Coronary Artery Disease

Coronary artery disease

develops when the major blood vessels that supply your heart become damaged or diseased.

Coronary atherosclerosis

most common cause of cardiovascular disease in the United States and is characterized by an abnormal accumulation of lipid or fatty substances and fibrous tissue in the vessel wall

• Ischemia

• Chest pain: angina pectoris

• Atypical symptoms of myocardial ischemia (shortness of breath, nausea, and weakness)

• Myocardial infarction

• Dysrhythmias, sudden death

Clinical Manifestations

(Coronary atherosclerosis)

prevention of CHD

major management goal of Coronary atherosclerosis

Angina Pectoris

a clinical syndrome characterized by paroxysms of pain or a feeling of pressure in the anterior chest.

Angina Pectoris

The cause is insufficient coronary blood flow, resulting in an inadequate supply of oxygen to meet the myocardial demand.

physical exertion, exposure to cold, eating a heavy meal, or stress or any emotion- provoking situation that increases blood pressure, heart rate, and myocardial workload

Factors affecting anginal pain

• Pain varies from a feeling of indigestion to a choking or heavy sensation in the upper chest ranging from discomfort to agonizing pain. The patient with diabetes mellitus may not experience severe pain.

• it is accompanied by severe apprehension and a feeling of impending death.

• The pain is usually retrosternal, deep in the chest behind the upper or middle third of the sternum.

• Discomfort is poorly localized and may radiate to the neck, jaw, shoulders, and inner aspect of the upper arms (usually the left arm).

• A feeling of weakness or numbness in the arms, wrists, and hands, as well as shortness of breath, pallor, diaphoresis, dizziness or lightheadedness, and nausea and vomiting, may accompany the pain. Anxiety may occur.

• An important characteristic is that it subsides when the precipitating cause is removed or with nitroglycerin

Clinical Manifestations (Angina Pectoris)

dyspnea

presenting symptom in the elderly (Angina Pectoris)

to decrease the oxygen demand of themyocardium and to increase the oxygen supply

The objectives of the medical management of angina are

• Nitrates, the mainstay of therapy (nitroglycerin)

• Beta-adrenergic blockers (metoprolol and atenolol)

• Calcium channel blockers/calcium ion antagonists (amlodipine and diltiazem)

• Antiplatelet and anticoagulant medications (aspirin, clopidogrel, heparin, glycoprotein [GP] IIb/IIIa agents [abciximab, tirofiban, eptifibatide])

• Oxygen therapy

Pharmacologic Therapy (Angina Pectoris)

• Ineffective cardiac tissue perfusion secondary to CAD as evidenced by chest pain or other prodromal symptoms

• Death anxiety

• Deficient knowledge about underlying disease and methods for avoiding complications

• Noncompliance, ineffective management of therapeutic regimen related to failure to accept necessary lifestyle changes

Nursing Diagnoses (Angina Pectoris)

• Take immediate action if patient reports pain

• Direct the patient to stop all activities and sit or rest in bed in a semi-Fowler's position to reduce the oxygen requirements of the ischemic myocardium.

• Measure vital signs and observe for signs of respiratory distress.

• Administer nitroglycerin sublingually and asses the patient's response (repeat up to three doses).

• Administer oxygen therapy if the patient's respiratory rate is increased or if the oxygen saturation level is decreased.

• If the pain is significant and continues after these interventions, the patient is further evaluated for acute MI and may be transferred to a higher-acuity nursing unit.

Nursing Interventions

Treating Angina

• Sudden or excessive exertion

• Exposure to cold

• Tobacco use

• Heavy meals

• Excessive weight

• Some over-the-counter drugs, such as diet pills, nasal decongestants, or drugs that increase heartrate and blood pressure

Factors that Trigger Angina Episodes

Acute coronary syndrome (ACS)

an emergent situation characterized by an acute onset of myocardial ischemia that results in myocardial death

preinfarction angina

In unstable angina, there is reduced blood flow in acoronary artery, often due to rupture of an atherosclerotic plaque, but the artery is not completelyoccluded. This is an acute situation that is sometimes referred to as

myocardium

In an MI, an area of the ________ is permanently destroyed, typically because plaque rupture and subsequent thrombus formation result in complete occlusion of the artery

• Chest pain that occurs suddenly and continues despite rest and medication is the primary presenting symptom.

• Some patients have prodromal symptoms or a previous diagnosis of coronary artery disease(CAD), but about half report no previous symptoms.

• Patient may present with a combination of symptoms, including chest pain, shortness of breath, indigestion, nausea, and anxiety.

• Patient may have cool, pale, and moist skin; heart rate and respiratory rate may be faster than normal. These signs and symptoms, which are caused by stimulation of the sympathetic nervous system, may be present for only a short time or may persist

Clinical Manifestations (ACS)

• Reperfusion via emergency use of thrombolytic medications or percutaneous coronary intervention (PCI).

• Reduce myocardial oxygen demand and increase oxygen supply with medications, oxygen administration, and bed rest.

• Coronary artery bypass or minimally invasive direct coronary artery bypass (MIDCAB).

Medical Management (ACS)

hypotension with oliguria

early sign of cardiogenic shock

• Ineffective cardiac tissue perfusion related to reduced coronary blood flow

• Risk for imbalanced fluid volume

• Risk for ineffective peripheral tissue perfusion related to decreased cardiac output from left ventricular dysfunction

• Death anxiety

• Deficient knowledge about post-ACS self-care

Nursing Diagnoses (ACS)

relief of pain or ischemic signs (eg, ST-segment changes) and symptoms, prevention of myocardial damage, absence of respiratory dysfunction, maintenance or attainment of adequate tissue perfusion, reduced anxiety, adherence to the self-care program, and absence or early recognition of complications

Nursing Interventions (ACS)

decrease chest discomfort and dyspnea

Assist patient to rest with back elevated or in cardiac chair to

overloading the heart and lungs

Monitor fluid volume status to prevent

pooling of fluid in lung bases

Encourage patient to breathe deeply and change position often to prevent

reduce myocardial oxygen consumption

Keep patient on bed or chair rest to

myocardial revascularization

CAD has been treated by ___________ since the 1960s

CABG (Coronary Artery Bypass Graft)

a surgical procedure in which a blood vessel is grafted to an occluded coronary artery so that blood can flow beyond the occlusion; it is also called a bypass graft

• Alleviation of angina that cannot be controlled with medication or PCI

• Treatment of left main coronary artery stenosis or multivessel CAD

• Prevention and treatment of MI, dysrhythmias, or heart failure

• Treatment for complications from an unsuccessful PCI

The major indications for CABG are:

Traditional Coronary Artery Bypass Graft

the surgeon performs a median sternotomy and connects the patient to the cardiopulmonary bypass (CPB) machine. Next, a blood vessel from another part of the patient's body (eg, saphenous vein, left internal mammary artery) is grafted distal to the coronary artery lesion, bypassing the obstruction

Cardiopulmonary Bypass

The procedure mechanically circulates and oxygenates blood for the body while bypassing the heart and lungs. CPB maintains perfusion to body organs and tissues and allows the surgeon to complete the anastomoses in a motionless, bloodless surgical field.

Cardiopulmonary Bypass

accomplished by placing a cannula in the right atrium, vena cava, or femoral vein to withdraw blood from the body. The cannula is connected to tubing filled with an isotonic crystalloid solution. Venous blood removed from the body by the cannula is filtered, oxygenated, cooled or warmed by the machine, and then returned to the body. The cannula used to return the oxygenated blood is usually inserted in the ascending aorta, or it may be inserted in the femoral artery

Off-pump CABG (OPCAB)

involves a standard median sternotomy incision, but the surgery is performed without CPB. A beta-adrenergic blocker may be used to slow the heart rate. The surgeon also uses a myocardial stabilization device to hold the site still for the anastomosis of the bypass graft into the coronary artery while

the heart continues to beat