Cardiovascular Diagnostics, Therapeutics, and Pathophysiology

Flashcards covering cardiovascular diagnostics (ECG, imaging, biomarkers), therapeutic procedures (PCI, CABG, rhythm devices), hypertension management, and peripheral vascular diseases (PAD and CVI).

12-Lead ECG

A snapshot of the heart's electrical activity that should be obtained within $10$ minutes of a patient presenting with chest pain.

It records electrical signals from multiple angles, helping to identify arrhythmias, ischemia, and other cardiac conditions.

Telemetry

A form of continuous cardiac monitoring used to identify dysrhythmias, myocardial ischemia, or conduction abnormalities over time.

A mnemonic for 5-lead ECG placement

White on the Right / Clouds over Grass: where the White lead (RA) is placed on the right and the Green lead (RL) is placed below it.

Smoke over Fire / Red on the Left: where the Black lead (LA) is placed on the left and the Red lead (LL) is placed below it.

I heart chocolate: Brown by the heart

ST elevation

An ECG finding that suggests acute myocardial injury (STEMI).

Peaked T waves

An ECG finding that suggests the electrolyte disturbance Hyperkalemia.

U waves

An ECG finding that suggests the electrolyte disturbance Hypokalemia.

Prolonged QT interval

An ECG finding indicating a risk for ventricular dysrhythmias, often caused by hypocalcemia or specific medications.

Holter Monitor

A continuous ECG recording device worn for $24$–$48$ hours to detect intermittent dysrhythmias or causes of syncope.

Ejection Fraction (EF)

The percentage of blood ejected from the left ventricle with each contraction; the normal range is $55$–$70\%$, while reduced levels are common in systolic heart failure.

Transesophageal Echocardiogram (TEE)

An invasive ultrasound procedure requiring NPO status for $6$–$8$ hours used for enhanced visualization of the valves, left atrium, and aorta.

Nurse should assess for gag reflex afterwards and maintain NPO status until gag returns.

Pharmacologic stress test

A diagnostic test for patients unable to exercise that uses medications like dobutamine or adenosine to increase myocardial oxygen demand.

Troponin

The most sensitive indicator of myocardial injury; This protein complex is released when cardiac muscle is damaged.

Elevated levels indicate:

• acute MI

• myocardial injury

• myocarditis

it rises in $3$–$6$ hours, peaks in $12$–$24$ hours, and remains elevated for $7$–$14$ days.

CK-MB

A cardiac biomarker that is less specific than Troponin and returns to normal in $48$–$72$ hours; it is useful for detecting reinfarction because it drops quicker than troponin.

BNP (B-type natriuretic peptide)

A peptide released when ventricles are stretched; elevated levels suggest heart failure or volume overload.

Cardiac Catheterization

The gold standard for coronary artery evaluation that uses contrast dye to visualize arteries, assess blockages, and measure cardiac pressures.

The contrast dye can damage kidneys.

Access sites: femoral artery, radial artery

• must remain flat with leg straight for 6 hours with frequent neurovascular checks after femoral access.

Risks: bleeding, infection, dysrhythmias, and allergic reactions to the dye.

The 6 Ps

The components of a neurovascular assessment: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, and Poikilothermia.

Percutaneous Coronary Intervention (PCI)

A minimally invasive procedure, such as balloon angioplasty or stent placement, used to open narrowed or blocked coronary arteries.

Indications:

• Acute myocardial infarction, unstable angina, and ischemic symptoms.

Goal: Restore myocardial perfusion and improve blood flow to the heart muscle.

Drug-Eluting Stent (DES)

A stent coated with medication to lower restenosis risk; it requires DAPT for usually at least $6$ to $12$ months.

DAPT

Dual anti-platelet therapy, which consists of aspirin plus a PGY12 inhibitor such as clopidogrel or Prasugrel.

Acute Stent Thrombosis

A high-mortality complication ($40$–$50\%$) that can occur if antiplatelet medications are stopped early after a PCI.

Coronary Artery Bypass Graft (CABG)

Open-heart surgery creating an alternate route for blood flow around blocked coronary arteries, frequently using the Internal Mammary Artery (preferred) or Great Saphenous Vein.

Indications: Severe coronary artery disease, left main coronary artery stenosis, persistent angina, or multivessel disease not amenable to PCI.

Cardiac Tamponade

A life-threatening condition where blood accumulates in the pericardial sac, compressing the heart and preventing adequate filling.

Symptoms include: tachycardia, narrow pulse pressure, and decreased chest tube drainage with worsening instability.

Beck's Triad

A set of three clinical signs for cardiac tamponade: Hypotension, Jugular venous distention (JVD), and Muffled heart sounds.

Permanent Pacemaker

An implanted device that provides electrical stimulation when intrinsic conduction is inadequate, such as in symptomatic bradycardia, sick sinus syndrome, or heart block.

Symptoms to prompt: syncope, dizziness, or fatigue due to inadequate heart rate.

Implantable Cardioverter Defibrillator (ICD)

A device used to detect and treat lethal ventricular dysrhythmias; patients must report multiple shocks to EMS immediately.

One shock: call cardiologist

Loss of consciousness after shock is a medical emergency!

Indications: ventricular tachycardia, ventricular fibrillation, or high risk of sudden cardiac death.

Certain patients with severe heart failure at high risk of lethal dysrhythmias once EF less than 20%.

Cardioversion

The delivery of a synchronized electrical shock to correct organized but abnormal rhythms (like Atrial Fibrillation, Atrial flutter, and supraventricular tachycardia) in patients WITH a pulse.

Defibrillation

The delivery of an unsynchronized, high-energy shock for life-threatening arrhythmias (VF or pulseless VT) in patients WITHOUT a pulse.

Priorities:

• confirm rhythm

• clear the patient

• resume CPR immediately after shock and ensure proper post-resuscitation care.

Blood Pressure Formula

$BP = CO \times SVR$, where $CO$ is Cardiac Output (heart rate x stroke volume) and $SVR$ is Systemic Vascular Resistance, measured by vascular resistance levels in the systemic circulation.

Stage 2 Hypertension

A blood pressure classification defined by a Systolic reading of $140\,mm\,Hg$ or higher OR a Diastolic reading of $90\,mm\,Hg$ or higher. This is usually where patients require lifestyle modifications and possible medication to manage blood pressure.

Secondary Hypertension

High blood pressure caused by an underlying disease process, such as renal disease, or medications like oral contraceptives and steroids.

DASH Diet

A dietary approach for hypertension that emphasizes fruits, vegetables, and whole grains while limiting sodium and saturated fat.

ACE Inhibitors

First-line HTN medications (e.g., Lisinopril) that require monitoring for dry cough, angioedema, and elevated potassium. Avoid in pregnancy.

These decrease vasoconstriction and reduce cardiac workload by relaxing blood vessels. They inhibit the angiotensin-converting enzyme, leading to lower blood pressure.

Also beneficial in diabetes, CKD, and heart failure.

Hypertensive Emergency

Severe hypertension (typically 180 systolic and 120 diastolic) accompanied by acute target-organ damage (e.g., stroke, MI, AKI, acute heart failure/pulmonary edema) requiring immediate IV therapy.

Peripheral Artery Disease (PAD)

An arterial perfusion problem caused by atherosclerosis that leads to narrowing of the arteries, reducing blood flow to the limbs. Patients typically experience intermittent claudication, which is a sharp, stabbing pain in the muscles (usually in the legs) during physical activity such as walking, which resolves with rest. Other signs and symptoms include cool, pale skin and diminished or absent pulses in the affected limb. Pain worsens with elevation.

Risk factors:smoking, diabetes, hyperlipidemia, hypertension, and a sedentary lifestyle.

Diagnosis often involves the Ankle-Brachial Index (ABI) test,

Treatment may include lifestyle modifications, medications, and in severe cases, surgical options such as Percutaneous Coronary Intervention (PCI) or bypass surgery.

Chronic Venous Insufficiency (CVI)

A condition where the veins cannot adequately pump blood back to the heart, leading to venous pooling. Patients commonly experience symptoms such as:

1. Edema: Swelling in the legs and ankles due to fluid accumulation.

2. Brown Skin Pigmentation: Leaky veins allow blood to escape into the surrounding tissue, leading to hemosiderin deposition and discoloration.

3. Aching Pain: Discomfort in the legs, often worsening with prolonged standing and relieved by elevation.

Risk Factors: Age, obesity, history of deep vein thrombosis (DVT), pregnancy, and sedentary lifestyle.

Complications: Can lead to venous ulcers, infections, and in severe cases, thrombosis.

Management: Includes lifestyle modifications (e.g., weight loss, exercise), compression therapy (use of compression stockings to improve venous return), medications to manage symptoms, and for refractory cases, surgical options may be considered.

Intermittent Claudication

Sharp, stabbing muscle pain that occurs during exercise and is relieved by rest, typical of Peripheral Artery Disease.

Ankle-Brachial Index (ABI)

A diagnostic test where a value less than $0.90$ is indicative of Peripheral Artery Disease (PAD).

Dependent Rubor

The redness of the extremity when it is lowered, occurring in patients with Peripheral Artery Disease (PAD).

Common ECG Findings to Recognize

1. ST Elevation: Indicates acute myocardial injury (STEMI).

2. ST Depression: Myocardial ischemia

3. Inverted T waves: Myocardial ischemia

4. Peaked T Waves: Suggests hyperkalemia (high potassium levels).

5. U Waves: Indicates hypokalemia (low potassium levels).

6. Prolonged QT Interval: Suggests risk for ventricular dysrhythmias, often from hypocalcemia or medications.

Transthoracic Echocardiography (TTE)

A non-invasive ultrasound procedure used to visualize heart structures, assess cardiac function, and detect abnormalities; does not require NPO status and provides real-time imaging.

• It may require the patient to lay on the left side to make the heart easier to visualize

• indications are weird ECGs

Exercise Stress Test

A diagnostic test that assesses the heart's performance under physical stress. It typically involves a patient walking on a treadmill or pedaling a stationary bike while being monitored with an ECG to evaluate heart rhythm, blood pressure, and symptoms.

Cardiac Catheterization Nursing Care

Nursing responsibilities include:

1. Pre-procedure: Ensure informed consent is obtained, monitor allergies (especially to contrast dye), assess renal function, and maintain NPO status.

2. During the procedure: Monitor vital signs, provide patient comfort, and assist with the procedure as directed.

3. Post-procedure: Monitor the access site for bleeding or hematoma, assess vital signs regularly, check for pulses in the affected limb, and patient education regarding activity limitations and signs of complications.

Bare-Metal Stent (BMS)

A standard stent without medication coating; it typically requires a shorter duration of dual anti-platelet therapy (DAPT) compared to drug-eluting stents but has a higher risk of restenosis over time.

Percutaneous Coronary Intervention (PCI) Nursing Care

Nursing responsibilities include:

1. Pre-procedure: Verify patient identification and consent, educate about the procedure, check for allergies (especially to contrast dye), and assess renal function.

2. During the procedure: Monitor vital signs, provide patient comfort, and assist with the procedure as directed; ensure ECG monitoring is in place.

3. Post-procedure: Monitor the access site for bleeding or hematoma, assess peripheral pulses in the affected limb, monitor vital signs, and educate the patient about activity restrictions and signs of complications.

Postoperative Priorities and Care after CABG

1. Monitoring Vital Signs: Regularly check heart rate, blood pressure, and respiratory status to detect any abnormalities early.

2. Assessing Cardiac Function: Monitor for signs of myocardial ischemia or cardiac failure.

3. Pain Management: Administer analgesics as prescribed to manage chest pain and discomfort.

4. Monitor Surgical Site: Inspect the chest incision for signs of infection, bleeding, or hematoma.

5. Pulmonary Care: Encourage deep breathing exercises and use of incentive spirometer to prevent pneumonia.

6. Fluid Management: Administer IV fluids per protocol and monitor electrolyte levels, ensuring proper hydration and balance.

7. Patient Education: Educate the patient on activity restrictions, medication regimen, and signs of complications to watch for post-discharge.

Nursing Care after Pacemaker Insertion

1. Monitor Heart Rate and Rhythm: Continuously assess the patient's heart rate and rhythm to ensure the pacemaker is functioning appropriately.

2. Check Surgical Site: Inspect the insertion site for bleeding, signs of infection, or hematoma formation.

3. Restrict arm movement: avoid raising arm above shoulder or lifting more than 10 lbs for two weeks

4. Patient Education: Inform the patient to carry device identification card, keep follow-up appointments, avoid MRIs (unless compatible), and report dizziness, syncope, or palpitations.

5. Assess for Complications: Watch for signs of complications, such as improper pacing, displacement of the pacemaker leads, or battery failure.

6. Pain Management: Administer analgesics as needed for post-operative pain and discomfort.

7. Monitor Vital Signs: Regularly check vital signs, including blood pressure and oxygen saturation, ensuring stability.

8. Educate on Lifestyle Changes: Discuss any necessary lifestyle modifications, such as avoiding certain physical activities or electric fields that may interfere with the pacemaker.

Cardioversion Nursing Care

1. Pre-procedure: Obtain informed consent from the patient, ensure the patient is well-informed about the procedure, and assess for any contraindications such as anticoagulation status.

2. During the procedure: Monitor vital signs, maintain a clear airway, and ensure ECG monitoring is in place; assist the physician in preparing the equipment for the synchronized shock.

3. Post-procedure: Monitor the patient for return of normal rhythm, check vital signs, assess for signs of complications such as hypotension or arrhythmia, and provide post-procedure education on the recovery process and follow-up care.

Primary Hypertension

A type of high blood pressure that has no identifiable cause, also known as essential hypertension. It is often related to genetic factors, poor diet, lack of physical activity, and obesity.

Hypertensive Emergency Nursing Priorities

1. Monitor Vital Signs: Regularly check blood pressure to assess the effectiveness of treatment.

2. Assess for Target Organ Damage: Look for signs of complications such as severe headache, vision changes, chest pain, dyspnea, neurologic deficits, or altered mental status.

3. Administer IV Medications: Prepare and give antihypertensive medications as prescribed to rapidly lower blood pressure.

4. Maintain Patient Safety: Ensure the patient's safety to prevent falls and injury due to high blood pressure.

5. Education: Educate the patient about the importance of medication adherence and lifestyle modifications post-crisis.

6. Frequent Neurological Assessments: Monitor for any changes in neurological status, particularly if the patient presents with signs of stroke.