The Cardiovascular System and CAD Risk Factors

• The cardiovascular system consists of the heart, blood vessels, and lymphatic structures.
• The cardiovascular system delivers oxygen and nutrients to cells and removes carbon dioxide and waste.
• The heart, a pump the size of a fist, propels blood through the circulatory system.
• The heart has four chambers: two atria and two ventricles.
• The heart receives nutrition and oxygen from two coronary arteries.
• The electrical impulse pathway in the heart:
• Begins at the SA node (pacemaker).
• Travels to the AV node.
• Proceeds to the bundle of His.
• Divides into right and left bundle branches.
• Terminates at the Purkinje fibers.
• Three types of blood vessels carry blood to and from the heart: arteries, veins, and capillaries.

Risk Factors for Coronary Artery Disease (CAD)

• Risk factors are classified as nonmodifiable and modifiable.

Nonmodifiable Risk Factors

• Advancing age
• Male gender
• Black race
• Positive family history of CAD

Modifiable Risk Factors

• Cigarette smoking
• Hyperlipidemia
• Stress
• Obesity
• Sedentary lifestyle
• Hypertension
• High cholesterol and saturated fat diet

Patient Care for Cardiovascular Disorders

• You must understand risk factors and incorporate them into patient teaching.

Diagnostic Tests for Cardiovascular Function

• Chest radiograph
• Arteriography
• Cardiac catheterization
• ECG
• Echocardiogram
• Telemetry
• Stress test
• PET
• Thallium scanning

Laboratory Examinations for Cardiovascular Function

• Blood cultures
• CBC (complete blood count)
• PT (prothrombin time)
• INR (international normalized ratio)
• PTT (partial thromboplastin time)
• ESR (erythrocyte sedimentation rate)
• Serum electrolytes
• Lipids (VLDL, LDL, HDL)
• Triglycerides
• Arterial blood gases
• BNP (B-type natriuretic peptide)
• Serum cardiac markers
• Troponin I is a myocardial muscle protein released after myocardial injury and is useful in diagnosing an MI.

Coronary Artery Disease (CAD)

• CAD includes conditions that obstruct blood flow in the coronary arteries.
• Myocardial ischemia occurs when myocardial oxygen demand exceeds supply, resulting in chest pain or angina.

Patient Teaching for Angina Pectoris

• Take nitroglycerin before exertion.
• Eat small, frequent meals.
• Balance exercise with rest.
• Stop activity at the first sign of chest pain.
• Avoid extreme weather conditions.
• Quit smoking.
• Seek a calm environment.

Myocardial Infarction (MI)

• Subjective data may include:
• Heavy pressure or squeezing in the chest.
• Retrosternal pain radiating to the left arm and jaw.
• Anxiety
• Nausea
• Dyspnea
• Objective data may include:
• Pallor
• Hypertension
• Cardiac rhythm changes
• Vomiting
• Fever
• Diaphoresis

Nursing Diagnoses for MI

• Acute pain
• Ineffective tissue perfusion
• Activity intolerance
• Decreased cardiac output
• Anxiety
• Constipation

Cardiac Rehabilitation

• Cardiac rehabilitation services help patients with heart disease recover faster and return to full and productive lives and improves patient compliance.

Heart Failure (HF)

• HF leads to congestion of the heart, lungs, and systemic circulation due to the heart's inability to pump effectively.
• HF is viewed as a neurohormonal problem that progresses due to chronic release of substances like catecholamines, which can be toxic to the heart.
• 1 L of fluid equals 1 kg (2.2 lb); a weight gain of 2.2 lb signifies a gain of 1 L of body fluid.

Heart Failure Symptoms

• Left ventricular failure:
• Dyspnea
• Cough
• Frothy, blood-tinged sputum
• Pulmonary crackles
• Pulmonary vascular congestion with pleural effusion
• Right ventricular failure:
• Edema in feet, ankles, and sacrum (may progress to thighs and genitalia)
• Liver congestion
• Ascites
• Distended jugular veins

Medical Management of Heart Failure

• Increase cardiac efficiency with digitalis, vasodilators, and ACE inhibitors.
• Administer carvedilol (beta blocker) for mild to moderate HF.
• Lower oxygen requirements through bed rest.
• Provide oxygen therapy if hypoxic.
• Treat edema and pulmonary congestion with diuretics and sodium-restricted diet.
• Weigh daily to monitor fluid retention.

Nursing Interventions for Valvular Heart Disease

• Administer prescribed medications (diuretics, digoxin, antidysrhythmics).
• Monitor I&O and daily weight.
• Auscultate breath sounds and heart sounds.
• Take blood pressure.
• Assess capillary perfusion, pedal pulses, and presence of edema.

Teaching for Valvular Heart Disease

• Dietary management
• Activity limitations
• Antibiotic prophylaxis before invasive procedures

Cardiomyopathy

• Most patients have a severe, progressively deteriorating course, with the majority older than age 55 years dying within 2 years of symptom onset.

Peripheral Vascular Disease (PVD)

• PVD is any abnormal condition affecting blood vessels outside the heart and lymphatic vessels.
• Arteriosclerosis is the underlying problem associated with PVD.

Hypertension

• Hypertension occurs when there is a sustained elevated systolic blood pressure greater than 140 mm Hg and/or sustained elevated diastolic blood pressure of greater than 90 mm Hg on two or more readings.

Nursing Interventions for Hypertension

• Blood pressure management through:
• Patient teaching
• Risk factor recognition
• Drug therapy
• Dietary management
• Exercise
• Stress-reduction techniques

Aneurysm

• An aneurysm is an enlarged, dilated portion of an artery and may be the result of arteriosclerosis, trauma, or a congenital defect.

Thromboangiitis Obliterans (Buerger Disease)

• Teaching for Buerger disease focuses on the hazards of cigarette smoking.

Venous Disorders

• Two major venous disorders are thrombophlebitis and varicose veins.
• Thrombophlebitis may result in calf pain on dorsiflexion of the foot (positive Homans sign), but it appears in only 10% of patients with DVT.

Patient Teaching for Thrombophlebitis

• Avoid prolonged sitting or standing.
• Avoid dehydration.
• Reduce weight if obese.
• Perform dorsiflexion-extension exercises of feet and legs.
• Do not cross legs at the knees.
• Elevate legs when sitting.

Learn about the cardiovascular system, including the heart, blood vessels, and their function in delivering oxygen and nutrients. The focus is on the heart's structure, electrical impulse pathway, and coronary arteries. Also, learn about modifiable and nonmodifiable risk factors for coronary artery disease (CAD).