HEART (Cardiologic System)
ANGINA
- chest pain due to diminished O2 supply to the myocardium
- Causes:
a. atherosclerosis – fatty plaque deposits in the intima of the artery
b. arteriosclerosis – calcium deposits in the media f the artery causing hardening
- Types of Angina:
a. Stable (Effort) – ↑activity = pain, relieved by rest
b. Unstable (Pre-infarction) – ↑activity = pain, not relieved by rest nor NTG
c. Prinzmetal (Variant) – pain at rest with vasospasm , relieved by NTG
d. Intractable – continued pain not relieved by NTG
- Characteristics of chest pain:
- Substernal or retrosternal pain that radiates to arms neck and jaws
- Squeezing and heavy tightness of the chest
- Lasts for a few minutes and then subsides
- Precipitating Factors: 5 Es
Exercise
Exertion
Emotions
Eating heavy meal
Exposure to cold
- Diagnostics
a. NTG test – shows relief from pain
b. ECG – reveals ST and T wave changes
c. Thallium 201 Imaging
d. Technetium-99 Imaging
- Nursing Diagnoses
1. Pain related to imbalance in myocardial oxygen demand
2. Decreased cardiac output related to reduced preload and afterload
3. Anxiety related to pain, uncertain prognosis and threatening environment
- Management:
Instruct px to stop all activities
Place in a comfortable position
Give antianginal drugs – i.e. Nitroglycerin
Administer O2
Maintain cardiac output
Decrease Anxiety
CORONARY ARTERY DISEASE - i.e. coronary atherosclerosis
- results from focal narrowing of coronary arteries
- incidence increases progressively with age
Etiology - May involve combination of factors:
a. genetic predisposition
b. metabolic disturbances
c. hypertension
d. altered platelet function à predisposes to plaque formation
Risk factors
- Advanced age
- Obesity
- Male or postmenopausal female
- Sedentary lifestyle
- Hyperlipidemia
- Family history of CAD
- Smoking
- Diabetes mellitus
- Chronic stress
- Chronic oral contraceptive use
- Pathophysiology: Formation of fatty, fibrous plaques on the intima of coronary arteries à Narrowing of the arterial lumen à Reduced blood flow to the heart à Myocardial ischemia and cell damage à Formation and subsequent embolism.
CORONARY ARTERY DISEASE (continued)
Assessment Findings
a. Angina pectoris - most characteristic symptom
- mild to severe burning or squeezing retrosternal pain à may radiate to arm, jaw, neck, shoulder
- Relieved by rest and nitrates
b. Nausea and vomiting e. Cool, clammy skin
c. Dizziness and syncope f. Apprehension or a sense of impending doom
d. Diaphoresis
Laboratory and diagnostic study findings à ECG may appear normal when client is pain free
- ECG = ischemic changes (e.g. ST depression, T-wave inversion) during angina or exercise.
Nursing Management
> Administer prescribed meds – nitrates, antiplatelets, anticoagulants, antilipidemic, ß-blockers, CCB
> Provide care during acute anginal attack
1. Instruct client to stop all activities
2. Place px in a comfortable position
3. Place an NTG tablet under the tongue; wait for 5 minutes
> Request a STAT 12-lead ECG.
Support/reassure client and significant others during attack
> Promote Pain Relief - Encourage the client to reduce activity to a point at which pain does not occur
Prepare client for possible treatment
Drugs:
1. Nitrates - Nitroglycerin
2. Antiplatelets
a. Aspirin (ASA) - 160 or 325 mg tab p.o. given to pxs with angina
- prevents platelet activation
- reduces incidence of MI and death from CAD
- side effects: a. GI upset b. GI bleeding
b. Antiplatelets - Clopidogrel (Plavix), Ticlopidine (Ticlid)
- Given to patients who are allergic to ASA
- Effects seen after a few days
- Side effects: a. GI upset b. decreased neutrophil count
3. Anticoagulants
a. Unfractionated Heparin - may be given as IV bolus q 4 to 6 h and given as continuous infusion
- prevents formation of new blood clots
- amount based on results of aPTT
- heparin therapy considered therapeutic when aPTT is 1.5 to 2 times the normal aPTT value
b. Low-Molecular-Weight Heparin (LMWH) or Enoxaparin (Lovenox) or Dalteparin (Fragmin) – given SQ
- provides more effective and stable anticoagulation
- no need to monitor aPTT results
Both unfractionated heparin and LMWH increase the risk of bleeding
- antidote for Heparin: Protamine Sulfate
c. Warfarin (Coumadin) - Suppresses formation of prothrombin from vit. K
- Monitor for PT
- Warfarin therapy is considered therapeutic if INR is between 2.0 to 3.0
- Known to be affected by many medications
- Antidote: Vitamin K
4. Antilipidemics
a. Bile Acid Sequestrants – Cholestyramine (Questran), Colestipol, Niacin (Vit. B3 or Nicotinic Acid)
b. Fibric Acid Derivatives (Fibrates) – Gemfibrozil, Clofibrate
c. Statins – Atorvastatin (Lipitor), Simvastatin
5. Beta-blockers – antihypertensives – e.g. Metoprolol (Neobloc), Atenolol, Propranolol (Inderal)
6. Calcium Channel Blockers – (NeVaDA
Bleeding Precautions for pxs in Anticoagulant therapy
a. Apply pressure to the site of any needle puncture for a longer time than usual
b. Avoid IM injections
c. Avoid tissue injury and bruising from trauma
d. Avoid use of constrictive devices – e.g. continuous use of automatic BP cuff
e. Instruct px to use soft-bristled toothbrush
f. Teach px to use electric razor when shaving
g. Educate px to recognize signs of hemorrhage – e.g. hematuria, bleeding gums
h. Examine stool for occult blood
NOTES ON ECG/EKG
NON-INVASIVE
1. Electrocardiogram - graphic record produced by electrocardiograph
2. Electrocardiograph - a device used for recording the electrical activity of the myocardium by placing leads to certain points in the chest region
3. Electrocardiography - study of records of electric activity generated by the heart muscle
Placement of the Six (6) Electrodes
> V1 = 4th right intercostal space right parasternal border
> V2 = 4th left intercostal space left parasternal border
> V3 = halfway between V2 and V4
> V4 = 5th left intercostal space midclavicular line
> V5 = left anterior axillary line halfway between V4 and V6
> V6 = midaxillary line level with V4
Placement of Four (4) Lead Wires
> Lead 1 = RA right arm > Lead 3 = RL right leg
> Lead 2 = LA left arm > Lead 4 = LL left leg
6 CHEST LEADS –
V1 – V4 = anterior wall
V5 – V6 = lateral wall
Treatment Modalities used in CAD:
a. Percutaneous Transluminal Coronary Angioplasty (PTCA)
- It is a catheter-based therapy which is performed to relieve obstruction
- compressing blockage (atheroma) into intimal artery lining à ↑blood flow through the artery
- inserting an intravascular stent over the balloon during a PTCA
b. Coronary Artery Bypass Grafting (CABG)
- uses a blood vessel from the body to bypass occluded vessel à ↑blood flow through myocardium
- MEDIAN STERNOTOMY - Incision made in the sternum.
- Provides access for cardiac bypass & other procedures.
- Heart and vessels are altered to improve functioning
- Heart should be in cardioplegia
- Vena cavae & ascending aorta are cannulated & connected to tubings of a heart-lung machine.
- Commonly used replacements: femoral artery & vein; saphenous vein
- TYPES OF CANNULA used in CABG
a. Venous cannula: straight ended with multiple holes
b. Aortic cannula: angled tip, blood is directed towards the descending aorta
Nursing Management (continued)
> Provide teaching for the client and family
> Encourage: client à cardiac rehab program
Significant other/s à support group
> Provide teaching for the client and family
> Encourage family members and significant others to take a CPR course
MYOCARDIAL INFARCTION
- Reduced coronary blood flow à Deprivation of adequate blood supply to the myocardium à Destruction of myocardial tissue
- Effects of infarction - dependent on location and extent
- MI incidence: Men > Women
- Etiology
a. Atherosclerosis à narrowing of coronary artery à coronary artery spasm/complete arterial occlusion (embolism or thrombus)
b. hemorrhage or shock à ↓blood flow à profound imbalance b/n myocardial O2 supply & demand.
c. Ischemia à depress cardiac function à trigger autonomic nervous system responses à ↑imbalance b/n myocardial O2 supply and demand.
d. Persistent ischemia à tissue necrosis/scar tissue formation à permanent loss of myocardial contractility in the affected area
e. ↓Myocardial contractility, ↓pumping capacity à inadequate CO àCardiogenic shock
f. Ischemic myocardium is electrically unstable
> arrythmias include lethal ventricular fibrillation and ventricular tachycardia
> infarcts which interfere with the cardiac conduction system may lead to heart block or conduction defects
- Assessment Findings
1. Chest pain - persistent & crushing pain located substernally that radiates to arm, neck, jaw, or back
- unrelieved by rest or nitrates; silent MI may produce no pain
2. Nausea and vomiting
3. Dyspnea with or without crackles
4. Palpitations or syncope
5. Restlessness and anxiety or feeling of impending doom
6. Tachycardia or bradycardia
7. Decreased blood pressure
8. Altered S3 heart sounds – may indicate left ventricular failure
9. Oliguria
10. Levine’s sign
Laboratory and diagnostic findings
> ECG – > T-wave inversion or ST elevation or abnormal Q wave (old infarct)
> Serum enzyme studies: ↑Troponin I & T, CPK and CPK-MB, AST, LDH (flipped LDH pattern), Myoglobin
> Elevated WBC count – leads to elevated temperature
> Elevated ESR
Nursing Management
1. Administer Drug Therapy
2. Administer prescribed meds
- Morphine - Nitrates
- Antilipidemics - Thrombolytics
- Anticoagulants in acute situation - Stool softeners during rehabilitation
3. Administer Drug Therapy – in sequence! - Remember MONA!
- Morphine Oxygen = 2-4 L/min Nitroglycerin Aspirin
Morphine Sulfate (Duramorph, Astramorph) - given IV; serves as both analgesic & anxiolytic
- MOA: Reduces preload thus decreasing workload of the heart
- Side effects: a. hypotension b. respiratory depression
Thrombolytics – given IV
- Dissolves and lyses thrombus in the coronary artery
- Not used if px has a bleeding disorder
- Not given to patients with unstable angina
- Antidote: Aminocaproic Acid
- examples:
a. Streptokinase (Kabikinase, Streptase)
b. Tissue plasminogen activator (t-PA) - Alteplase (Activase)
c. Reteplase (r-PA, TNKase)
Nursing Management of MI (Continued)
4. Prepare the client for treatment such as PTCA and CABG
5. Provide client and Family teaching.
a. Encourage family members and significant others to take a CPR course.
b. Guidelines for the client with CAD are provided in client and family teaching.
6. Provide ongoing assessment.
a. Monitor cardiac enzymes
b. Monitor hemodynamic parameters as necessary through the multilumen pulmonary artery catheter
7. Minimize anxiety
8. Minimize metabolic demands.
> Institute a liquid diet
> advance to a low-sodium, low-cholesterol, low-fat, solid diet as tolerated
9. Encourage patient to participate in cardiac rehabilitation program
*Phases of Cardiac Rehab
Phase I = starts as px is admitted for ACS; consists of low-level activities
- initial education for px & family
a. s/sx that indicate the need to be brought to the ER c. rest-activity balance
b. medication regimen d. follow-up appointments with MD
Phase II = starts after px is discharged
= usually lasts for 4 to 6 weeks but may extend up to 6 months
- consists of supervised (often ECG-monitored) individualized exercise training
- education related to lifestyle modification
Phase III = focuses on maintaining cardiovascular stability and long-term conditioning (px is self-directed)
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