Cardiac Notes

Blood Flow Through the Heart

• Blood flows from the body to the right atrium, then to the right ventricle, and then to the lungs for oxygenation.

• Oxygenated blood returns from the lungs to the left atrium, then to the left ventricle, and finally out to the body.

Heart Valves

• Mitral Valve: Located between the left atrium and left ventricle.

• Tricuspid Valve: Located between the right atrium and right ventricle.

• Pulmonic Valve: (Semilunar) Located between the right ventricle and pulmonary artery.

• Aortic Valve: (Semilunar) Located between the left ventricle and aorta.

• Chordae Tendineae: Tendon-like cords that attach the mitral and tricuspid valves to the papillary muscles.

• Papillary Muscles: Located in the ventricles; they contract to prevent the valves from inverting during ventricular contraction.

Conduction System

• SA Node: Sinoatrial node; the heart's natural pacemaker.

• AV Node: Atrioventricular node; delays the electrical impulse to allow the atria to contract before the ventricles.

• Bundle of His: Conducts the electrical impulse from the AV node to the bundle branches.

• Left Bundle Branch: Divides into the anterior and posterior fascicles to conduct impulses to the left ventricle.

• Right Bundle Branch: Conducts impulses to the right ventricle.

• Purkinje Fibers: Distribute the electrical impulse throughout the ventricles, causing them to contract.

History and Physical Exam of the Adult

• History of Current Complaint:

  • Chest pain: Onset, location, duration, character, aggravating/alleviating factors.

  • Irregularities of heart rhythm (palpitations).

  • Respiratory manifestations: Dyspnea (shortness of breath), especially exertional dyspnea and orthopnea (difficulty breathing when lying down).

  • Paroxysmal nocturnal dyspnea (sudden, severe shortness of breath at night).

  • Fatigue or dizziness.

• Past Health History:

  • Major illnesses and cardiac surgical history.

  • Family heart history/childhood & infectious diseases.

  • Psychosocial history.

• Medications & Allergies:

  • Cardiac medications, diuretics, aspirin, and chewable antacids.

• Risk Factors:

  • Dietary/nutrition habits.

  • Exercise and social habits.

  • Occupation, geographic location, and environment.

Cardiac Assessment: Physical Signs

• Skin Color: Dusky skin, pallor (pale skin), or cyanosis (bluish skin).

• Syncope, Dizziness, Vertigo: Fainting, lightheadedness, or a sensation of spinning.

• Generalized Edema: Swelling throughout the body.

• Weight Gain and Dependent, Pitting Edema: Swelling in the legs, feet, or arms that leaves a pit when pressed.

• Respiratory Distress: Difficulty breathing.

Focused Cardiac Assessment

• Blood Pressure: Measured bilaterally in both arms.

• Orthostatic VS: Blood pressure and heart rate measurements taken in different positions (lying, sitting, standing) to assess for changes.

• Pulse Pressure: Calculated as $SBP - DBP = Pulse$. Assess pulse rhythm and force.

• Pulse Deficit: Difference between the apical pulse and the peripheral pulse; indicates a dysrhythmia.

• Respirations: Assessment includes rate, rhythm, depth, and quality.

Heart Sounds - Location

• S1 and S2:

  • S2 Loudest: Base of the heart (Aortic & Pulmonic areas).

  • S1 & S2 Sound Equally: Erb's Point

  • S1 Loudest: Apex of the Heart (Mitral & Tricuspid areas).

Normal Heart Sounds: S1 & S2

• S1 = "lub"

  • Tricuspid and Mitral valves close nearly simultaneously.

  • Best heard at the apex of the heart.

  • Marks the beginning of systole (ventricular contraction).

• S2 = "dub"

  • Aortic and Pulmonic valves close nearly simultaneously.

  • Best heard at the base of the heart.

  • Marks the beginning of diastole (ventricular relaxation).

Heart Sound: S3: Ventricular Gallop

• Turbulence of blood going into ventricles (passive filling, not a contraction).

• Low-intensity vibration of ventricle walls.

• May be normal in young adults.

• Common with left ventricular heart failure or mitral valve regurgitation.

Abnormal Heart Sounds

• S3 – Ventricular Gallop: Early diastolic filling of the left ventricle.

• S4 – Atrial Gallop: Left atrial contraction filling into stiff ventricles.

• Pericardial Friction Rub: Indicates inflamed pericardium.

• Murmurs: Indicate ineffective valves; can be systolic or diastolic.

Heart Sounds: S4—Atrial Gallop

• Heard with atrial contraction if there is resistance to ventricular filling (active filling).

• Decreased ventricular compliance.

• Common in patients with CAD (coronary artery disease), cardiomyopathy, left ventricular hypertrophy, or aortic stenosis.

• May be heard in the elderly, but is always pathological.

Major Purpose of the Heart Valves

• Prevent the backward flow of blood

Pericardial Friction Rub

• Caused by pericarditis (inflammation of the pericardium).

• Best heard at the apex of the heart (apical).

• Associated with chest pain and shortness of breath (SOB).

• Managed with EKG, NSAIDs, ASA, and drainage.

Murmurs in Adults

• Abnormal sound in the heart or neighboring large blood vessels.

• Heard during systole, diastole, or both.

• Graded on a 1-6 point grading system.

• Causes: cardiac valve disorder (atherosclerosis, regurgitation) & abnormal blood flow patterns.

• Can occur during pregnancy or exercise.

Physical Assessment Head and Neck

• Neck Veins: Assess for Jugular Vein Distention (JVD).

  • Evaluate with the head of the bed (HOB) at 30-45 degrees.

• Chest:

  • Auscultate heart sounds.

  • Palpate carotid, abdominal aorta, and femoral arteries.

Auscultation: Bruit

• Listen over major arteries:

  • Carotid arteries.

  • Abdominal aorta.

• Listen for a bruit: a blowing sound.

• Palpate for a thrill: a vibration.

• Causes:

  • Narrowed vessel

  • Aneurysm

Physical Assessment - Lungs

• Breath sounds: Assess for abnormalities.

  • Left-sided heart failure: Tachypnea (rapid breathing), crackles, blood-tinged sputum, pulmonary edema.

  • Right-sided heart failure: Lungs generally not affected, but may have heart palpitations and generalized edema.

Physical Assessment - Abdomen

• Inspection:

  • Distension: ascites (fluid accumulation in the abdomen).

• Auscultation:

  • Aortic bruits/thrills.

  • Renal bruits/thrills.

• Palpation:

  • Enlarged liver.

Physical Assessment - Edema

• Generalized Edema: Swelling throughout the whole body.

• Dependent Edema: Swelling confined to dependent areas (e.g., legs, feet).

• Pitting Edema: Swelling that leaves a "pit" when pressed.

• Scale:

  • Grade 1+ x 2 = 2mm indentation

  • Grade 2+ (x 2 mm) = 4mm

  • Grade 3+ (x2 mm) = 6mm

  • Grade 4+ (x2 mm) = 8mm

Age-Related Changes

• Cardiac Valves:

  • Thicker & stiffer.

  • Infections & Vegetation.

  • Murmurs more common.

• Conduction System:

  • Bradycardia & dysrhythmias.

  • Seen on EKG: increase in PR and QRS interval.

• Left Ventricle:

  • Increased size.

  • Stiffer, less contractility.

  • Decreased response to workload.

• Arteries:

  • Thicker and stiffer (atherosclerosis).

  • Increased systemic vascular resistance.

  • Increased sensitivity to ADH (Antidiuretic Hormone) which leads to HTN.

  • Orthostatic HTN.

History and Physical Exam of the Child

• Acute Assessment: Observe the child for signs of distress

  • Pallor, sweating, cyanosis, or increased work of breathing

  • Level of activity, do they appear uncomfortable?

  • Interactions with parents/caregivers

• History – General Health

  • Feeding difficulties

  • Growth delays

  • Decreased exercise/play tolerance

  • Prenatal history (exposure to drugs, lithium, phenytoin, alcohol)

  • Maternal illness: Diabetes, rubella, systemic lupus erythematosus

  • Born premature or other family history

• Cardiac Assessment

  • Periods of cyanosis, sweating, SOB, palpitations, and edema

  • Chest pain and syncope (rare)

  • Cardiac monitor

  • Heart Sounds: Congenital displacement

Heart Sounds in children

• Move across the chest in smaller increments.

• Assess lying, sitting, and standing.

• Murmurs are common.

  • Affects 50% of children

• S1 (apex) and S2 (base, 2nd intercostal): normal.

• S3: could be innocent.

• S4: atrial gallop.

  • Target apical heart rates by age:

    • newborn: 100-170

    • 6 months 1 yr 90-130

    • 2-3 years: 80-120

    • 10 years and older: 60-120

Diagnostic Tests

• Non-invasive:

  • EKG

  • Echocardiogram

  • Chest X-ray

  • Holter Monitor

Electrocardiogram: ECG (EKG)

• Measures electrical conduction in the heart.

• Diagnoses abnormal heart rhythms, heart size, position.

• 3 Types: 1, 3, and 12 lead

  • 12 Lead used for diagnostic

EKG/ECG

• Performed at the bedside by trained nurse/tech

• Used to diagnose:

  • Abnormal heart rhythms

  • Electrical abnormalities

  • Narrowed arteries

  • Effects of medications

  • Ischemia, injury, infarctions, prior MI

  • Pacemaker status

Cardiac Action Potential & Automaticity

• Electrical Activity—The action potential:

  • Depolarization

    • Sodium ($Na$) moves into the cell and potassium ($K^+$) moves out

    • Calcium ($Ca^{2+}$) inside cells causes an increase in cardiac contraction of the heart

    • Inside of cells becomes more positively charged

  • S1: Contraction

  • Repolarization

    • Potassium ($K^+$) moves back into the cell and sodium ($Na$) moves back out

    • Inside of cells moves back to a more negative charge

  • S2: Relaxation

  • Spontaneous depolarization

  • SA Node Automaticity

Cardiac Cycle on ECG

• Includes systole, diastole, atrial depolarization, ventricular depolarization, and ventricular repolarization.

• Key components: P wave, QRS complex, T wave, and R-R interval.

EKG interpretation

• Key components: P wave, QRS complex, T wave.

• Measurements:

  • 0.04 sec

  • 0.20 sec

• Intervals:

  • PR interval

  • QRS interval

  • QT interval

Cardiac Cycle on EKG/ECG. Intervals and Segments

• The image shows the different waves on an EKG to include P wave, QRS complex, and T wave.

• It shows the different segments and intervals to include PR segment, PR interval, ST segment, QRS interval, and QT interval.

EKG/ECG

• P wave

  • Atrial depolarization

• PR interval

  • Time for electrical impulse conduction through the atria and the AV node

  • Duration 0.12 – 0.20 sec

• Baseline between P wave and QRS complex is the isoelectric line

• QRS complex

  • Ventricular depolarization

  • Normal Duration <0.12 sec

  • Wide QRS = hyperkalemia

EKG/ECG

• ST Segment

  • Normally Isoelectric (no electrical charge)

  • ST Depression usually hypokalemia

  • Elevated ST: myocardial ischemia

• T wave

  • Ventricular repolarization

  • Flattened T wave: hypokalemia

  • Peaked T wave: hyperkalemia

  • Inverted T wave: hypokalemia

• U wave (if present)

  • hypokalemia

Hypo/hyperkalemia: changes to the EKG

• HYPOkalemia:

  • P wave = peaked

  • T wave (flattening, shallow or inverted)

  • ST-segment depression

  • U waves = prominent

  • PR interval = prolonged

• HYPERkalemia:

  • P wave = flattened

  • QRS = Prolonged or wide

  • T wave = peaked

  • PR Interval = Prolonged

  • ST-Segment Depression

Holter Monitoring

• 24- 48-hour wearable EKG while performing daily routine

• Records arrythmias

• Evaluate medications or pacemaker therapy

• Remove for showers

• Diary Card (must be maintained accurately)

  • Activity

  • Symptom

  • Exact time

Zio Patch monitor

• Single Lead

• Water resistant

• Readings up to 14 days

• Captures a variety of cardiac dysrhythmias

• Better accuracy than Holter

Echocardiogram

• Evaluates:

  • Heart size & shape

  • Valve structure & function

  • Blood flow & pumping function

  • Ejection fraction

• Client Instructions:

  • Lie Still; No talking

  • Breath normally

Diagnostic Tests: Invasive Cardiac Catheterization

• View of aorta through coronary arteries

• Evaluates heart pressures/function

• Stent placement

• Biopsy

• Diagnosis

Cardiac Catheterization

• Local anesthetic or sedation given, general in certain cases

• Right Heart

  • Insert through vein (jugular, AC)

• Left Heart

  • Insert through a femoral (most common) brachial, radial, or axillary artery

• Coronary Angiography: Cardiac cath with injection of contrast medium

Cardiac Cath: Pre-Op Procedures

• Informed consent

• Assess allergies. Assess for Shellfish and Iodine Allergies

• NPO 6-8 hrs prior

• VS

• Mark peripheral pulses

• Labs:

  • Creatinine, BUN levels

  • PT/INR, aPTT

• Education

  • Lie still

  • Fluttery feeling

  • Flushing/ warmth

  • Cough

  • Palpitations

  • Remain flat on back for 2-12 hours postprocedure

Cardiac Catheterization: Post-procedure Interventions

• Monitor VS

• Assess CMS (circulation, motion, sensation)

• Cardiac monitoring

• Maintain pressure dressing

• Monitor for bleeding

• Encourage fluids

• Assess S/S of dye hypersensitivity

• Keep extremity extended (no bending)

• Do not elevate HOB – (lay supine)

• No getting up for 6-12 hours (lay supine)

Lab values

• Lipids:

  • Triglycerides:

    • 40 to <160 mg/dL (males)

    • 35 to <135 mg/dL (females)

  • Total Cholesterol: <200 mg/dL

  • LDL: (bad cholesterol) <130 mg/dL

  • HDL: (good cholesterol)

    • Male: >45 mg/dL

    • Female: >55mg/dL

  • ADH 1-5 pg/mL

Lab values (cont’d)

• RBC

  • men – 4.0 to 6.0 x $10^{12}$/L.

  • women – 3.8 to 5.2 x $10^{12}$/L.

• Hgb

  • men: 13.2 and 16.6 (g/dL)

  • women: 11.6 and 15 g/dL

• Cardiac Markers:

  • CK-MB: normal 0%

  • Troponin-I: < 0.03 ng/mL

  • Troponin-T: <0.2 ng/mL

  • BNP – b-type natriuretic peptide: <100 pg/mL

Cardiac Medications

• Classes: Beta Blockers, Calcium Channel Blockers, Cardiac Glycosides

Beta-Adrenergic Blockers (Beta-Blockers)

• B1 selective

  • Relaxes the heart

  • e.g., Metoprolol (Lopressor) Atenolol, Esmolol

• B1 and B2 Non-selective

  • Relaxes the heart and lungs

  • eg. Propranolol (Inderal), Carvedilol (Coreg)

• Two Types:

  • Hypertension

  • Supraventricular tachydysrhythmias

  • Heart Failure; Angina; Myocardial Infarction

  • Migraine (Inderal)

  • Anxiety

Beta Blockers

• Mechanism of action:

  • Blocks beta-receptors of the sympathetic nervous system.

  • Prevent adrenaline from binding to receptors.

• Effects:

  • Reduce heart rate

  • Reduce blood pressure

  • Decrease myocardial contractility by slowing AV conduction

Beta Blockers

• Adverse Effects:

  • Hypotension, bradycardia,

  • Bronchospasm, dyspnea (Lt HF)

  • JVD, edema, weight gain (Rt HF)

  • Cold extremities, exacerbation of Raynaud's disease

  • Fatigue, dizziness, orthostatic hypotension

• Nursing Implications:

  • Hold Apical Rate < 60

  • Hold Systolic < 90

  • Heart Failure

  • Asthmatics

  • Pregnancy

  • Patient Teaching

  • Pulse, BP checks

  • Diabetics =Glucose checks

  • Do not stop abruptly

Calcium Channel Blockers

• Amlodipine, Cardizem, Procardia, Verapamil

• Affect smooth muscle contraction by blocking calcium during depolarization, relaxing smooth muscles in the heart

• Treatment:

  • Angina

  • Hypertension

  • Supraventricular tachycardia

Calcium Channel Blockers

• Less $Ca^{2+}$ in the muscle = less force of contraction

• Slows the SA/AV node = decreased HR (diltiazem & verapamil)

• Vasodilation- (peripheral and/or coronary)

• Relaxes smooth muscle

Calcium Channel Blockers

• Adverse Effects:

  • Bradycardia, hypotension

  • Chest pain

  • Bronchospasm, dyspnea

  • Peripheral edema

  • Fatigue

  • Dizziness, orthostatic hypotension, flushing

  • Headache

  • Reflex tachycardia

• Nursing Implications:

  • Hold if Systolic <90

  • Hold if Pulse <50

  • Monitor Labs; Liver and renal studies

  • Administration issues

  • Patient Teaching

  • Pulse, BP checks

  • All Adverse effects

  • Do not stop abruptly

  • No grapefruit/juice

Cardiac Glycoside: Inotropic Agents - Digoxin

• Mechanism of Action: Inhibits Na K+ ATPase enzyme, Increases force of heart's contractions

• Used to Treat: Atrial Fibrillation, Atrial Flutter, Congestive Heart Failure

• Side Effects: Unusual Tiredness and Fatigue, Anxiety, Hallucinations

• Poisoning and Toxicity: Visual Disturbances, Nausea or Vomiting, Arrhythmias, Electrolyte Imbalances, Can be worsened by other medications

• Contraindication: Ventricular Fibrillations

Digoxin: Nursing Implications

• Monitor:

  • S/Sx of toxicity

  • Serum digoxin level

    • Hold if > 2 ng/ml = toxic

  • Hold medication if apical pulse < 60

  • Monitor electrolytes: Potassium, Calcium, and Magnesium level

  • Have antidote available for dig toxicity

    • Digoxin immune fab (digibind)

• Patient teaching:

  • Avoid foods high in K+ potassium (unless on diuretics)

  • Check pulse daily, hold if <60

  • s/s toxicity & report to PCP

  • Abdominal pain

  • N/V, anorexia

  • Visual disturbances

  • Arrhythmias

  • Must have dig levels drawn as prescribed

Nursing Process and Care Plan

• Assessment:

  • General physical assessment with focused cardiac assessment –Chief Complaint

  • Health history, family history, psychosocial

  • Diagnostic tests and labs: EKG, Chest Xray, cardiac enzymes

  • Respiratory signs/symptoms

Nursing Diagnosis

• Decreased Cardiac Output

• Decreased Activity Tolerance

• Acute Pain

• Fear/Anxiety

• Risk for Impaired Gas Exchange

• Fatigue

Planning (Expected Outcome)

• Patient will maintain BP within an individually acceptable range.

Implementation

• Reduce activities that put stress on the heart such as limit visitors each hour.

• Monitor and record BP in both arms q 2 hours.

• Administer propranolol (beta blocker) as directed.

Evaluation

(Outcome met/not met/partially met)