NANDA Nursing Diagnosis for Myocardial Infarction: A Comprehensive Guide for Healthcare Professionals

Introduction

Acute Myocardial Infarction (MI), commonly known as a heart attack, remains a leading cause of mortality worldwide, significantly impacting healthcare systems and patient lives. Globally, the prevalence of MI is staggering, with millions affected and hundreds of thousands of deaths occurring annually in the United States alone. MI is broadly categorized into Non-ST-segment elevation MI (NSTEMI) and ST-segment elevation MI (STEMI), with unstable angina presenting as a closely related condition to NSTEMI, differing primarily in the elevation of cardiac markers. Prompt recognition and intervention are critical in managing MI to minimize irreversible damage to the heart muscle and improve patient outcomes.

Myocardial Infarction results in irreversible damage to the heart muscle due to prolonged ischemia and oxygen deprivation. This ischemic event can lead to significant impairments in both diastolic and systolic heart function, predisposing patients to life-threatening arrhythmias and a cascade of serious complications. The cornerstone of MI management is timely reperfusion therapy aimed at restoring coronary blood flow. The prognosis dramatically improves with earlier treatment, ideally within 6 hours of symptom onset, emphasizing the critical nature of rapid response and intervention in acute MI.

Diagnosing an MI involves a comprehensive assessment based on established criteria, typically requiring at least two of the following:

1. Clinical presentation indicative of myocardial ischemia.
2. New ST-segment deviations on an electrocardiogram (ECG) or the presence of a new left bundle branch block (LBBB).
3. Development of pathological Q waves on serial ECGs.
4. Evidence from imaging studies revealing new regional wall motion abnormalities.
5. Identification of an intracoronary thrombus during autopsy or angiography.

NANDA Nursing Diagnoses for Myocardial Infarction

Nursing diagnoses are crucial for guiding patient care, especially in acute conditions like myocardial infarction. Utilizing the NANDA-I framework, several relevant nursing diagnoses can be identified for patients experiencing MI. These diagnoses address the multifaceted needs of patients, ranging from physiological to psychosocial aspects of care. Here are key NANDA nursing diagnoses relevant to myocardial infarction:

• Acute Pain: Related to myocardial ischemia and tissue injury, often manifested as chest pain, radiating pain, or discomfort.
• Activity Intolerance: Related to imbalance between oxygen supply and demand secondary to myocardial damage, evidenced by fatigue, dyspnea on exertion, and weakness.
• Fear/Anxiety: Related to the threat to physiological integrity and potential for death, expressed as feelings of apprehension, worry, and restlessness.
• Decreased Cardiac Output, Risk for: Risk factors include altered contractility, altered heart rate/rhythm, and structural changes due to MI.
• Ineffective Peripheral Tissue Perfusion, Risk for: Related to decreased cardiac output and compromised circulation, increasing the risk of ischemia in peripheral tissues.
• Excess Fluid Volume, Risk for: Related to potential heart failure secondary to MI, leading to fluid retention.
• Deficient Knowledge: Related to lack of information regarding the disease process, treatment regimen, risk factor modification, and rehabilitation.

Etiology and Pathophysiology of Myocardial Infarction

The primary cause of acute myocardial infarction is a critical reduction in coronary blood flow, leading to a mismatch between myocardial oxygen supply and demand, culminating in cardiac ischemia. This diminished blood flow is often multifactorial, with the rupture of atherosclerotic plaques being the most common initiating event. Plaque rupture triggers thrombus formation, acutely obstructing coronary arteries and severely restricting blood flow to the myocardium.

While atherosclerosis is the predominant underlying pathology, other etiologies can contribute to myocardial ischemia and infarction. These include coronary artery embolism, accounting for a smaller percentage of cases, cocaine-induced vasospasm leading to ischemia, spontaneous coronary artery dissection, and coronary vasospasm unrelated to illicit drug use. Understanding these diverse causes is crucial for comprehensive patient assessment and targeted management strategies.

Risk Factors for Myocardial Infarction

Atherosclerosis is implicated in approximately 70% of fatal acute myocardial infarction events, underscoring the importance of addressing atherosclerotic risk factors in primary and secondary prevention. Modifiable risk factors are strikingly significant, accounting for a vast majority of MI cases – approximately 90% in men and 94% in women. These modifiable factors include:

• Cigarette smoking: A potent vasoconstrictor and promoter of atherosclerosis.
• Physical inactivity: Lack of regular exercise contributes to cardiovascular disease.
• Hypertension: Elevated blood pressure increases strain on the heart and arteries.
• Obesity: Excess body weight is associated with multiple cardiovascular risk factors.
• Dyslipidemia: Abnormal cholesterol, LDL, and triglyceride levels accelerate atherosclerosis.

Non-modifiable risk factors also play a role and include age, sex, and family history of premature coronary artery disease. While these cannot be altered, their identification is important for risk stratification and personalized prevention strategies.

Assessment and Clinical Presentation of Myocardial Infarction

The clinical presentation of acute myocardial infarction can vary widely, and reliance solely on history and physical examination can be misleading. A detailed history focusing on the onset, character, and associated symptoms is essential. Classic symptoms such as chest pain are frequently described as a crushing, squeezing, or pressure sensation, often radiating to the left arm, jaw, or back. However, symptom presentation can be atypical, especially in women, the elderly, and individuals with diabetes.

Recent studies have highlighted diaphoresis (excessive sweating) and bilateral arm pain as particularly strong predictors of myocardial infarction in men. Associated symptoms that should raise clinical suspicion include:

• Lightheadedness and dizziness
• Unexplained anxiety
• Cough, sometimes with frothy sputum if pulmonary edema develops
• Choking sensation
• Diaphoresis
• Wheezing
• Irregular heart rate or palpitations

Physical examination in patients with suspected MI should prioritize vital signs assessment and overall appearance, noting signs like diaphoresis, pallor, and distress. Auscultation of the lungs and heart is crucial. Key findings on physical exam may include:

• Heart rate abnormalities: Tachycardia, bradycardia, atrial fibrillation, or ventricular arrhythmias.
• Unequal pulses: May suggest aortic dissection, a critical differential diagnosis.
• Blood pressure variability: Typically elevated initially, but hypotension may indicate cardiogenic shock.
• Respiratory findings: Tachypnea and fever may be present.
• Jugular venous distention: Suggestive of right ventricular failure.
• Cardiac auscultation: Soft S1, presence of S4 gallop, new mitral regurgitation murmur. A loud holosystolic murmur could indicate ventricular septal rupture.
• Pulmonary findings: Wheezing and rales (crackles) may indicate pulmonary edema.
• Extremities: Cold, clammy skin, edema, or cyanosis may be present.

Specimen of myocardial infarction showing damage to the left ventricle and interventricular septum, with asterisk indicating left ventricular hypertrophy.

Diagnostic Evaluation of Myocardial Infarction

Prompt and accurate diagnosis is paramount in myocardial infarction management. Electrocardiography (ECG) is the cornerstone of initial evaluation in patients presenting with chest pain or symptoms suggestive of MI. It is crucial to recognize that women, elderly patients, and diabetics may present with atypical symptoms such as abdominal pain, dizziness, or shortness of breath, even in the absence of chest pain. In these populations, a high index of suspicion and low threshold for ECG testing are essential.

While ECG is highly specific for MI (95% to 97%), its sensitivity is lower (approximately 30%). Strategies to improve ECG sensitivity include utilizing right-sided and posterior leads and performing serial ECGs to detect evolving changes. Early ischemic changes, such as peaked T-waves (“hyperacute T waves”), may precede ST-segment elevation. ST-segment elevation of greater than 2 mm in two contiguous leads is highly indicative of STEMI (ST-elevation myocardial infarction). Specific lead groupings correspond to different myocardial regions (inferior, septal, anterior, lateral), aiding in localizing the infarct. Reciprocal ST-depressions in anatomically opposite regions are often observed in STEMI.

Diagnosing STEMI via ECG can be challenging in certain situations, particularly in patients with pre-existing left bundle branch block (LBBB) or those with pacemakers. Specific criteria, such as Sgarbosa’s criteria, have been developed to assist in STEMI diagnosis in these complex cases. Isolated ST-elevation in aVR should raise suspicion for left main coronary artery occlusion. Wellens’ sign, characterized by deeply biphasic T waves in V2 and V3, is a critical ECG finding predictive of proximal left anterior descending artery occlusion and impending anterior wall MI.

Patients presenting with myocardial infarction may not always exhibit ST-segment elevation on ECG. In cases of typical chest pain with subtle ECG abnormalities like ST-depressions or T-wave inversions, NSTEMI (Non-ST-elevation myocardial infarction) should be considered. Serial ECGs are invaluable in detecting dynamic ischemic changes in NSTEMI. Notably, a normal ECG does not rule out NSTEMI.

Clinical decision-making in suspected NSTEMI often involves risk stratification tools. Given the limited sensitivity of ECG for STEMI, cardiac troponin assays are universally employed to detect myocardial injury. The HEART score, a validated risk stratification tool, integrates clinical suspicion, patient risk factors, ECG findings, and troponin levels to categorize patients into different risk levels for adverse cardiac events.

Laboratory Investigations for Myocardial Infarction

• Cardiac Troponins: Highly sensitive and specific biomarkers of myocardial injury; serial measurements are essential.
• Complete Blood Count (CBC): To assess overall hematological status.
• Lipid Profile: To evaluate for underlying dyslipidemia and guide long-term management.
• Renal Function Tests: To assess baseline renal function and guide medication dosing, especially in patients undergoing angiography.
• Metabolic Panel: To evaluate electrolytes, glucose, and overall metabolic status.

Heart attack warning signs in women, highlighting symptoms that may differ from classic male presentations.

Medical Management of Myocardial Infarction

Immediate medical management of both STEMI and NSTEMI is critical and follows established protocols. Upon presentation, all patients should receive aspirin (160 mg to 325 mg) to chew immediately, unless contraindicated. Establishing intravenous access and administering supplemental oxygen if saturation is below 91% are essential initial steps. Opioid analgesics, such as morphine, may be used for pain control, along with sublingual nitroglycerin, provided blood pressure is adequate.

STEMI Management: The cornerstone of STEMI treatment is immediate coronary reperfusion. Emergent percutaneous coronary intervention (PCI) is the preferred reperfusion strategy when available within guideline-recommended timeframes. Prior to PCI, patients should receive dual antiplatelet therapy, typically including aspirin and a P2Y12 inhibitor (e.g., ticagrelor), along with intravenous heparin infusion. Glycoprotein IIb/IIIa inhibitors or direct thrombin inhibitors may be administered during PCI in selected cases.

If PCI cannot be performed within 90 minutes of STEMI diagnosis, intravenous thrombolytic therapy should be initiated to achieve timely reperfusion.

NSTEMI Management: Management of NSTEMI differs based on patient stability and risk stratification. Stable, asymptomatic NSTEMI patients may not require emergent PCI and can be initially managed medically with antiplatelet agents and anticoagulation. However, PCI within 48 hours of admission is often beneficial, potentially improving in-hospital mortality and reducing length of stay. Emergent PCI is indicated in NSTEMI patients with ongoing refractory ischemia, hemodynamic instability, or electrical instability.

Discharge medication regimens for patients post-myocardial infarction typically include aspirin, high-dose statin therapy, beta-blockers, and ACE inhibitors or ARBs, depending on individual patient characteristics and comorbidities. PCI, if contemplated, should ideally be performed within 12 hours of symptom onset. Fibrinolytic therapy, if considered, should be administered within 120 minutes of presentation. Parenteral anticoagulation, in addition to antiplatelet therapy, is generally recommended for all MI patients.

Nursing Management of Myocardial Infarction

Nursing care is integral to the comprehensive management of myocardial infarction, focusing on continuous monitoring, prompt intervention, and patient education. Key nursing interventions include:

• Obtain daily 12-lead ECGs to monitor for changes and arrhythmias.
• Ensure two large-bore intravenous (IV) lines are in place for medication administration and fluid resuscitation.
• Monitor cardiac enzymes serially to assess myocardial injury progression.
• Initiate and titrate medications as per physician orders for acute MI management.
• Administer morphine or other analgesics as prescribed for pain management.
• Initiate aspirin and administer nitroglycerin (0.4 mg sublingual) as per protocol.
• Provide supplemental oxygen if pulse oximetry is less than 94% on room air.
• Ensure timely cardiology consultation and follow-up.
• Monitor vital signs frequently, including heart rate, blood pressure, respiratory rate, and oxygen saturation.
• Monitor daily weight and urine output to assess fluid balance.
• Administer heparin or other anticoagulants as ordered, especially for STEMI.
• For patients undergoing cardiac catheterization or PCI, meticulously monitor the groin puncture site for hematoma formation and assess distal leg pulses to detect vascular complications.

ECG showing Pardee waves indicative of acute myocardial infarction in inferior leads II, III, and aVF, with reciprocal changes in anterolateral leads.

Recognizing When to Seek Help

Patient education on recognizing warning signs and when to seek immediate medical attention is crucial for improving outcomes in myocardial infarction. Patients should be instructed to seek immediate medical help if they experience:

• Hypotension (low blood pressure)
• Nausea and vomiting, especially in conjunction with chest pain
• Continuing or worsening chest pain or discomfort
• New onset of leg pain, coldness, or loss of distal leg pulses, which could suggest emboli or compromised circulation.
• Sudden change in mental status, confusion, or disorientation
• Persistent oxygen desaturation
• Tachycardia or new onset arrhythmias
• Sudden onset of a loud heart murmur, which may indicate new-onset mitral regurgitation or ventricular rupture.

Outcome Identification and Goals of Care

The primary goals of nursing care and medical management in myocardial infarction are to:

• Improve breathing and oxygenation.
• Achieve relief from chest pain and discomfort.
• Enhance myocardial tissue perfusion and prevent further ischemia.
• Facilitate the patient’s return to their pre-MI functional status and quality of life.

Monitoring and Ongoing Assessment

Continuous monitoring is essential in patients with myocardial infarction to detect complications and guide ongoing management. Key monitoring parameters include:

• Continuous ECG monitoring for arrhythmias and ST-segment changes.
• Serial cardiac enzyme measurements to track myocardial injury.
• Pulse oximetry to assess oxygenation status.
• Frequent vital sign monitoring.
• Regular assessment of chest pain intensity and characteristics.
• Palpation of peripheral pulses, particularly leg pulses, to assess peripheral perfusion.
• Auscultation of the chest for rales (crackles) indicative of pulmonary edema and new heart murmurs suggesting valvular dysfunction or structural complications.

Coordination of Interprofessional Care

Optimal management of acute myocardial infarction necessitates a collaborative, interprofessional team approach. The core team typically includes:

• Cardiologist: Leads the medical management and interventional strategies.
• Cardiac Surgeon: For patients requiring surgical interventions.
• Interventional Cardiologist: Performs PCI procedures.
• Intensivist or Critical Care Physician: Manages complex or unstable patients in the ICU.
• Cardiac Rehabilitation Specialist: Guides post-MI recovery and rehabilitation.
• Critical Care and Cardiology Nurses: Provide specialized nursing care and monitoring.
• Physical Therapists: Assist with early mobilization and rehabilitation.
• Pharmacist: Manages medication therapy, ensures appropriate dosing, and provides patient education on medications and potential side effects.
• Nurse Practitioner: Provides advanced nursing care, patient education, and coordination of care.
• Social Worker: Facilitates discharge planning, home care arrangements, cardiac rehabilitation enrollment, and access to support services.

Effective triage in the emergency department and rapid communication among team members are crucial to minimize time to reperfusion. Patient education, particularly by nurses and pharmacists, on nitroglycerin use and when to call emergency services is vital for pre-hospital care. Post-discharge, comprehensive cardiac rehabilitation programs, lifestyle modification counseling (diet, exercise, smoking cessation), and medication adherence are critical for long-term secondary prevention and improved outcomes.

ECG segment elevation mimicking myocardial infarction in a patient with pulmonary embolism, highlighting differential diagnosis.

Health Teaching and Health Promotion

Comprehensive health education is essential for patients post-myocardial infarction to promote lifestyle changes and reduce future cardiac events. Key health teaching points include:

• Adhering to a heart-healthy, low-salt diet.
• Strict medication compliance with prescribed medications.
• Maintaining a healthy body weight.
• Engaging in regular physical activity and enrolling in a cardiac rehabilitation program.
• Controlling blood pressure, blood glucose levels, and lipids.
• Smoking cessation.
• Regular follow-up appointments with healthcare providers.

Risk Management Strategies

Effective risk management is crucial in preventing recurrent cardiac events post-MI. Key risk management strategies include:

• Emphasizing the importance of not ignoring chest pain and promptly contacting a healthcare provider.
• Ensuring timely referral to a cardiologist for patients with abnormal vital signs or ECG findings.
• Prompt consultation with a physician for abnormal laboratory parameters.

Discharge Planning and Continuity of Care

Effective discharge planning is essential to ensure a smooth transition from hospital to home and to support long-term recovery. Key discharge planning components include:

• Reinforcing the importance of adhering to a heart-healthy diet.
• Encouraging ambulation and gradual increase in physical activity.
• Emphasizing medication adherence.
• Scheduling follow-up appointments in clinic as needed.
• Reinforcing smoking cessation and avoidance of tobacco products.

Evidence-Based Issues and Best Practices

Evidence-based practice underscores the critical importance of early MI treatment to improve prognosis. Nurses play a vital role in recognizing MI symptoms promptly and initiating timely interventions. Reducing modifiable risk factors through patient education and lifestyle interventions is paramount in improving long-term outcomes and reducing the burden of coronary artery disease.

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Disclosure: Oren Mechanic declares no relevant financial relationships with ineligible companies.

Disclosure: Michael Gavin declares no relevant financial relationships with ineligible companies.

Disclosure: Shamai Grossman declares no relevant financial relationships with ineligible companies.

Disclosure: Kim Ziegler declares no relevant financial relationships with ineligible companies.