Valvular Heart Disease

Definition:

Valvular heart disease involves outflow obstruction or incompetence of one of four valves of heart. The distribution of disease varies greatly based on population and risk factors. The most valvular diseases are Rheumatic, Congenital or Degenerative.

Most common cause of valvular heart disease in Tanzania is Rheumatic heart disease.

 

Types of valvular disease

• Aortic Stenosis
• Pathophysiology: LV hypertrophies in order to overcome outflow obstruction but this compensatory change becomes maladaptive and leads to LV dilatation and CCF
• Etiology: 1) rheumatic, 2) calcification of normal valve in elderly, 3) calcification/fibrosis of congenital bicuspid valve
• Symptoms: syncope / angina / CCF (heart failure is a late sign of worsening AS)
• Exam: pulsus parvus et tardus, soft S2, crescendo/decrescendo systolic murmur at RUSB (if loud enough, can be heard throughout precordium) (as the stenosis becomes more severe the murmur will peak later in systole), loud and harsh, radiates to carotids
• Severity graded by echocardiogram and symptoms
• As symptoms develop prognosis becomes worse and presence of Syncope/CCF/Angina are poor predictors
• Treatment: definitive is surgical. Medical therapy in symptomatic patients and cannot get surgery, control HTN. Avoid venodilators (nitrates) and beta-blockers in severe AS
• Aortic Insufficiency/ Regurgitation
• Pathophysiology: In diastole, blood flows from aorta into LV due to incompetence of aortic valve which increases End Diastolic Volume and Stroke Volume and leads to CCF
• Etiology: 1) rheumatic fever, 2) endocarditis, trauma, connective tissue disease, congenital biscuspid aortic valve, HTN
• Symptoms: angina / CCF
• Exam: abrupt upstroke of pulse with a quick collapse, wide pulse pressure, displacement of apex beat, early diastolic murmur on left sternal border
• Treatment: definitive is surgical. Medical therapy includes hydralazine, ACE inhibitors for severe AI and pt can not get surgery. Digoxin if has CCF.

• Mitral Stenosis
• Pathophysiology: stenotic valve atrial pressures are very high and result in outflow obstruction from LA to LV. Elevated atrial pressure leads to atrial dilatation and often atrial fibrillation. Elevated atrial pressure causes elevated pulmonary pressures and pulmonary symptoms.
• Etiology: most common rheumatic heart disease, congenital
• Symptoms: SOB, palpitations, dyspnea on exertion, atrial fibrillation
• Exam: opening snap heard in diastole after S2 followed by a low-pitch rumbling murmur heard best at the apex (when severe PAH occurs a TR murmur may exist)
• Treatment: Surgery required if patient symptomatic. Can use beta blockers. Existence of atrial fibrillation OR prior systemic emboli require anticoagulation
• Mitral Regurgitation (RHD in 30% of cases, often secondary to ischemia)
• Pathophysiology: abnormal coaptation of mitral leaflets creates a regurgitant orifice and a resultant regurgitant volume creating a volume overload of the LV
• Etiology: 1) rheumatic heart disease, 2) endocarditis, ischemia, connective tissue
• Symptoms: pulmonary edema, progressive shortness of breath, fatigue
• Exam: high-pitched, blowing, holosystolic murmur at apex, radiates to axilla. Murmur increases with handgrip and decreases with valsalva. Brisk carotid upstroke
• Treatment: surgery in symptomatic severe MR, decrease afterload with ACE inhibitors, hydralazine. Decrease preload with diuretics

 

Acute Rheumatic Fever and Rheumatic Heart Disease

Acute Rheumatic Fever

Definition:

It is a nonsuppurative consequence of a pharyngeal infection by group A streptococcus (Strep pyogenes) and occurs 2-3 weeks after throat symptoms and is diagnosed clinically with Jones criteria. Worldwide an estimated 10-20 million people get acute RF yearly. Rheumatic heart disease is the most common cause of valvular heart disease in the world. Most common in children ages 4-9 years old, but adults can get acute rheumatic fever also.

 

Diagnosis: 

Generally a clinical diagnosis with laboratory confirmation; Jones criteria are often used

Jones Criteria: 2 major criteria or one major and 2 minor criteria PLUS evidence of recent streptococcal infection.

• Major Criteria
• Carditis:  pancarditis affecting all layers from the heart (pericardium to the endocardium).  Look for signs of pericarditis, new and changing murmurs, especially mitral regurgitation; this acute presentation is different from the later sequelae of rheumatic heart disease (mitral stenosis). Congestive heart failure symptoms which look similar to viral myocarditis
  -any degree of heart block
  -cardiomegaly on CXR
• Arthritis:  migratory polyarthritis usually of large joints. each affected joint inflamed for less than one week and typically over 6 joints involved
• Chorea:  also called Sydenham chorea or St. Vitus dance. It’s an abrupt, purposeless, nonrhythmic, involuntary movements, usually worse on one side. chorea can occur up to 8 months after strep infection
• Subcutaneous nodules:  firm, painless, noninflamed, variable in size, symmetric when multiple and located over bony surfaces or near tendons, appear earlier in course of ARF and usually only in patients with carditis
• Erythema marginatum:  pink, evanescent, non-itchy rash on trunk and limbs, but not on face. Heat brings lesions out.
• Minor criteria
• Fever
• Arthralgia
• Previous rheumatic fever or rheumatic heart disease

Laboratory Diagnosis:

-Increased ASO titer or strep antibodies

-Positive throat culture for Group A beta-hemolytic strep

Recent scarlet fever

**Antibodies are better than culture because the culture is often negative.  Antibody titer usually peaks at 4-5 weeks after pharygitis.  Cannot use titers as indicator of disease activity after initial illness. 

 

Treatment:

Once the diagnosis is established, a course of therapy with penicillin is indicated to eradicate the streptococcal infection. Salicylates are often effective in treating fever and arthritis.

Acute treatment: oral penicillin 500mg BD-TDS for 10 days, or 1.2 mU IM once

Use erythromycin 40mg/kg/day divided in 2-4 doses or a cephalosporin if PCN allergic

Treat even if no pharyngitis at the time of diagnosis; culture family contacts and treat if positive

?? Dose ASA

?? Steroids

Chronic treatment: PCN 250 mg BD or sulfadiazine 1000mg/day, or PCN IM 1.2 mU q month*, or erthyromycin 250 mg BD

If chronic therapy is terminated, patients with mitral stenosis should get prophylaxis for specific dental, GU, and GI procedures

 

Rheumatic heart disease

Rheumatic heart disease occurs 10-20 years after original attack.  Probably develops in over 50% of patients with initial carditis.

 

Pathophysiology:  Tiny nodules gather on the valve leaflets in acute rheumatic fever.  Over time fibrin deposition occurs and valves thicken or fuse (fibrosis).  Another proposed mechanism is acute inflammation causing adhesion of commisures and then degenerative sequelae.  A subclinical inflammatory process caused by the stress of chronic turbulent flow due to the deformed valve contributes to the progression of stenosis.  With time there is a gradual loss of valve area.

 

Valve findings and when they occur

Mitral stenosis is most common finding, followed by aortic stenosis.  Some studies suggest that over 70% of MS is caused by RHD.  Stenosis occurs 10-20 years after infection but symptoms may be delayed as late as 40 years. If antibiotic treatment is not adequate in ARF (not available vs. more virulent strains causing earlier adhesion of leaflets), onset of symptoms often occurs earlier.

 

When does the patient need an intervention?

Symptoms drive the need for intervention.  Can do closed or open commisurotomy, percutaneous balloon valvotomy, or valve replacement. Mitral valve replacement should occur in symptomatic patients (NYHA Class III-IV) with severe mitral stenosis

 

Complications of rheumatic heart disease

Congestive heart failure:  Mortality is related to patient’s functional status. 

Atrial fibrillation:  occurs in over 45% of mitral stenosis patients

Pulmonary HTN:  mean survival without surgery 2.4 years

Thromboembolic events:  mostly occur in patients with atrial fibrillation, but can happen in normal sinus rhythm in patients with mitral stenosis

Bacterial endocarditis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Valvular Heart disease, Acute Rheumatic Fever, Rheumatic Heart Disease Clinical Cases

 

Case 1:

 

50 yo male with history of HTN presents with one episode of syncope.  He described the event as passing out at his house while he was standing, with a loss of consciousness for a few seconds.  No associated palpitations or shortness of breath or chest pain. When he woke up, he was at his baseline mental status and knew exactly what happened.  On exam, his blood pressure is 150/90 and HR is 80.  You note that on his cardiac exam he has a loud, harsh systolic murmur with radiation to carotids.

 

1.      What kind of valvular lesion is this characteristic of?

            -aortic stenosis

2.      What other symptoms go long with this valvular lesion?

            -heart failure symptoms: dyspnea on exertion, orthopnea, PND, lower         extremity swelling

            -angina

3.      What test do you want to order to define this valvular lesion better?

            -echocardiogram

 

The patient then tells you that for the past 1 year he has been having chest discomfort with exertion.  He also notices that both of his legs have become more swollen in past few months and he is more fatigued than usual. He will also wake up at night feeling short of breath and needs to sleep with 3 pillows (last year he only slept with 1 pillow). He does not take any blood pressure medication.  He currently does not have a job.

 

1.      Is this history concerning?

            -yes

2.      What kind of treatment is indicated?

            -surgical replacement of aortic valve

3.      What blood pressure medication should you start him on?

            -ACE inhibitors

 

Case 2:

 

10 yo girl with no past medical history comes into the hospital with her parents. Her parents tell you that they have been noticing that their daughter is behaving strangely and think she is sick.  They see her doing a strange dance at times and when you ask the girl about the dance, she says she can not help herself. She also complains of wrist, knee and ankle pain.  You notice that she also has a faint rash on her back and trunk area.

 

1.      What disease process do you suspect at this point?

            -acute rheumatic fever

2.      Does she fit into Jones’ criteria?

            -yes, she has 3 major criteria – arthritis, chorea, erythema marginatum

3.      What investigation do you want to order?

            -ASO titre, throat culture, ECG, CXR

4.      What treatments would you start?

            -penicillin

 

The girl’s parents ask you how serious this disease process is and if there will be any long term complications.

 

1.      What are the long term complications?

            -rheumatic heart disease develops in 50% of patients with initial carditis

            -complications of rheumatic heart disease include mitral stenosis and/or      aortic stenosis which can lead to congestive cardiac failure, atrial fibrillation,   pulmonary hypertension, thromboembolic events, and bacterial endocarditis

2.      Will she need any medications in the future because of these diseases?

            -if she develops mitral or aortic stenosis, she will need ACE inhibitors

            -if she develops CCF, she will need ACE inhibitors and possibly diuretics

            -if she develops atrial fibrillation or thromboembolic events, she will need    warfarin