ASSESSMENT OF CARDIOVASCULAR FUNCTION. NUR240 Lecture 1. LECTURE OBJECTIVES. Review anatomy & physiology of the cardiovascular system. Discuss relevant aspects of the patient history. Describe physical assessment of cardiovascular status.
ASSESSMENT OF CARDIOVASCULAR FUNCTION
(What makes it “tick”!)
Functions of the heart & CV system
CARDIAC CELLS HAVE UNIQUE PROPERTIES
PERICARDIUM / PERICARDIAL SAC
Right & Left arteries encircle the heart and supply blood to the myocardium during ventricular relaxation( diastole)
LEFT MAIN CORONARY ARTERY
L ANTERIOR DESCENDING (LAD)
L CIRCUMFLEX (LCX)
RIGHT CORONARY ARTERY
The heart can’t pump unless an electrical stimulus occurs
Action Potential (AP) – electrical change
(depolarization = contraction)
Brought about by release of calcium
(+ charge) into cells- mechanical change
Intrinsic Pacemakers – depolarize and generate the AP
The pacemaker with the fastest rate of depolarization stimulates the AP
-what can affect SA/AV node function ?
CARDIAC CYCLE – all the activities occurring in the heart during one contraction, and subsequent period of relaxation. Graphically represented on an EKG (ECG)
EKG – A 12 lead EKG is a graphic record of the electrical forces produced by the heart
Polarized (resting) cell – represented on EKG as baseline or isoelectric line
Depolarization – impulse over specialized cardiac cells (not neuromuscular impulse)
Repolarized cell – returns to normal. Na moves out of cell, K moves in – requires ATP
How will ischemic tissue change the cardiac cycle ?
A 12 Lead EKG shows electrical activity from 12 different positions in the heart, concentrating on (L) ventricle
A 14 Lead EKG includes (R) ventricle activity
Control of SV and HR = SV&HR are continually adjusted by the body, and are affected by the return of blood from the tissues (think of exercise)
CO = SVxHR
Extrinsic control of HR is a more powerful way of controlling CO than changing SV
Preload = degree of myocardial fiber stretch at the end of diastole and just before contraction
Afterload = pressure against which ventricles must eject blood. This pressure is affected by systemic vascular resistance (SVR)
Cardiac status of all patients should be routinely assessed. Everyone has a
What else ?
M- Monitor for pain
O- O2 and pulse ox
V- Vital signs
I- Intravenous fluids
E- EKG monitoring
Abnormal Sounds: Gallops
S3 ventricular gallop – heard in early diastole
S4 atrial gallop – generally abnormal
Turbulent blood flow in valvular disorders and septal defects
Timing of murmurs is a must!
Systolic murmurs occur between S1 & S2
Diastolic murmurs occur between
S2 & S1
Grade 1 – 6 identifies intensity of murmur
JVD associated with (R) HF, SVC obstruction (Normal is 3-10cm H20)
continuous cardiac monitoring
Evaluates heart wall thickness, valve structure, differentiates murmurs
determines coronary lesion size, location, evaluate (L) ventricular function, measures heart pressures
Cardiac enzymes = enzymes are released when cells are damaged (MI). Enzymes are found in many tissues/muscles, and some are specific to cardiac tissue.
Serial measurement can aid in dx, and monitor course of MI
Cardiac enzymes =
CPK – MB (CK-MB),myoglobin, Troponin
In general, the greater the rise in the serum level of an enzyme, the greater the degree or extent of damage to the muscle.
Mary is attending a sophomore level nursing class on anatomy and physiology. Which statement, if made by Mary, demonstrates a good understanding of the anatomy and physiology of the heart?
A."The heart is encapsulated by a protective coating called the endocardium.“
B."The SA node is considered the main regulator of heart rate.“
C."The left atrium receives deoxygenated venous blood from all peripheral tissues.“
D."Stroke volume is the amount of blood ejected by the right ventricle during each diastole
Kirsten is completing her graduate clinical rotation in a large urban teaching hospital in a medical coronary care unit (CCU). Which observation demonstrates a good understanding of completing a thorough cardiac examination?
Edward is a 40-year-old white male. He is an accountant who works on average 11 hours per day. He reports feeling stressed each day, even with mundane things such as a traffic jam. His father had a massive myocardial infarction at the age of 48. His mother has a history of congestive heart failure. He seldom has time to exercise, but does eat balanced meals when possible, although he does not get to eat three meals a day. Select all factors that place Edward at risk for heart disease.