Heart Flashcards
Where does coronary circulation begin?
Sinus of valsalva, where the RCA and LCA arise.
What are the coronary arteries?
Left main branches into LAD and LCX
RCA- usu goes to PDA (90% are right-dom)
but PDA can also come from LCX
What do the LAD and LCX supply?
LAD- anterior of LV, apex, IV septum, and the part of the RV that borders the IV septum
LCX is in groove that separates LA and LV, gives of marginal branches that supply LV.
What do RCA and PDA supply?
RCA is between RA and RV- supplies lateral portion of RV
PDA supplies AV node.
What are the Ao and mitral valves and where are they located?
Aortic valve- bt LV and Ao. 3 leaflets, 3 sinuses (one for RCA, one for LCA, on non-coronary sinus)
Mitral valve- bt LA and LV. 2 leaflets (anterior goes farther across the valve). Chordae tendenae attach leaflets to papillary muscles in LV.
What is the most common cause of mortality in the US?
Atherosclerosis of coronary arteries.
When does coronary artery stenosis become hemodynamically significant?
When the lumen decreases to 75% of the native area.
HPE for ischemic heart dz
Substernal chest pain/prs that radiates down arms, to jaw, teeth, back.
Usually happens during activity/emotional stress.
Evidence of PVD- diminished pulses,
Signs of ventricular failure- cardiomegaly, congestive heart failure, S3 or S4, MR murmur
Stable vs unstable angina
Stable- pain is reproducible and resolves with rest
Unstable- pain occurs at rest, does not improve with rest, is new and severe, is progressive. Suggests impending infarct.
Dx Eval for ischemic heart dz
EKG- signs of ischemia or old infarct
CXR- enlarged heart, pulm congestion
Exercise stress test- tells if myocardium is at risk
Nuclear med scans (thallium)- use to localize ischemic areas
Echo- myocardial fn and valve fn
Angiography- gold standard. shows lesions in coronary arteries.
RX for ischemic heart dz- who gets surgery?
Surgery for severe dz of LM or severe dz in the 3 mjr coronary arteries. Do coronary bypass.
What vessels are used during coronary bypass?
IMA (preferred)
Saphenous vein
Causes of Ao Stenosis (AS)
Bicuspid valve- px’s by 70yo.
Rheumatic fever- causes fusion and calcification
Degenerative stenosis- causes calcification.
Unicuspid valve (px’s early in life)
What is the physiologic response to AS?
LVH- this preserves stroke volume and cardiac output.
But, LVH and the increasing resistance of the valve result in decreased CO, pulm HTN, and myocardial ischemia
HPE
Pts have angina, syncope, dyspnea (dyspnea means it’s bad)
Hear a mid-systolic ejection murmur
Cardiomegaly, signs of CHF
Pulsus tardus et parvus
What is pulsus tardus et parvus
delayed/diminished pulse at the carotid
Dx eval for AS
Echo or cardiac catheterization
What extent of AS signifies severe dz? (in cm)
Normal Ao valve area is 3-4 cm.
<1cm means severe dz.
Rx for AS
If sxtic- valve replacement.
If asxtic- operate if there is progressive cardiomegaly. (surg >med rx)
Causes of Ao Insufficiency (AI)
rheum fever CT disorders- marfan's, ehlers-danlos endocarditis Ao dissection trauma
What happens when there is AI?
Incompetent valve causes decreased CO, so there is LV dilation.
Larger LV means greater wall stress, so myocardial O2 demand is increased.
HPE of AI
Angina sx, dyspnea
Crescendo-decrescendo diastolic murmur
Wide pulse prs, water-hammer
PMI displaced/diffuse
Dx eval for AI
Echo
Rx for AI
If sxtic- valve replacement surg
Causes of mitral stenosis (MS)
rheumatic heart dz
malignant carcinoid
SLE
What is rheumatic heart dz?
Occurs after gp A strep pharyngitis.
Causes pancarditis, which makes valve leaflets fibrose and fuse into fishmouth.
See aschoff nodules.
Pathophysiology of MS
fibrosis/fusion of valve leaflets causes less blood flow through valve
Increased LA prs cause LA hypertrophy,
this causes Afib or pulm HTN
P-HTN can cause RVH and r-sided HF
HPE of MS
Dyspnea, fatigue Sometimes hemoptysis from the P-HTN Cachexia, sx of CHF pulm rales, tachypnea JVD peripehral edema ascities sternal heave of RVH Opening snap followed by low rumbling murmor Decreased splitting of S2 (pulm part louder) Afib
Dx eval for MS
CXR- cardiomegaly, LA hypertrophy, pulm edema
EKG- afib, LA hypertrophy (broad, notched P-waves), R axis dev (for RVH)
Echo
Cardiac cath- shows prs gradient across valves, so can calculate area of opening
Rx for MS
valvulotomy or valve replacement
Cause of mitral regurg (MR)
Rheumatic fever
idopathic calcification a/w HTN, DM, AS, renal failure
What happens when there is MR? (pathophys)
LV dilation to preserve CO
A lot is ejected retrograde- so increased cardiac work, increased LA volume, incrsd pulm venous prs
Can lead to LA enlargement and Afib and/or pulm HTN (which can lead to RV failure)
HPE of MR
Dyspnea, orthopnea, fatigue Cachexia Irreg pulse w rapid upstroke, waves Pulm rales Sternal heave. Holosystolic murmur radiating to axilla/back PMI displaced
Dx eval for MR
CXR- cardiomeg and pulm edema
EKG- LVH or both LVH and RVH; LA enlargement, P mitrale (broad, notched p waves)
Echo
Cardiac cath- shows pulm prs and CO
Rx for MR
Reduce afterload! - ACE inhib, nitroglycerin, diuretics
Surg if CHF interferes w live, if there is worsened P-HTN or LV dilation, or if Afib
Rx if there is life-threatening MR from endocarditis, ischemia, trauma
Aggressive afterload reduction
Balloon pump
Abx if needed
Try to convert emergency into elective procedure
mid-systolic ejection murmur
Ao stenosis
crescendo-decrescendo diastolic murmur
Ao insufficiency
opening snap, then low rumbling murmur
Mitral stenosis
holosystolic murmur radiating to axilla or back
mitral regurg
