Common cardiovascular disorders

Below are several common cardiovascular disorders, along with their causes, pathophysiology, signs and symptoms, diagnostic test findings, treatments, and nursing interventions.

Common cardiovascular disorders: Arterial occlusive disease

A common complication of atherosclerosis, arterial occlusive disease may affect any artery but typically affects the peripheral arteries, such as the carotid (and its branches) and the lower extremity arteries (femoral, popliteal, posterior tibial, anterior tibial, and peroneal). The upper extremity arteries (subclavian, axillary, brachial, radial, and ulnar) are less commonly affected. Arterial occlusions may be acute or chronic. Men suffer from arterial occlusive disease more commonly than women.

Common cardiovascular disorders: What causes it

Risk factors for arterial occlusive disease include smoking, aging, hypertension, hyperlipidemia, diabetes mellitus, and family history of vascular disorders, MI, or stroke. Causes include:

  • emboli formation
  • infection
  • thrombosis
  • trauma or fracture
  • vasculitis.

Common cardiovascular disorders: Pathophysiology

In arterial occlusive disease, obstruction or narrowing of the lumen of the aorta and its major branches causes an interruption of blood flow, usually to the legs and feet.

Prognosis? It all depends…

Focus Topic: Common cardiovascular disorders

Prognosis depends on the location of the occlusion, the development of collateral circulation to counteract reduced blood flow and, in acute disease, the time elapsed between occlusion and its removal.

Common cardiovascular disorders: What to look for

Signs and symptoms depend on the severity and site of the arterial occlusion. Acute arterial occlusion may produce the five classic Ps:

  1. paralysis
  2. pain
  3. paresthesia
  4. pallor
  5. pulselessness.

Other signs and symptoms include:

  • unequally cool extremities when compared with each other
  • intermittent claudication
  • severe pain in the toes or feet (aggravated by elevating the extremity and sometimes relieved by keeping the extremity in a dependent position)
  • ulcers or gangrene
  • pallor on elevation, followed by redness with dependency
  • delayed capillary filling, hair loss, or trophic nail changes
  • diminished or absent extremity pulses.

Common cardiovascular disorders: What tests tell you

  • Arteriography demonstrates the type (thrombus or embolus), location, and degree of obstruction and helps evaluate the collateral circulation. It’s particularly useful for diagnosing chronic forms of the disease and evaluating candidates for reconstructive surgery.
  • Duplex Doppler ultrasonography uses ultrasound to visualize vessles and measure the speed, direction, and pattern of blood flow.
  • Plethysmography detects arterial pulsations to quantify the blood flow in an extremity.
  • Pulse volume recordings can determine the level of ischemia in an extremity.

Common cardiovascular disorders: How it’s treated

Treatment for arterial occlusive disease depends on the cause, location, and size of the obstruction.

Mild disease… moderate measures

Focus Topic: Common cardiovascular disorders

For patients with mild chronic disease, it usually consists of risk factor reduction, such as smoking cessation and hypertension control as well as supportive measures such as walking exercise.

Drug therapy includes dextran and antiplatelet and hemorheologic drugs, such as aspirin, ticlopidine, pentoxifylline (Trental), and cilostazol (Pletal). Thrombolytic therapy may be used to treat an acute arterial thrombosis. Patients with hyperlipidemia may be treated with antilipemic drugs.

Severe disease… surgery

Focus Topic: Common cardiovascular disorders

Appropriate surgical procedures may include embolectomy, thromboendarterectomy, patch grafting, and bypass grafting. The patient may require amputation if arterial reconstructive surgery fails or complications develop.

Lower the risk

Focus Topic: Common cardiovascular disorders

Invasive endovascular techniques carry less risk than surgery and may include balloon angioplasty, atherectomy, and stenting. Other appropriate therapy includes heparin to prevent emboli (for embolic occlusion) and bowel resection after restoration of blood flow (for mesenteric artery occlusion).

Common cardiovascular disorders: What to do

  • For information on nursing care of patients who undergo vascular surgery, see “Vascular repair,”.
  • Following treatment, evaluate the patient. He should be able to increase exercise tolerance without developing pain and should have normal peripheral pulses. The patient should also maintain good skin color and temperature in his extremities. (See Arterial occlusive disease teaching tips.)

Arterial occlusive disease teaching tips

Focus Topic: Common cardiovascular disorders

  • Teach proper foot care or other appropriate measures, depending on the affected area.
  • Instruct the patient about signs and symptoms of recurrence (pain, pallor, numbness, paralysis, absence of pulse) that can result from a recurrent occlusion or occlusion at another site.
  • Caution the patient against wearing constrictive clothing or crossing his legs while sitting.
  • Advise the patient to stop smoking and refer him to a smoking-cessation program if appropriate.
  • Encourage the patient to closely follow his prescribed medication regimen.
  • Teach the patient to check his pulses daily.

Common cardiovascular disorders: Coronary artery disease

Coronary artery disease (CAD) refers to any narrowing or obstruction of arterial lumina that interferes with cardiac perfusion. Deprived of sufficient blood, the myocardium can develop various ischemic diseases, including angina pectoris, MI, heart failure, sudden death, and cardiac arrhythmias.

Not an equal opportunity disease

Focus Topic: Common cardiovascular disorders

CAD affects more Whites than Blacks and more men than women. After menopause, however, the risk of CAD in women increases to equal that of men. CAD occurs more commonly in industrial countries than underdeveloped areas and affects affluent people more than poor people.

Common cardiovascular disorders: What causes it

Most commonly, atherosclerosis leads to CAD. Other possible causes include:

  • arteritis
  • coronary artery spasm
  • certain infectious diseases
  • congenital abnormalities.

Patients with certain risk factors appear to face a greater likelihood of developing CAD. These factors include:

  • family history of heart disease
  • obesity
  • smoking
  • high-fat, high-carbohydrate diet
  • sedentary lifestyle
  • menopause
  • stress
  • diabetes
  • hypertension
  • hyperlipoproteinemia.

Common cardiovascular disorders: Pathophysiology

Fatty, fibrous plaques progressively occlude the coronary arteries, reducing the volume of blood that can flow through them, leading to myocardial ischemia.

A precarious balance

Focus Topic: Common cardiovascular disorders

As atherosclerosis progresses, luminal narrowing and vascular changes impair the diseased vessel’s ability to dilate. This causes a precarious balance between myocardial oxygen supply and demand, threatening the myocardium beyond the lesion.

When the balance tips…

Focus Topic: Common cardiovascular disorders

When oxygen demand exceeds what the diseased vessels can supply, localized myocardial ischemia results.

Transient ischemia causes reversible changes at the cellular and tissue levels, depressing myocardial function. Untreated, it can lead to tissue injury or necrosis. Oxygen deprivation forces the myocardium to shift from aerobic to anaerobic metabolism. As a result, lactic acid (the end product of anaerobic metabolism) accumulates and cellular pH decreases.

…things fall apart

Focus Topic: Common cardiovascular disorders

The combination of hypoxia, reduced energy availability, and acidosis rapidly impairs left ventricular function. The strength of contractions drops in the affected myocardial region as the fibers shorten inadequately, with less force and velocity. Plus, the ischemic section’s wall moves abnormally. This typically results in the heart ejecting less blood with each contraction. If blood flow through the coronary arteries isn’t restored, an MI will result. If blood flow is restored, aerobic metabolism and contractility return.

Common cardiovascular disorders: What to look for

Angina, the classic symptom of CAD, occurs as a burning, squeezing, or crushing tightness in the substernal or precordial chest. It may radiate to the left arm, neck, jaw, or shoulder blade. Women, however, may experience atypical chest pain. (See Atypical chest pain in women.)

Angina has four major forms:

  • stable — pain that’s predictable in frequency and duration and relieved with nitrates and rest
  • unstable — increased pain that’s easily induced
  • Prinzmetal’s or variant — pain that results from unpredictable coronary artery spasm
  • microvascular — angina-like chest pain in a patient with normal coronary arteries that results from impaired vasodilator reserve.

Other signs and symptoms of CAD include:

  • nausea
  • vomiting
  • weakness
  • diaphoresis
  • cool extremities.

Atypical chest pain in women

Focus Topic: Common cardiovascular disorders

Women with coronary artery disease commonly experience atypical chest pain, vague chest pain, or a lack of chest pain. However, they may also experience classic chest pain, which may occur without any relationship to activity or stress.

Although men tend to complain of crushing pain in the center of the chest, women are more likely to experience arm or shoulder pain; jaw, neck, or throat pain; toothache; back pain; or pain under the breastbone or in the stomach.

Other signs and symptoms women may experience include nausea or dizziness; shortness of breath; unexplained anxiety, weakness, or fatigue; and palpitations, cold sweat, or paleness.

Common cardiovascular disorders: What tests tell you

  • ECG shows ischemia and, possibly, arrhythmias such as premature ventricular contractions. A pain-free patient may have a normal ECG. Arrhythmias may occur without infarction, secondary to ischemia.
  • Exercise ECG may provoke chest pain and signs of myocardial ischemia in response to physical exertion.
  • Coronary angiography reveals coronary artery stenosis or obstruction and collateral circulation and shows the condition of the arteries beyond the narrowed area.

Keep on running

Focus Topic: Common cardiovascular disorders

  • During treadmill exercise, myocardial perfusion imaging with thallium-201 detects ischemic areas of the myocardium, visualized as “cold spots.”
  • Laboratory evaluation of cardiac markers may be performed to confirm or rule out a diagnosis of MI. The patient may also undergo serum lipid studies to detect and classify hyperlipidemia.
  • An elevated Hb A1C level indicates an increased risk for atherosclerosis and adverse cardiac events; an elevated C-reactive protein level points to a higher cadiac risk. Although these two tests alone can’t determine if a patient with angina has CAD, they do help detect a higher risk for CAD.

Common cardiovascular disorders: How it’s treated

For patients with angina, CAD treatment seeks to reduce myocardial oxygen demand or increase oxygen supply. Nitrates reduce myocardial oxygen consumption. Beta-adrenergic blockers can reduce the workload and oxygen demands of the heart by reducing heart rate and peripheral resistance to blood flow. If angina results from coronary artery spasm, the patient may receive calcium channel blockers. Antiplatelet drugs minimize platelet aggregation and the danger of coronary occlusion. Antilipemic drugs can reduce elevated serum cholesterol or triglyceride levels.

Obstructive lesions may call for coronary artery bypass surgery or PTCA. Other alternatives include laser angioplasty, minimally invasive surgery, rotational atherectomy, and stent placement.

Common cardiovascular disorders: What to do

  • Monitor blood pressure and heart rate during an anginal episode.
  • Take an ECG before administering nitroglycerin or other nitrates for angina.
  • Record the duration of pain, the amount of medication required to relieve it, and accompanying symptoms. Keep nitroglycerin available for immediate use.
  • Evaluate the patient. Note if the patient experiences pain or shortness of breath at rest or with usual activity. Assess whether he can tolerate activity. (See Coronary artery disease teaching tips.)

Coronary artery disease teaching tips

Focus Topic: Common cardiovascular disorders

  • Explain all procedures and tests, answer questions appropriately, and provide support.
  • Instruct the patient to seek medical attention immediately if he feels symptoms of angina.
  • Help the patient determine which activities precipitate episodes of pain. Help him identify and select more effective coping mechanisms to deal with stress.
  • Stress the need to follow the prescribed drug regimen.
  • Encourage the patient to maintain the prescribed diet.
  • Encourage regular moderate exercise. Refer the patient to a local cardiac rehabilation center if appropriate.
  • If the patient smokes, refer him to a smokingcessation program.
  • Refer the patient to the American Heart Association for more information and support.

 

FURTHER READING/STUDY:

Resouces: