Mitral regurgitation Flashcards
(20 cards)
What is mitral regurgitation?
retrograde flow of blood from LV to LA during systole
aka mitral insufficiency
How can MR be classified based on aetiology?
Primary: direct involvement of valve leaflets or chordae tendinae
Secondary: changes of LV lead to valvular incompetence
How can MR be classified according to onset?
Acute: Acute dysfunction of MV leads to volume overload + Sx of acute heart failure.
Chronic: Occurs over many years, results in volume overload + LV dysfunction
Describe the pathophysiology of acute MR
↑ LA volume with normal LA compliance + ↑ LV end-diastolic volume
→ rapid ↑ in LA + pulmonary pressures
→ pulmonary venous congestion
→ pulmonary edema
Describe pathophysiology of decompensated chronic MR
Progressive LV enlargement + myocardial dysfunction
→ ↓ stroke volume
→ ↑ end-systolic + end-diastolic volume
→ ↑ LV + LA pressure
→ pulmonary congestion, possible acute pulmonary edema, pulmonary HTN, + RH strain
Name 2 conditions associated with MR
Ehlers-Danlos syndrome
Marfan syndrome
List 4 primary causes of MR
Degenerative mitral valve disease e.g. mitral valve prolapse (most common)
Rheumatic heart disease
Infective endocarditis: vegetations prevent valve closure
Ischemic MR: papillary muscle rupture following acute MI
Give 2 secondary causes of MR
Coronary artery disease or prior MI causing papillary muscle involvement
Dilated cardiomyopathy + left-sided HF
Describe symptoms in MR
Most asymptomatic,
Mild to mod MR may stay largely asymptomatic indefinitely.
Sx tend to be due to LV failure, arrhythmias or pulmonary HTN.
List 4 symptoms of MR
Dyspnoea
Fatigue
Pedal oedema
Palpitations (new onset AF common)
List 4 signs of MR
Pansystolic murmur that radiates to axilla (highpitched, blowing)
Laterally displaced, thrusting apex beat
Soft S1 (due to incomplete closure of valve)
S3 (if LV dysfunction)
List 3 signs of mitral valve prolapse
Mid-systolic click
Late systolic murmur
The click moves towards S1 when standing and away when lying down
What does an ECG look like in MR?
Acute: Normal/ sinus tachy/ AF
Chronic: broad p wave +/- p mitrale (atrial enlargement), AF
Describe the CXR findings in chronic MR
Decompensated MR + acute MR: signs of pulmonary congestion
Chronic: LA enlargement, Cardiomegaly (due to LV dilation)
What investigation is diagnostic of MR?
TTE
Allows assessment of LV ejection fraction + end-systolic dimension
Describe management of acute MR
Emergency surgery: repair/ replacement
Whilst awaiting surgery, manage Sx of HF
Describe management of acute MR prior to surgery
Furosemide: for pulmonary oedema
Nitroprusside: reduces MR by reducing systemic vascular resistance
Intraaortic balloon counterpulsation: to increase CO
Describe management of asymptomatic chronic MR
LVEF >60%: watchful waiting
LVEF <60%: repair/ replacement
Describe management of symptomatic chronic MR
Repair/ replacement
If high surgical risk: transcatheter mitral valve intervention
HF Mx to optimise cardiac function: diuretics, ACEi + BB
Which surgical intervention is preferred in MR?
Evidence for REPAIR over replacement is strong in degenerative regurgitation
Lower mortality + complications
