Cardiovascular Flashcards
What does pulse pressure refer to?
Pulse pressure equals the difference between the systolic and diastolic arterial pressures.
Which of the following does NOT contribute to the delivery of oxygen to the tissue?
Blood pressure, cardiac output, hemoglobin, or PaO2?
Blood pressure
Define arterial blood pressure
The product of cardiac output (CO) and total peripheral resistance (TPR) also known as systemic vascular resistance (SVR).
Define hypotension
A systolic ABP of <100 mmHg or MAP of <60 mmHg.
If the dicrotic notch on an arterial wave form is high and approaches the systolic pressure, what can this indicate?
Vasoconstriction
Describe the top of an arterial wave form
The peak systolic blood pressure where maximum pressure is generated during ventricular ejection of blood into the systemic arterial system.
What does the start of an arterial waveform represent and what is the name of the limb?
The systolic upstroke or anacrotic limb
Describe the rapid decline on an arterial waveform and what is the name of the limb?
There is a rapid decline in arterial pressure as ventricular contraction comes to an end shown on the dicrotic limb. The dicrotic indicates aortic valve closure.
What does the lowest point indicate in an arterial waveform?
Diastolic blood pressure.
What does the area under the arterial waveform represent?
Mean arterial pressure.
What is the difference between the systolic and diastolic blood pressure?
The pulse pressure.
If the dicrotic notch on an arterial wave form is low and approaches the diastolic pressure, what can this indicate?
Vasodilation
What can cause an arterial waveform to become overdamped or dull/rounded in appearance.
Air bubbles in the connection tubing, a blood clot in the arterial catheter, and if the connection tubing is too compliant or not stiff enough.
What will an underdamped arterial waveform appear like?
Tall and sharp
Define coronary perfusion pressure
The pressure gradient that drives coronary blood pressure and is a surrogate for coronary blood flow. It is the difference between diastolic aortic pressure (DAP) and right atrial diastolic pressure (RADP).
What is DAP - RADP = and what do they mean?
DAP - RADP = CPP
Diastolic aortic pressure - right atrial diastolic pressure = coronary perfusion pressure
What measurement of CPP is thought to be needed for ROSC to occur?
15 mmHg
Define vasodilation
The INCREASE (opening/dilation) in the internal diameter of blood vessels that is caused by the relaxation of smooth muscles within the wall of the vessels can an INCREASE in blood flow due to a DECREASE in SVR.
Key characteristics of a normal sinus rhythm (NSR)
Often a narrow QRS complex and upright P wave in lead II
Key characteristics of sinus bradycardia
A narrow QRS with upright P wave and a HR below 50.
*Can be produced with vagal stimulation or due to Sick Sinus Syndrome, drug induced or shock.
Key characteristics of sinus tachycardia
Narrow QRS and HR above 150 but below 180.
*Results from increased sympathetic stimulation (pain, fever, increased oxygen demand, hypovolemia).
Key characteristics of a sinus arrhythmia
Narrow QRS with upright P wave, but irregular pattern that fluctuates with inspiration (HR increases) and expiration (HR decreases).