Cardiac/Vascular Nurse Exam Secrets Study Guide (31 page)

Early intervention provides better outcomes and improvements in the condition. Patients who seek treatment sooner than later tend to have better outcomes over the longer term. Elderly patients who are in poor health with other comorbid conditions are more likely to experience more serious complications as compared to younger patients who are in good health.

First-degree atrioventricular block

Complications associated with first-degree atrioventricular block include progression of condition to a higher degree of atrioventricular block, reduction in left ventricular stroke volume and cardiac output leading to left ventricular systolic dysfunction, and pacemaker syndrome. Patients who progress usually progress to Mobitz type I, second-degree atrioventricular block but sometimes progress to complete atrioventricular block.

The prognosis associated with first-degree atrioventricular block is excellent, especially in patients with asymptomatic disease. First-degree atrioventricular block does not present with increased mortality or morbidity. However, patients that present with comorbid intranodal blocks have an increased risk of developing complete atrioventricular block, which comes with a high risk of serious complications including death.

Second-degree atrioventricular block type I

Second-degree atrioventricular block type I is typically a benign condition that does not require immediate treatment. The complications associated with more mild forms of the condition are minimal, except in patients with poor health or other cardiovascular comorbid conditions.

Patients undergoing treatment with agents that have the potential to induce second-degree atrioventricular block type I should be monitored closely and doses should be adjusted if the condition is induced by the medication.

The prognosis of second-degree atrioventricular block type I depends on the extent and degree of the block. Atrioventricular nodal blocks, which make up most of the type I blocks carry a better prognosis than intra or infra bundle blocks. Intra-and/or infra-bundle blocks can progress to higher degrees of atrioventricular block including complete atrioventricular block.

Second-degree atrioventricular block type II

The prognosis for patients with second-degree atrioventricular block type II is not as good as the prognosis for patients with second-degree atrioventricular block type I. Typically, second-degree atrioventricular block type II progresses to complete heart block and carries risk of syncope, stroke, myocardial infarction, and congestive heart failure. In particular, intra-and/or infra-bundle blocks can progress to higher degrees of atrioventricular block including complete atrioventricular block.

Patients undergoing treatment with agents that have the potential to induce second-degree atrioventricular block type II should be monitored closely and doses should be adjusted if the condition is induced by the medication.

Third-degree atrioventricular block

The prognosis of third-degree atrioventricular block is excellent for patients who receive treatment with permanent pacing. However, patients who are untreated or seek treatment too late are at higher risk for serious complications. Patients with other comorbid cardiovascular health conditions and/or are in poor health have a poorer prognosis. Patients diagnosed with third-degree atrioventricular block are at a high risk for stroke, congestive heart failure, and myocardial infarction.

Patients undergoing treatment with agents that have the potential to induce third-degree atrioventricular block should be monitored closely and doses should be adjusted if the condition is induced by the medication.

Cardiogenic shock

Complications associated with cardiogenic shock include cardiopulmonary arrest, dysrhythmia, renal failure, multisystem organ failure, ventricular aneurysm, thromboembolic disease, stroke, congestive heart failure, and death.

The prognosis for patients diagnosed with cardiogenic shock is very poor. Approximately 50% of patients who experience cardiogenic shock do not survive. The reason that patients diagnosed with cardiogenic shock are able to survive is prompt treatment with pharmacologic agents and/or surgical intervention. The ability to restore blood flow to vital organ systems improves outcomes and prognosis. Patients who undergo treatment promptly with pharmacologic intervention or surgical intervention have an improved prognosis. Evidence of right ventricular dilation on echocardiogram may indicate worse prognosis than other underlying causes of the condition.

Percutaneous transluminal coronary angioplasty (PTCA)

Contraindications for a percutaneous transluminal coronary angioplasty procedure include high-risk coronary anatomy, severe coronary artery disease, bleeding disorder, and/or multiple episodes of percutaneous transluminal coronary angioplasty restenosis.

Complications associated with percutaneous transluminal coronary angioplasty include abrupt closure of diseased coronary artery, periprocedural myocardial infarction, coronary restenosis, bleeding, or hematoma at catheter introduction site, arterial embolism, pseudoaneurysm, retroperitoneal bleeding, and sudden death. Bleeding from the site of catheter insertion (usually the femoral artery) and anaphylaxis to the dye used are also major risk factors.

Other complications may occur due to the patient’s overall health, allergies, and other comorbid conditions. Therefore, practicing clinicians need to take a careful medical history and perform a physical examination prior to the procedure.

Coronary artery bypass graft (CABG)

Potential risk factors:

• Death
  
• Pain: incisional or related to new-onset myocardial infarction
  
• Bleeding: surgical trauma, thrombocytopenia, anemia or disseminated intravascular coagulopathy (DIC)
  
• Myocardial depression: cardiac dysfunction
  
• Cardiac tamponade: increased pericardial fluid
  
• Myocardial infarction: additional injury occurring after surgery
  
• Dysrhythmia: most commonly atrial fibrillation
  
• Pulmonary complications: pulmonary edema, atelectasis, pneumothorax
  
• Renal impairment: mild to acute renal failure
  
• Neuropsychological problems: cerebral ischemia, infarction, emboli, postcardiotomy delirium (ranging from elation and denial to hallucinations and neurological symptoms), brachial plexus or ulnar nerve injury
  
• Postpericardiotomy syndrome: autoimmune response to surgical injury
  
• Infection: wound, sepsis
  
• Gastrointestinal problems: distention, ileus, hepatic dysfunction, mesenteric ischemia
  

Cardiac tamponade

Swift identification and treatment of cardiac tamponade (a buildup of fluid in the pericardial space) is a critical factor in patient mortality. Key symptoms include the classic Beck triad: increased jugular vein pressure with visual vein distention (Kussmaul sign), decreased blood pressure (pulsus paradoxus) and diminished heart sounds. Other signs and symptoms might include increased heart rate, cold and clammy hands and/or feet, cough, dyspnea, decreased consciousness or fainting and anxiety. In advanced cases, Ewart (Pins) sign may also be present: an area of breath sound dullness or bronchophony (very audible and high-pitched voice sounds in the lung) is evident below the left scapula.

Abdominal aortic aneurysms

Most aortic aneurysms are asymptomatic, making early detection more difficult. If the patient presents with symptoms the most common will be pain that is dull and deep within the abdominal cavity and radiating into the back. The pain may be alleviated or eased by change of position. The other noticeable symptom that might be detected by the patient or medical personnel is a palpable, abnormal pulsation within the abdominal cavity. Identification of the aneurysm is made with ultrasound or CT scan. Surgical repair is the primary route of treatment. When the aneurysm is small enough that it doesn’t require surgery, then treatment will focus on preventing growth or rupture through smoking cessation, controlling blood pressure, and cholesterol levels while monitoring the aneurysm size every 6–12 months.

Differences between a coronary artery bypass graft (CABG) and minimally invasive direct coronary artery bypass (MIDCAB)

Traditional CABG surgery involves restoring cardiac blood flow by grafting in a new vein or artery to direct blood around a blockage in the coronary artery. This procedure requires a large incision, stopping the heart and use of a heart-lung machine.

MIDCAB uses a smaller incision and can be performed on a still-beating, but slowed, heart. Prime candidates for this operation are those patients with proximal left anterior descending lesion. This requires less time and therefore, shorter exposure to anesthesia with earlier extubation. Initial pain during recovery may be greater than with CABG, but it is relieved more quickly. There are fewer risks associated with the procedure and expenses are reduced. Patients receiving MIDCAB report better physical activity and sleeping conditions than those undergoing CABG.

Medications that can cause variations in the effectiveness of digoxin

Antacids, amiloride, cholestyramine, neomycin and sulfasalazine reduce the effect of digoxin. Herbal remedies such as plantain and St. John’s wort may also decrease effectiveness.

Albuterol, amiodarone, captopril, cyclosporine, diltiazem, erythromycin, nifedipine, omeprazole, quinidine, tetracycline, thyroxin and verapamil can cause higher blood levels of digoxin and risk toxicity. Herbal remedies of gossypol, horsetail, licorice, oleander, Siberian ginseng and squill (scilla) also carry a greater risk for digoxin toxicity.

Betel pal, fumitory, goldenseal, hawthorn, lily of the valley, motherwort, rue and shepherd’s purse should be avoided completely.

Therapeutic digoxin blood levels are between 0.8–2 ng/ml. Monitor lab results and pulse prior to each administration of digoxin.

Medications and foods that may alter the effectiveness of warfarin sodium (Coumadin)

Multiple medications will react with Coumadin and vary the effectiveness. Monitor PT and INR levels closely to maintain therapeutic levels. Review all medications and supplements carefully. Pay special attention to pain relievers, hormones (oral contraceptives, testosterone, estrogen and thyroid), steroids, hypolipidemics, antidiabetics, antibiotics and tricyclic antidepressants. Most common herbal remedies, including garlic, ginger, ginkgo, ginseng, licorice and angelica, should not be combined with warfarin use. Alcohol use should be minimized, and any source of vitamin K (green leafy vegetables, vitamin supplements and green tea) should be kept at a constant level.

Medications and foods that may alter the effectiveness of Lipitor

Antacids, colestipol and isradipine may decrease the effectiveness of Lipitor. Erythromycin, fluconazole, itraconazole, ketoconazole and voriconazole may increase Lipitor blood levels. Lipitor also interacts unfavorably with digoxin and contraceptives, changing the effectiveness of these medications. Lipitor in combination with antifungal, cyclosporine, erythromycin, fibric acid and niacin can increase the risk of developing muscle weakness. Herbal supplements including eucalyptus, kava and red yeast rice can cause adverse reactions. Grapefruit juice should not be ingested while taking Lipitor. Use cautiously in the patient with a known history of heavy alcohol use, liver and/or renal disease.

Risks associated with vascular repair

Vascular repair procedures include aortic aneurysm repair, bypass grafting, vena cava filter insertion and embolism removal. Postoperatively, monitor for

• Bleeding: external at incision site or internal, causing low blood pressure, increased heart rate, diminished respirations, restlessness, confusion, abdominal pain, increased girth or rigidity.
  
• Occlusion: diminished or absent peripheral pulses, abnormal sensation and/or pain, reduced oxygen saturation and cyanosis.
  
• Infection: fever; redness; warmth; drainage; pain; abnormal heart rate, respiration, or blood pressure; or cough and congestion.
  
• Renal impairment: swelling, weight gain, low urinary output and increased blood urea nitrogen (BUN) and creatinine levels.
  

Arrhythmias as seen on ECG

Sinus node

The sinus node is the primary pacemaker for the heart, setting a normal rate and rhythm of 60–100.

• Sinus arrhythmia: ECG rate falls within normal limits, but there is a slight change in rhythm correlating to breathing (increased pulse with inspiration, slowing with expiration).
  
• Sinus bradycardia: Rhythm is normal, all parts of the ECG appear normal, with a rate below 60 beats per minute.
  
• Sinus tachycardia: Rhythm is normal, ECG is normal, but rate is greater than 100 beats per minute.
  
• Sinus arrest: Rate is normal, but rhythm is interrupted by occasional missing PQRST complexes. This is referred to as a sinus pause if only one or two beats are dropped; sinus arrest refers to 3 or more missing complexes.
  
• Sick sinus syndrome: Irregular rhythm in which the waves and complexes vary instead of forming a predictable pattern.
  

Junctional

Premature junctional contraction (PJC): Rate and rhythm are fundamentally regular with occasional early, inverted P wave and following QRS complex.

Junctional escape rhythm: Regular rate and rhythm appears to be normal sinus rhythm except for inverted P waves.

Accelerated junctional rhythm: Regular rhythm of 60–100 beats per minute. P wave may be absent or appear inverted before or after the QRS complex. Everything else appears normal.