PE: May show a mid or late systolic “click” due to snapping of the chordae or scallop ± late systolic or holosystolic regurg. murmur
Clinical: Usually asymptomatic, but may have dyspnea, fatigue, chest pain, or even psychiatric symptoms
The leaflets balloon into the LA with “interchordal hooding.” The chordae are frequently elongated and thinned and occasionally rupture. The TV is also affected in 20 – 40% & sometimes even the AV and PV.
Can see “friction lesions” where leaflets strike the LA walls or rub against each other. Can get thrombi on these surfaces.
Microscopic: Attenuation of the fibrosa layer with increased myxoid tissue. Ditto in chordae. Valves may show secondary fibrous thickening, especially in friction areas.
Psychiatric symptoms include depression, anxiety, and personality disorders.
Strictly speaking, if MV prolapse is due to a connective tissue disorder, it might be reasonable to classify it as a congenital valvular disorder.
Complications of Floppy MV (3%)
Mitral insufficiency – slow onset or sudden with chordal rupture
Rheumatic disease is an immune mediated inflammatory disease that occurs about 3 weeks (range 1 to 5 weeks) after a bout of acute pharyngitis due to group A (beta hemolytic) streptococcus (not after infections of skin or other sites; not after infections with other strep.) usually in children 5 – 15 years.
Occurs in only about 3% of pts with group A strep pharyngitis & has been declining over 30 years
(? Better treatment, ? decreased virulence of bug).
Diagnosed clinically by the Jones criteria – need 2 major or 1 major + 2 minor along with evidence of a preceding group A strep infection:
Minor criteria: Fever, arthralgias, increased serum acute phase reactants
After an initial attack of rheumatic fever, the pt is more vulnerable to a future attack & carditis is likely to worsen with each subsequent attack. Valve damage is cumulative.
Histologically, granuloma-like lesions called Aschoff bodies characterize the acute phase. Aschoff bodies contain plump macrophages called Anitschkow cells, T-lymphocytes, ± a few plasma cells, and fibrinoid material. Aschoff bodies may be found in any layer of the heart (recall from C603 Lab).
The acute valvulitis is characterized by inflammation & fibrinoid necrosis along the lines of closure, especially on the left-sided valves, with small (1 – 2 mm) verrucous vegetations along the lines of closure. Mitral valve regurgitation may cause plaques in the LA (jet lesion) called MacCallum plaques.
Chronic Rheumatic Disease
Involves the valves – not the pericardium or myocardium