Cardiac

Chambers of the heart

right atrium, right ventricle, left atrium, left ventricle

AV valves of the heart

tricuspid and mitral

Semilunar valves

pulmonary valve and aortic valve

Endocardium

inner lining of the heart

Myocardium

muscular, middle layer of the heart

Epicardium or pericardium

outermost layer of the heart

What does the right side of the heart do?

receives deoxygenated blood from the body and pumps it to the lungs

What does the left side of the heart do?

pumps oxygen-rich blood to the body

Blood flow to and from the heart order

1. Body

2. Inferior or superior vena cava

3. Right atrium

4. Tricuspid valve

5. Right ventricle

6. Pulmonary valve

7. Pulmonary arteries

8. Lungs

9. Pulmonary veins

10. Left atrium

11. Mitral valve

12. Left ventricle

13. Aortic valve

14. Aorta

15. Body

What do pulmonary arteries do?

They carry unoxygenated blood away from the heart to the lungs

What do pulmonary veins do?

They return oxygenated blood back to the heart

Stroke volume

The amount of blood ejected by the left ventricle with each contraction

Heart rate

Number of heart beats per minute

Cardiac output

Heart rate x stroke volume

Electrical conduction of the heart

SA node, AV node, Bundle of His, left and right bundle branches, Purkinje fibers

Normal sinus rhythm involves...

The firing of all electrical conductions

Preload

Volume of blood in ventricles at end of diastole

Afterload

Resistance that the left ventricle must overcome to eject blood

Autonomic nervous system

-Baroreceptors

-Adrenal medulla

-Sympathetic and parasympathetic nerve fibers

-Vagus nerve

-Carotid sinus nerve

What regulates blood pressure?

-Baroreceptors and stretch receptors

-Volume status

-Hormonal pathways

What are baroreceptors?

They are located in the walls of the aortic arch and carotid sinuses; send messages to the brainstem to stimulate the sympathetic nervous system to increase HR

What are stretch receptors?

They sense stretch related to pressure changes in the vena cave and right atrium.

How does hypovolemia regulate blood pressure?

Sympathetic response is to elevate the HR, attempting to maintain cardiac output even though each heartbeat is pushing out less blood. BP is low because of low volume

How does hypervolemia regulate blood pressure?

Parasympathetic response to decrease the HR, blood vessels dilate, and decrease strength of atrial contractions bringing down the HR

RAAS system

Renin is produced by the kidneys in response to impaired blood flow & tissue perfusion and converts angiotensinogen in the blood to angiotensin I; ACE converts angiotensin I to angiotensin II. Angiotensin II then encourages vasoconstriction and stimulates the release of aldosterone. Aldosterone then promotes Na and water retention as well as K excretion.

Vasopressin

Antidiuretic hormone that regulates body fluid balance by controlling how much water the kidneys absorb or excrete

Vascular system

Arteries

Arterioles

Capillaries

Venules

Veins

Valves

Lymph

What do the coronary arteries do?

Supply oxygenated blood to the heart muscle, comes directly from the aorta

Cardiovascular changes that occur with aging

-Reduced elasticity of vessels (arteriosclerosis)

-Accumulation of plaque in the arteries (atherosclerosis)

-Less efficient cardiovascular response to stress-reduction in elasticity of heart tissue

-Increased likelihood of rhythm changes

-Venous valve change may contribute to pooling

Cardiovascular risk factors

Cigarette smoking, activity, diet, blood pressure, lipids, DM, weight, ethnicity, alcohol intake, stress, age, family history, genetics, gender, and other biologic factors

Nursing responsibilites regarding hypertension

-Obtain accurate measurements

-Review trends and symptoms

-Support medication adherence

-Discuss sustainable lifestyle changes

-Tailor education to patient needs

Nursing interventions for HTN: assess

-Neurological assessment

-BP reading

-Exam optic fundi

-Auscultation for bruits

-Palpate for edema and present pulses

-Examine labs

-Examine BMI and waist circumference

-Administer meds

-Propose DASH diet

-Teach pt

Medications used to treat HTN

-Diuretics

-Calcium channel blockers

-Vasodilators

-Betablockers

-ACE inhibitors

-ARBs

Nursing Interventions for HTN: Educate

-Teach adherence to medication regimen

-Adherence to lifestyle changes

-Teach to monitor BP at home

-Watch for signs and symptoms

-Eliminate smoking

-Limit alcohol intake

-Regularly exercise

-Lose weight

How do diuretics treat HTN?

Increase urine output by inhibiting sodium and water reabsorption by the kidney, this lowers blood volume

-Thiazide

-Actone

-Ide

How do calcium channel blockers treat HTN?

They block calcium from entering the muscle cells of the heart and arteries, causing decreased contraction of the heart and dilates arteries.

-Dipine

How do beta blockers treat HTN?

They block the effects of the sympathetic nervous system (epinephrine) to decrease HR and force of heart contractions, thus lowering BP.

-lol

How do ACE inhibitors treat HTN?

By inhibiting the conversion of angiotensin 1 to angiotensin II, preventing vasoconstriction; restricts volume retention.

-pril

How do ARBs treat HTN?

They block the effects of angiotensin II by binding to it and its receptors. This prevents vasoconstriction and restricts volume retention

-sartan

What can I educate a patient about regarding HTN?

Smoking cessation, medication compliance, low Na, low fat, educate on BMI, incorporate exercise, decreasing stress, and decreasing alcohol consumption

Cardiac assessment

1. Observe: skin, edema, nail changes, venous patterns

2. Palpate: pulses, skin temp, edema, capillary refill

3. Auscultate: Heart rate, rhythm, apical pulse

4. Measure: BP, assess BP positional changes

5. Compare & Report: trends, note symptoms, and escalate concerning changes

What hair characteristics could point to cardiovascular issues?

Brittle, dry. Poor nutrition possibly due to cardiac or vascular insufficiency

What eye characteristics could point to cardiovascular issues?

-Blue-tinged conjunctiva: cyanosis

-Raised yellow-orange plaque under eyelids: elevated cholesterol

What lip characteristics could point to cardiovascular issues?

Blue: cyanosis

Dry: dehydration

What jugular characteristics could point to cardiovascular issues?

Distended vein could indicate hypervolemia, right-sided heart failure, pericardial tamponade, or constructive pericarditis

What chest characteristics could point to cardiovascular issues?

Crackles: left-sided heart failure

Rate, rhythm, murmurs

What vital sign characteristics could point to cardiovascular issues?

BP, HR, RR, temp, oxygen saturation,

Abdomen characteristics that could point to cardiovascular issues

Fluid accumulation or enlarged liver can indicate right-side heart failure

What skin characteristics could point to cardiovascular issues?

Dry and cool skin can be from poor nutrition. Blue skin could indicate cyanosis. Pallor could suggest anemia or poor circulation

What nail characteristics could point to cardiovascular issues?

Cyanosis, clubbing, thick nails

What lower extremity characteristics could point to cardiovascular issues?

Absence of hair is a sign of poor circulation

What leg/feet/ankle characteristics could point to cardiovascular issues?

Edema, weak pulse, little sensation

Heart murmur

An abnormal sound from the heart produced by defects in the chambers or valves

LDL

Bad cholesterol; low density lipoprotein that carries cholesterol from the liver to the rest of the body. Too much LDL can lead to a buildup of plaque. It can increase the risk of heart disease and stroke. Eat a low saturated fat diet, avoid trans fats and fried foods, eat more fiber, and exercise regularly

LDL normal range

Less than 100 mg/dL

HDL

Good cholesterol; high density lipoprotein. It carries cholesterol from the arteries and other parts of the body to the liver. Helps protect the heart. Increase it by exercising regularly, eating healthy fats, eating fatty fish, and quitting smoking

HDL normal range

60 mg/dL

What is troponin?

A regulatory protein that moves tropomyosin aside & exposes myosin binding sites when Ca+ is released during muscle contraction. These labs are monitored to detect heart muscle injury or to diagnose/rule out a heart attack

C-reactive protein

Marker indicating arterial inflammation. Helps predict the risk of heart disease, heart attack, and stroke. Also used to detect high levels of inflammation from acute infections or injury

Brain Natriuretic peptide

Produced by the chambers of the heart when the heart muscle is stretched or works harder to pump blood, used to quickly find out if a person's SOB or swelling is caused by heart failure

Creatinine Kinase myocardial bands

Released into the bloodstream when the heart tissue is injured or stressed. It elevates 4-6 hours after a heart event, and it peaks at 24 hours before returning to normal after a few days. NOTE: small amounts can be present in muscle related injuries.

How do chest x-rays diagnose cardiovascular conditions?

They provide information about the chest and may show cardiac enlargement or lung findings

Catheter or angiography

An invasive assessment of the coronary vessels

Holter Monitor

• Ambulatory exam in which the patient wears electrodes over several days during all their

normal activities

• Symptoms such as chest pain or SOB can be correlated with rhythm changes.

• The patient keeps a lot of their activity noting the time and what they are doing when the

symptom occurs

Stress Test

• Evaluates heart functioning when an increased workload is placed on the heart

• Evaluates functional ability of the heart

• Screening tool for symptoms of CAD that may be apparent only when heart is stressed

• Usually done on a regular treadmill or stationary bike

• Patients are monitored for heart rate, rhythm, and blood pressure

• This test can be combined with nuclear imaging to evaluate perfusion of the heart

What is an echocardiogram?

An ultrasound of the heart. It enables a doctor to examine the heart valves, determine the size/structure of your heart, and assess how well it is functioning. Estimates how forcefully the heart is pumping blood and can spot areas of the heart wall that have been injured by a previous MI or other cause.

Electrocardiogram

• Also known as ECG

• Performed for assessment screenings preop or for complaints of chest pain

• Graphic representation that illustrates electrical activity

• Electrodes placed on extremities and chest wall conduct electrical activity from the heart.

• Identifies the patient's baseline rhythm and rate

• Recognizes significant changes in baseline rhythm and rate

• Recognizes lethal arrythmias that require action immediately

• Evaluates heart damage

ECG interpretation checklist

-Rate: fast, slow, within normal range?

-Rhythm: regular or irregular?

-P wave: present and consistent?

-QRS wave: present and consistent?

-Is each P wave followed by a QRS, and vice versa?

-Intervals and morphology: are they within the criteria taught?

-What are the symptoms, vitals, and clinical context?

Sinus bradycardia / tachycardia

Heart rhythm that ORIGINATES FROM THE SINUS NODE and has a rate that is faster or slower than normal (less than 60, greater than 100)

P wave

atrial depolarization

QRS wave

ventricular depolarization

T wave

ventricular repolarization

Premature ventricular contractions or PVC

Extra, abnormal heartbeats that starts in the ventricles rather than the heart's normal electrical pathway. Consists of a wide QRS, no preceding P wave, and compensatory pause after the contraction as the heart resets. Disrupts the regular ventricular rhythm of the heart.

Causes of PVC

Low potassium, coffee, alcohol, heart disease, stress, or other unknown causes

How does hypertension affect the heart?

Can cause heart failure, systolic dysfunction, and dilated cardiomyopathy

How does hypertension affect the kidneys?

Progressive kidney damage and renal failure

How does hypertension affect the brain?

Stroke or other vascular complications

How does hypertension affect the blood vessels?

Damages vascular tissue and contributes to cardiovascular risks such as hypertensive crisis

How does hypertension affect the eyes?

It increases retinal arterial pressure and damages the microvasculature, leading to retinopathy or retinal damage.

Hypertensive crisis

A very high blood pressure reading that can be urgent or an emergency especially with evidence or symptoms of acute organ injury

What to do for a hypertensive crisis

Repeat or confirm the blood pressure reading, assess symptoms, and follow local escalation protocols. This situation requires IV antihypertensives, an admit to the ICU to ensure the BP does not drop below 25% within the 2-6 hours. Then wean to oral antihypertensives

Stroke

Disruption of blood flow to the brain

Ischemic stroke

Most common type of stroke in older people, occurs when the flow of blood to the brain is blocked by the narrowing or blockage of a carotid artery

Hemorrhagic stroke

A stroke where the blood loss is caused by the rupture of a blood vessel

Risk factors for a stroke

• High blood pressure

• Atherosclerosis

• Heart disease

• Smoking or tobacco use

• Atrial fibrillation (Afib)

• Diabetes

• Overweight or Obesity

• Blood disorders

• Excessive alcohol

• Certain medications

Orthostatic hypotension

-Blood pressure decreases as a patient moves from laying to an upright position

-Caused by pooling of blood in lower extremities when in upright position which reduces the amount of blood that returns to the heart and brain

-Normally the autonomic nervous system signals an increased HR to increase cardiac output

-Autonomic response is impaired while patients are on antihypertensives. So, when they move to an upright position, the patient can feel dizzy, experience syncope, and fall

Orthostatic hypotension nursing priorities

-Have patient sit up slowly and sit on the edge of the bed for 1-2 minutes

-Assess blood pressures 3 different ways, sitting, lying, standing

-A reduction of 20 systolic or 15 diastolic denotes orthostatic hypotension

-Instruct patient safety measures to prevent falls and injury

Coronary artery disease

Atherosclerosis of the coronary arteries that reduces the blood supply to the heart muscle. Lipid and inflammatory material accumulate in the arterial wall. The narrowing causes reduced perfusion to the heart muscle. Ischemia may occur, aka reduced oxygen supply to the myocardium

Coronary artery disease symptoms

Chest discomfort, SOB, fatigue, activity intolerance

CAD risk reduction

Physical activity, nutrition support, tobacco cessation, and management of blood pressure, lipids, and diabetes

CAD treatment

Lipid-lowering drugs, antiplatelet, antianginal, and other therapies based on the patient conditions

Angina

Caused by an imbalance of oxygen supply and demand. Chest discomfort associated with myocardial ischemia. It can occur when oxygen demand exceeds supply. Can be caused by atherosclerosis

Angina symptoms

-Pressure, tightness, squeezing, heaviness, or discomfort; it may radiate to the arm, jaw, neck, shoulder, or back

-Usually lasts

What do you do with new, severe, persistent, or worsening angina?

Escalate urgently according to emergency protocol

Angina assessment

-PQRST

Interventions for angina

-Administer aspirin

-Administer oxygen

-Assess VS

-Assess pain

-Administer nitro

-Obtain 12-lead ECG

-Provide continuous cardiac monitoring

-Provide emotional support

Stable angina

-Often predictable with exertion or emotional stress

-Typically follows a familiar pattern

-May improve with rest or prescribed medication

-Still requires assessment and care planning

Unstable angina

-New, worsening, or less predictable discomfort

-May occur at rest

-May last longer or respond differently

-Treat as potentially urgent; follow acute-care protocol

Myocardial infarction

-Ischemia that causes injury

-Heart muscle receives insufficient blood flow oxygen. Myocardial tissue is abruptly and severely deprived of oxygen

-Cell injury progresses when perfusion is not restored

-Myocardial injury and death may be replaced by scar tissue

-Rapid recognition and reperfusion-focused care can limit damage

-Follow current emergency protocols and the treating team's direction

-ST elevation

MI symptoms

-Chest pressure, tightness, heaviness, or pain

-SOB

-Sweating, nausea, pallor, weakness

-Pain/discomfort in the arm, jaw, neck, shoulder, or back

-Indigestion-like discomfort or fullness

-Unusual fatigue or weakness

-Dizziness, nausea, SOB

-Anxiety or impending doom

NOTE: absence of dramatic chest pain does not exclude MI. Treat concerning symptoms seriously