Week 5 (Diseases of Cardiovascular Structures) Flashcards
Areas of auscultation for each valve
APTM: all physicians take money
Aortic valve: 2nd right intercostal space
Pulmonic valve: 2nd left intercostal space
Tricuspid valve: lower left sternal border
Mitral valve: apex
Two methods to calculate valve flow rate and area
1) Cardiac catheterization: divide CO by period of time that the valve is open (diastolic filling time for mitral and systolic ejection time for aortic valve)
2) Doppler echocardiography: uses high frequency ultrasound to evaluate cardiac structures and hemodynamics
What happens to systole and diastole when HR increases?
Length of systole shortens somewhat with increasing HR
Diastolic filling time and each diastolic filling period is shortened with increasing HR
Increasing HR without any increase in CO markedly increases mitral valve flow (and makes mitral stenosis worse)
Valve lesions that cause pressure vs. volume overload
Pressure overload caused when valve lesion causes obstruction to ventricular outflow which causes hypertrophy (more than dilation) of the affected ventricle, thereby maintaining a more favorable LaPlace relationship
Volume overload caused when regurgitant lesions of either inflow or outflow valves cause ventricle to dilate to accommodate mandatory increase in SV (and develop hypertrophy to a lesser extent)
Mitral stenosis
Causes: recurrent attacks of acute rheumatic fever resulting in rheumatic heart disease (common), congenital (parachute mitral valve, supravalvar mitral ring), systemic disease (carcinoid, SLE, rheumatoid arthritis, mucopolysaccharidosis, healed endocarditis)
Specific to rheumatic: mitral orifice restricted by commissural fusion, scarring and/or calcification of leaflets, variable degrees of subvalvar pathology (thickening and shortening of chordae and elongation of papillary muscles); stenosed valve may become tapered like a funnel or rendered into “fish mouth”
Afib is common and results from dilation of atrium from elevated pressure and inflammation and scarring of atrial walls from rheumatic process
Stagnation of blood in atrium often results in thrombus formation and may cause systemic embolism
Is considered severe if mitral valve area <1cm2, resting mean pressure gradient >10, PHT > 220ms
Auscultation findings in mitral stenosis
Loud S1: elevated LA pressure, mitral valve closes later and more loudly than normal; JVP is a-wave dominant and a-wave occurs with loud S1
Opening snap: happens early diastole; mitral valve opens earlier than normal (LA pressure), fused leaflets abruptly halt mitral valve opening (like sail hitting the wind hard) in diastole causing OS
Mid-diastolic murmur: corresponds with high LA-LV gradient
Presystolic murmur: at very end of diastole when you have atrial kick, get increased volume because increased flow
Hear murmurs better at apex; hear OS better at base/aortic region
Complications with mitral stenosis
Afib is very common
Embolic events are common
Serious and feared complication is pulmonary hemorrhage resulting from rupture of high pressure bronchial veins (which drain into LA)
Should be considered in differential for any pt presenting with hemoptysis
Pregnancy often provokes symptoms in previously asymptomatic subjects with mitral stenosis because of added burden of increased blood vol and CO (in pregnant woman with sx, use beta blockers or diuretics)
Therapies for mitral stenosis
1) Control HR to increase diastolic filling time, decrease LA pressure and decrease pulm capillary bed pressure to prevent pulmonary edema; use digoxin, beta blockers, NOT arterial vasodilators (nitrates) or ACEI because lower SVR decreases BP/cerebral perfusion pressure provoking tachycardia and decreased diastolic filling time
2) Diligent dental care with endocarditis prophylaxis (amoxicillin 2g one hr before procedure)
3) Prevention and conversion of afib: antiarrhythmatics to maintain sinus rhythm (amiodarone); electrical or chemical cardioversion (after anticoagulation or TEE); all pts should be chronically anticoagulated with warfarin with target INR 2
4) Percutaneous balloon valvuloplasty is widely used; contraindicated if more than mild regurg or LA thrombus; have to go in thru RA, create small PFO getting to LA but that’s okay because helps decompress LA!
5) Surgical treatment if patient not candidate for balloon valvuloplasty (open mitral valvotomy if mild, mitral valve repair, or mitral valve replacement)
Mitral regurgitation
Causes: leaflet abnormalities (myxomatous degen of leaflets, rheumatic disease, endocarditis), congenital, annular abnormalities, chordal abnormalities (rupture resulting in flail leaflet, rheumatic), papillary muscle abnormalities (rupture, ischemia, amyloid, sarcoid)
Chronic mitral regurg well tolerated since heart can compensate for volume overload with increased compliance and increased SV
Symptoms of fatigue due to low CO late in disease when heart markedly enlarged or when afterload increases because of HTN or peripheral vascular changes of aging
Eventually, something can tip the pt over and compensatory mechanisms fail, heart dilates, HTN downstream causes more mitral regurg, can develop atrial arrhythmia
Acute mitral regurg may subject the left heart chambers to a smaller volume overload than chronic regurg, but LV diastolic pressure and LA pressure during ventricular systole increases so considerable back pressure on pulmonary veins and resultant dyspnea
Forward CO may be compromised by inability of L heart chambers to accommodate sufficient volume to maintain normal forward SV in face of back leakage
Findings in mitral regurg
Inspection: apex beat displaced to 7th L intercostal space, outward excursion of stethoscope head during systole
Auscultation: blowing murmur; thudding sound with inward return of stethescope; heart murmur is holosystolic best heard over apex and radiates toward axilla; loud S1 initiates explosive systolic murmur and barely hear the S1 and S2; if failing ventricle, have S3 at apex and means poor prognosis
If ruptured cord, have early systolic murmur that is not holosystolic because of pressure gradients (means LA pressure really high)
Mitral valve prolapse
Volume of regurgitant flow is usually small, but some patients may develop progressively severe regurg or rupture of chordae
Causes: myxomatous degeneration, rheumatic fever, or chordae rupture
Symptoms frequently out of proportion to relatively mild hemodynamic impairment (chest pain and severe fatigue, palpitations/arrhythmias)
Most frequent valve lesion, occurs in young (skinny?) women people
Usually benign but can predispose to infective endocarditis
Sounds: late systolic crescendo (loudest at S2) heard best over apex murmur with midsystolic click (due to sudden tensing of chordae tendinae)
Murmur enhanced by maneuvers that decrease venous return (standing or valsalva), murmur may disappear if you squat down
Management of mitral regurgitation
Is a self-perpetuating processs in that ventricular, anular and atrial dilation progressively increase severity of valve incompetence
Valve repair or replacement should be performed if pt has symptoms, or asymptomatic in presence of LV dilation and decreasing systolic function, or with mitral valve prolapse with severe MR (torn chord/flail leaflet)
Medical therapy for chronic mitral regurg similar to that in patients with CHF:
1) Afterload reduction: ACEI, ARB
2) Diuretic and nitrates reduce preload and intravascular volume
3) Ventricular rate controlling agents and antiarrhythmics: beta blockers and digitalis
Aortic stenosis
Causes: most commonly bicuspid (if under 70yo), rarely unicuspid or quadracuspid; acquired “senile” calcific aortic stenosis (if over 70yo), post-inflammatory (rheumatic), combination of congenital and acquired
Stenosis of semilunar valve or ventricular outflow results in pressure overload, and elevation of ventricular pressure to overcome the obstruction
Pulsus parvus et tardus: arterial pressure pulse downstream from the obstruction rises slowly (slow carotid upstroke?); arterial pulse pressure diminished and duration of ventricular ejection lengthens (delay)
LV which is ischemic or in borderline compensation at rest is rendered increasingly ischemic with and after exercise –> exertional dyspnea due to increased filling pressure of ischemic and hypertrophic ventricle, angina, syncope, sudden death
Severe if aortic valve area <0.75 cm2 or if mean systolic gradient >50 mmHg
Findings in aortic stenosis
Auscultation: ejection click (due to abrupt halting of valve leaflets; heard at 3rd RICS?) right after S1 followed by crescendo-decrescendo midsystolic systolic ejection murmur (heard best at base/aortic area) that radiates to carotids; ends before S2
In severe AS, the LV pressure rises and increases LV-Aortic gradient and murmur will peak later
Inspection: carotid pulses delayed and diminished
Other findings: high velocity outflow on CW doppler
Natural history of aortic stenosis
Good ventricle can compensate for outflow obstruction with hypertrophy so AS may be well tolerated for years until demands of hypertrophy cause decompensation or sudden death
Once symptoms develop, risk of death from AS increases (angina gets 5 years, syncope gets 2 years and CHF gets 1 year)
Rheumatic AS (usually mitral valve involved too though) becomes symptomatic in 40s or 30 years after attack of rheumatic fever
Congenital bicuspid AS has bimodal distribution of infancy and >40yo
Senile calcific AS unlikely in patients <65
Management of aortic stenosis
Severe symptomatic AS treated surgically by aortic valve replacement or less frequently aortic valve repair (for minimally calcified bicuspid valves)
Patients <70 without contraindications or averseness to warfarin receive mechanical valve which does not require reoperation
Patients >70 or those with contraindication to warfarin of women wishing to become pregnant receive bioprosthetic (porcine or bovine pericardial) valve (but these show structural deterioration and require reoperation, no good)
Life-long endocarditis prophylaxis
Aortic regurgitation
Backflow of blood into LV results from failure of coaptation of aortic valve leaflets
Caused by valvar or aortic root disease: scarring of leaflets (congenital bicuspid, rheumatic scarring), aortic root pathology (tertiary syphilis, Marfan’s, ankylosing spondylitis, dissecting aneurysm)
Get dilation which cannot occur indefinitely, and low aortic diastolic pressure cannot provide adequate perfusion pressure for coronary arteries
LV may have to pump 10-20 L/min just to maintain NET output of 5 L/min
Resulting dilation and hypertrophy lead to massive increase in heart size
Findings in aortic regurgitation
Bounding (Corrigan’s) pulse
Head bobbing (Musset’s sign)
Auscultation: to-fro murmur that is midsystolic and early diastolic
Hear to-FRO in 3rd right intercostal space
Hear TO-fro in 2nd right intercostal space
Diastolic murmur: Austin Flint/pseudo mitral stenosis in severe AR heard at apex
If have AF, triple cadence consisting of midsystolic murmur, S2 initiating a brief early diastolic murmur, AF itself is mid-diastolic murmur superimposed on early diastolic murmur (to-fro-FRO); tachycardia; dynamic, displaced apical impulse (AF head at apex)
Chronic AR: at base hear midsystolic murmur (Ao outflow), end diastolic murmur (Ao regurg) and at apex hear Austin Flint (mitral inflow), split S1 (S1 + ejection sound)
Acute AR: at base hear midsystolic murmur (Ao outflow), end diastolic murmur abbreviated, at apex hear Austin Flint (mitral inflow) and absent S1 (ejection sound only); absence of S1 is because mitral valve flutters to near closed in middle of diastole because LV pressure so high = functional mitral stenosis; this pt is going to die
Markers of severe aortic regurgitation
Regurgitant jet width/LV outflow tract diameter ratio > 60%
Regurgitant jet area/LV outflow tract area >60%
Aortic regurgitation PHT <250
Natural history of aortic regurgitation
Compensatory mechanisms in chronic regurgitation may permit two to three decades of absent or minimal symptoms
Because of inherent limitations of these compensations, rapid deterioration occurs once decompensation sets in
Rapid decline often results from irreversible LV dilation and dysfunction
Management of aortic regurgitation
Once symptoms develop and ventricles enlarge or demonstrate decrease in systolic function, operative repair or replacement is imperative
Medical management of chronic regurgitation with afterload reducing agents (ACEI, ARB, CCB) may delay progression to poorly tolerated ventricular failure
Urgent/emergent surgery is warranted in acute severe AR
What is cholesterol required for?
Cell membranes
Precursor for other steroids: cortisol, progesterone, estrogen, testosterone, bile acids
Summary of lipoprotein functions
Chylomicron: deliver TGs (fatty acids) from dietary fat to peripheral tissue (muscle, adipose); turn into chylomicron remnants after LPL+ApoCII acts on them
Chylomicron remnants: deliver dietary cholesterol to the liver
VLDL: deliver TGs from the liver to peripheral tissue (muscle, adipose)
IDL: deliver TGs and cholesterol to liver
LDL: deliver cholesterol (derived from liver synthesis) to peripheral tisues (muscle, adipose) because tissues do receptor mediated endocytosis to take up LDL; formed after hepatic lipase (HL) modifies IDL; is this because VLDL has run out of TG to give away and is only left with mostly cholesterol?
HDL: collects (scavenges) cholesterol from peripheral tissues and delivers it back to liver (mediates reverse cholesterol transport!); acts as repository for ApoC and ApoE (which are needed for chylomicron and VLDL metabolism)
LDL, HDL, and TGs (the lipids)
LDL: lousy cholesterol; major cholesterol carrier in the blood; excess most likely leads to atherosclerosis; pro-inflammatory?
HDL: healthy cholesterol; transports cholesterol away from arteries and back to liver (via ABC-1 transporter, and mature HDL taken up by liver via hepatic scavenger receptor class B) to be eliminated; antioxidant and anti-inflammatory properties
Triglycerides: chemical form in which most fat exists in foods; made in the body from other energy sources like carbs; calories ingested in meal that are not immediately used by tissues are converted to TGs; hormones regulate release from fat tissue to meet body’s needs for energy between meals
Type I Familial Hyperchylomicronemia
High chylomicrons, high TG, high cholesterol
Creamy plasma
AR, deficient in lipoprotein lipase or altered ApoCII (rare)
Causes pancreatitis (this can kill kids), hepatosplenomegaly, eruptive/pruritic xanthomas (no increased risk for atherosclerosis)
Treatment is low fat diet (no drug therapy)
Type IIa Familial Hypercholesterolemia
High LDL, high cholesterol
Clear plasma
AD, absent or decreased LDL receptors
Causes accelerated atherosclerosis, tendon (Achilles) xanthomas, corneal arcus
Treatment is low cholesterol and low saturated fat in diet; drug therapy to lower LDL
Type IIb Familial Combined Hyperlipidemia
Similar to IIa but VLDL also increased, in addition to TGs and cholesterol
Plasma often turbid
Caused by overproduction of VLDL by the liver
Treatment is dietary restriction of cholesterol, saturated fat and alcohol; Drug therapy (maybe target TGs too)
Type IV Familial Hypertriglyceridemia
High VLDL, TGs
Plasma turbid
AD, hepatic overproduction of VLDL or decreased removal of VLDL TG
Causes pancreatitis
Treatment is weight reduction, dietary restriction of carbs, modified fat, low alcohol consumption; drug therapy
More common now because associated with diabetes
Exogenous vs. endogenous pathways of cholesterol metabolism
Exogenous (dietary) lipid pathway: TG and cholesterol packaged into chylomicrons in epithelial cells of intestines –> chylomicrons circulate in lymph then get into blood –> LPL located on luminal surface of capillary endothelial cells releases FFA from TGs from chylomicrons to go into adipose and muscle cells –> chylomicron remnant particles removed from plasma via receptors on the liver
Endogenous lipid pathway: Liver synthesizes TG and cholesterol ester and packages them into VLDL to be released into blood –> LPL located on luminal surface of capillary endothelial cells releases FFA to be taken up by adipose and muscle cells –> some VLDL remnants are taken back up by liver via LDL receptor but remaining remnant particles become IDL –> some IDL reabsorbed by liver via LDL receptor but other IDL particles hydrolyzed by hapatic lipase (HL) to form LDL –> some LDL taken up by liver via LDL receptor but some LDL is taken up by peripheral tissue cells that have LDL receptors –> free cholesterol is released and accumulates within cells
What is the half-life for clearance of LDL?
Half-life for clearance of LDL is 24 hours
Every day about half of circulating LDL is removed via receptor mediated endocytosis
How is LDL taken up into the liver or into tissue cells?
LDL binds its receptor because ApoB100 on LDL recognizes the LDL receptor on liver or tissue cells
Once bound, entire LDL molecule is engulfed by the cell in clathrin coated pits via receptor mediated endocytosis
Endosomes turn into lysosomes and LDL is degraded
Effect of different drugs on LDL, HDL, TGs
Cholesterol absorption inhibitors (CAIs): 18% decrease LDL, 8% decrease TGs
FIbrates: 5-20% decrease LDL, 10-35% increase HDL, 20-50% decrease TGs
Niacin: 5-25% decrease LDL, 15-35% increase HDL, 20-50% decrease TGs
Resins: 15-30% decrease LDL, 3-5% increase HDL
Statins: 18-60% decrease LDL, 5-15% increase HDL, 7-30% decrease TGs
Statins
HMG-CoA Reductase inhibitors (statin is a false substrate/competitive inhibitor)
Inhibit HMG-CoA to mevalonate
Have shallow dose response curve, so initial dose is great but doubling the dose thereafter only gives 5-8% increase in efficacy
Adverse effects of statins
Pregnancy category X!!
Think liver and muscle problems because this is where cholesterol metabolized
Headache, rash, GI disturbance (dyspepsia, cramps, flatulence, constipation, abdominal pain)
Hepatotoxicity (d/c med if LFTs more than 3x upper normal limit; check LFTs at baseline, 6 wks then periodically after)
Myopathy (0.5% of patients) risk highest with lovastatin and especially in combination with fibrates
CYP3A4 drug interactions with many statins
FDA advice 2012 said new risk of T2DM and cognitive impairment (reversible within a few weeks of stopping drug), risk to liver was called rare
Red yeast rice
Fermented rice product on which red yeast has grown
RYR contains several compounds collectively known as monacolins
Monacolin K is an HMG-CoA reductase inhibitor and is the same chemical as lovastatin (same risks too)
Large variation in active compounds in RYR supplements (some supplements contaminated with citrinin, a nephrotoxic mycotoxin)–dirty preparation
Cholesterol absorption inhibitor (CAI)
Ezetimibe is the only CAI
Blocks cholesterol absorption at intestinal brush border; localize to the intestinal wall, enterohepatic circulation, minimal systemic exposure
No effect on absorption of lipid-soluble vitamins
Indications: high LDL
Pros: once daily, additive in combination with statin, limited systemic exposure, very well tolerated
Cons: some systemic exposure, 3-fold increase incidence of LFT abnormalities in combination with statins, no outcomes data
Despite LDL lowering, Ezetimibe has not been shown to decrease CV risk above what is provided by statins so seldom used in monotherapy but may be useful in combination therapy with statins
Bile acid sequestrants (resins)
Cholestyramine, colesevelam, colestipol
Bind bile acid in the intestines, interrupting enterohepatic circulation and increasing fecal excretion of the acid –> liver uses more cholesterol to make more bile acid –> decrease intrahepatic cholesterol pool –> causes some increased HMG-CoA reductase expression, increased VLDL production/secretion and LDL production, but mostly increases LDL receptors to increase LDL clearance from blood and reduce plasma LDL
Reduces LDL 20-30%
Indications: high LDL
Can be used to relieve pruritis in pts with cholestasis and/or to relieve diarrhea in post-cholecystectomy patients
Used in children because NOT systemic
Adverse effects of bile acid sequestrants (resins)
Must be taken with fluid (dispensed in powder or large tablet form)
Constipation, bloating, indigestion, nausea
Large doses may decrease absorption of fats or fat soluble vitamins
Drug interactions common (decrease drug concentration) so must take other drugs 1 hour before resin or 4 hours after
Nicotinic acid (niacin, vitamin B3)
Appears to suppress synthesis of VLDL, IDL and LDL in the liver; may increase TG catabolism and decrease HDL catabolism (in the kidney), reduces ApoB, increasees ApoA and increases HDL
Inhibits lipolysis in adipose tissue; reduces hepatic VLDL secretion into circulation (this is what FA says)
Indications: high LDL and/or high TG, combined hyperlipidemia
No additional benefit if given with statins, and also small unexplained increase in ischemic stroke with niacin
May not be used anymore since no benefit shown to pharmacologic elevation in HDL
Adverse effects of niacin
Flushing: harmless cutaneous vasodilation but very uncomfortable, can give aspirin 30 min before dose
Pruritis, rashes, dry skin
Acanthosis nigricans (velvet warty hyperpigmentation associated with insulin resistance)
Nausea and abdominal discomfort
Peptic disease
Hepatotoxicity: rare fulminant hepatic necrosis occurs with older OTC sustained release forme
Hyperuricemia in 1/5 patients that may precipitate gout
Glucose intolerance
Fibrates (fibric acid derivatives)
Gemfibrozil, clofibrate, bezafibrate, fenofibrate
Agonist of PPAR-alpha (control gene expression) to increase mitochondrial beta oxidation of FFA and decrease TG secretion and to decrease ApoCIII production (which usually inhibits TG metabolism) but increase ApoA-V production to increase TG clearance –> all lead to decreased TGs
Increase clearance of VLDL by increasing action of LPL; decrease VLDL production
Increase ApoA1 secretion and upregulate ABC-A1 to increase HDL
Indications: high TG and low HDL
Adverse effects of fibrates
Rashes
GI upset
Gallstones (upper abdominal discomfort, intolerance of fried food, bloating): increased biliary cholesterol saturation, use with caution in patients with biliary disease
Displaces warfarin from plasma albumin since drug is highly protein bound, so decrease warfarin dose to reduce myopathy?
Will increase risk of statin-induced myopathy when used together (rhabdomyolysis rarely)
CYP3A4 inducers and inhibitors
CYP3A4 inducers (cause decreased activity of statins): GCs, rifampin, phenytoin, carbamazepine
CYP3A4 inhibitors (cause increased blood levels of statins): nefazodone, fluvoxamine, ketoconazole, itraconazole, erythromycin, sertraline, grapefruit juice
Pericardium
Protective sac around the heart
Made up of visceral (inside; fine, shiny) which goes around heart then reflects back on itself to form parietal (outside) layer
Contains 5-15 mL of clear fluid
Pericardial effusion
Abnormal collection of fluid in the pericardial space
Causes: pericarditis, hemopericardium, chylopericardium
Causes of pericarditis
Idiopathic
Infectious (viral, bacterial, mycobacterial, fungal)
Autoimmune (SLE, RA, scleroderma, PAN)
Dressler’s syndrome
Neoplastic disease (breast, lung, thyroid, lymphoma/leukemia, melanoma)
Uremia
Hypothyroidism (leaky capillaries cause pericardial effusion)
Drugs (INH, procainamide, hydralazine, cyclosporine)
Are all pericardial effusions symptomatic?
No
Symptoms depend on size of effusion and rate of accumulation
Slowly accumulating effusions initially asymptomatic but eventually cause cough, hoarseness, dyspnea, dysphagia
Rapidly accumulating effusions can cause hemodynamic compromise (cardiac tamponade) with collection of as little as 100mL of fluid
Cardiac tamponade
Increase in pericardial pressure that impairs cardiac function
Think of it as diastolic dysfunction, since increased pericardial pressure is so high that the ventricles cannot fill so diminished preload and decreased stroke volume
Physiologic consequences: impaired filling of cardiac chambers, SV declines, compensatory activation of sympathetic nervous system with tachycardia and increased SVR
Often presents as shock (obstructive shock), have muffled heart sounds due to abnormal layer of fluid around heart
Beck’s triad: low BP, increased JVD, distant/muffled heart sounds
Have pulsus paradoxus
Echo findings: compression of RA and RV in diastole (because they have less muscle and easier to compress than left side), increased flow into RV with bulging of intraventricular septum into LV and decreased LV filling during inspiration, IVC distended and difficulty draining into right heart
Catheterization findings: pressure in atria and diastolic pressure in ventricles elevated and equalized in all 4 chambers, equal to elevated pericardial pressure
Treatment: volume resuscitation, vasopressors, pericardiocentesis (stick needle under xyphoid process directed toward L shoulder to drain fluid), surgical management
Acute pericarditis
Inflammation of both layers of pericardium (visceral and parietal)
Classic presentation is sharp chest pain relieved with leaning forward (keeping inflamed pericardium from rubbing against firm structures including spine behind it), pain may radiate to left trapezius ridge
Pericardial rub on exam (three components: rapid ventricular filling, atrial systole, ventricular systole) sounds like choo-choo-train; evanescent and will disappear if pericardial effusion separates inflamed visceral and parietal layers so they can’t rub against each other
EKG changes: diffuse ST segment elevation (often in all leads except aVR and V1), PR segment depression, T wave inversions, if large effusion, heart swinging back and forth in effusion can create QRS complexes that increase and decrease in size as it goes to and away from electrodes
If thought to be viral/idiopathic then treat with NSAIDs, colchicine or GCs (rarely, and increase risk of recurrence of pericarditis)–don’t need to know what virus it is because no virus-specific therapy
For patients with recurrent effusions, consider pericardial window (hole in pericardium to let it drain) that provides continuous drainage into pleural or peritoneal cavity where it will be reabsorbed
Workup for pericarditis
EKG and echo
CBC
Troponin I
BUN/creatinine
Only if you think necessary: ESR/CRP, ANA, rheumatoid factor, complement levels, thyroid function tests, PPD or quantiferon gold, HIV serology
Dressler’s syndrome
AKA postmyocardial infarction syndrome
Seen 2 weeks to several months after MI
Autoimmune mechanism resulting in fibrinous pericarditis
Low grade fever, pleuritic chest pain, pericardial friction rub (3 components, with 1 systolic and 2 diastolic) and/or pericardial effusion
Treated with NSAIDs
Constrictive pericarditis
Chronic inflammation leads to thick fibrotic or calcified pericardium
Causes: tuberculous pericarditis, viral infection, connective tissue disorders, radiation, viral pericarditis where inflammation did not completely respove
Chronic inflammatory that develops over months to years
Symptoms: abdominal pain, ascites, lower extremity swelling, dyspnea
Physical findings: Kussmaul sign (paradoxic rise in JVP with inspiration because vena cava accommodates increased fluid but heart doesn’t so fluid reflects back into jugular vein), pericardial knock heard along left sternal border due to abrupt cessation of early, rapid diastolic filling; no pulsus paradoxus because RA can’t expand to let more fluid in
Diagnostic testing: CXR for pericardial calcification, echo for thickened pericardium with reduced mobility and abnormalities of ventricular septal wall motion, CT or MRI to look at pericardial thickness, R heart cath for square root sign of diastolic ventricular pressure curve (top of square root sign is because ventricular pressure stays flat because can’t fill any more)
Myocarditis
Inflammation in myocardium
Non-viral infectious causes of myocarditis: borrelia (Lyme disease) which presents as conduction system disorder, trypanosoma cruzi (Chagas disease), trichinosis (trichinella spiralis)
Most comonly associated with viral infections: coxsackie B, adenoviruses, parvovirus B19, CMV, HIV
Symptoms/signs of viral myocarditis: early sx of acute viral infection (fevers, myalgias, fatigue), sx of heart failure several weeks later (tachycardia, hypotension, elevated JVP, S3, crackles, peripheral edema)
Labs and imaging: elevated troponin, rising viral titers, on EKG see sinus tachycardia and nonspecific ST and T wave abnormalities; pericarditis findings if patient has myopericarditis, echo to look for enlarging chamber size, MRI to look for focal changes in myocardial tissue suggesting inflammation
Treatment of viral myocarditis: antivirals and immunosuppressants are not successful, treat pts with decreased EF with beta blockade, ACEI, aldosterone antagonists and diuretics as needed
Prognosis of viral myocarditis: 1/3 patients recover fully, 1/3 stabilize on medical therapy but have permanent decrease in EF, 1/3 advance and should be considered for heart transplantation
Cardiotoxic drugs
Cocaine
Alcohol
Anthracyclines (chemotherapy): doxorubicin, danorubicin
Hypersensitivity myocarditis
Often reaction to a drug: antibiotics, diuretics, antihypertensives
Path: eosinophilic infiltrate in perivascular and interstitial spaces in the heart
Hemochromatosis or hemosiderosis
Iron overload
Heart is dilated and rust-brown in color
Iron deposition is most prominent in ventricles
Marked accumulation of hemosiderin seen in cardiac myocytes with use of Prussian blue stain
Hypothyroidism as cause of myocardial injury
Advanced hypothyroidism (myxedema) causes heart to be flabby and dilated
Restrictive cardiomyopathies
Disorders that lead to increased myocardial stiffness
Patients present with predominantly RV failure (and LV failure) without cardiomegaly or systolic dysfunction
Causes: amyloidosis, sarcoidosis, carcinoid heart disease, scleroderma, radiation
Other findings in mitral stenosis
Subtle radiographic manifestations since significant cardiac enlargement uncommon, but LA enlargement causes straightening of L superior cardiac border, elevating L mainstem bronchus and may produce “double density” caused by superimposition of ovoid density of increased volume of blood in chamber
LA enlargement may have broad and notched P waves in V1, II, or large fibrillatory waves if afib present; vertical or right axis in frontal plane due to normal/underdeveloped LV because of diminished inflow, but pressure-burdened RV
Can get RV hypertrophy and thus increased R wave in R precordial leads (V1-3?)
What determines the harshness of a heart murmur?
The velocity of blood and the pressre gradient between 2 areas (use 4v2 to calculate pressure gradient)
Where are murmurs and valve click/sounds heard best?
Murmurs best heard downstream
Valve clicks/sounds reflect back and are heard best upstream
How does tachycardia worsen mitral stenosis?
Higher HR means LA pressure increases because shortened diastolic emptying period so LA doesn’t have any time to decompress
Patient can build up so much pressure they get pulmonary edema and cannot breathe
Opening snap, mid-diastolic murmur, presystolic murmur and S1 all get louder
Give beta blockers to bring down HR and get LA pressure lower
Are murmurs louder on inspiration or expiration?
RILE
Right side murmurs (pulmonic and tricuspid) louder on inspiration (increases RA return)
Left side murmurs (aortic and mitral) louder on expiration (increases LA return)
PCSK9 and drugs that target it
PCSK9 is an enzyme that eats up LDL receptors
If you’re lucky you’re born with low PCSK9 and will have tons of LDL receptors and clear LDL from the blood really well
REGN727 (and the drug Shannon is working on!) is an antibody that binds and neutralizes PCSK9 so it can’t eat up LDL receptors –> lowers cholesterol (could be a good new cholesterol-lowering drug!)
Pulsus paradoxus
Inflate BP cuff above pts anticipated systolic BP and listen for first Korotkoff sound
At first, hear Korotkoff sound that is intermittent rather than regular, and this is because you CANNOT hear sound during inspiration because systolic BP during inspiration is lower. This is because when you inhale, RA and RV fills more and pushes interventricular septum into LV which then has smaller size, less preload, less SV and thus lower systolic BP
Bring pressure in BP cuff down more and listen until Korotkoff sounds are regular, heard during inspiration also.
If difference between when first Korotkiff sound heard only during expiration and when it is heard during both inspiration and expiration is more than 10 mmHg, then have pulsus paradoxus which is suggestive of cardiac tamponade
Differentiating MI, PE and pericarditis
MI and pericarditis are retrosternal but PE can be pain all over
All are sudden onset
PE and pericarditis are sharp stabbing pain but MI is elephant on chest, pressure
Pain doesn’t change with respiration for MI; for pericarditis lungs rubbing will cause pain with inspiration and doesn’t completely go away when exhale; for PE if you hold your breath pain goes away
Takatsubo cardiomyopathy
“Broken heart syndrome”
Catecholamine surge from acutely traumatic incident can lead to myocyte toxicity with apical ballooning of the heart seen on echocardiogram
Acute rheumatic fever
Inflammatory disease of heart, joints, CNS and subcutaneous tissue that develops after an infection with Group A beta hemolytic streptococci (S. pyogenes)
Cumulative long term damage to heart valves from recurrent ARF (with preceding strep infection) results in rheumatic heart disease (RHD)
Epidemiology of RHD
25-40% of all CV disease in the world, affecting 15.6 million worldwide
50% of those who have ARF develop chronic valvular damage (RHD)
2% of Australian Aboriginal population affected
RHF occurs most commonly in ages 5-15, recurrences also occurring most frequently in this group but can occur into adulthood (but usually occur within first 5 years)
Pathogenesis of ARF
Result of infection with a rheumatogenic strain (M proteins, antigenic subtypes, emm genes have all been implicated) in a susceptible host
Triggering specific T cell activation and humoral responses against epitopes in myosin and laminin that are similar to Strep M protein (molecular mimicry)
Clinical presentation of ARF
Mean latency after initial infection is 3 weeks (in 2/3 of cases the initial infection is asymptomatic)
Fever
Polyarthritis in 50-75%
Carditis in 40-60%
Carditis
Pericardium: rub or effusion
Myocardium: usually asymptomatic but can see conduction delays with prolonged PR interval
Endocardium: new murmur, often mitral, or aortic regurgitation in children; in late adolescence stenotic lesions common
Aschoff nodule
Marks acute rheumatic carditis
Granulomatous inflammation
Aschoff giant cell: large cell with two or more nuclei with prominent nucleoli
Scattered inflammatory cells accompany Aschoff giant cells
Polyarthritis of ARF
Migratory, asymmetrical, most commonly knees, ankles, elbows, wrists
Painful swollen joints which may contain sterile exudative effusions
Responds well to NSAIDs
Sydenham’s chorea or St. Vitus’ dance
Latency may be as long as 6 months
Predominantly in females
Involves arms and face most
Associated with emotional lability, personality change and obsessive/compulsive behaviors
Jones criteria
Positive throat culture
OR
Elevated or increasing streptococcal antibody titer (ASO)
AND
2 major or 1 major and 2 minor manifestations
Major criteria: carditis, polyarthritis, chorea, subQ nodules, erythema marginatum
Minor criteria: fever, arthralgia, elevated acute phase reactants, prolonged PR
Management of ARF
Treat underlying strep with penicillin
Arthritis and/or mild carditis: aspirin 80-100mg/kg for 2 weeks, then reduced doses for 2-4 more weeks
Corticosteroids no proven benefit, but used to treat symptomatic carditis
Ensure secondary prophylaxis to prevent further cardiac damage
Likelihood of rheumatic heart disease is associated with severity of acute carditis and recurrent episodes of rheumatic fever
75% of recurrences occur within 2 years and 90% within 5 years
Appropriate prophylaxis for dental and medical procedures to prevent infectious endocarditis
Primary prophylaxis for ARF
Treatment of an initial pharyngitis or skin infection within 9 days to prevent initial episode of rheumatic fever
Requires access to medical care, and does not prevent ARF in persons with ARF triggered by asymptomatic strep infection (2/3 of cases)
Secondary prophylaxis
Prevention of subsequent strep infections with:
Injections of IM benzathine penicillin G (every 3 to 4 weeks)
Daily adminitstration of oral penicillin, sulfadiazine, or erythromycin
For 5 years after last attack or until age 21, whichever is longer
10 years after last attack in persons with residual RHD and at least until age 40
Epidemiology of endocarditis
Mortality 20-30%
25% of cases due to underlying RHD in developed countries (used to be 75%?)
More prosthetic valve replacements
More nosocomial acquisition (S. aureus and S. epidermidis)
>50% of patients over 50yo
Degenerative lesions assuming greater importance especially in persons >60
More males than females
Types of infective endocarditis
Native valve
Prosthetic valve
Special risk factors are IV drug use and nosocomial bacteremia
Three key features leading to infective endocarditis
1) Portal of entry
2) Transient bacteremia with organisms that can adhere to valves
3) Turbulent flow/abnormal valve that facilitates adhesion and propagation of the organism and vegetation
Causes of transient bacteremia
Dental infections/procedures
Surgical procedures
Line infections
Trauma
IVDU
UTI
Pneumonia
Microbiology of all types of IE
Streptococci 55-68%
Staphylococcus 20-35%
Enterococci 5-18%
Other bacteria (HACEK, pseudomonas): 2-13%
Fungi 2-4%
Culture negative 5-24%
Endocarditis among IVDU
Right sided common (52%; because injecting into veins so gets to R heart first), aortic valve (25%), mitral valve (20%)
Infection of more than 1 valve occurs
S aureus predominates
Yeast and pseudomonas species more common in this group
Mortality higher if HIV+ and increases with declining T cell counts
Prosthetic valve endocarditis
Early (first 60 days post op): S epidermidis predominates, followed by S aureus probably from perioperative contamination
Progressive endothelialization over 6 months reduces susceptibility to IE (cells depositing over the valve)
Late: organisms include staph, strep, enterococci, HACEK group
Nosocomial endocarditis
Secondary to invasive procedures especially intracardiac devices and intravascular access (central lines), so S aureus is a common causative organism
<50% have predisposing cardiac conditions
Bacteremia from GI or GU source may be the cause (enterococci or yeast)
Mortality >50% (but not all attributable to endocarditis, but to predisposing conditions)
Pathogenesis of infectious endocarditis
Turbulent flow from congenital abnormality (MVP, bicuspid AV), scarring from RHD or age related sclerosis, prosthetic valves
Direct mechanical damage from catheters, pacemaker leads
Inflammatory lesions from IVDU
Erosion of the valve surface allows for direct contact between blood and the subendothelium, exposing extracellular matrix proteins, thromboplastin and tissue factor (TF) triggering coagulation, also resulting in adherence of bacteria/fungi, persistence, proliferation causing local damage and growth of the vegetation, hematogenous dissemination
Pathogenesis of adhesion and propagation
Complex series of interactions between vascular endothelium, microorganism (surface properties, enzyme and toxin production), hemostatic mechanisms, host immune system
Bacterial factors: ability of an organism to bind to fibrinogen, fibronectin or platelets on damaged endothelium facilitates colonization during transient bacteremia; resistance to complement-mediated bactericidal activity of serum allows organism to persist
Host factors: fibronectin, a major surface glycoprotein produced by endothelial cells, platelets and fibroblasts in response to vascular injury; laminin and vWF have also been identified as important host factors in adherence (these all provide opportunity for bacteria to bind and also protection for ongoing proliferation)
Propagation: in response to inflammation, endothelial cells bind fibronectin; bacteria that can bind to the adhesive fibronectin are then internalized by endothelial cells triggering production of tissue factor (TF) and cytokines, promoting more coagulation and inflammation, rapidly creating a protective sheath of fibrin and platelets, an ideal niche for the bacteria to reproduce and further the propagation of the vegetation
Tissue invasion and abscess formation: bacteria produce exoenzymes and exotoxins that promote bacterial growth and local tissue breakdown leading to cardiac dysfunction and septic emboli can seed other organs causing complications at distant sites
Cardiac complications of IE
Valvular insufficiency from erosion or perforation of a leaflet, rupture of chordae, papillary muscle
Fistula into myocardium or the pericardial sac
Valvular stenosis
Myocardial infarction (rare)
Conduction disturbances from perivalvular abscess
Presentation of IE
Acute IE incubation is <2 weeks
Subacute IE symptoms last a median of 5 weeks and immunologic manifestations predominate
Fever >1 week
New or changing murmur (MR, AR)
Cardiac dysfunction
Embolic or immunopathologic events (splenomegaly (septic emboli to spleen), elevated sed rate, leukocytosis, hematuria, anemia)
Embolic complications of left sided endocarditis
70-95% of persons in preantibiotic era had demonstrable embolic events
Currently 15-35% have embolic complications (bc people present earlier with fevers and get treatment earlier)
Emboli to liver, skin, brain (occur in 20%, cause infarction, abscess, mycotic aneurysm, SAH, meningitis, focal neuro deficit similar to stroke sx)
Cutaneous manifestations of IE
20-40% have petechiae
Janeway lesions (small, painless, erythematous lesions on palm or sole) due to septic emboli with bacteria, neutrophils and SQ hemorrhage and necrosis
Osler nodes (tender raised lesions on finger or toe pads) diffuse infiltrate of neutrophils and monocytes in the dermal vessels with immune complex deposition; tender and erythematous
Immunopathologic complications
RF (IgG/IgM) develops in 50% of patients who have infection > 6 weeks
Diffuse glomerulonephritis from deposition of circulating immune complexes in the kidney
Osler nodes from cutaneous immune complex deposition
Splenomegaly, arthralgias are common
Lab findings in IE
70-90% have anemia
5-15% have thrombocytopenia
20-30% have leukocytosis
90%+ have ESR elevated
40-50% have RF elevated
40-50% have UA abnormal (hematuria, pyuria, bacteria)
Diagnosis of IE
Valvular lesion and an organism
Blood cultures negative in 10% of cases: due to antibiotics in prior 2 weeks, due to fastidious organisms which may not grow well in media used or may not respond to standard empiric treatment
Duke criteria
Combined microbiologic and echocardiographic criteria
Negative echo does not rule out and positive does not rule in disease (lupus causes fibrin and platelet deposition that could look like endocarditis on echo)
Major Duke criteria: >2/2+ blood cultures with typical organisms in absence of primary focus; endocardial lesion on TEE or TTE (oscillating mass, abscess, new dehiscence of prosthetic valve), new valvular regurgitation
Minor Duke criteria: predisposing condition (RHD), fever, vascular lesions (emboli, mycotic aneurysm, pulmonary infarct, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesion), immunologic (glomerulonephritis, Osler nodes, Roth spots, rheumatoid factor)
Definite: surgical pathology/bacteriology of vegetation, abscess or emboli; 2 major criteria; 1 major + 3 minor criteria; 5 minor criteria
Possible: 1 major criteria + 1 minor criteria; 3 minor criteria
Prophylaxis for IE
Bacteremia from daily activities more likely to cause IE
Extremely small number of cases of IE potentially prevented even if prophylaxis is 100% effective
Risk of antibiotic adverse events may exceed potential benefit
At highest risk: previous IE, prosthetic valve, complex congenital heart disease, post-transplant valvulopathy
Prophylaxis for highest risk group only but no data actually demonstrates that prophylactic antibiotics prevent IE
No prophylaxis recommended for uncomplicated GI/GU procedures
Infective endocarditis (IE)
Infection of the endocardial surface of the heart
Most commonly affects heart valves
Usually bacteria, but can be chlamydia, rickettsia, fungi, mycoplasma…
Any structural defect that causes turbulence increases the risk of endocarditis
Diseases of the aorta and great vessels
Aneurysms
Dissections
Dissecting aneurysms
Dissections that become aneurysmal
Aortic anatomy
Three layers of aorta:
Intima: thin layer lined by endothelium (this is the layer that tears to cause dissection)
Media: thickest layer with elastic fibers arranged in spiral fashion for tensile strength (this is where dissection occurs)
Adventitia: thin fibrous layer with vasa vasorum
Etiology of aortopathy
Degenerative diseases
Connective tissue disorders
Atherosclerosis
Infection
Degenerative diseases
Cystic medial necrosis: necrosis of elastic fibers (pink) of media replaced by mucoid material (blue)
Connective tissue disease
Marfan Syndrome: mutation in gene encoding fibrillin-1 on chromosome 15; most patients die of aortic complication in 3rd decade if untreated; associated with MVP, ectopia lentis, elongated globe, pectus excavatum and carinatum, wrist and thumb sign, arm span-height ratio >1.05
Ehlers-Danlos Syndrome: mutation of COL3A1 gene encoding Type III collagen
Bicuspid aortic valve
3 aortic sinus, 2 cusps
Fusion of R and L cusps, or others
1-2% of population
Familial clustering
Associated with premature degenerative changes of media
What type of aneurysm typically has atherosclerosis?
Abdominal aortic aneurysm
Mycotic
S aureus
S epidermidis
Salmonella
Streptococcus
Syphillis: spirochetal organisms destroy media
Aortitis
Giant cell
Takayasu’s
Ankylosing spondylitis
Reiter’s syndrome
PAN
Bechet’s disease
Ascending and aortic root aneurysms
Clinical presentation: asymptomatic, chest pain (impending rupture or compression of overlying sternum), SVC or airway compression, high output failure (rupture into RA or SVC), hoarseness
Physical exam findings: normal, aortic insufficiency, extremis, concomitant aneurysms
Indication for operation in non-emergent: ascending aorta 5.5cm; descending aorta 6.5cm; growth of >1.0cm/yr, operate early for pts with connective tissue disease
Emergency: dissection, rupture
Acute aortic dissection
Incidence 3/100,000 per year
Up to 40% die prior to reaching hospital; overall surgical in house mortality 23.9% (actually now more like 10%)
Presentation: tearing/ripping chest pain radiating to back, confusion with MI, rupture, occlusion, retrograde dissection (AR), AI, rupture with tamponade, MI from coronary occlusion
Treatment of Type A (involves ascending aortaa) is surgical emergency: rupture, pericardial tamponade, coronary ischemia
Treatment of Type B (does not involve ascending aorta) is aggressive BP reduction, particularly with reduction of dP/dt (beta blockade!)
Complicated Type B aortic dissection
Rupture
Malperfusion: dynamic (occlusion with every heart beat), static (complete obstruction all the time)
Treatment: stent, fenestration (make pressure same in true and false lumen to alleviate malperfusion), open repair
Note: Type B does not involve ascending aorta
Acute Type A aortic dissection
Surgical emergency
Timely diagnosis is key: CT angio, TEE
Approximately 30% of cases are misdiagnosed
Note: Type A involves ascending aorta
Goals of operative repair for aortic dissection
Prevent intra-pericardial rupture
Prevent involvement of coronary ostia and aortic valve: coronary ischemia, AI
Keep patient alive!
Early mortality of aortic dissection
Unstable patients had nearly 2x mortality risk (30% vs 15%)
Cardiac tamponade, shock, CHF, CVA/stroke/coma, myocardial ischemia or MI (EKG with new Q waves or ST elevation), ARF, mesenteric ischemia or infarction at surgery
Indications for arch reconstruction
Aneurysm > 6cm (earlier if symptomatic)
Chronic dissection with aneurysm
Ulcer
Ruptured acute dissection
Traumatic transection
Indications for descending aorta reconstruction
Aneurysm > 6.5cm (earlier if symptomatic)
Chronic dissection with aneurysm
Ulcer
Ruptured acute dissection
Traumatic transection
Difference between dissection, penetrating ulcer and intramural hematoma
With dissection, see intimal tear; have flow communication; false lumen expands and can see intimal flap
With intramural hematoma (IMH) you cannot find the site of intimal tear; no continuous flow communication; also you have full true lumen and hematoma forms outside circular shape of vessel
Penetrating ulcer: atherosclerosis forms ulcer that penetrates aortic wall, can resemble an aneurysm or dissection
Note: IMH or penetrating ulcer can convert to a dissection!
Blunt trauma aortic injury
Repair needs to take into account concomitant injuries (closed head injury, rib fracture/pulm contusion, abdominal/spleen/liver/bowel injury, extremity, pelvis)
Contained rupture (adventitial layer) often comes as delayed presentation
Most common location is isthmus because it is tethered and has lots of shear force
Open vs. endograft repair: steep arches, graft infolding
Etiology of congenital heart disease (CHD)
Primary genetic factors: chromosomal aberrations (5%) vs. single mutant gene (3%)
Primary environmental factors: rubella, maternal diabetes, maternal alcohol abuse, lupus etc (1%)
Genetic-Environment interaction (90%)
Acyanotic vs. cyanotic excessive pulmonary flow CHD
Acyanotic: L to R shunt; VSD, PDA, ASD, atrioventricular septal defect (ASD, VSD, and mitral and tricuspid valves fuse?)
Cyanotis: R to L shunt; truncus arteriosus, total anomalous pulmonary venous return (TAPVR), D-transposition of great arteries (TGA), double outlet RV, single ventricle
Obstruction to outflow CHD
Pulmonary stenosis/atresia
Tetralogy of fallot (TOF)
Double outlet right ventricle
Aortic stenosis
Coarctation of aorta
Interrupted aortic arch
Ten most common congenital heart defects
VSD
PDA (remember, all babies born with PDA)
Tetralogy of Fallot
ASD
Pulmonic stenosis
Coarctation of aorta
Transposition of great arteries
Endocardial cushion defect
Aortic stenosis
Total anomalous pulmonary venous connection
Atrial septal defect (ASD)
WIndow-like opening between upper two chambers of the heart
Fixed split S2 (inhalation does not cause a greater split, but is just always split)
No murmur unless HUGE ASD and RV pumps a lot of blood through pulmonary valve to create murmur
Poor growth, pneumonia, heart failure, PHT, arrhythmias
7-10% of CHD
Closed with Amplatxer septal occluder device
Ventricular septal defect (VSD)
Window like opening between the lower two chambers of the heart
Often without symptoms but can have CHF (poor growth, pneumonia, heart failure, PHT, arrhythmias)
Can progress to Eisenmenger’s
Often these close spontaneously, some need surgery or device closure
Asymptomatic holosystolic murmur (S1 coincident, as soon as mitral closes, murmur starts and barely even hear S1)
Get LV dilation because right side has pressure load but blood goes back to left side so LV has volume overload and dilates
AV canal defect
A failure of the mitral and tricuspid valves to form into 2 valves, so they remain as one common valve with a primum ASD and an “inlet” VSD (basically heart is one big chamber?!)
Physiology of a large VSD–requires full surgical repair
Can progress to Eisenmenger’s
Associated with Down Syndrome
Coarctation of the aorta
Severe narrowing of the aorta behind the heart
High BP (in upper extremities, but low BP/pulses in femoral artery!), heart failure, strokes
7% of CHD
Treatment by stent implantation or surgery
Often presents with poor femoral pulse (but normal radial pulses because flow to subclavian is good/high)
Preductal and postductal refer to before or after ductus arteriosus, but both of these are after the subclaviam
Aortic valve stenosis
Fused, thickened aortic valve with small opening
Heart failure, shock, poor growth, asymptomatic
3-6% of CHD, males much more likely 4:1
Balloon aortic valvuloplasty or surgery (replacement repair, Ross)
Mild aortic stenosis can be observed
At risk for endocarditis
Physical findings: systolic murmur, thrill, click, decreased pulse pressure
Clinical features of CHF
1) Tachycardia
Low BP, so try to:
2) Increase preload to increase volume (retain fluid and get edema, tachypnea, respiratory distress, peripheral edema rare in kids)
3) Increase afterload to normalize BP (vasoconstriction causes you to be cold and clammy)
Treatment of CHF or cardiogenic shock
Can present like hypovolemic shock but if you give volume (10cc/kg fluid bolus) patient may not improve and may deteriorate
For high preload give diuretics (furosemide)
For poor contractility give digoxin, beta agonists (dobutamine, epi), phosphodiesterase inhibitors (milrinone)
For high afterload, give vasodilators (ACEI), phosphodiesterase inhibitors (milrinone)
Differential diagnosis of cyanotic CHD
Tetralogy of fallot (TET or TOF)
Transposition of the great arteries (TGA)
Tricuspid atresia (TA): absence of tricuspid valve and hypoplastic RV; requires ASD and VSD for viability
Truncus arteriosus (TRUNC): failure of truncus arteriosus to divide into pulmonary trunk and aorta; most have accompanying VSD
Total anomalous pulmonary venous return (TAPVR): pulmonary veins drain into right heart circulation (SVC, coronary sinus, etc); have ASD and PDA to allow R to L shunt to survive
Cyanosis
Blue discoloration of the skin and/or mucous membranes due to reduced (unsaturated) hemoglobin (usually >3 gm%) in the peripheral circulation
Mechanisms of cyanosis:
Unsaturated hemoglobin in peripheral arterial circulation due to intrapulmonary shunting and intracardiac shunting
Alveolar hypoventilation due to CNS depression
Polycythemia
Transposition of the great arteries
Aorta arises from pulmonary ventricle, pulmonary artery from systemic ventricle
In order to survive, have to have PDA and/or ASD, and ASD is better to have (need to get mixing of red and blue blood)
“Blue baby” (cyanosis)
5% of CHD
Palliation by balloon atrial septostomy
Treated with the arterial switch operation
TGA along with TOF are most common cyanotic heart lesions
Tetralogy of Fallot (TOF)
Pulmonary stenosis
RVH
Overriding aorta: overrides VSD; aortic valve is right about VSD so communicates with both ventricles
VSD
Presentation: murmur with or without cyanosis
Physical exam: +/- cyanosis, clubbing, increased RV impulse, single loud S2 (aortic valve only?), harsh midsystolic murmur (pulmonary stenosis)
Boot shaped heart on CXR (due to RVH)
Clinical course: benign or progressive cyanosis and/or hypercyanotic (Tet) spells
Pathophysiology of Tet spell: increased RV outflow tract obstruction, decreased peripheral systemic resistance, possible acidemia and anemia
Transcatheter pulmonary valve replacement
In dissection, how can you tell true lumen from false lumen?
True lumen is smaller, more bright on CT angio
False lumen is bigger, less bright on CT angio
Specific environmental and genetic factors that cause CHD
Trisomy 21: VSD, AV canal
Turner’s syndrome: bicuspid aortic valve, coarctation of aorta (preductal, before ductus arteriosus)
Noonan’s syndrome (AD): pulmonic stenosis
Tuberous sclerosis (AD): myocardial rhabdomyoma
Single gene mutations on chrom 6 and 14: hypertrophic cardiomyopathy
Alcohol: VSD, PDA, ASD
Rubella: peripheral pulmonic stenosis, PDA, VSD, ASD
Diabetes: TGA, VSD, CA
High blood sugar during pregnancy: thick hypertrophied heart that resolves spontaneously
Lupus: heart block
