Cardiovascular disorders and tests Flashcards
Pulse pressure
Difference between systolic and diastolic blood pressure readings. Pulse pressure is a measure of the cardiac output.
Pulse pressure is usually 30 to 40mmHg.
Low pulse pressure vs.
high pulse pressure
Low pulse pressure —less than 30 indicates decrease in cardiac output.
High pulse pressure is commonly seen with aging result of stiffening of the arterial vessels. Can lead to left ventricular hypertrophy and heart failure.
Pulse deficit
Exists when apical heart rate is faster than radial pulse rate.
Rating peripheral pulses
0=absent pulse
1+=Pulse is weak
2+ or 3+ = normal, 3+ being fuller
4+= Pulse is very full and pounding, possibly visible
Other pulse rating scales can range from 0 to 3+.
Best to chart pulse scales as 1+/3 or 1+/4 to clearly indicate rating scale being used.
Jugular neck vein distention (JVD)
Distended neck veins suggest:
development of right-sided heart failure or
circulatory volume overload
Heart Sounds S1, S2, S3, S4
S1- “lub”- closure of Mitral and tricuspid heart valves
S2- “dub”- Closure of aortic and Pulm valves
S3- Ventricular Gallup. Occurs immediately after S2. Commonly occurs in heart failure or mitral regurgitation.
S4- Atrial Gallup. Occurs immediately before S1. Left ventricular hypertrophy and coronary artery disease
Murmurs
Sounds that occurred due to turbulence blood flow through the heart. Can be caused by incompetent heart valve or congenital defect.
Cardiac enzymes
CK and CK-MB- Elevated within 3 to 9 hours of the event and return to normal within 1 to 3 days.
LDH rises 6 to 8 hours after infarction and remains elevated for 5 to 7 days.
Troponin and myoglobin- elevate within 3 to 5 hours and remain elevated for anywhere from 10 to 14 days. Troponin is more specific for cardiac ischemia then myoglobin.
Normal lab values for: serum potassium, serum sodium, serum calcium, BUN, serum creatinine
Potassium 3.5 -5.5 Sodium 135 -145 Calcium 8.5- 10.5 BUN 10 -20 Creatinine 0.7-1.5
PTT - Partial thromboplastin time
Monitors patients with heparin therapy.
Normal PTT is 25-38 seconds.
Therapeutic values are 1.5 - 2.5 times the reference value.
PT -prothrombin time
Monitors warfarin
Normal PT is less than 14 seconds.
Therapeutic value is 1.5 - 2.5 times the reference value.
Internal Normalized Ratio -INR
Standardized method of reporting PT to eliminate lab variations.
INR is maintained between 2.0- 3.5 for patients receiving warfarin.
Normal Digoxin level
1-2 mg/ml.
Toxic level is over 3mg/ml.
Cardiac catheterization
Used to visual coronary arteries.
Catheter is usually threaded from femoral artery to heart. (Can also be inserted through brachial artery)
Dye is injected to visualize vessels and any obstructions.
Preop nursing care for cardiac cath
- Fast for 8-12 hours prior
- History of shellfish, iodine or contrast media
- assess quality of peripheral pulses to provide baseline for comparison post op.
- administer prescribed sedatives
Postop care for cardiac cath
- assess circulation- pulses, temp and color of affected extremity every 15 min for first hour then Q1-2 hours after.
- observe site for bleeding and swelling
- drink lots of fluid to flush dyes
- watch for dysrhythmias and chest pain
- if femoral site is used, bed rest for 3-4 hrs. Leg extended and HOB no higher than 30 degrees
- if brachial, arm kept straight by arm board. Does not require bedrest as long as vitals stable
Angiograms, AkA arteriograms
Used to visualize arterial vascular system and dx vascular disorders.
Commonly used to dx peripheral vascular disease.
Catheter into artery, contrast media injected so xrays may be taken.
Venograms are used to dx DVT.
