Ch 35: Assessment of Cardiovascular Flashcards
Coronary arteries
Supply the heart muscle with blood. They originate on the aorta just beyond the aortic valve.
LMCA Left main coronary artery
LAD left anterior descending
LCX left circumflex Half of the AV node
RCA. right coronary artery, perfuses the right heart and inferior wall of the left heart. Supplies blood to the AV node in almost everyone, and half of the SA node
Blood flow to the heart occurs primarily during diastole. You must have a mean arterial pressure/MAP of at least 60.
Flow of blood through the heart
IVC & SVC > RA > tricuspid valve > RV > pulmonic valve > pulmonary artery > lungs > pulmonary veins > LA > mitral (bicuspid) valve > LV > aortic valve > aorta
Cardiac output
The heart rate x the stroke volume.
4 to 7 L per minute in adults
60 mL with each beat
Amount pumped by left ventricle
Heart rate
60-100
parasympathetic/vagus nerve slows it
Sympathetic increases it.
Epinephrine and norepinephrine stimulate it.
Betablockers block the sympathetic>slow the HR.
Ex. Metoprolol. Check HR and BP before giving
Stroke volume
Amount ejected from left ventricle with each beat
Preload: degree of myocardial fiber stretch at end of diastole, the volume contained in the ventricles at end of diastole.
Determined by amnt of blood returning to heart from venous and pulmonary system.
Sterlings law: more the heart is filled, the stronger is contracts.
Afterload: pressure resistance the ventricles must overcome to eject blood thru semilunar valves and into the blood vessels. Affected by arterial BP and diameter of blood vessels.
impedance: pressure needed to open aortic valve
Myocardial contractility: force of contraction increased by sympathetic stimulation, calcium release, positive inotropic drugs. Decreased by hypoxia and acidemia
Diastole
2/3 cardiac cycle
relaxation and filling of the atria and ventricles
passive
systole
contraction
emptying of atria and ventricles
Blood Pressure
Determined primarily by the quantity of blood flow or cardiac output as well as the resistance in the arterials. It equals cardiac output x peripheral vascular resistance
3 things regulate it:
ANS which excites or inhibits the sympathetic nervous system in response to chemo (peripheral respond to hypoxemia) (central receptors respond to hypercapnia and acidosis) and baro (respond to increased pressure) receptors
Kidneys which activate the renin-angiotensin-aldosterone system (Na and water retention, vasoconstriction)
Endocrine which releases hormones to stimulate the sympathetic nervous system
External factors: exercise, pain, stress, etc..
Systolic: pressure generated by LV to distribute blood into aorta during contraction
Diastolic: pressure against the arterial walls during relaxation
Changes with Aging
See pic 35-1
Calcification and degeneration of mitral and aortic valves
Pacemaker cells decreased, fewer muscle fibers, conduction time increases
Left ventricle increases in size, becomes stiff and less distensible, fibrotic changes decrease the speed of diastolic filling
Aorta thickens and stiffens, increased systolic BP, vascular resistance increases which leads to L/ventricle hypertrophy
Baro receptors become less sensitive.
Angina pain
Sudden, usually response to exertion, emotion, or extremes in temperature. Usually is squeezing, viselike pain. Substernal, may spread across the chest and back or down the arms. Usually the left side of the chest without radiation, my less than 15 minutes, relieved with rest, nitrate, or O2
Myocardial infarction pain
Severe, without any factors, often in early morning. Intense stabbing, viselike pain or pressure, severe. Substernal and may spread throughout the anterior chest into the arms, jaw, back, or down the arms. Continuous or no chest discomfort, relieved with morphine, cardiac drugs, and O2
Pericarditis pain
Sudden, sharp, stabbing, moderate to severe pain. Substernal, usually spreads to the left side for the back. It is intermittent. Relieved with sitting upright, analgesia, or anti-inflammatories.
Pleuropulmonary pain
Has a variable onset. A moderate ache worse on inspiration. In the lung fields. Continuous until the underlying condition is treated or the patient has rested
Esophageal/gastric pain
Variable onset. Squeezing, heartburn, variable severity. Substernal, may spread to the shoulders or the abdomen. Variable duration. May be relieved with antacid administration, food intake, or a sitting position
Anxiety pain
Variable, maybe in response to stress or fatigue. Dull ache to sharp stabbing. May be associated with numbness in fingers. Usually lasts 30 minutes or longer is relieved with opioids.
Classification of cardiovascular disease
See pic table 35-2
Class I: no limitations in activity, activity does not cause fatigue or pain
Class II: slight limitation, comfortable at rest, fatigue, palpitation, dyspnea, or pain with activity
Class III: marked limitations, comfortable at rest, little activity causes fatigue, pain, etc
Class IV: inability to carry on activities, anginal syndrome and cardiac insufficiency at rest, and activity causes discomfort
anascara
generalized edema
Postural - orthostatic hypotension
A decrease of more than 20 mm HG at the systolic pressure or more than 10 mm HG diastolic pressure, as well as a 10 to 20% increase in the heart rate.
Causes include cardiovascular drugs, blood volume decrease, prolonged bed rest, age-related changes, or disorders of the ANS
First measure when the patient is supine. After remaining in that position for three minutes, the patient changes position to sitting or standing. After the position change, wait for one minute before retaking the pulse and blood pressure. Note any dizziness.
Pulse pressure
The difference between systolic and diastolic values. Narrowed pressure is rarely normal and can be from increased peripheral vascular resistance, decreased stroke volume in patients with heart failure, hypovolemia, or shock. It can be from mitral stenosis or regurgitation.
An increased pulse pressure may occur in patients with a slow heart rate, aortic regurgitation, atherosclerosis, hypertension, and aging
Heart sounds
S1: 1st heart sound, closure of mitral and tricuspid AV valves. Listen at l/lower sternal border or apex
S2: 2nd heart sound, closure of aortic and pulmonic semilunar valves. Listen at base of heart during end of ventricular systole
Abnormal:
splitting of S2 - paradoxical splitting heard on expiration, early closure of pulmonic or late closure of aortic
Pericardial friction rub
Gallops.
Murmurs: turbulent blood flow
Diastolic filling sounds S3 & S4
S3 ventricular gallop during filling of ventricular diastole (pt on left side)
S4 atrial gallop
S3 and S4 together is called summation > severe heart failure, quadruple gallop
S4
grading of murmurs
Classified according to timing in cardiac cycle.
Grades:
I: very faint
II: faint but recognizable
III: loud but moderate intensity
IV: loud with palpable thrill
V: very loud, palpable thrill, audible with stethoscope partially off chest
VI: extremely loud, stethoscope above chest, palpable thrill
Cardiac labs
See pic Chart 35-3
Troponin
Myocardial muscle protein that is released into the bloodstream with injury to myocardial muscle. T and I are not found in healthy patient. Obtaining cardiac markers in the ER is often done to evaluate an MI. Indicates MI or infarction.
T <.03
Creatinine kinase
Enzyme specific to cells of the brain, myocardium, and skeletal muscle. Indicates tissue necrosis or injury with levels following a predictable rise and fall during a specific period.
CK-MM skeletal muscle
CK-MB myocardial muscle
CK-BB brain
CK-MB is specific for MI, peaks 24 hours after chest pain. Shows within 3 hours.
Myoglobulin
Protein found in cardiac and skeletal muscle it can be detected two hours after an MI with a rapid decline after seven hours. Not as useful as troponin levels.
<90
Women’s health considerations
Feel discomfort or indigestion. Abdominal fullness, chronic fatigue despite adequate rest
Aching, choking, strangling, tingling, squeezing, constricting, viselike.
Some may only have SOB, despite major ischemia. Dyspnea on exertion is sometimes the only symptom of heart failure, especially for women
Serum markers of Myocardial Damage
Troponin—Troponin T and troponin I Creatine kinase (CK) Myoglobin Serum lipids ØTotal cholesterol 40 mg/ dL ØLDL <70 mg/dL for cardiovascular patients Homocysteine Highly sensitive C-reactive protein
Catheterization risk
MI, stroke, arterial bleed, thromboembolism, lethal dysrhythmias, arterial dissection, CABG death
Purposes of the vascular system
Provides a route for blood to travel
carry cellular wastes to excretory organs
allows lymphatic flow to drain tissue fluid back to circulation
returns blood to the heart for recirculation
is divided into the arterial and venous systems.
Cardiac index
Cardiac output / body surface area
2.7-3.2L/min/m2
Risk factors for cardiovascular disease
Having a first degree relative such as a parent, sibling, or child is a major risk factor, more important than hypertension obesity diabetes.
Age
Gender: men have a higher risk except for in the oldest age group of 80 and up
Postmenopausal, obesity-especially abdominal (BMI >30). Diabetes mellitus. American Indians and Alaska natives. Asians have the lowest rate. Cigarette use, physical inactivity, psychological variables ( stress, anger, depression). Hypertension, hyperlipidemia, Renal disease, anemia, stroke, bleeding disorders, connective tissue diseases, chronic pulmonary diseases, heart disease, thrombophlebitis, streptococcal infections, congenital problems, drug use, income
Oral contraceptives if they smoke, have diabetes, or hypertension
Smoke: CAD and PVD, 4 smokes=2x risk, 20=4x. 3-4 yrs after quitting for risk to decrease.
Symptoms of cardiovascular disease
Chest pain or discomfort, dyspnea, fatigue, palpitations, weight gain, syncope, and extremity pain. Chest pain should be considered ischemic until proven otherwise. When assessing for symptoms use terms such as discomfort, heaviness, pressure, indigestion.
Paroxysmal nocturnal dyspnea
Any patient with heart disease, difficulty breathing that develops after lying down for several hours and causes the patient to awakened abruptly with a feeling of suffocation and panic. It occurs because the heart is unable to compensate for the increased volume when blood from the lower extremities is redistributed to the venous system, which increases venous return to the heart. A diseased heart is ineffective in pumping the additional fluid into the circulatory system, and pulmonary congestion results.
Best indicator of fluid balance
Is weight. 1 L equals 1 kg equals 2.2 pounds
Syncope
Brief loss of consciousness caused by decreased perfusion to the brain. Conditions such as cardiac rhythm disturbances, ventricular dysrhythmias, valvular disorders, aortic stenosis may trigger this. Near syncope refers to dizziness but ability to remain upright.
In the aging adult it can be caused by sensitivity in the carotid arteries. Pressure applied while turning the head, shrugging shoulders, or performing the Valsalva maneuver can stimulate a vagal response.
Intermittent claudication
Pain relieved by resting or lowering the affected extremity decreased tissue demands or enhanced arterial blood flow. Patient reported cramping sensation in their legs or Buttocks associated with an activity such as walking.
Cyanosis
May show up as graying in dark skinned patients. Central cyanosis is decreased oxygenation of the arterial blood in the lungs and appears in the conjunctiva and mucous membranes of the mouth and tongue. It can indicate impaired lung function or a right to left shunt found in congenital heart conditions. It can produce a bluish or dark discoloration of the nailbeds, earlobes, lips, and toes because of desaturation of hemoglobin
Parenteral cyanosis occurs when blood flow to the peripheral vessels is decreased by the vasoconstriction. This results from low cardiac output or increased extraction of oxygen from peripheral tissues. Usually a result of arterial or venous insufficiency. Ruber/redness that replaces pallor in a dependent foot suggests arterial insufficiency
Edema
Bilateral edema of the legs maybe seen with heart failure or chronic venous insufficiency. Abdominal and leg edema can be seen with heart disease and cirrhosis of deliver. Localized in one extremity may be the result of venous obstruction or lymphatic blockage.
Dependent foot and ankle edema is a side effect of antihypertensive drugs such as Norvasc.
1+ to 4+. Pitting or non
Blood pressure numbers
HTN > 140/90
PreHTN 120-139/80-89
Norm <120/80
Need at least 90/60
Paradoxical blood pressure
And exaggerated decrease in systolic pressure by more than 10 during the inspiratory phase of the respiratory cycle. Clinical conditions that can produce this include pericardial tamponade, constrictive pericarditis, and pulmonary hypertension
Bruits
Swishing sounds that occur from turbulent bloodflow in narrowed or atherosclerotic artery. Use the bell of the stethoscope over the carotid artery while the patients holds his breath. They are usually not heard until is narrowed by 50%. You usually don’t hear it after it is blocked by 90% or more.
Precordium
The area over the heart. Inspect the chest from the side at a rite angle and downward over areas where vibrations are visible. Note any prominent pulses. Movement over the aortic, Pulmonic, and tricuspid areas is abnormal. Pulses in the mitral area/apex are normal and refered to as apical pulse or PMI. IT SHOULD BE AT THE LEFT FIFTH INTERCOSTAL SPACE IN THE MIDCLAVICULAR LINE. IF IT APPEARS IN MORE THAN ONE INTERCOSTAL SPACE AND HAS SHIFTED THE PATIENT MAY HAVE LEFT VENTRICULAR HYPERTROPHY
Serum lipids
Total cholesterol < 200 Triglycerides 40 LDL bad < 70 if high risk or DM < 100 LDL is of significant importance in determining risk for CVD.
Usually a fasting blood sample and a 12 hour fast for triglycerides
Potassium imbalance
Hypokalemia Increased electrical instability, ventricular dysrhythmias, increased risk of digitalis toxicity.
Hyperkalemia includes slow ventricular conduction, Peaked T waves, and contraction followed by asystole.
Calcium imbalance
Hypocalcemia include ventricular dysrhythmias, prolonged QT interval, cardiac arrest.
Hypercalcemia shortens the QT interval and causes AV block, digitalis hypersensitivity, cardiac arrest.
Magnesium imbalance
Hypo torsades de pointes, a ventricular dysrhythmia. Prolongs the QT interval causing this specific type.
Stress test
No meals for two hours before the test, possibly withhold meds, no smoking alcohol or caffeine the day of the test. A 12 lead ECG is attached.
The patient will exercise until he predetermined heart rate is reached and maintained.
Signs and symptoms such as chest pain, fatigue, extreme dyspnea, vertigo, Hypotension, dysrhythmias appear.
Significant ST segment depression or T. wave inversion occurs.
The 20 minute protocol is complete.
Always have a crash cart in the room available. No hot shower for 1 to 2 hours after the test because it can cause hypotension. If unable to exercise, Dobutamine can be given with similar effects.
Myocardial nuclear perfusion imaging
Useful for detecting a.m. I, decreased myocardial bloodflow, and for evaluating left ventricular ejection. They are noninvasive, the amount of radioisotope is small, radiation exposure risks are minimal. Avoid cigarettes and caffeine for four hours before.
Hemodynamic monitoring
Invasive, provides info about vascular capacity, blood volume, pump effectiveness, and tissue perfusion. It directly measures the pressures in the heart and great vessels. Informed consent required.
Pulmonary artery wedge pressure. PAWP
Also known as the pulmonary artery occlusive pressure. PAOP
Patient must remain still and in the supine or Trendelenburg position for insertion of the catheter. Usually goes through the internal jugular or subclavian and into the right atrium and to the pulmonary artery. Verify with chest X-ray.
RAtrial 1-8 > RV failure. < hypovolemia
PAarteryP 15-26 systolic. 5-15 diastolic. Mean 15.
PAWP Reflects left atrial pressure and left ventricular and diastolic pressure. 4-12
> Left ventricular failure, hypervolemia, mitral regurgitation, or intracardiac shunt
< Hypovolemia or after load reduction
During pressure recording make sure the transducer is at the level of phlebostatic axis/fourth intercostal space. Patient is usually supine at 45° elevation
Art line
Indirect measurement of arterial blood pressure. Blood pressures are usually 10 to 15 mm greater than indirect cuff measurements. You may use it to obtain blood samples and ABGs.
Home care after catheterization
No heavy lifting or exercise for 1 week
Remove dressing after 24 hours
Will have bruising
Observe for bleeding, warmth, swelling,