Heart

Structure of the Heart

Coronary Arteries

Electrophysiologic Properties • Excitability- ability to depolarize in response to stimulus • Automaticity – ability of cardiac pacemaker to initiate an impulse spontaneously and repetitively • Contractility- ability to contract • Refractoriness- inability to respond to a new stimulus while still in a state of depolarization • Conductivity- ability of heart fibers to propagate electrical impulses along and

Cardiac Conduction System

Electrical Activity of the Heart •Electrical impulses from your heart muscle (the myocardium) cause your heart to beat (contract).

•S-A node (sinoatrial node) •A-V node (atrioventricular node) •Bundle of His •Purkinje system

Electrical Pathway STEP 1. The S-A node (natural pacemaker) creates an electrical signal

STEP 2. The electrical signal follows natural electrical pathways through both atria. The movement of electricity causes the atria to contract, which helps push blood into the ventricles

STEP 3. The electrical signal reaches the A-V node (electrical bridge). There, the signal pauses to give the ventricles time to fill with blood.

STEP 4. The electrical signal spreads through the Bundle of His and Purkinje system. The movement of electricity causes the ventricles to contract and push blood out to your lungs and body

CO= SV x HR • Control of heart rate – Autonomic nervous system and baroreceptors

Autonomic Nervous System Affectation of the CVS • 1. Parasympathetic – Release of Acetylcholine • 2. Sympathetic – Release of Norepinephrine

Control of Stroke Volume •Preload: Length of the myocardial fiber of the left ventricle at the end of diastole Frank-Starling law – The greater the myocardial fiber length, the greater the force of contraction •Afterload: The amount of pressure required by the left ventricle to open the aortic valve during systole and to eject blood :affected by systemic vascular resistance and pulmonary vascular resistance *Contractility is increased by catecholamines (Adrenal medulla), SNS, some medications and decreased by hypoxemia, acidosis, some medications

ASSESSMENT of the CARDIOVASCULAR SYSTEM I. Risk Factors A. NON-MODIFIABLE RISK FACTORS 1. AGE • 55 y/o. Effects of Age- related changes in cardiovascular sx become more pronounced • Symptomatic C.A.D. appears predominantly in clients over 40y/o • Clients in their 30’s, and even in their 20’s sometimes suffer from anginal attacks or M.I • 50% of  Attacks occur in individual >65y/o

2. GENDER • Men are at a greater risk for the development of CVD • Risk for women increases significantly at menopause 3. RACE • Black Americans have a higher risk for developing CVD than the general population because of their high incidence of HPN. 4. FAMILY HISTORY • The presence of Coronary Atherosclerosis in a parent or sibling under 50y/o is associated w/ the same findings in another family member.

B. MODIFIABLE RISK FACTORS 1. CIGARETTE SMOKING • Major contributing factor of CVD • ♂ adult smokers have a 70% higher mortality rate than ♂ non-smokers • All smokers have more than 2x the risk of  attack than the non-smokers • Smoking triples the risk of MI in women and doubles the risk of MI in men.

2. HYPERTENSION ♂ over 45y/o and with BP ↑ 140/90 & adult ♀ w/ BP ↑ 160/95 have a 50% ↑ chance of mortality HPN can be prevented through adherence to medical regimen 3. ↑SERUM CHOLESTEROL (HYPERLIPIDEMIA) Hyperlipidemia ↑es the risk of developing C.A.D. among clients w/cholesterol level of >300mg/dl; is 3x more likely to develop C.V.D than in clients with <200mg/dl of cholesterol level A diet high in saturated fat, cholesterol and calories is thought to be a major factor in the development of hyperlipidemia

4. DIABETES MELLITUS Diabetes leads to early atherosclerosis Clients w/ DM are at much risk for CAD 5. OBESITY ↑ workload & O2 demand of the heart Associated w/ ↑ed caloric intake and elevated levels of LDL 6. LACK OF EXERCISE Exercise can improve the efficiency of the  Exercise may reduce the risk of CAD by ↓ weight, ↓ BP & ↑ protective lipoprotein HDL Sexual activity

7. STRESS >Stress stimulates the CVS by the release of Catecholamines Type A personality = found to have 2x risk of developing CVD compared w/ the Type B person 8. ORAL CONTRACEPTIVES Use of oral contraceptives or birth control pills has been associated with an risk of CVD 9. DIET Intake of food with ↑Na, Cholesterol, Saturated fat content & caffeine Nurse also assess attitudes toward food Cultural beliefs and economic status can affect the choice of food

10. HABITS • Smoking (duration & the # of cigarette sticks daily) • Cigarette smoking ↑es the risk of CAD & worsens hypertension • Alcohol intake

PHYSICAL EXAMINATION • A general inspection • Assessment of BP, arterial pulses, and jugular venous pulse • Percussion, palpation, and auscultation of the heart • Evaluation for edema

GENERAL APPEARANCE Begin with inspection. • Does the client lie quietly, or is there restlessness or continual moving about? • Can the client lie flat, or is only an upright, erect position tolerated? • Does the facial expression reflect pain or obvious signs of respiratory distress? • Are there signs of significant cyanosis or pallor? • Can the client answer questions without dyspnea during the interview?

LEVEL OF CONSCIOUSNESS • What is the client’s affect? • Are there obvious signs of anxiety, fear, depression, or anger? • How does the client react to those in the immediate vicinity, including significant others? WEIGHT MANAGEMENT – daily weight, height, waist circumference BMI

HEAD, NECK, NAILS, AND SKIN • Pay particular attention to the eyes, ear lobes, lips, and buccal mucosa. – arcus senilis – xanthelasma • Central cyanosis indicates poor arterial circulation. • Peripheral cyanosis, seen in lips, ear lobes, and nail beds, suggests peripheral vasoconstriction. • Blanch Test • Schamroth’s Test • Assess skin turgor (elasticity) by lifting a fold of skin • Pallor

• PALLOR – Result of inadequate circulating blood – Characterized by the absence of underlying red tones (browned skin – yellowish brown; black skinned – ashen gray) – Usually evident in areas least pigmentation: conjunctiva, oral mucous membranes, nail beds, palms of the hand, soles of the feet • CYANOSIS – Bluish discoloration of the skin – Usually evident in the: nail beds and buccal mucosa (in dark-skinned, assess the palpebral conjunctiva, palms and soles)

■ EDEMA

-Inspect dependent areas for edema. ■ BLOOD PRESSURE - Measure BP in both arms initially to rule out dissecting aortic aneurysm, coarctation of the aorta, vascular obstruction, vascular outlet syndromes, and errors in measurement.

 PULSE -If the pulse is irregular, assess for a pulse deficit 0+ = nonpalpable pulse 1+ = weak thready pulse, difficult to palpate +2 = diminished pulse, cannot be obliterated +3 = easy to palpate, full pulse, cannot be obliterated +4 = full bounding pulse  RESPIRATIONS -The rate, rhythm, depth, and quality of the breathing pattern. -Auscultate the lungs for the presence of crackles, rhochi (dry rattling), or other abnormal breath sounds.

■ HEAD AND NECK • Neck Veins -Neck vein distention can estimate central venous pressure (CVP). The amount of distention reflects pressure and volume changes in the right atrium. • Carotid Arteries -Check and compare the rate, rhythm, and amplitude of the pulses. -Note whether a bruit is present

■ CHEST Precordium -Perform inspection and palpation of the precordium together to determine the presence of normal and abnormal pulsations. -The point of maximum intensity (PMI) or apical impulse is usually seen at the apex. -Right ventricular enlargement can produce an abnormal pulsation that may be seen as a sustained thrust along the left sternal border. 5 cardinal landmarks: Aortic area – R 2nd ICS Tricuspid Area -5th ICS L sternal border Pulmonic area – L 2nd ICS Erb’s point – 3rd L ICS Apex – 5th ICS midclavicular line

Heart Sounds -Note the quality (crisp or muffled), intensity (loud or soft), rhythm (irregular or regular), and presence of extra sounds (murmurs). S1 – closing of AV valves, depolarization heard best over the tricuspid and mitral area S2 – closing of semilunar valves, repolarization, heard best at aortic and pulmonic area S3 – occurs in early diastole during rapid filling of ventricles S4 – occurs in later stage during atrial contraction and active filling of ventricles

Pericardial Friction Rub • Infammation of the pericardial sac by rubbing together of visceral and parietal pericardium • Best heard at the apex • Scrathy, grating much like a squeky leather • Accentuated when leaning forward or lies prone and exhales ■LUNGS Tachypnea Tachypnea, or rapid respirations, is often associated with pain and anxiety accompanying myocardial ischemic pain. Crackles Crackles are high-pitched, noncontinuous sounds.

■ ABDOMEN Examination of the abdomen provides information regarding cardiac competence. Inspection and Palpation -Inspection may reveal abdominal distention. -Palpation may confirm the presence of ascites and an enlarged liver. Auscultation Loud bruits, heard with the bell just over or above the umbilicus, may indicate an aortic obstruction or aortic aneurysm

SYMPTOM ANALYSIS 6 Cardinal Symptoms of CVD •

• • • • •

Chest pain Irregularities of heart rhythm Respiratory Manifestation Syncope Fatigue Weight gain and dependent edema

Assessing Chest Pain

Chest pain -Timing -Quality -Quantity -Location -Precipitating Factor -Relieving Factor -Associated Manifestaton

ANGINA TIME:

MI

5-15 MINS

30 MINS

MILD

SEVERE

QUALITY: SEVERITY:

LOCATION: Retrosternal (Left-sternum)Radiates bilateral(arms, neck & jaw) but usually to the left side RELIEVING FX: REST, NITROGLYCERIN, O2

B. IRREGULARITIES OF HEART RHYTHM – PALPITATIONS -derived from the Latin palpitare, “to throb.” Palpitations are uncomfortable sensations in the chest associated with wide range of dysrhythmias. - Question the client about (1) medications; (2) the frequency of palpitations, precipitating factors, and aggravating or relieving factors; and (3) any manifestations such as dizziness or shortness of breath associated with the onset of the palpitations. -Nervousness, heavy meals, lack of sleep, large intake of coffee, tea, alcohol, tobacco, anemia, thyrotoxicosis

RESPIRATORY MANIFESTATIONS DYSPNEA = defined as shortness of breath or labored breathing. 1. EXERTIONAL DYSPNEA or Dyspnea on exertion (DOE)- Most common. -It occurs during mild to moderate exercise or activity and disappears with rest. 2. ORTHOPNEA. Orthopnea (difficult breathing) results from an increase in hydrostatic pressure in the lungs when the person is lying flat and is relieved when the person assumes an upright or semivertical position -Ask clients what actions they take to facilitate breathing. 3. PAROXYSMAL NOCTURNAL DYSPNEA. Paroxysmal nocturnal dyspnea (PND) is dyspnea during sleep that awakens the sleeper with a “terrifying breathing attack.”

D. SYNCOPE - or fainting, is a transient loss of consciousness related to inadequate cerebral perfusion. E. FATIGUE - Easy fatigability on mild exertion is a frequent problem for clients experiencing cardiac disease; F. WEIGHT GAIN AND DEPENDENT EDEMA -As the heart fails, or the blood volume expands, fluid accumulates. -Daily weight measurement is important for clients with cardiac problems. G. OTHER ASSOCIATED MANIFESTATIONS g.1 Cyanosis is a subtle bluish discoloration. -Blanch Test g.2 Clubbing of the fingernails is seen in association with significant cardiopulmonary disease. -Schamroth’s test g.3 Hemoptysis

Diagnostic Tests Non – Invasive: Nursing Responsibilities: Explain the purpose and procedure to the client; answer question. Schedule of the test. Perform any preliminary care. Promote emotional and physical comfort.

Laboratory Tests • Purpose: – Diagnose a variety of cardiovascular ailments – Screen people considered at risk of CVD – Determine baseline values – Identify concurrent disorders – Evaluate effectiveness of interventions

Preprocedures: • Determine dietary restrictions before test • Note time the drug was administered if to obtain serum drug levels. • Ask client if he/she is taking blood thinners such as Warfarin Sodium (Coumadin)  delays coagulation and requires longer time to hold pressure over venipuncture site • Gently invert lab tubes to prevent clotting of specimens for CBC • Apply pressure on puncture site.

CBC – ordered for all patients with documented or suspected heart disease for evaluation of the overall health status. Cardiac enzymes – CK, LDH, Troponin Myoglobin – released from the circulation within 1 to 2 hours of infarction. Not recommended if there is evidence of muscle damage, trauma, or renal failure because of greater potential for false positive lab results Creatinine Kinase 3 isoenzymes: CK MM CK BB CK MB – myocardial muscle, elevated within 6 to 8 after onset of MI, maximum levels at 14 to 36 hours and returns to normal after 48 to 72 hours. Samples should be taken immediately on admission and every 6 to 8 hours for the first 24 hours.

Lactic acid dehydrogenase Normal range: 100 to 225 mu/ml. Onset: 12 hours Peak: 48 hours Duration: returns to normal in 10 to 14 days Troponin (I, C, T) I – modulates contractile state C – binds calcium T – binds I and C Troponin I and T – cardiac specific Onset: 4 to 6 hours Duration – 4 to 7 days

Serum Lipids Major Classes of Lipoproteins: 1. chylomicrons – composed mainly of triglycerides; originated in the intestine 2. Very Low Density Lipoproteins – composed of triglycerides; synthesized by the liver 3. Low Density Lipoproteins – 50% cholesterol 4. High Density Lipoproteins – composed mainly of protein with a modest amount of cholesterol

Serum electrolytes: – Potassium – NV: 3.5 to 5 mEq/L – Hypokalemia – decrease level due to diuretic therapy, vomiting, diarrhea, and alkalosis. Increases cardiac electrical instability, characteristic U wave in ECG – Hyperkalemia – associated with kidney disease, and endocrine disorders. Characteristic tall T wave on ECG. – Sodium – NV: 135 to 145 mEq/L – Calcium – NV: 4.5 to 5.5 mEq/L – Hypocalcemia – can lead to serious ventricular dysrhythmias, prolonged QT interval and cardiac arrest. – Hypercalcemia – shortens the QT interval and causes AV block, tachycardia, bradycardia, and cardiac arrest.

– Magnesium – NV: 1.5 to 2.5 mEq/L – Hypomagnesemia – severe cadiac dysrhythmias including ventricular tachycardia, and fibrillation – Hypermagnesemia – hypotension, bradycardia, and prolonged PR and wide QRS complex.

– Phosphorus - NV: 1.2 to 3.0 mEq/L – Hypophosphatemia – same w/ hypercalcemia – Hyperphosphatemia – same w/ hypocalcemia,

Blood Glucose

ECG – graphic representation of the electrical forces within the heart 12 lead ECG

Tracings: P wave – depolarization of the atria PR interval – the time it takes for the impulse to spread from the atria to the ventricles QRS complex – ventricular depolarization T wave – ventricular repolarization

Preprocedures: • Remove metal objects • No pain or electricity • Avoid stimulants such as coffee, tea, and smoking 30 minutes to 1 hour before the test. During procedure: – Attach the electrodes to the client’s skin • Precordial leads: – V1 (red) – 4 ICS right sterna border – V2 (yellow) – 4 ICS left sternal border – V3 (green) – in between 2 and 4 – V4 (brown) – 5th ICS MCL – V5 (black) – 5th ICS anterior axillary line – V6 (violet) – 5th ICS MAL

• Limb leads: – Left upper extremity – yellow – Left lower extremity – green – Right upper extremity – red – Right lower extremity - black

–

Connect the electrodes to the cable

– Instruct to lie still, breathe normally and refrain from talking. Post-procedure: • Record client’s age, weight, and height and medications being taken. • Wipe off the gel from client’s skin

2. Signal average – used to detect impulses called late potentials and if pt. is at risk for Vtach that may result in sudden death

3. Holter Monitoring – can be worn for a day or longer, used to detect dysrhythmias that may not appear in routine ECG

Stress Test – valuable tool in detecting and evaluating CAD It involves: Using controlled and carefully supervised exercise Evaluating the coronary arteries Nursing Responsibilities: (Prior to the Test) • Inform the client about the purpose and risks of the exercise. • Obtain a signed consent. • Instruct not to eat or smoke for 2 to 3 hours before test,. • No alcohol 4 to 6 hours before test • Wear appropriate attire • No strenuous activity 12 hours prior to test • Take the baseline data: ECG at rest, HR – client must have a detailed physical exam before testing. ECG is closely monitored by a physician

Post procedure: • Monitor BP, HR and rhythm strip fro at least 15 minutes after or until ECG returns to baseline • Avoid warm bath Reasons for Terminating the Test: • Chest pain of fatigue • Greatly increased heart rate • Severe hypertension • Dyspnea • Untoward s/sx of myocardial ischemia/heart failure. d. Chest x-ray (PAL) – to determine the size, silhouette and position of the heart

e. Echocardiography (2D Echo) – • Based on the principles of ultrasound • Records the structure and motion of a heart area in relation to its distance from anterior chest wall • Detects cardiomyopathy, valvular d/o, ischemia, tumor and chamber size

f. MRI – provides the best information on chamber size, wall motion, valvular function and great vessel blood flow

2. Invasive Cardiac Catheterization – involves the insertion of a catheter into the heart and surrounding vessels to obtain detailed information about the structure and performance of the heart, valves and circulatory system. May include the studies of the right, left side of the heart and coronary arteries.

Indications: • Confirm a diagnosis of heart disease and determine the extent to which the disease has affected the structure and function of the heart • Determine congenital anomalies • Obtain a clear picture of cardiac anatomy before heart surgery • Obtain pressures within the heart chambers and the great vessels (aorta & pulmonary artery) • Measure blood oxygen concentration, tension and saturation within the heart chambers • Determine Cardiac Output • Perform angiography for better coronary artery visualization • Obtain endocardial biopsy specimens • Allow infusions of fibrolytic agents directly into an occluded coronary artery to restore coronary blood flow

2 types of Cardiac Catheterization • Right Sided Catheterization • Left Sided Catheterization – The catheter can be passed retrograde (backward) from the brachial and femoral artery into the aorta and then to the left ventricle – Rarely during Right sided catheterization, the middle or lower third of the atrial septum is punctured and the catheter is passed transeptally into the left atrium

• Angiography – invaluable tool in cardiac diagnosis and offers a great assistance in understanding heart and vessel disease. Injection of contrast agent via IV at the desired locations under study.

• CINE ANGIOGRAPHY – moving pictures are obtained during cardiac catheterization

• CORONARY ANGIOGRAPHY – contrast material is directly injected to the coronary arteries

• Hemodynamic Studies – pressures provide information about blood volume, fluid balance and how well the heart is pumping. (CVP, Pulmonary Artery Pressure, Cardiac output measurement, Intra-arterial pressure monitoring)

Central Venous Pressure • It reflects the pressure under which the blood is returned to the SVC & RA • Determined by vascular tone, blood volume, and the ability of the right side of the heart to receive and pump blood • Can be measured with a central venous line placed in the SVC or a balloon flotation catheter in the PA • Normal CVP pressure is 2-12mmHg

Nursing Interventions • HOB elevated at 45 degrees angle • Straining, coughing or any activity that increases intrathoracic pressure produces false high results • Patients with ventilator – take readings at the point of end expiration • Check connections of catheter and attachments to prevent air embolism • Check dressing at insertion site to prevent infection • To maintain patency of the system, a small amt of fld is delivered under pressure at a constant rate of flow • COMPLICATIONS: pneumothorax, phlebitis, air emboli, fld overload, dysrhythmias, sepsis, and micro electric shock

Pulmonary Artery Pressure

• Determines the left ventricular pressure • Can assist in determining when the left ventricle is understretched, overstretched, or appropriately stretched. Pulmonary Artery Catheter – provides continuous direct monitoring of PA pressure Has 4 lumen: 1. Proximal lumen – terminates in the right atrium, allowing CVP measurement, fluid infusion, & venous access for bld. samples. 2. Distal lumen – terminates in the PA & measure PA systolic, diastolic & mean pressure, and pulmonary capillary wedge pressure (PCWP) – indicator of left ventricular pressure 3. 3rd lumen – for inflation & deflation of balloon 4 . 4th lumen (thermistor port) – permits measurement of CO

Nsg. Resp: • Explain that the procedure will be uncomfortable but not painful • Local anesthesia will be given at anesthesia site • Catheter is inserted via percutaneous puncture at the brachial, subclavian, jugular or femoral vein. • When catheter is wedged, is the most accurate indicator of left ventricular end-diastolic pressure or left ventricular preload. • Normal PCWP is 8-13 mmHg. Greater than 18-20mmHg indicates ↑ left ventricular pressure (L-sided heart failure) – may coincide with congestion. More than 30mmHg – edema

Pulmonary Artery Catheter and Pressure Monitoring System

Arterial Pressure Monitoring System

Intra-arterial Pressure monitoring • Common method of obtaining BP measurements for acutely ill clients • Provides continuous detection of arterial BP via an indwelling catheter for those with decrease CO, fluctuating hemodynamic status, and progressive peripheral vasoconstriction • Intraarterial readings are higher 10 mmHg than cuff BP readings

Nursing Interventions • Before the procedure – perform allens test – Maintain aseptic technique – Check neurovascular status q 2hrs

• After the procedure – Apply 5min pressure – Maintain intact dressings for 12hrs

End of Presentation! Thank You!