NSG210 Exam 2 - Valvular Heart Disease Chapter Summary (Hinkle Ch. 24)
Source: Hinkle & Cheever, Brunner & Suddarth’s 15th ed., Ch. 24 “Management of Patients With Structural, Infectious, and Inflammatory Cardiac Disorders”, valve section pp. 765-776. The syllabus lists this as “Ch. 25”; Ch. 24 is the matching chapter in the 15th edition (Ch. 22 is arrhythmias). Condensed from the full outline nsg210-exam-2-outline-hinkle-ch24.
The Core Idea
- Stenosis: the valve does not open fully. Forward flow is blocked, so pressure builds behind the valve.
- Regurgitation (insufficiency): the valve does not close fully. Blood leaks backward, so volume builds behind the valve.
- Mitral and aortic (left side) disorders cause the most problems. Left-sided disease backs up into the lungs (pulmonary congestion, left heart failure) and can eventually cause right heart failure.
- AV valves (mitral, tricuspid) are open in diastole and closed in systole. Semilunar valves (aortic, pulmonic) are open in systole and closed in diastole.
- Murmur timing rule: a stenosis murmur happens when the valve should be open. A regurgitation murmur happens when the valve should be closed.
The Five Disorders at a Glance
| Disorder | Murmur | Hallmark findings | Key cause | Main treatment |
|---|---|---|---|---|
| Mitral valve prolapse | Systolic mitral click, apex | Usually no symptoms; fatigue, palpitations, chest pain, anxiety | Connective tissue disorder, inherited | Symptom control; avoid caffeine, alcohol, nicotine |
| Mitral regurgitation | Systolic, high-pitched blowing, apex, radiates to left axilla | Dyspnea, fatigue, weakness, palpitations; acute MR (after MI) = sudden severe HF | Degenerative (MVP), ischemia, rheumatic disease | Afterload reduction (ACE inhibitors, ARBs, hydralazine, beta-blockers); repair (annuloplasty) |
| Mitral stenosis | Diastolic, low-pitched rumbling, apex | DOE first; dry cough, wheezing, hemoptysis; atrial fibrillation | Rheumatic endocarditis | Anticoagulation, rate control for A-fib, avoid strenuous activity and pregnancy; commissurotomy |
| Aortic regurgitation | Diastolic, high-pitched blowing, 3rd-4th ICS left sternal border | Pounding heartbeat felt in head and neck; widened pulse pressure; water hammer (Corrigan) pulse | Bicuspid valve, rheumatic disease, syphilis, aortic dilation or dissection | ACE inhibitors, dihydropyridine CCBs; valve replacement before LV fails |
| Aortic stenosis | Systolic, loud harsh crescendo-decrescendo, right 2nd ICS, radiates to carotids | Triad: angina, syncope, DOE (heart failure); narrow pulse pressure; S4; thrill | Degenerative calcification (older adults); bicuspid valve | Valve replacement (surgical or TAVR); balloon valvuloplasty as palliation |
Disorder Details Worth Knowing
Mitral valve prolapse
- A mitral leaflet balloons back into the left atrium during systole. Twice as common in women.
- The first and often only sign is a mitral click. A murmur means it has progressed to regurgitation.
- Prophylactic antibiotics are NOT recommended before dental work.
- Teaching: read OTC labels (cough medicines with caffeine, alcohol, ephedrine, or epinephrine can trigger arrhythmias); first-degree relatives may be screened. Pregnancy without complications needs no special cardiac monitoring.
Mitral regurgitation
- Each beat pushes blood back into the left atrium. The atrium dilates, the lungs congest, and the extra volume overloads the left ventricle until it dilates and fails.
- Pulse may be irregular (A-fib). Heart failure symptoms are the signal to consider repair or replacement.
Mitral stenosis
- The opening narrows from about three fingers wide to a pencil width. The left atrium cannot empty, so it dilates and becomes electrically unstable, causing atrial fibrillation and clots.
- A fast heart rate shortens diastole, which leaves less time to fill the ventricle and worsens symptoms. This is why patients avoid strenuous exertion, competitive sports and pregnancy.
- The enlarged left atrium presses on the left bronchus, causing a dry cough and wheezing.
- Prevention: treat strep throat properly to prevent rheumatic fever. Secondary prophylaxis (for example, penicillin G IM every 4 weeks) may last 10 years or more.
Aortic regurgitation
- Blood falls back into the left ventricle during diastole. The ventricle dilates and hypertrophies, raising systolic pressure, while reflex vasodilation lowers diastolic pressure. The result is a widened pulse pressure.
- Beta-blockers are used less because a slower heart rate lengthens diastole, which allows more backflow.
- Surgery is recommended for any symptomatic patient and for any significant LV dilation, even without symptoms.
Aortic stenosis
- The left ventricle pushes against a narrowed outlet, which causes hypertrophy and then failure.
- Angina occurs because the thick muscle needs more oxygen while coronary filling time is shorter. Syncope occurs because cardiac output cannot rise to perfuse the brain.
- Pulse pressure is narrow (30 mmHg or less), and BP is normal or low.
- Stress testing is used cautiously and not in symptomatic patients (risk of VT or VF).
- Nitroglycerin caution: venodilation drops preload and cardiac output, which can cause syncope. Teach the patient to rest first and to sit or lie down when taking it.
Repair vs Replacement
Repair (valvuloplasty) is preferred when possible because the patient keeps their own valve.
- Commissurotomy separates fused leaflets and is used for mitral stenosis. The balloon (percutaneous) approach goes from the right atrium through the atrial septum. It is contraindicated with an atrial or ventricular thrombus or with significant MR. Expected complications: some MR, bleeding at the insertion site, emboli (stroke).
- Annuloplasty repairs the valve ring and is used for regurgitation. A ruptured chordae with severe MR is an urgent indication.
- Leaflet repair: resection, plication, chordae release, or patching.
- Aortic balloon valvuloplasty restenoses in about 50% of patients within 6 months, so it is a palliation or a bridge to TAVR.
Replacement is used when the valve is too calcified or fibrotic to repair.
- TAVR (transcatheter aortic valve replacement): catheter-delivered tissue valve, no bypass, no sternotomy.
- MitraClip: a transcatheter clip that joins the mitral leaflets for degenerative MR.
- After replacing a stenotic valve, heart failure improves in hours to days. After replacing a regurgitant valve, recovery may take months.
| Valve type | Lasts | Anticoagulation | Best for |
|---|---|---|---|
| Mechanical | Longest | Lifelong warfarin | Younger patients; kidney injury, hypercalcemia, endocarditis |
| Bioprosthesis (pig, cow, horse) | 7-15 years | Not long-term | Women of childbearing age, over 70, cannot take anticoagulants |
| Homograft (human donor) | 10-15 years | Not long-term | Younger patients needing aortic root replacement |
| Autograft (Ross procedure, own pulmonic valve moved to aortic position) | Over 20 years | None | Children, young adults, women of childbearing age |
Nursing Priorities
Assessment
- Compare vital signs to baseline. Auscultate heart and lungs, and palpate peripheral pulses.
- Watch for heart failure: fatigue, DOE, cough, orthopnea, PND, crackles, daily weight gain.
- Watch for arrhythmias (especially A-fib with mitral disease): irregular pulse, palpitations.
- Watch for dizziness, syncope, and angina (especially aortic stenosis).
Teaching
- Diseased and prosthetic valves attract bacteria and raise the risk of endocarditis. Teach good oral hygiene and regular dental care, and tell every provider about the valve disease.
- Report fever, chills, malaise, weight loss, and new petechiae (possible endocarditis).
- Weigh daily and report sudden gain. Balance rest and activity.
After valve procedures
- Balloon valvuloplasty: care as for a post-cardiac catheterization patient, plus checks for heart failure, emboli, and heart sounds at least every 4 hours. The stay is 24-48 hours.
- Surgical repair or replacement: ICU first, telemetry in 24-72 hours, discharge in 3-7 days.
- Warfarin targets (per text): INR 2-3.5 for mitral replacement, 1.8-2.2 for aortic replacement. After an annuloplasty ring or tissue valve, anticoagulation usually lasts only 3 months unless the patient has A-fib or a prior clot.
- Warfarin teaching: take it at the same time daily, keep lab appointments, avoid injury, and report bleeding (gums, petechiae, tarry stools).
- Get a baseline echocardiogram 3-4 weeks after discharge, then every 1-2 years.
Likely Exam Angles
- A murmur description leads to the disorder. Use the table: timing plus location usually identifies it.
- A patient with mitral stenosis and A-fib: the priority is anticoagulation and rate control (risk of stroke from atrial thrombus).
- Aortic stenosis plus a new syncope or angina: this is serious and signals the need for valve replacement. Be cautious with nitroglycerin.
- Widened pulse pressure and bounding pulse point to aortic regurgitation. Narrow pulse pressure points to aortic stenosis.
- A woman who wants future pregnancy needs a bioprosthetic valve (avoids warfarin, which crosses the placenta). A young patient who wants durability needs a mechanical valve and lifelong warfarin.
- MVP: reassure, teach to avoid stimulants, and no routine antibiotic prophylaxis.
- Acute MR after an MI presents as sudden severe heart failure and pulmonary edema.