Cardiac Flashcards
Developmental Competence: Infants and Children
Fetal heart begins to beat after 3 weeks’ gestation
Right and left ventricles equal in weight and muscle wall thickness and both pumping into systemic circulation
Inflation and aeration of lungs at birth produces circulatory changes
Now blood is oxygenated through lungs rather than through placenta
Now left ventricle has greater workload of pumping into systemic circulation
The heart is more horizontal in the chest thus the apex is higher
Developmental Competence: Pregnant Woman
Blood volume increases by 30% to 50% during pregnancy
Most rapid expansion occurs during second trimester
Creates an increase in stroke volume and cardiac output and an increased pulse rate of 10 to 15 beats per minute
Despite increased cardiac output, arterial blood pressure decreases in pregnancy as a result of peripheral vasodilation
Blood pressure drops to lowest point during second trimester, then rises after that
Blood pressure varies with person’s position
Hemodynamic Changes with Aging
With aging, there is an increase in systolic BP due to thickening and stiffening of the arteries
Left ventricular wall becomes thicker but the overall size of the heart does not change
Ability of heart to adjust cardiac output with exercise is decreased
Cardiac function in adults
Amount of collagen in the heart increases and elastin decreases. These changes affect the contractile and distensible properties of the myocardium
Heart valves become thick and stiff
Dysrythmias increase with age
Frequent need for pacemakers
SA node fails
Less sensitive to β-adrenergic agonist drugs
Risk of orthostatic hypotension
Increase in SBP; decrease or no change in DBP
Hypertension and heart failure also increase with age
Diastole
Ventricles relaxed
Tricuspid and mitral (AV) valves are open
Pressure in atria higher than that in ventricles, so blood pours rapidly into ventricles
Toward end of diastole, atria contract and push last amount of blood into ventricles (about 25% of stroke volume) called atrial kick
Systole
Ventricular pressure becomes higher than that in atria
Mitral and tricuspid valves close
Closure of AV valves contributes to first heart sound (S1) and signals beginning of systole
AV valves close to prevent any regurgitation of blood back up into atria during contraction
For a very brief moment, all four valves are closed and ventricular walls contract
presystole, atrial systole or the atrial kick
The contraction of the atria and the end of diastole
Heart’s Pumping Ability
In resting adult, heart normally pumps between 4 and 6 L of blood per minute throughout body: This is cardiac output
Heart can alter its cardiac output to adapt to metabolic needs of body
Preload and afterload affect heart’s ability to increase cardiac output
Cardiac output
equals volume of blood in each systole (called stroke volume) times number of beats per minute (rate)
Preload
known as chamber volume
Preload is venous return, which builds during diastole
How well ventricular muscle can stretch at end of diastole
According to Frank-Starling law, the greater the stretch, the stronger the heart’s contraction
This increased contractility results in an increased volume of blood ejected, increased stroke volume
Afterload
Afterload is the opposing pressure that the ventricle must generate to open aortic valve
Afterload is the resistance against which ventricle must pump its blood
After aortic valve opens, rapid ejection occurs
Factors Affecting Cardiac Output
Preload
Volume of blood in ventricles at the end of diastole
Contractility
How well ventricles can move blood forward
Afterload
Peripheral resistance against which the left ventricle must pump
S1
Occurs when AV valves close (beginning of systole)
Can hear S1 over all precordium, but loudest at apex
S2
Occurs when semilunar valves close
Signals end of systole
Although heard over all precordium, S2 loudest at base
Split S2
Left ventricular systole is slightly shorter so the aortic valve closes earlier than the pulmonic valve and sometimes you can hear it
Normal if heard on inspiration
Heard best at the base
S3 (ventricular gallop)
Normal diastole is silent. Certain conditions cause vibrations in the chest which can be heard. The ventricles are resistant to filling during early rapid filling. This occurs immediately after S2
It is the most difficult to hear, normally disappears when a person sits up
Heard best with the bell
Can be normal in kids but also may signify heart failure
Can be heard in high cardiac output states (hyperthyroidism, anemia and pregnancy)
S4 (atrial gallup)–
Occurs at the end of diastole when the ventricle is resistant to filling. The atria contract and push blood into a non-compliant ventricle which causes vibrations.
S4 occurs just before S1.
Hear best with the bell at the apex
Due to aortic stenosis, hypertrophic cardiomyopathy, diseases that reduce ventricular compliance
Can be heard in adults over 50 after exercise
Abnormal
Midsystolic click
heard in Mitral Valve Prolapse, mitral valves balloon up into atrium with contraction, tensing of valve and chordae tendineae makes the click
Ejection click
stenotic semilunar valves make a click in early systole
Prosthetic Aortic Valve
(sounds like the ticking of a loud watch)
Pericardial Friction Rub
Inflammation of the pericardium
Scratchy sound like sandpaper
Heard best if patient sits up and leans forward
Murmurs
A murmur is a gentle, blowing, swooshing sound that can be heard on chest wall
Conditions that can result in murmurs:
Velocity of blood increases (flow murmur) as in exercise.
Viscosity of blood decreases as in anemia.
Structural defects in valves (a stenotic (stiff) or narrow valve or an incompetent or regurigant valve, or unusual opening in the chamber)
All heart sounds are described by
Frequency or pitch: described as high pitched or low pitched
Intensity or loudness: loud or soft
Duration: very short for heart sounds; silent periods are longer
Timing: systole or diastole
Jugular Venous Pulse/Pressure
reflects filling pressure
Jugular veins empty unoxygenated blood directly into superior vena cava.
It is a backwards wave (right atrium) caused by events occurring upstream
Two jugular veins present on each side of neck.
Internal jugular lies deep and is not visible
External jugular is superficial
Because no valves exist to separate the superior vena cava and the right atrium, the jugular veins give information about the activity of the right side of the heart
Specifically reflects filling pressures and volume changes
Recumbency
at night produces fluid resorption and excretion
diaphoresis
sweating
orthostatic BP
especially if dizziness or lightheadedness, fatigue reported. Lay flat for 3 minutes, then take baseline BP and pulse, Have the patient sit up and take BP and pulse, have the patient stand and check BP and pulse within 1 minute. A drop of > 20 mmHg sys and 10 mmHg diastolic
Auscultate Carotid
Use BELL of stethoscope
Take a breath, exhale, and hold it briefly while you listen
Listening for:
A bruit is a swishing or blowing sound, it indicates turbulence
It is a marker for atherosclerotic disease which increases a persons risk for TIA or stroke
Apply bell of stethoscope on carotid at 3 levels
Jaw angle
mid cervical area
Base of neck
You will only hear a bruit when the lumen is occluded 1/2 to 2/3
How to distinguish the JVP from CP
JVP is lower, more lateral to the sternomastoid muscle, CP is higher and medial to this muscle.
Quality - JVP more wavelike 2 waves per cycle, CP brisk, 1 wave per cycle.
Respiration - JVP varies with respiration, it descends with inspiration, CP doesn’t vary.
JVP isn’t palpable , CP is.
Level of JVP drops and disappears as person is brought to sitting position, CP is unaffected by change in position.
Heave or lift
is a forceful thrusting of the ventricle during systole. It occurs with ventricular hypertrophy
A right ventricular heave is seen at the sternal border, a left ventricular heave is seen at the apex
Thrill
is a palpable vibration, it feels the throat of purring cat, it indicates turbulent blood flow (it is the feel of a murmur), however you may not always feel a thrill with a murmur –
if felt on right could indicate aortic stenosis and systemic hypertension,
if felt on the left could indicate pulmonic stenosis
Heart Valve and location
Aortic valve area: Second right interspace
Pulmonic valve area: Second left interspace
Tricuspid valve area: Left lower sternal border
Mitral valve area: Fifth interspace at around left midclavicular line
Erb’s point: At 3rd left intercostal; can hear S1 and S2
Pulse deficit
Apical and radial pulse rates should match
A pulse deficit signals weak contraction of the ventricles (afib and HF)
Heart sounds
Identify S1 as this serves as a reference point for the timing of all other sounds. S1 is the lub. S 1 is louder than S2 at the apex and S2 is louder at the base, S1 coincides with the carotid artery pulse. Split S2 is normal and is heard at the end of inspiration in some people. After listening with the diaphragm, listen with the Bell. The most common extra sound you will hear is a midsystolic click with mitral valve prolapse
Heart murmurs
Systolic murmurs-Can occur with a healthy heart (innocent) or with heart disease
Diastolic murmurs- Always indicates heart disease
Describe by timing, loudness, pitch, pattern, quality, location, radiation
Timing is early, mid or late systole or diastole or throughout the cardiac cycle (pansystolic)
Loudness is graded 1-6
Describe where heard best
CV Disease
In the U.S., more than 1 in 3 adults have one or more forms of cardiovascular heart disease (CVD)
Higher percent of men than women have hypertension until 45 years, after which the percentages are similar
After age 64 years, women have much higher percentage HTN than men
Hypertension is 2 to 3 times more common among women taking oral contraceptives, especially obese and older women
Hypertension in Blacks is among highest in world and is rising
CVD and Women
Leading cause of death in women
Women tend to have smaller coronary arteries than men, women tend to delay care more often due to presentation of symptoms
Within the first year following an MI, women age 45 and older are 26% more likely to die than their male counterparts (19%)
Women may report different symptoms than the typical “chest pain” experienced by men, thus clinical diagnosis may be delayed
Only symptom is fatigue
Diagnosis of Chest Pain
Cardiovascular (Ischemic) – Angina, MI
Cardiovascular (non-ischemic) – pericarditis, aortic dissection, Pulmonary Hypertension
Pulmonary – Pulmonary Embolism (blood clot), pneumonia, pneumothorax
Gastrointestinal – GERD, Esophageal spasm, cholecystitis (inflammation of gallbladder), pancreatitis
Dermatologic – Herpes Zoster (shingles can cause pain before the rash shows up)
Musculoskeletal/Neurologic – Costochrondritis (inflammation of costo cartilage), chest wall muscle strain
Psychogenic – depression, anxiety, Panic attack
Cholesterol numbers
Total cholesterol for >200,
LDL of >150
HDL of <40 in men and <50 in women and men 45 years and older.
This patient is postmenopausal, obese and high LDL
