Chapter 15: Cardiovascular Therapeutic Management

A patient is diagnosed with third-degree heart failure. The nurse reviews the patient's medication list. Which classifications of drugs should be avoided with this patient? (Select all that apply.) a. Nonsteroidal antiinflammatory drugs (NSAIDs). b. Antidysrhythmics. c. Angiotensin-converting enzyme (ACE) inhibitors. d. Calcium channel blockers e. Beta-blockers.

Answer: A, B, D. Rationale: Types of medications that have been found to worsen heart failure should be avoided, including most antidysrhythmics, calcium channel blockers, and nonsteroidal antiinflammatory medications. Angiotensin-converting enzyme inhibitors and beta-blockers are used to treat heart failure.

Which patients would be a candidate for fibrinolytic therapy? (Select all that apply.) a. The patient's chest pain started 8 hours ago. She has a diagnosis of non-ST-elevation myocardial infarction (NSTEMI). b. The patient's chest pain started 3 hours ago, and her electrocardiogram (ECG) shows a new left bundle branch block. c. The patient presents to the emergency department with chest pain of 30 minutes' duration. She has a history of cerebrovascular accident 1 month ago. d. The patient has a history of unstable angina. He has been experiencing chest pain with sudden onset. e. The patient's chest pain started 1 hour ago, and his ECG shows ST elevation.

Answer: B, E. Rationale: Eligibility criteria for administering fibrinolytics include chest pain of less than 12 hours' duration and persistent ST elevation. Exclusion criteria include recent surgery, cerebrovascular accident, and trauma.

A nurse is providing care to a patient on fibrinolytic therapy. Which of the following statements from the patient warrants further assessment and intervention by the nurse? a. "My back is killing me!" b. "There is blood on my toothbrush!" c. "Look at the bruises on my arms!" d. "My arm is bleeding where my IV is!"

Answer: a. "My back is killing me!" Rationale: The nurse must continually monitor for clinical manifestations of bleeding. Mild gingival bleeding and oozing around venipuncture sites are common and not causes for concern. However, severe lower back pain and ecchymoses are suggestive of retroperitoneal bleeding. If serious bleeding occurs, all fibrinolytic heparin therapies are discontinued, and volume expanders, coagulation factors, or both are administered.

A patient suddenly develops a wide QRS complex tachycardia. The patient's heart rate is 220 beats/min and regular; blood pressure is 96/40 mm Hg; and respiratory rate is 22 breaths/min, and the patient is awake without complaint except for palpitations. Which of the following interventions would be best to try first? a. Adenosine 6 mg rapid IV push. b. Lidocaine 1 mg/kg IV push. c. Verapamil 5 mg IV push. d. Digoxin 0.5 mg IV push.

Answer: a. Adenosine 6 mg rapid IV push. Rationale: Adenosine (Adenocard) is an antidysrhythmic agent that remains unclassified under the current system. Adenosine occurs endogenously in the body as a building block of adenosine triphosphate (ATP). Given in intravenous boluses, adenosine slows conduction through the atrioventricular (AV) node, causing transient AV block. It is used clinically to convert supraventricular tachycardias and to facilitate differential diagnosis of rapid dysrhythmias.

What two medications are commonly prescribed at discharge for patients who have had a coronary artery stent placed? a. Aspirin and prasugrel. b. Aspirin and abciximab. c. Clopidogrel and eptifibatide. d. Tirofiban and tricagrelor.

Answer: a. Aspirin and prasugrel. Rationale: Because platelet activation is a complex process involving multiple pathways, combination therapy with two or more agents has proven most effective. The current standard of care for percutaneous coronary intervention typically includes dual antiplatelet therapy with aspirin and a thienopyridine. These oral agents are administered before the procedure and continued at discharge. Abciximab, eptifibatide, and tirofiban are all intravenous antiplatelet agents.

Which finding is a reliable indicator of reperfusion after fibrinolytic therapy? a. Dysrhythmias. b. Q waves. c. Elevated ST segments. d. Immediate rapid decrease in cardiac biomarkers.

Answer: a. Dysrhythmias. Rationale: Initially, when there is reperfusion, ischemic chest pain ceases abruptly as blood flow is restored. Another reliable indicator of reperfusion is the appearance of various "reperfusion" dysrhythmias. Premature ventricular contractions, bradycardias, heart block, ventricular tachycardia, and (rarely) ventricular fibrillation may occur.

The patient is 72 hours postoperative for a coronary artery bypass graft (CABG). The patient's vital signs include temperature 103° F, heart rate 112, respiratory rate 22, blood pressure 134/78 mm Hg, and O2 saturation 94% on 3L nasal cannula. The nurse suspects that the patient has developed what problem? a. Infection and notifies the physician immediately. b. Infection, which is common postoperatively, and monitors the patient's condition. c. Cardiac tamponade and notifies the physician immediately. d. Delirium caused by the elevated temperature.

Answer: a. Infection and notifies the physician immediately. Rationale: Postoperative fever is fairly common after cardiopulmonary bypass. However, persistent temperature elevation to greater than 101° F (38.3° C) must be investigated. Sternal wound infections and infective endocarditis are the most devastating infectious complications, but leg wound infections, pneumonia, and urinary tract infections also can occur. A potentially lethal complication, cardiac tamponade may occur after surgery if blood accumulates in the mediastinal space, impairing the heart's ability to pump. Signs of tamponade include elevated and equalized filling pressures (eg, central venous pressure, pulmonary artery diastolic pressure, pulmonary artery occlusion pressure), decreased cardiac output, decreased blood pressure, jugular venous distention, pulsus paradoxus, muffled heart sounds, sudden cessation of chest tube drainage, and a widened cardiac silhouette on radiographs. The risk of delirium is increased in cardiac surgery patients, especially elderly patients, and is associated with increased mortality rates and reduced quality of life and cognitive function. Nursing staff can play a critical role in the prevention and recognition of delirium.

How does a percutaneous transluminal coronary angioplasty (PTCA) improve blood flow? a. The balloon stretches the vessel wall, fractures the plaque, and enlarges the vessel lumen. b. Medication is delivered through the catheter that dissolves the plague and enhances vessel patency. c. The balloon removes blood clots from the vessel improving patency of the vessel. d. The balloon compresses the plaque against the vessel wall enlarging the vessel lumen.

Answer: a. The balloon stretches the vessel wall, fractures the plaque, and enlarges the vessel lumen. Rationale: Percutaneous transluminal coronary angioplasty involves the use of a balloon-tipped catheter that, when advanced through an atherosclerotic lesion (atheroma), can be inflated intermittently for the purpose of dilating the stenotic area and improving blood flow through it. The high balloon-inflation pressure stretches the vessel wall, fractures the plaque, and enlarges the vessel lumen.

Adenosine is an antidysrhythmic agent that is given primarily what reason? a. To convert supraventricular tachycardias. b. To suppress premature ventricular contractions (PVCs). c. To treat second and third degree AV blocks. d. To coarsen ventricular fibrillation so that defibrillation is effective.

Answer: a. To convert supraventricular tachycardias. Rationale: Adenosine occurs endogenously in the body as a building block of adenosine triphosphate (ATP). Given in intravenous boluses, adenosine slows conduction through the atrioventricular (AV) node, causing transient AV block. It is used clinically to convert supraventricular tachycardias and to facilitate the differential diagnosis of rapid dysrhythmias.

A transvenous pacemaker is inserted through the right subclavian vein and threaded into the right ventricle. The pacemaker is placed on demand at a rate of 70. What is the three letter code for this pacing mode? a. VVI b. AOO c. DDD d. VAT

Answer: a. VVI Rationale: The original code is based on three categories, each represented by a letter. The first letter refers to the cardiac chamber that is paced. The second letter designates which chamber is sensed, and the third letter indicates the pacemaker's response to the sensed event. A VVI pacemaker paces the ventricle when the pacemaker fails to sense an intrinsic ventricular depolarization.

Which dosage of dopamine results in stimulation of beta1 receptors and increased myocardial contractility? a. 1 mcg/kg/min. b. 5 mcg/kg/min. c. 15 mcg/kg/min. d. 20 mcg/kg/min.

Answer: b. 5 mcg/kg/min. Rationale: At low dosages of 1 to 2 mcg/kg/min, dopamine stimulates dopaminergic receptors, causing renal and mesenteric vasodilation. Moderate dosages result in stimulation of beta1 receptors to increase myocardial contractility and improve cardiac output. At dosages greater than 10 mg/kg/min, dopamine predominantly stimulates alpha receptors, resulting in vasoconstriction that often negates both the beta-adrenergic and dopaminergic effects.

Through what mechanism does enalapril decrease blood pressure? a. Direct arterial vasodilation. b. Block the conversion of angiotensin I to angiotensin II. c. Increase fluid excretion at the loop of Henle. d. Peripheral vasoconstriction and central vasodilation.

Answer: b. Block the conversion of angiotensin I to angiotensin II. Rationale: Enalapril is an angiotensin-converting enzyme (ACE) inhibitors that produces vasodilation by blocking the conversion of angiotensin I to angiotensin II. Because angiotensin is a potent vasoconstrictor, limiting its production decreases peripheral vascular resistance. In contrast to the direct vasodilators and nifedipine, ACE inhibitors do not cause reflex tachycardia or induce sodium and water retention.

Which mechanism is responsible for the augmentation of coronary arterial blood flow and increased myocardial oxygen supply seen with the intraaortic balloon pump? a. The vacuum created in the aorta as a result of balloon deflation. b. Diastolic inflation with retrograde perfusion. c. Forward flow to the peripheral circulation. d. Inflation during systole to augment blood pressure.

Answer: b. Diastolic inflation with retrograde perfusion. Rationale: The blood volume in the aorta below the level of the balloon is propelled forward toward the peripheral vascular system, which may enhance renal perfusion. Subsequently, the deflation of the balloon just before the opening of the aortic valve creates a potential space or vacuum in the aorta, toward which blood flows unimpeded during ventricular ejection. This decreased resistance to left ventricular ejection, or decreased afterload, facilitates ventricular emptying and reduces myocardial oxygen demands.

Which anticoagulant enhances the activity of antithrombin III and does not require activated partial thromboplastin time (aPTT) or activated clotting time (ACT) monitoring? a. Heparin b. Enoxaparin c. Bivalirudin d. Argatroban

Answer: b. Enoxaparin Rationale: Enoxaparin (Lovenox) enhances activity of antithrombin III, a more predictable response than heparin, because enoxaparin is not largely bound to protein. There is no need for activated partial thromboplastin time (aPTT) or activated clotting time (ACT) monitoring, and there is a lower risk of heparin-induced thrombocytopenia (HIT) than with unfractionated heparin (UFH). Heparin sodium enhances activity of antithrombin III, a natural anticoagulant, to prevent clot formation. The effectiveness of treatment may be monitored by aPTT or ACT. Response is variable because of binding with plasma proteins effects may be reversed with protamine sulfate. Bivalirudin (Angiomax) directly inhibits thrombin. It may be administered alone or in combination with glycoprotein IIb/IIIa inhibitors and produces a dose-dependent increase in aPTT and ACT. It may be used instead of UFH for patients with HIT. Argatroban (Argatroban) directly inhibits thrombin. It may be used instead of UFH for patients with HIT. Whereas ACT is monitored during percutaneous coronary intervention, aPTT is used during prolonged infusion.

Which calcium channel blocker is beneficial in the treatment of patients with coronary artery disease or ischemic stroke? a. Nifedipine b. Nicardipine c. Clevidipine d. Diltiazem

Answer: b. Nicardipine Rationale: Nicardipine was the first available intravenous calcium channel blocker and as such could be more easily titrated to control blood pressure. Because this medication has vasodilatory effects on coronary and cerebral vessels, it has proven beneficial in treating hypertension in patients with coronary artery disease or ischemic stroke. Nifedipine is available only in an oral form, but in the past it was prescribed sublingually during hypertensive emergencies. Clevidipine is a new, short-acting calcium channel blocker that allows for even more precise titration of blood pressure in the management of acute hypertension. Diltiazem (Cardizem) is from the benzothiazine group of calcium channel blockers. These medications dilate coronary arteries but have little effect on the peripheral vasculature. They are used in the treatment of angina, especially that which has a vasospastic component, and as antidysrhythmics in the treatment of supraventricular tachycardias.

When analyzing the electocardiogram (ECG) strip of the patient with a pacemaker, the nurse notices there is a spike before each QRS complex. What is this phenomenon indicative of? a. 60-cycle electrical interference; check equipment. b. Pacing artifact; the pacemaker is sensing and capturing. c. Electrical artifact; the pacemaker is not sensing. d. Patient movement; check electrodes.

Answer: b. Pacing artifact; the pacemaker is sensing and capturing. Rationale: The pacing artifact is the spike that is seen on the electrocardiographic tracing as the pacing stimulus is delivered to the heart. A P wave is visible after the pacing artifact if the atrium is being paced. Similarly, a QRS complex follows a ventricular pacing artifact. With dual-chamber pacing, a pacing artifact precedes both the P wave and the QRS complex.

When is a patient a candidate for a surgical repair of an abdominal aortic aneurysm (AAA)? a. Size is 1 cm. b. Patient experiencing symptoms. c. Aneurysm size unchanged over several years. d. Size less than 4 cm.

Answer: b. Patient experiencing symptoms. Rationale: An abdominal aortic aneurysm (AAA) is usually repaired when the aneurysm is 5 cm or larger, creating symptoms, or rapidly expanding. This is done to prevent the high mortality rate associated with abdominal rupture.

What is the preferred initial treatment of an acute myocardial infarction? a. Fibrinolytic therapy. b. Percutaneous coronary intervention (PCI). c. Coronary artery bypass surgery (CABG). d. Implanted Cardioverter defibrillator (ICD).

Answer: b. Percutaneous coronary intervention (PCI). Rationale: Percutaneous coronary intervention (PCI) is now preferred as the initial method of treatment for acute myocardial infarction (MI; primary PCI). PCI includes balloon angioplasty, atherectomy, and stent implantation, as well as a number of adjunctive devices used to facilitate successful revascularization in coronary vessels.

What parameter must be assessed frequently in the patient with an intraaortic balloon in place? a. Skin turgor in the affected extremity. b. Peripheral pulses distal to the insertion site. c. Blood pressures in both arms and legs. d. Oxygen saturation.

Answer: b. Peripheral pulses distal to the insertion site. Rationale: One complication of intraaortic balloon support is lower extremity ischemia resulting from occlusion of the femoral artery by the catheter itself or by emboli caused by thrombus formation on the balloon. Although ischemic complications have decreased with sheathless insertion techniques and the introduction of smaller balloon catheters, evaluation of peripheral circulation remains an important nursing assessment. The presence and quality of peripheral pulses distal to the catheter insertion site are assessed frequently along with color, temperature, and capillary refill of the involved extremity. Signs of diminished perfusion must be reported immediately.

Which of the following statements regarding beta-blockers is correct? a. They increase heart rate and are contraindicated in tachydysrhythmias. b. They result in bronchospasm and should not be used in patients with chronic obstructive pulmonary disease (COPD). c. They increase cardiac output and help with left ventricular failure. d. They are helpful in increasing atrioventricular node conduction and are used in heart blocks.

Answer: b. They result in bronchospasm and should not be used in patients with chronic obstructive pulmonary disease (COPD). Rationale: Knowledge of the effects of adrenergic-receptor stimulation allows for anticipation of not only the therapeutic responses brought about by beta-blockade but also the potential adverse effects of these agents. For example, bronchospasm can be precipitated by noncardioselective beta-blockers in a patient with chronic obstructive pulmonary disease secondary to blocking the effects of beta2 receptors in the lungs.

The possibility of microshock when handling a temporary pacemaker can be minimized by which intervention? a. Decreasing the milliamperes. b. Wearing gloves. c. Positioning the patient on the left side. d. Wearing rubber-soled shoes.

Answer: b. Wearing gloves. Rationale: The possibility of "microshock" can be minimized by wearing gloves when handling the pacing wires and by proper insulation of terminal pins of pacing wires when they are not in use. The latter can be accomplished either by using caps provided by the manufacturer or by improvising with a plastic syringe or section of disposable rubber glove. The wires are to be taped securely to the patient's chest to prevent accidental electrode displacement.

A patient is connected to an external temporary pulse generator. What does the sensitivity control regulate? a. The time interval between the atrial and ventricular pacing stimuli. b. The amount of electrical current and is measured in milliamperes. c. The ability of the pacemaker to detect the heart's intrinsic electrical activity. d. The number of impulses that can be delivered to the heart per minute.

Answer: c. The ability of the pacemaker to detect the heart's intrinsic electrical activity. Rationale: The sensitivity control regulates the ability of the pacemaker to detect the heart's intrinsic electrical activity. Sensitivity is measured in millivolts (mV) and determines the size of the intracardiac signal that the generator will recognize.

Why are vasopressors used cautiously in the treatment of critical care patients? a. They cause vasoconstriction of the smooth muscles. b. They cause vasodilation of the smooth muscles. c. They increase afterload. d. They decrease preload.

Answer: c. They increase afterload. Rationale: Vasopressors are not widely used in the treatment of critically ill cardiac patients because the dramatic increase in afterload is taxing to a damaged heart. Vasopressin, also known as antidiuretic hormone, has become popular in the critical care setting for its vasoconstrictive effects. At higher doses, vasopressin directly stimulates V1 receptors in vascular smooth muscle, resulting in vasoconstriction of capillaries and small arterioles.

A patient has an implantable cardioverter defibrillator (ICD) for chronic ventricular tachydysrhythmias. What action should the nurse take when the patient's rhythm deteriorates to ventricular fibrillation? a. Apply an external defibrillator to the patient. b. Call a code and start cardiopulmonary resuscitation (CPR) on the patient. c. Wait for the ICD to defibrillate the patient. d. Turn the ICD off and administer epinephrine.

Answer: c. Wait for the ICD to defibrillate the patient. Rationale: If the dysrhythmia deteriorates into ventricular fibrillation, the implantable cardioverter defibrillator is programmed to defibrillate at a higher energy. If the dysrhythmia terminates spontaneously, the device will not discharge.

A patient is admitted after a positive exercise treadmill test with a diagnosis of coronary artery disease (CAD) and stable angina. Radiographic tests show that the patient has blockage in the left main coronary artery and four other vessels. The nurse anticipates that the patient's treatment plan will include what treatment or procedure? a. Medical therapy b. PCI c. TAVR d. CABG

Answer: d. CABG Rationale: Early studies demonstrated coronary artery bypass graft (CABG) surgery was more effective than medical therapy for improving survival in patients with left main or three-vessel coronary artery disease and at relieving anginal symptoms. Medical therapy is recommended if the ischemia is prevented by antianginal medications that are well tolerated by the patient. Surgical revascularization has been shown to be more efficacious than percutaneous coronary intervention (PCI) in patients with multivessel or left main coronary disease. Transcatheter aortic valve replacement (TAVR) is a transformational therapy for patients who have severe aortic stenosis but who are extremely high-risk surgical candidates or who are inoperable by virtue of associated co-morbidities.

A patient is admitted after a femorotibial bypass graft. What nursing action is critical in the immediate postoperative period? a. Frequent assessment of the skin. b. Hourly assessment of intake and output. c. Monitoring for ST segment changes. d. Frequent pulse checks to the affected limb.

Answer: d. Frequent pulse checks to the affected limb. Rationale: The primary focus of nursing care in the immediate postprocedural period is assessment of the adequacy of perfusion to the affected limb and identification of complications. Pulse checks are performed frequently, and the physician is notified of any decrease in the strength of the Doppler signal. Because distal perfusion is compromised in this patient population, nursing measures to prevent skin breakdown are implemented. If the repair was performed above the renal arteries, kidney function may be impaired as a result of interruption of renal blood flow during the procedure. Urine output is therefore assessed hourly and supported with fluids and diuretics as needed. Because patients with peripheral vascular disease are at high risk for cardiac events, ST segment monitoring is performed to detect episodes of myocardial ischemia throughout the perioperative period.

What is the rationale for administrating a fibrinolytic agent to a patient experiencing acute ST-elevation myocardial infarction (STEMI)? a. Dilation of the blocked coronary artery. b. Anticoagulation to prevent formation of new emboli. c. Dissolution of atherosclerotic plaque at the site of blockage. d. Restoration of blood flow via lysis of the thrombus.

Answer: d. Restoration of blood flow via lysis of the thrombus. Rationale: The administration of a fibrinolytic agent results in the lysis of the acute thrombus, thus recanalizing, or opening, the obstructed coronary artery and restoring blood flow to the affected tissue. After perfusion is restored, adjunctive measures are taken to prevent further clot formation and reocclusion.

Noninvasive emergency pacing is best achieved via the use of which type of temporary pacing? a. Transvenous (endocardial) b. Epicardial c. Transthoracic d. Transcutaneous

Answer: d. Transcutaneous Rationale: Transcutaneous cardiac pacing involves the use of two large skin electrodes, one placed anteriorly and the other posteriorly on the chest, connected to an external pulse generator. It is a rapid, noninvasive procedure that nurses can perform in the emergency setting and is recommended for the treatment of symptomatic bradycardia.