MS 23

Valvular Pathophysiology Terminology

Stenosis
- Valve opening narrowed; cusps stiff/fused
- $\downarrow$ forward blood flow $\Rightarrow$ $\downarrow$ cardiac output (CO)
Regurgitation / Insufficiency
- Valve fails to close completely $\Rightarrow$ retrograde blood flow
- Volume overload of proximal chamber; eventual ventricular dilation & HF

Review of Valve States

Normal valve: cusps meet, no back-flow
Stenosed valve: fused cusps prevent full opening → emptying impeded
Insufficient valve: fails to seal during closure → back-flow despite normal opening

Rheumatic Fever

Auto-immune sequela $2\text{–}3$ wk after group-A $\beta$ -hemolytic streptococcal URI
Preventable by prompt penicillin therapy
S/S: poly-arthritis, sub-cutaneous nodules, chorea, carditis, fever, arthralgia, pneumonitis

Mitral Valve Prolapse (MVP)

Patho: one/both mitral leaflets bulge into LA during systole; poor coaptation → mitral regurgitation (MR)
Etiology: hereditary, connective-tissue d/o (e.g., Marfan), myxomatous degeneration, infection, IHD, cardiomyopathy
S/S (often none): anxiety, atypical non-exertional CP, dizziness, dysrhythmias, dyspnea, fatigue
Rare complications: arrhythmia, emboli, HF, IE, MR
Diagnostics: mid-systolic click/late systolic murmur, ECG, 2-D/Doppler echo, coronary angio
Treatment: none if mild; lifestyle (avoid caffeine/stimulants), stress control, $\beta$ -blockers (tachy), anti-arrhythmics, ASA/anticoag, surgery when severe

Mitral Stenosis (MS)

Thickened valve & shortened chordae → narrow orifice
LA enlargement → pulmonary HTN → RV dilation/failure; $\downarrow$ CO
Causes: rheumatic fever (common), congenital, SLE, Ca $^{++}$ deposits
S/S: may be silent; diastolic murmur, AF, ankle/feet edema, exertional dyspnea, cough, hemoptysis, fatigue, dizziness, palpitations
Complications: emboli, HF, pulmonary edema, stroke, seizures
Diagnostics: ECG (P-wave changes), CXR (chamber enlargement), 2-D/Doppler echo, CT/MRI, angiogram
Therapy: anticoag for AF, percutaneous balloon valvuloplasty in cath lab, surgical repair (commissurotomy/annuloplasty) or replacement

Mitral Regurgitation (MR)

Incomplete closure → back-flow LA → LV volume overload/dilation → HF
Causes: rheumatic HD, IE, HTN, chordal disruption, post-MI, MVP
S/S: often none; holosystolic murmur, dyspnea/cough/hemoptysis/edema, fatigue, syncope, palpitations, AF
Complications: AF, pulmonary HTN, HF, IE
Diagnostics: ECG (P-wave), CXR, Doppler echo, TEE
Therapy: observe if asymptomatic; anticoag, rate-control (CCB, $\beta$ -blocker, digoxin) for AF, repair/replacement

Aortic Stenosis (AS)

Narrowed aortic orifice; LV must generate high pressure → concentric hypertrophy, $\downarrow$ CO, HF
Causes: congenital bicuspid, rheumatic HD, age-related calcification
S/S: latent yrs → early (dizziness/syncope, DOE, activity intolerance, systolic murmur) ; late (angina, edema, fatigue, orthopnea)
Complications: HF, arrhythmia, emboli, IE, sudden death
Diagnostics: ECG, CXR (LVH), serial echo, cath
Treatment: Surgical or transcatheter (TAVR), valvotomy; manage HF

Aortic Regurgitation (AR)

Incompetent closure → LV volume overload → dilation/failure; $\downarrow$ CO, pulmonary edema
Etiology: rheumatic HD, congenital/age, syphilis, IE, severe HTN, ankylosing spondylitis, RA, aortic dissection
S/S: prolonged asymptomatic phase; exertional dyspnea/fatigue, diastolic murmur, Corrigan (water-hammer) pulse, wide pulse pressure, atypical angina
Complications: IE, HF
Diagnostics: ECG, CXR, echo, angiogram
Treatment: vasodilators, digitalis, diuretics, surgery/TAVR when severe

Nursing Process – Valvular Disorders

Data: history, VS, symptom review
Dx examples: Acute Pain, Decreased CO, Activity Intolerance
Goals: pain relief, stable VS/O $2$ , resume activity, clear lungs, understanding
Interventions:
- Pain: nitro, pacing
- Cardiac function: VS, I&O, wt, Na $^+$ restriction, smoking cessation, meds
- QoL: assist ADLs, rest, energy conserve
- Fluid: weights, edema monitor, diuretics (check $K^+$ )
- Education: meds, INR monthly (warfarin), med alert ID, endocarditis prophylaxis
Evaluation: pain ↓, normal VS, less fatigue, no edema, comprehends teaching, symptom-free

Valve Surgery & Repair

Approaches: minimally invasive (endoscopic, robotic), traditional open, TAVR
Repair: Balloon valvuloplasty (stenosis), Commissurotomy (split cusps), Annuloplasty (tighten annulus for insufficiency)
Replacement:
- Mechanical: durable; causes turbulent flow → lifelong anticoag (target INR per HCP)
- Biological: porcine, bovine, allograft, autograft; less durable, no lifelong anticoag; preferred elderly or when anticoag contra-indicated
Complications:
- Biological: degeneration, calcification
- Mechanical: bleeding (INR), thrombo-embolism, anemia, IE

Infective Endocarditis (IE)

Endocardial infection; vegetations damage leaflets & can embolize
Etiology: bacteremia (dental, IV drugs, valvular disease, prosthetic valves, immunocomp., gingival disease)
Prevention: meticulous oral hygiene, prophylactic antibiotics per guideline
S/S: fever, murmur, splinter hemorrhages, petechiae, Janeway lesions, Osler nodes, Roth spots
Complications: vegetative emboli,valve stenosis/regurgitation, HF
Diagnostics: multiple blood cultures, echo
Treatment: prolonged IV antimicrobials, rest, possible home IV, valve surgery
Nursing: monitor VS/cardiac, report HF/emboli, teach hygiene, fever reporting, prophylaxis

Pericarditis

Inflammation of pericardium → impaired ventricular filling → $\downarrow$ CO & BP
Etiologies: infection, Lyme/Lupus, meds, CT disorders, neoplasm, post-MI (Dressler), renal failure, trauma, viral
S/S: sharp/grating substernal CP radiating; worse deep breath, relieved sitting forward; pericardial friction rub, dyspnea, low-grade fever, cough
Diagnostics: ECG (diffuse ST↑), echo, WBC, pericardiocentesis labs, CT/MRI
Treatment: pericardiocentesis/window/-ectomy; treat cause (abx, dialysis); bedrest, NSAIDs, colchicine (severe), corticosteroids if NSAID fails
Complications: pericardial effusion, cardiac tamponade (requires emergent pericardiocentesis)
Nursing: VS, tamponade signs (JVD, muffled heart tone, ↓BP), NSAID pain relief, positioning, education

Myocarditis

Myocardial inflammation, usually viral; rare
S/S: may mimic viral illness, chest pain, tachycardia; severity correlates with myocyte necrosis
Diagnostics: endomyocardial biopsy, MRI, echo, ECG
Treatment: rest (critical), O $2$ , treat cause, manage HF; NSAIDs no longer used

Cardiomyopathy

Types & Patho:
- Dilated: enlarged chambers, thin walls, ↓contractility, blood stasis; commonest, major HF cause
- Hypertrophic: hereditary LV wall thickening; ↓filling; risk sudden death
- Restrictive: stiff myocardium; impaired filling, preserved systolic ejection; rare
S/S:
- All: HF manifestations
- Dilated: DOE, orthopnea, fatigue
- Hypertrophic: DOE, resting angina
- Restrictive: DOE, syncope, arrhythmias, thrombi
Diagnostics: CXR (cardiomegaly), echo, ECG, cath, labs
Therapy: no cure; anticoag, HF regimen; specifics:
- Dilated: ACEi, ARB, $\beta$ -blocker, diuretic, aldosterone antagonist, digoxin; Bi-V pacing, ICD, transplant
- Restrictive: vasodilators, transplant
- Hypertrophic: $\beta$ /CCB, surgical myectomy, septal ablation
Nursing: VS, HF/embolus watch, digoxin toxicity, energy conserve, emotional support, no ETOH; educate meds, CPR, hospice if needed

Thrombophlebitis & DVT

Patho: thrombus forms then venous inflammation; superficial vs deep (DVT = serious)
Virchow Triad:
1. Venous stasis (immobility, long standing/sitting, postop, bedrest)
2. Endothelial injury (IV catheters > $48$ h, trauma)
3. Hypercoagulability (smoking, OCP, estrogen, blood d/o, abrupt cessation anticoag)
Prevention:
- Risk assess; hydration; compression stockings/IPC; early ambulation; analgesia for mobilization; ROM & leg exercises; change IV sites; DB&C; no smoking; prophylactic anticoag (Factor-Xa inhibitors, dabigatran, heparin, warfarin) w/ lab monitoring
S/S:
- Often asymptomatic
- Superficial: red, warm, tender cord
- DVT: unilateral swelling, edema, calf pain, warmth, venous distention
Complications: pulmonary embolism (life-threat), chronic venous insufficiency, varicosities, recurrent DVT
Diagnostics: D-dimer, coag labs, duplex ultrasound, venography, MRI, CT
Treatment:
- Superficial: warm moist heat, analgesic, NSAID, compression
- DVT: LMWH/heparin, warfarin (monitor INR/PTT), leg elevation, heat, compression, thrombolytics, thrombectomy
Nursing Dx: Acute Pain, Impaired Skin Integrity, Anxiety, Knowledge Deficit
Interventions: assess risk, monitor, give meds per INR, pain mgmt, PE surveillance, education

Case & Review Highlights (Exam Clues)

Warfarin with mechanical valve: bruising → protect pt, check INR, notify HCP
DVT care: measure leg girth same site; risk factors = sedentary job, smoking, OCP
Prevent DVT: avoid prolonged sitting/standing, maintain hydration
Restrictive cardiomyopathy: report crackles, dyspnea, edema, fatigue (HF signs)
Post-op thrombosis prevention: early ambulation, compression stockings, leg exercises
Severe AS obstruction indicators: chest pain & arrhythmias with VS changes
Endocarditis discharge: maintain q6-mo dental cleaning for prophylaxis
Varicose veins concept map: comfort, perfusion, teaching, stress & finance interplay

Equations / Numeric References

Therapeutic INR for mechanical valve typically $2.5\text{–}3.5$ (verify per HCP)
Fever cutoff: $>100.4^{\circ}F$ / $38^{\circ}C$ considered significant
Wide pulse pressure in AR: $\text{SBP} - \text{DBP} > 60\,\text{mmHg}$
Pericardial tamponade Beck’s triad: $\downarrow BP$ , muffled heart tones, JVD

Ethical / Practical Considerations

Cultural acceptability of porcine/bovine valves
Lifelong anticoagulation: safety, cost, lifestyle adaptation, diet interactions
Home IV antibiotics: aseptic technique, patient teaching, resource allocation
Transplant candidacy & end-of-life planning in cardiomyopathy

Summary Connections & Clinical Pearls

Rheumatic fever prevention ↓ risk of MS & MR decades later.
Any new murmur + fever → evaluate for IE.
MVP common, usually benign; educate pts to avoid stimulants & manage stress.
In valvular disease, onset of HF or AF often prompts surgical referral.
Sudden syncope or angina in AS signals critical obstruction— emergent eval.
Cardiac tamponade after pericarditis or trauma requires immediate pericardiocentesis.
Thrombophlebitis prevention hinges on mobility, hydration & anticoag compliance.