CARDIOVASCULAR FUNCTION NUR-224

Explain cardiac anatomy/physiology and the conduction system of the heart.

Incorporate assessment of cardiac risk factors into the health history and physical assessment of the patient with cardiovascular disease.

Discuss clinical indications, patient preparation and other elated nursing implications fro common test and procedures used to assess and diagnose cardiovascular diseases.

OBJECTIVES

Three layers Endocardium Myocardium Epicardium

Four chambers Heart valves

THE HEART

Surrounded by pericardium Pericardial fluid 10-30 mL Divided by septum Left ventricular wall 2-3 x as thick as right

ventricle Atrial wall thinner than ventricles

HEART

Inferior and superior vena cava send deoxygenated blood to right atrium

Blood passes through tricuspid valve to right ventricle blood passes from right ventricle through pulmonic valve via pulmonary artery to lungs

Blood from lungs enters left atrium via pulmonary veins

Passes through mitral valve to left ventricle Blood ejected to body through aortic valve

aorta peripheral system

BLOOD FLOW THROUGH THE HEART

STRUCTURE OF THE HEART

CORONARY ARTERIES

Depolarization (contraction of heart) Sinoatrial node – pacemaker of heart Contraction of atria AV node Bundle of His Right and left bundle branches Purkinje fibers

CONDUCTION SYSTEM

Systole Contraction of myocardium Ejection of blood from ventricles

Diastole Relaxation of myocardium Filling of coronary arteries Atrium is emptying into the ventricles

MECHANICAL SYSTEM

Number of times the ventricles contract each minute

60-100 Regulated by: Autonomic Nervous

System Sympathetic Parasympathetic

HEART RATE

Amount of blood pumped by each ventricle during a given period

Amount of blood ejected from ventricle with each beat (stroke volume) x heart rate

CO = SV x HR 4 – 7 L/min

CARDIAC OUTPUT

Stroke volume: amount of blood ejected with each heartbeat

Cardiac output: amount of blood pumped by ventricle in liters per minute

Preload: degree of cardiac muscle fiber tension at end of diastole (prior to contraction)

Afterload: resistance that ventricles must overcome to eject the blood

Contractility: ability of cardiac muscle to shorten in response to electrical impulse

CARDIAC OUTPUT

Health history Family/genetic history

ASSESSMENT

Chest pain Dyspnea Peripheral edema, weight gain Palpitations Fatigue Dizziness, syncope, changes in level of

consciousness

COMMON SYMPTOMS

Medications Nutrition Elimination Activity, exercise Sleep, rest

Self-concept Roles,

relationships Sexuality Risk factors

ASSESSMENT

Inspection Palpation Percussion Auscultation

PHYSICAL ASSESMENT

Normal skin color Capillary refill < 3 seconds Thorax symmetrical No jugular vein distention with patient at

45° Absence of clubbing

INSPECTION

PMI palpable at 5th ICS mid-clavicular line No thrills, heaves Slight pulsation of abdominal aorta in

epigastric region Carotid and extremity pulses equal

bilaterally No pedal edema

PALPATION

Normal heart sounds S1 and S2 heart sounds heard Apical-radial rate equal and regular No murmurs or extra heart sounds No S3 or S4 Pericardial friction rub

AUSCULTATION

HEART SOUNDS

Extremities

Lungs

Abdomen

ASSESSMENT OF OTHER SYSTEMS

Laboratory test: Diagnose the cause of cardiac-related

signs/symptoms Determine baseline values before initiating

therapeutic interventions Ensure therapeutic levels of medication are

maintained Evaluate the patient’s response to the

therapeutic regimen Identify abnormalities

DIAGNOSTIC EVALUATION

Cholesterol - normal level <200mg/dL Major sources – diet, liver

Low density lipoproteins LDLs <160

High-density lipoproteins HDLs

Triglycerides <200

BLOOD CHEMISTRIES

CXR/Fluoroscopy Electrocardiography Cardiac stress testing Echocardiography

DIAGNOSTIC STUDIES

Coronary arteries dilate to 4x their normal in response to increased metabolic demands for oxygen.

Coronary arteries affected by atherosclerosis dilate less, compromising blood flow to the myocardium ischemia

Noninvasive test Abnormalities in CV function are more likely

to be detected during times of increased stress.

CARDIAC STRESS TESTING

Determine :• presence of CAD• cause of chest pain • functional capacity of the heart after MI/

heart surgery• effective of antianginal/antiarrhythmic • dysrhythmias/ physical exercise

CARDIAC STRESS TESTING

Pre-Test Physical and Baseline ECG Signed consent Patient teaching Report cardiac symptoms during test NPO 4 hours pre-test Withhold meds Emergency and resuscitation

equipment need to be at site of test at all times

CARDIAC STRESS TESTING

Testing procedure Exercise equipment Increase HR to target rate for age and

gender OR c/o chest pain or fatigue Speed or incline increased every 2-3

minutes to increase stress on patient ECG and BP monitored throughout the test Rest for 15 minutes post test while being

monitored

CARDIAC STRESS TESTING

Invasive procedure study used to measure cardiac chamber pressures, assess patency of coronary arteries

Requires ECG, emergency equipment must be available

Assessment prior to test: allergies, blood work

Assessment of patient postprocedure: circulation, potential for bleeding, potential for dysrhythmias

Activity restrictions Patient education pre/postprocedure

CARDIAC CATHERIZATION

Preparation √ allergies to shellfish Signed consent form D/C anticoagulants,

ASA, salicylates, herbals affecting coagulants

Contraindicated; patients with bleeding disorders Elderly, dehydrated Severe renal failure

Patient Teaching Palpitations as

catheter enters left ventricle

Heat/hot flash as contrast medium injected

Sensation of need to cough as medium injected into right side of heart

CARDIAC CATHETERIZATION

During Procedure nausea pain at insertion

siteSTAT Intervention chest pain dysrhythmias changes in

peripheral pulses neuro assessment

Post Procedure VS & Neuro checks insertion site pressure dressing bleeding/hematomaAssessment extremities - s/s

ischemia r/t clots bed rest 4-6 hrs

post procedure

CARDIAC CATHERIZATION

CVP Pulmonary artery pressure Intra-arterial BP monitoring

HEMODYNAMIC MONITORING

HEMODYNAMIC MONITORING