Cardiac Flashcards
holosystolic murmur loudest over L mid-sternal border
VSD
Fixed, wide splitting of S2
ASD
Note: Tetralogy of Fallot is the most common cyanotic heart lesion on tests and in real life. ASDs–fixed split S2–are left-to-right (non-cyanotic lesions), at least until they reverse down the line (Eisenmenger syndrome).
mucosal cyanosis and fingernail clubbing
tetralogy of fallot, late features of ASD or VSD
precordial continuous, machine-like murmur in systole and diastole
PDA
bifid carotid pulse with brisk upstroke
hypertrophic obstructive cardiomyopathy
murmur increases with inspiration. best heard at L 3rd and 4th intercostal spaces
tricuspid regurg
best heard at apex and radiates to axilla
mitral regurg
opening snap and low-pitched diastolic rumbling
mitral stenosis
right sided valvular fibrous plaques are pathognomonic for what?
Carcinoid syndrome
dx- elevated 5-HIAA
Young athlete with sudden cardiac death has what? How does the heart appear on autopsy?
Hypertrophic cardiomyopathy (HCM) massive myocyte hypertrophy and myofiber disarray
Progressive onset of HF after recent viral infx indicates what? What happens to contractility (systolic function)
dilated cardiomyopathy.
Decreases - dec ventricular contraction force
B1 selective antagonists act on what? B2 selective antagonsits act on what?
1 - predominate in heart (drugs starting with A-M)
2 - predominate in lungs (drugs starting with N-Z)
What’s Beck’s triad and what is it a sign of?
- dec arterial P
- Inc systemic venous P
- small, quiet heart
= cardiac tamponade
Dec of >10mmHg in systolic pressure w/inspiration
Pulsus paradoxus. Sign of cardiac tamponade or constrictive pericarditis
Inc in systemic venous pressure on inspiration
Kussmaul sign
sign of pericarditis
S3 (ventricular gallop after S2) indicates what?
Ventricular enlargement (MR, AR, HF, dilated or ischemic cardiomyopathy). Best heard in L lateral decubitus at the apex and at end of expiration. Note: normal in YOUNG adults, kids, pregnancy
S4 (diastolic sound immediately preceding S1) indicates what?
decreased ventricular COMPLIANCE (AS, HCM, restrictive cardiomyopathy, Hypertensive HD) - inc stiffness
Due to sudden rise of end diastolic pressure
Note: normal in healthy OLDER adults
Path of electrical conduction through the heart
SA –> atria –> AV –> purkinje –> ventricles
Fastest to slowest areas of electrical conduction in the heart
Purkinje –> atrial mm –> ventricular mm –> AV node
park at venture ave
Head bobbing is a sign of what?
Aortic regurg
Inc LV end diastolic vol –> eccentric hypertrophy. Worse on left lateral decubitus.
Inc SV, wide pulse pressure
Recurrent temporary arrhythmias, due to accessory conduction pathway (Eg bundle of Kent) - AV re-entry circuit involving AV node and accessory pathway.
WPW
shortened PR interval, Delta wave, widened QRS
What endogenous factor is the most important mediator of coronary vascular dilation in large arteries and pre-arteriolar vessels?
Nitric oxide - synth from arginine and o2 by endothelial cells –> vasc smooth mm relaxation by guanylate cyclase-med cGMP
Adenosine (product of ATP metabolism) does what to small coronary arterioles?
vasoDILATES
o2 extraction from what part of the body exceeds that of any other tissue or organ in the body?
Myocardium. Coronary venous blood drains into RA via coronary sinus
What’s the most freq mech of sudden cardiac death in the 1st 48 h after acute MI?
Ventricular fibrillation. Related to electrical instability in the ischemic myocardium
How does AS and afib lead to acute pulm edema?
Loss of atrial contraction (Afib) reduces LV preload and cardiac output –> systemic hypotension.
Dec forward filling of LV also causes backup of blood in LA and pulm veins –> acute pulm edema
In patients with hypertrophic cardiomyopathy, dynamic LV outflow tract obstruction is due to what?
Abnormal systolic anterior motion of the anterior leaflet of the MV toward a hypertrophied interventricular septum
What is the initiating step of infective endocarditis?
Fibrin deposition - vegetations form on fibrin-platelet nidus on damaged endothelial surface
Meds with negative chronotropic effects (dec HR)
BB, nondihydropyridine CCB (verapamil, diltiazem)
cardiac glycosides (digoxin)
amiodarine
sotalol
cholinergic agonists (pilocarpine, rivastigmine)
Plaque rupture is related to plaque stability rather than size or degree of narrowing. What can reduce plaque stability?
Macrophages in the intima producing metalloproteinases which degrade extracellular matrix proteins (eg collagen)
Posterior descending/interventricular a (PDA) arises from right CORONARY artery (RCA)
Right-dominant circulation (85%)
Posterior descending/interventricular a (PDA) arises from left CORONARY artery (LCA)
Left-dominant circulation (8%)
Note: the PDA also supplies blood to the AV node via the AV artery
Posterior descending/interventricular a (PDA) arises from RCA and LCA
Codominant circulation
regional wall motion abnormalities (eg cardiac wall dyskinesia) are caused by what?
coronary artery disease
eg posterior wall hypokinesia due to RCA stenosis
Coarctation of aorta: how does blood get to aorta distal to site of coarctation?
Anterograde from internal thoracic (branch of subclavian)–> anterior intercostals –> retrograde through posterior intercostals
Most common murmur assoc with bicuspid aortic valve ?!
Systolic click. If AS is also present, a systolic ejection murmur at R upper sternal border with radiation to carotids
Loss of myocytes with fibrosis and vacuolization of myocytes in the subendocardium can be seen with what?
Long-standing stable angina pectoris - due to sustained ischemia
sign of irreversible cell injury (mito permanently unable to generate ATP)
What does MR do to pulmonary vascular resistance and how?
Decrease PVR - inc pulm perfusion dilate blood vessels that would normally be collapsed by surrounding lung tissue –> dec PVR
Hypertrophic cardiomyopathy can be due to AD mutations affecting what genes?
cardiac sarcomere genes - cardiac beta-myosin heavy chain and myosin-binding protein C gene
During systole (QRS on EKG) there is minimal blood flow where in the body?
L ventricular myocardium - Myocardial blood vessels are compressed
(note: RV pressures much lower in LV, and inc in systemic BP maintains constant blood flow to RV)