

Answer 22

• Cardiac output
• Pulmonary capillary wedge pressure

As the balloon is occluded, the P measured at the catheter tip is the pulmonary cap wedge P which reflects the left atrial pressure transmitted through the pulmonary circulation into the pulmonary caps

Question 23

What is vascular resistance? Types?

Answer 23

Ratio of pressure gradient to blood flow

• Systemic vascular resistance
• Pulmonary vascular resistance

Question 24

Equations for:

• Systemic vascular resistance
• Pulmonary vascular resistance

Relative relationship?

Answer 24

Systemic vascular resistance: SVR = (AO-RA)/CO Pulmonary vascular resistance: PVR = (PA-LA)/CO

SVR is ~10x higher than PVR

Question 25

What is **regional ventricular function**?

Answer 25

Extent of myocardial thickening and wall motion of various myocardial segments

Question 26

How is regional ventricular function measured?

Answer 26

- Echocardiography - Radionuclide angiography - Cardiac catheterization with contrast dye angiography

Question 27

How may wall motion be described?

Answer 27

- Normal - Hypokinetic - Akinetic - Dyskinetic

Question 28

How is left ventricular mass most commonly measured?

Answer 28

Echocardiography

Question 29

What can increase LVM (left ventricular mass)?

Answer 29

**HYPERTROPHY** - Either concentric or eccentric due to pressure or volume load

Question 30

Left ventricular hypertrophy predicts what?

Answer 30

Left ventricular hypertrophy predicts a **worse clinical prognosis** in patients with **hypertension and various cardiac diseases**

Question 31

Why do we measure ventricular response to stress?

Answer 31

- To assess overall ventricular reserve - To determine functional significance of coronary stenosis in pts with CAD

Question 32

Types of stress tests (3)? Examples?

Answer 32

**- Isotonic exercise**: treadmill and bike **- Isometric exercise**: handgrip **- Pharmacologic**: dobutamine, adenosine, or dipyridamole

Question 33

What is a key predictor of significant coronary artery disease?

Answer 33

- Development of a regional wall motion abnormality **INDUCED** during any stress test is a **HALLMARK of ischemia due to coronary artery disease (CAD)** - This is a major reason for using stress tests to assess regional ventricular function response to stress

Question 34

What are measurements of diastolic function?

Answer 34

- Measure end-diastolic pressures in LV and RV during cardiac catheterization - Diastolic filling parameters by Doppler echocradiography

Question 35

Key points of measurements of cardiac function: - Atrial waveforms: - Ventricular waveforms: - Ventricular Diastolic Pressure = \_\_\_\_ - RAP= \_\_; RVP= \_\_ - LAP= \_\_; LVP= \_\_ - Cardiac performance vs. contractility - Systolic function: \_\_\_\_\_\_\_\_\_\_\_\_\_ - Cardiac performance: measured by _________ & influenced by \_\_\_\_\_\_\_ - Contractility: \_\_\_\_\_\_\_\_\_\_\_- conditions=inotropic state - Systolic function: \_\_\_\_\_\_\_ - LVEDV= ___ ;LVESV=\_\_\_\_; SV= \_\_\_ - EF= \_\_\_(%); EF= \_\_\_\_\_\_ - CO= \_\_\_; CI= \_\_\_ - SVR= \_\_\_\_\_\_\_ - Resistance= \_\_\_\_\_

Answer 35

Key points of measurements of cardiac function: - Atrial waveforms: **a, c & v (+); x & y (-)** - Ventricular waveforms: **early/late filling** - Ventricular Diastolic Pressure = **Atrial Pressure** - RAP=0-8; RVP=15-30/0-8 mm Hg - LAP=3-12; LVP=100-140/3-12 mm Hg - Cardiac performance vs. contractility - Systolic function: **volumes, EF, CO, SVR** - Cardiac performance: measured by **EF, SV & CO** & influenced by **contractility** - Contractility: inherent ability to generate power independently of loading conditions=inotropic state - Systolic function: **volume, EF, CO, SVR** - LVEDV=79+11; LVESV=28+6; SV=D-S - EF= SV/EDV (%); EF= 67+7 (\>50%) - CO= **SV x HR** (volume ejected/beat x number of heart beats); CI= **CO/BSA** - SVR= **pressure drop (AP-RAP)/flow (CO)** - Resistance = **pressure/flow**

Question 36

All of the following are associated with pressure overload concentric LVH except: A. Systemic hypertension B. Aortic stenosis C. Mitral regurgitation D. Pulmonary hypertension

Answer 36

All of the following are associated with pressure overload concentric LVH except: A. Systemic hypertension B. Aortic stenosis **C. Mitral regurgitation** D. Pulmonary hypertension

Question 37

Which of the following has the highest wall stress? A. HTN with concentric LVH B. Aortic stenosis with concentric LVH C. D.

Answer 37

Which of the following has the highest wall stress? A. HTN with concentric LVH B. Aortic stenosis with concentric LVH C. D. \*\*\*

Question 38

which of the following is the correct way of calculating cardiac output? A. SV x VR B. HR x EDV C. SV x HR D. HR x CI

Answer 38

which of the following is the correct way of calculating cardiac output? A. SV x VR B. HR x EDV **C. SV x HR** D. HR x CI

Question 39

All of the following affect wall stress except: A. IVP B. HR C. Ventricular size D. Wall thickness

Answer 39

All of the following affect wall stress except: A. IVP **B. HR** C. Ventricular size D. Wall thickness

Question 40

Which of the following phases of diastole occurs first? A. Atrial kick

Answer 40

Which of the following phases of diastole occurs first? A. Atrial kick

Question 41

True/False questions

Answer 41

?