Cardiac Flashcards
What is aortic stenosis
Obstruction to left ventricular systolic outflow across the aortic valve
What are the causes of Aortic stenosis?
o Age-related degeneration + calcification of aortic leaflets with subsequent stenosis (develops 60-80 years)
o Presence of congenital bicuspid rather than tricuspid aortic valve (develops 30-50 years)
o Rheumatic heart disease
o Infective endocarditis
What are the clinical features of Aortic stenosis on history?
Chest pain/dyspnoea/syncope
What are the clinical features of Aortic stenosis on exam?
Displaced hyperdynamic apex beat
Mid systolic ejection murmur maximal over aortic area and extending into carotids
Loudest with patient sitting up and in full expiration (RILE right sided louder on inspiration, left sided on expiration)
What are Ix for Aortic stenosis?
ECG - LVH and LV strain
TTE - Valve area, Mean gradient, jet velocity
Coronary angiogram
How do you assess severity of aortic stenosis?
symptoms are not reliable - assessed on TTE findings
What is the criteria for LVH on ECG?
Sokolov- lyon criteria - R waves V5 or V6 + S wave in V1 > 35mm
What is DI for aortic stenosis?
Ratio of LVOT velocity to AV velocity
<0.25 = severe AS
Helps to identify severe AS in failing low flow AS
What are the class I indications for aortic stenosis surgery?
(1) severe AS
(2) asymptomatic severe AS with LVEF <50%
(3) asymptomatic severe AS undergoing CABG or surgery on the aorta or other heart valves
What are the haemodynamic goals for aortic stenosis?
Slow, full and tight
- Low normal HR (avoid tachycardia)
- Maintain sinus rhythm
- Increase LV preload (maintain a full ventricle)
o Optimize intravascular fluid volume to maintain venous return + LV filling - Increase SVR
What is mitral regurg?
Retrograde blood flow into the left atrium resulting from an incompetent mitral valve
What are causes of MR?
Primary MR: Leaflet, chordal, papillary muscle abnormalities eg endocarditis, rheumatic fever
Secondary: LV dilation causing abnormal MV function eg myocardial ischaemia
What are the clinical features of mitral regurg on history?
Fatigue, weakness
Acute MR presents as pulmonary oedema/cardiogenic shock
What are the clinical features of mitral regurg on exam?
Apical pan-systolic murmur with radiation to axilla
displaced + forceful apex beat
What are Ix for mitral regurg?
ECG - LVH, AF
CXR - LA + LV enlargement
TTE - dilated LA, hyperdynamic LV, pulm HTN
Coronary angiogram - exclude ischaemia
What are TTE signs that indicate disease severity for mitral regurg?
- Regurgitant volume (>60mls/beat = severe)
- Regurgitant fraction (>50% = severe)
- Regurgitant orifice area (>0.4cm2)
EF < 60% also suggests significant LV dysfunction
What is the medical management of acute and chronic mitral regurg?
Acute - afterload reduction eg with SNP
Chronic - antihypertensives eg ACE-i
What is the surgical indications for mitral regurg?
Only definitive treatment!
Repair is preferred to replacement
Class I indications include:
-Acute severe MR
- symptomatic patients with severe primary MR despite medical mx and LVEF > 30%
- asymptomatic patients with severe MR but with evidence of declining LV function
What patients are not suitable for surgical management of mitral regurg?
Patients with EF <30% or a left ventricular end-systolic dimension >55 mm do not experience improvement with mitral valve surgery
What are you haemodynamic goals for managing mitral regurg?
o Maintain sinus rhythm
o High normal HR ≈80bpm
o Maintain preload
o Maintain contractility
o Decrease afterload (avoid increases in SVR)
What are the causes of mitral stenosis?
- Rheumatic (most common)
- Congenital
- Other - RA/SLE/carcinoid
What are the clinical features of mitral stenosis on history?
Dyspnoea, Orthopnoea, PND
What are the clinical features of mitral stenosis on exam?
AF (irregular pulse)
If pulm HTN then right ventricular heave, palpable P2, Loud P2
Low-pitched rumbling diastolic murmur
What are signs of severe mitral stenosis on exam and Ix?
- Small pulse pressure
- Soft S1
- Pulm HTN
- TTE: small valve area (<1cm2), gradient across valve > 10mmHg, pulm Sys > 50
What is the medical management for mitral stenosis?
o Anticoagulation for prevention of systemic embolic events
o Ventricular rate control with β blockers/non-dihydropyridine calcium channel blockers/digoxin & aggressive treatment of tachyarrhythmias
o Treat congestive heart failure with diuretics + sodium restriction
What is the surgical managment of mitral stenosis?
- surgical valvotomy
- MV replacement
- Percutaneous balloon mitral valvotomy
What are the haemodynamic goals of mitral stenosis?
o Low normal HR (avoid tachycardia)
o Maintain sinus rhythm
o Maintain preload
o Increase SVR
What are the causes of aortic regurgitation?
- Leaflet abnormalities eg IE, congenital bicuspid aortic valve
- Aortic root or ascending aorta abnormalities eg Ehler’s Danlos, Marfan’s, aortic dissection