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)
Migratory superficial thrombophlebitis is what syndrome? Indicates what?
Trousseau syndrome
Sign of visceral cancer
If a pacemaker lead is put in the coronary sinus, but perforates the sinus, what artery is likely to be damaged?
Circumflex artery
WPW is caused by 2 electrical paths to the ventricle (1 - through AV node, 2 - through bundle of Kent). Patients with WPW and in Afib must have atrial signals travel only through the AV node. What drugs allow this?
Procainamide.
Drugs that slow AV node conduction should be avoided bc they allow more atrial impulses to travel through accessory route
Patient with HF and inc Cr would see what on UA?
Urine sodium <5 mEq/L
patient has decompensated HF
Most likely reason for inc Cr is prerenal azotemia (FENa <5)
Order in which serum markers for cardiac injury increases over time?
Troponin - w/in 8 h
CK-MB - 8-24h
AST - inc as CK-MB declines
LDH - diagnostic test of choice 2-7 days post infarct
In compensated HF, the circulatory system is stable with normal CO and elevated end-diastolic volume. Cardiac function curve shows what?
Depression (ie contractility is decreased) - shift L to R horizontally
Contractility is low in cardiac failure. Fluid retention leads to inc EDV –> improved interdigitation —> improved strength of contraction
WPW EKG
Early activation of ventricle: decreased PR interval ; Delta waves (slurred QRS)
Atria stim after ventricles in retrograde fashion: inverted P waves after QRS complexes
patient with syncope due to bradycardia should be treated with what?
Atropine - parasympatholytic effect –> inc HR and BP
If unsuccessful give dopamine or epinephrine.
Note: phenylephrine would inc BP not HR.
Pericardial tamponade causes RV or LV failure first?
RV because it has thinner walls that protrude to a greater extent than the LV into the pericardial sack with each heartbeat.
What findings are heard in mitral stenosis?
Decrescendo diastolic murmur with opening snap
Decreased interval between A2 and opening snap
Why must beta blocker use be monitored closely in patients with diabetes?
BB blunt normal premonitory response to hypoglycemia like palpitations and tremors. Exception is sweating bc this is regulated by sympathetic cholinergics
What is the most significant limiting factor to the long-term success of heart transplantation?
Concentric intimal thickening of coronary arteries - dev after 1st year post-transplant and leads to progressive occlusion of the coronary arteries –> MI . Form of chronic rejection
Myomectomy (portion of septal wall in LV removed) can cause what complication?
Complete heart block (third degree) - injury His bundle in septum –> Ventricles beat independent of SA activity.
Why are R sided pressures in the heart lower than L sided pressures?
R side of the heart has lower resistance than L due to lower resistance in the pulmonary vasculature.
How does the body compensate for inc capillary hydrostatic pressure, net plasma filtration, and interstitial fluid pressure in RHF?
Increase in lymphatic drainage compensates for moderate inc in central venous pressure
LV systolic dysfunction due to reduced coronary blood flow at rest that is partially or completely reversible by coronary revascularization
Hibernating myocardium
Afib EKG and what determines the ventricular contraction rate in Afib?
EKG: absent P waves, irregularly irregular R -R intervals, narrow QRS
Ventricular contraction rate - controlled by AV node refractory period
Nonbacterial thrombotic endocarditis is commonly associated with what?
Advanced malignancy
Chronic inflammatory disorders (eg antiphospholipid syndrome, SLE)
Sepsis
What are some causes of diastolic heart failure (dec ventricular compliance, normal LV ejection fraction and LVEDV)
Transthyretin-related amyloidosis
Sarcoidosis
HTN
obesity
Aerobic exercise: what is expected to increase in the ABG?
Increased - skeletal mm CO2 production –> inc pCO2 of mixed venous blood.
Decreased - venous O2 (mm extract O2)
Normal - arterial PO2, PCO2 and arterial pH
What parameter decreases during peak stress vs rest in a patient exercising?
Decreased total SVR
Increased - CO and splanchnic vasoconstriction, inc HR, SV
What is increased in a patient with R heart failure?
Dec CO –> RAAS activation –> inc symp output and inc arteriolar resistance (afterload)
IV drug users are at risk of developing what lung complication as a result of tricuspid valve endocarditis?
Septic pulmonary emboli (wedge-shaped hemorrhagic lesion)
Nitrates are primarily venodilators and do what to LVEDP, peripheral venous capacitance, SVR?
LVEDP - decrease
venous capacitance - inc (amt of blood in peripheral veins at a given point) - due to venodilation
SVR - dec
What is the most significant factor limiting coronary blood supply in a tachycardic patient?
Duration of diastole
MC site of thrombus formation in afib?
LA appendage
What arteries are most susceptible to atherosclerosis?
Lower abdominal aorta and coronary arteries develop the highest burden.
Aging-related isolated systolic HTN is due to what?
inc arterial stiffness – dec compliance of aorta and major peripheral arteries
Mutation in k channel. Inc risk of ventricular arrhythmia like torsade de pointes
Congenital long qt synd. Prolong repol.
MC predisposing condition for native valve infective endocarditis in developed vs developing nations?
Developed - MVP
Developing - Rheumatic heart disease
Enlargement of what part of the heart can result in L recurrent laryngeal nerve impingement/hoarseness?
LA
What is released from atria and ventricles in response to myocardial wall stretch (eg intravascular vol expansion)? What do the hormones promote?
ANP - atria
BNP - ventricles
Promote inc GFR, natriuresis, and diuresis
How do the following regulate ca? Calmodulin Na/Ca exchanger Ryanodine receptors Troponin C Voltage gated Ca channels
Calmodulin - Excitation-contraction coupling in SMOOTH mm, which lack troponin.
Na/Ca exchanger - mediates calcium efflux from CARDIAC cells prior to relaxation
Ryanodine - sense initial ca influx in SR, triggerinf further Ca release in cytoplasm (inc Ca conc 100x)
Troponin C - Ca binds to this –> moves tropomysin so actin and myosin can interact
Voltage gate Ca - permit influx of ca into CARDIAC myocytes
Single most important RF for intimal tears leading to aortic dissection?
HTN
MC site of aortic rupture (eg MVC) is where?
Aortic isthmus (after L subclavian a) (tethered by ligamentum arteriosum and relatively fixed and immobile compared to the adjacent descending aorta)
Postprandial epigastric pain and food aversion/wt loss in setting of generalized atherosclerosis is most analogous to what disease process?
Dx - Chronic mesenteric ischemia
Atherosclerosis of mesenteric arteries –> dec blood flow to intestines after meals –> intestinal angina (similar pathogenesis to angina pectoris)
Orthopnea is a specific sign of R or L heart failure
Left
Note: bilat lower extremity edema and congestive hepatomegaly are more specific for R-sided heart failure
Squatting in tetralogy of Fallot does what to the SVR:PVR ratio?
Increases SVR –> inc SVR:PVR ratio.
Note: Tetralogy of Fallot has low SVR:PVR ratio
What diuretic improves survival in patients with CHF and reduces LVEF?
Mineralocorticoid receptor antagonists (eg spironolactone, eplerenone)
Note: dont use in patients with hyperK or renal failure
What does nitroprusside do to preload and afterload?
DECREASES both
Diastolic HF = dec ventricular compliance
What happens to LVEF, LVEDV and LV filling pressures?
LVEF - normal
LVEDV - normal
LV filling pressure - increased
Coronary sinus dilation occurs secondary to what?
Pulm HTN
Coronary sinus communicates with RA and dilates secondary to anything that inc RA pressure. MCC is pulm HTN
RV MI presents with hypotension, elevated JVP and clear lungs. Most often occurs in the setting of what?
Acute LV inferior wall MI due to proximal R coronary occlusion.
Inc RA and CVP, dec pulm cap wedge pressure, dec CO.
SA node is normally the cardiac pacemaker. What becomes the cardiac pacemaker in complete (3rd degree) block?
AV node. P and QRS desynchronization on EKG
Where is AR heard?
R sternal border (early diastolic murmur)
Note: can be heard at the L sternal border
Patients with adult-type coarctation of the aorta die of HTN-assoc complications (eg LV failure, aortic aneurysm, intracranila hemorrhage). Why are they at inc risk for ruptured intracranial aneurysms?
There is an increased incidence of congenital berry aneurysms in the Circle of Willis in these patients
Note: there is also an inc incidence of aortic arch HTN
What is a major determinant of the forward-to-regurgitant flow ratio in patients with mitral regurg?
LV afterload.
Dec afterload will inc forward flow while reducing regurgitant flow
What can cause LV hypertrophy and LA enlargement?
Long-standing HTN
Initially LV hypertrophy, but patients may dev diastolic dysfunction with LA enlargement and CHF due to impaired ventricular compliance and filling
Unprovoked syncope in a previously asymp young person may result from a congenital QT prolongation syndrome. The 2 most important congenital synd with QT prolongation are what?
- Romano-Ward synd
- Jervell and Lange-Nielsen syndrome
Thought to result from mutations in a K channel protein –> delayed rectifier current (Ik) of the cardiac AP.
Organ susceptibility to infarction after occlusion of a feeding artery is ranked from greatest to least as follows:
CNS, myocardium, kidney, spleen, liver
Liver has dual/collateral blood supply
What physiologic finding would be most suggestive of combined mitral and aortic valve disease rather than exclusive mitral involvement?
Will see increased LV diastolic pressure
Hypovolemia (eg hemorrhage) results in a sympathetic reflex compensation that does what to arteries, veins and heart rate?
arterial AND venous CONSTRICTION
Increased HR
Describe skeletal mm stimulation and calcium amount
As the stimulation freq increases, the amount of Ca released from SR increases, and so is the amount of Calcium sequestered in order to release a greater amount of calcium w/ each successive contraction.
The first one is when you have the most calcium in SR. When you get the later ones w/ just a huge continuous contractile spike (tetanus) less calcium is in the SR and more Calcium is in the cytosol.
R vs L heart failure
L backs up into lungs - paroxysmal nocturnal dyspnea, dyspnea, crackles in lungs
R backs up into body - edema, jvd, abdominal distension, hepatomegaly
Man running for prolonged period has temp of 101.5F. What mechanism returns temp to normal?
evaporation of sweat - its vasodilation periphery - decrease temp
When sweat evaporates from the surface of your skin, it removes excess heat. To convert water from a liquid to a vapor, it takes a certain amount of heat (heat of vaporization).
Note: cutaneous vasoconstriction, shivering heat conserving mech - increase temp
How do you manage 3rd degree AV block?
Insertion of transvenous pacemaker
After recanalization of an occluded coronal artery, CK-MB and troponin I are increased- what’s the mechanism?
Recanalization -> reperfusion injury via ROS -> membrane lipid peroxidation –> spill ** out of cell
What does MR do to LVSV, LA pressure, PVR?
LVSV - decrease
LAP - increase
PVR - increase
MR is often due to ischemic heart disease , mitral valve prolapsed, or LV dilation (can hear S3).
How does celecoxib increase risk for MI?
Inhibition of PGI2 formation without inhibition of thromboxane A2 in platelets
nonselective NSAIDS inhibit COX1 in platelets causing inhibition of thromboxane A2 which promotes platelet aggregation and vasoconstriction, they also inhibit prostacyclins which inhibit platelet aggregation and cause vasodilation
selective COX2 inhibitors do NOT work on thromboxane, but do on prostacyclins….therefore there is an increase risk of thrombosis and MI
How can cardiac reperfusion injury result in arrhythmia?
blood flow restored –> neutrophils come and see dead cells–> generate free radicals to kill–> kill dead cells and few normal cells–> membrane damage (see increase in cardiac enzymes)–> release of electrolytes from cells–> especially K+ –> hyperkalemia—> cause of arrhythmias
What is electrical alternans
Electrical alternans on boards means a big pericardial effusion (and usually cardiac tamponade physiology). The heart cannot fill properly, preload decreases, hypotension and tachycardia ensue, fluid backup leads to elevated JVP.
Can be caused by renal failure
What cardiac finding indicates pulmonary arterial HTN?
P2 louder than A2
The left sided system is much higher pressure than the right side, hence the aortic valve closing is usually louder than pulmonic valve. A P2 louder than A2 means that the pulmonary artery pressure is significantly elevated.
