Heart Pathology (GOMEZ) Flashcards
do the flashies for before 41
do it
coarctation of the aorta
Infantile form – hypoplasia of aorta prior to patent ductus arteriosus (cyanosis of inferior body and weak femoral pulses)
Adult form – ridge-like fold opposite ligamentum arteriosus (HTN upper extremities with low pressure and pulses in lower extremities). Pansystolic murmur
Higher pressures in the upper arms, neck, head
Pressure drop in the legs (top half will be pink, bottom half blue)
kidneys sense lower pressure - turn on RAAS
treat with surgery
pulmonary stenosis and atresia
– smaller the orifice the worse the cyanosis
Supravalvular aortic stenosis
– elastin gene mutation with aortic dysplasia (thickening)
williams-beuren syndrome
deletion of about 28 genes from chromosome 7 with ELN gene (elastin) haploinsufficiency, hypercalcemia, glucose intolerance, facial and cognitive defects
ischemic heart disease
imbalance between the supply (perfusion) and demand of the heart for oxygenated blood
90% due to atherosclerotic coronary arterial obstruction
Leading cause of death in US for both males & females
Higher incidence in males than females
in premenopausal females IHD is uncommon
“Diminished coronary artery perfusion relative to myocardial demand” from interaction one or more of the following:
Fixed atherosclerotic narrowing (stenosis) of coronaries
Thrombosis overlying a disrupted plaque
Localized platelet aggregation
Vasospasm
Emboli (valvular vegetations, etc.)
Hypotension (if there is atherosclerosis)
Coronary artery vasculitis
Fixed obstruction >75% required to cause symptoms with exercise
Fixed obstruction > 90% can lead to ischemia at rest
4 clinical syndromes of Ischemic heart disease
Sudden Cardiac Death
Angina Pectoris
Chronic IHD with heart failure- killing myocytes progressively
Myocardial Infarction (MI)
role of atherosclerotic heart disease in ischemic heart disease
Acute plaque change:
Rupture/Fissuring
Erosion/Ulceration
Hemorrhage into an atheroma (plaque)
***abrupt plaque change followed by thrombosis tends to occur in plaques with large cores and thin caps
Acute plaque change does not usually occur in severely stenotic portions of arteries
2/3 of acute ruptures with subsequent thrombosis occur in vessels that are narrowed less than 50%
85% have stenosis < 70%
Plaques tend to involve entire RCA and proximal LAD and LCX
worst scenario = thrombosis that blocks the lumen –> leads to unstable angina and can lead to MI
stable angina
> 75 % stenosis
no plaque disruption
no plaque associated thrombus
unstable angina
variable stenoses
plaque distruption frequent
nonocclusive often with thromboemboli
transmural myocardial infarction
Ischemic necrosis involves >50%*** of the ventricular wall thickness
75% across is transmural as well
Commonly associated with acute plaque change with thrombosis
variable stenosis
frequent plaque disruption
subendocardial MI
Area of ischemic necrosis limited to the inner 1/3 or at most the inner 1/2
May occur as a result of acute plaque change and thrombosis
May result from prolonged and severe reduction in systemic blood pressure ,as encountered in shock
variable stenoses
variable plaque disruption
Widely variable, may be absent, partial/complete, or lysed
(plaque associated thrombus)
why does a small band of subendocardial tissue remain visible ?
sudden death>
usually severe stenoses
frequent plaque disruption
often small platelet aggregates or thrombi and /or thromboemboli
Prinzmetal angina
sustained vasospasm causing angina (chest pain- relieved by Nitroglycerin)
no significant atherosclerosis
very similar to cocaine abuse
Cardiac Raynaud
cold or emotion induced cardiac vasospasm
- If vasospasm is > 20 minutes can lead to myocardial infarction
Takotsubo cardiomyopathy
dilated cardiomyopathy secondary to emotional or physical stress with normal coronary angiogram (sometimes due to vasospasm)
sudden cardiac death
Unexpected death from cardiac causes early after onset of symptoms (1 to 24 hours) or sudden death from cardiac cause without antecedent acute symptoms
In US: > 400,000 deaths annually
Mechanism: Most often a lethal arrhythmia from electrical instability (irritability); ventricular fibrillation (80%) or asystole
Most commonly caused by Ischemic Heart Disease (IHD)
Should suspect non-ischemic SCD in younger people
– particularly in people < 40 years with SCD!!!!!
Possibilities:
Hypertrophic cardiomyopathy (18%)
Coronary artery anomalies (9%)
Myocarditis (3%)
Arrhythmogenic right ventricular cardiomyopathy (2%)
Ion channelopathies (2%)
Commotio cordis (3%) due to sudden v-fib caused by blunt impact to the heart
Congenital structural abnormalities (<1%)
long QT syndrome
manifests as arrhythmias associated with excessive prolongation of the cardiac repolarization; patients often present with stress-induced syncope or sudden cardiac death (SCD), and some forms are associated with swimming.
Short QT syndrome
patients have arrhythmias associated with abbreviated repolarization intervals; they can present with palpitations, syncope, and SCD.
Brugada syndrome
manifests as ECG abnormalities (ST segment elevations and right bundle branch block) in the absence of structural heart disease; patients classically present with syncope or SCD during rest or sleep, or after large meals.
CPVT syndrome
does not have characteristic ECG changes; patients often present in childhood with life-threatening arrhythmias due to adrenergic stimulation (stress-related).
what are channelopathies
Disorders of K+, Na+, or Ca++ channel structure or accessory proteins involved in channel function
Mostly autosomal dominant
chronic ischemic heart disease
Insidious onset of congestive heart failure in patients who have had past myocardial infarcts (MIs) or angina
patients usually have history of HTN
Cardiomegaly with left ventricular hypertrophy & dilatation
Evidence of previous healed MIs or ischemia (areas of myocardial fibrosis)
Develop arrhythmias, congestive heart failure and MIs
Chronic ischemia that does not
cause necrosis can lead to
hypokinetic myocardium with
myocyte hibernation
angina pectoris
Paroxysmal (anytime- usually stress induced) and usually recurrent attacks of substernal or precordial chest discomfort…..
ischemia doesn’t last long enough to kill myocyte (<20 min) so its reversible
Caused by transient myocardial ischemia that falls short of inducing the cellular necrosis that defines infarction
stable angina
↓perfusion 2ry to fixed-narrowing
Most common form of angina
Can be provoked by increased cardiac demand (emotion, exercise)
Usually relieved by rest or sublingual nitroglycerin
unstable angina (crescendo, pre-infarction)
usually have acute plaque change partially narrowing the lumen- not 100% occlusion
how do you know its unstable? worse symptoms, happens more often, doesn’t go away as quickly with nitro
Progressive increase in frequency and severity of attacks
Provoked by progressively less effort and may occur at rest
May be relieved by rest or sublingual nitroglycerin
Prinzmetal angina
episodic angina due to coronary artery spasm
Relieved by rest, nitroglycerin or calcium channel blockers
myocardial infarction
Definition: The death of cardiac muscle from ischemia
Epidemiology
Frequency of MI rises progressively with increasing age
10% MIs occur in individuals under age 40
40-45% occur in individuals under age 65
Men at far higher risk than women – women are protected during premenopausal period (but not post menopause w/ or w/o estrogen)
Lipid risk factors account for 50-60 % of MIs
Genetic risk factors for thrombosis (e.g., Prothrombin mutations, Hyperhomocystenemia) account for another 10-20%
peak incidence of MI?
peak incidence between 6 am and noon
intense emotional stress
typical sequence of events in MI
90%
Initial sudden change in plaque
Immediate formation of initial platelet plug over plaque
Vasospasm from platelet adhesion (vasoactive substances from platelets)
Propagation of platelet plug into stable clot via extrinsic clotting system
Within minutes, clot occludes lumen of the involved vessel
(thrombosis with coronary occlusion)
10% of transmural MI patients have no associated atherosclerosis
Vasospasm- isolated, prolonged, severe (e.g., cocaine)
Emboli- left atrium (atrial fibrillation) or ventricle (mural thrombus) , valve vegetations, paroxysmal emboli
Vasculitis, hemoglobinopathy, etc.
onset of ATP depletion
seconds
loss of contractility
<2 min
ATP reduced to
50%
10%
50 –> 10 min
10% - 40 min
Irreversible cell injury (necrosis)
20-40 min
microvascular injury
> 1hr
complete unsalvageable necrosis
6 hrs
reversible stage of MI
For approximately 30 minutes after the onset of even the most severe ischemia, myocardial injury is potentially reversible.
Thereafter, progressive loss of viability occurs that is complete by 6 to 12 hours. The benefits of reperfusion are greatest when it is achieved early, and are progressively lost when reperfusion is delayed.
0-1/2 hour of MI
no gross feature changes
no light micro findings
Relaxation of myofibrils; glycogen loss; mitochondrial swelling
reversible
1/2 hr to 4 hr post MI
no gross feature changes
usually no light micro findings
variable waviness of fibers at border
electron microscopic findings:
Sarcolemmal disruption; mitochondrial amorphous densities
irreversible
4-12 hour post MI
dark mottling gross features
usually none though
light microscopic
early coagulation necrosis, edema, hemorrhage
cellular changes
12 - 24 hrs post MI
dark mottling gross features
Ongoing coagulation necrosis; pyknosis of nuclei;
myocyte hypereosinophilia;
marginal contraction band necrosis;
early neutrophilic infiltrate***
acute MI - any infarct will have the first cells coming in be neutrophils (so doesn’t always = infection)
1-3 days post MI
mottling with yellow-tan infarct center
Coagulation necrosis, with loss of nuclei and striations;
brisk interstitial infiltrate of neutrophils***
3-7 days post MI
gross features:
Hyperemic border; central yellow-tan softening
light micros
Beginning disintegration of dead myofibers, with dying neutrophils; early phagocytosis of dead cells by macrophages*** at infarct border
> 2mo post MI
gross features:
scar
dense collagenous scar
can no longer tell WHEN the infarct occurred. scar is a scar is a scar
7-10 days post MI
Gross- maximally yellow tan and soft wutg
Well-developed phagocytosis of dead cells; early formation of fibrovascular granulation tissue at margins
myocytes are gone
around 1 week or so the wall may rupture
apex of heart
LAD- 40-50 %
most commonly blocked vessel
RCA
blockage tends to give more arrhythmia’s
distal RCA- most likely hits posterior wall
myocardial infarction modification by reperfusion
time limit on reperfusion?
Goal - salvage ischemic myocardium from potential infarction by restoration of tissue perfusion as quickly as possible (reperfusion)
Intervention techniques include:
Lysis of thrombus by fibrinolytic therapy (Streptokinase, Urokinase, or tissue plasminogen activator (TPA)
Balloon angioplasty
Coronary artery bypass graft
when we reperfuse the heart, we cause injury! but you are still better off reperfusing and it takes time for the myocytes to start working again
Reperfusion beyond 6 hours does not appreciably reduce myocardial infarct size
pathologic changes associated with reperfusion?
Reperfusion-induced arrhythmias
Myocardial hemorrhage with contraction bands
Irreversible myocardial damage in addition to that caused by the initial episode of ischemia (reperfusion injury)
Microvascular injury with endothelial swelling (no-reflow)
Reversible “Myocardial stunning” (prolonged ischemic dysfunction) with heart failure for days
clinical features of MI
Classic acute onset symptoms and signs:
Severe substernal chest pain with radiation of pain down left arm, neck, jaw, epigastrium
Weak, rapid pulse
Sweating profusely (diaphoretic)
Nausea
Dyspnea (difficulty breathing) secondary to pulmonary congestion and edema
angina is reversible whereas MI is not (pain does not subside)
10-25% of MI patients may be asymptomatic during the acute cardiac event *diabetics, heart transplant patients (no neural connections in new heart)
Occurrence of the MI discovered by EKG (Q waves, ST-segment changes, T-wave inversion) or other types of testing (labs)
STEMI –ST segment Elevation Myocardial Infarct (transmural***)
NSTEMI – Non-ST segment Elevation Myocardial Infarct (subendocardial***)
troponin I, C, or T and creatine phosphokinase, MB fraction [CK-MB]
myoglobin
released myocyte proteins in MI !
damage to myocardium does NOT equal MI. must have other factors to diagnose
myoglobin
initial elevation 1-4 hr after MI
nonspecific early marker
myoglobin –used to exclude MI not to diagnose
peak at 6 hr
18-24 hrs time to return to baseline after MI
CK-MB
go up 3-12 hours after infarct
peak elevation 10-24 hr
48-72 hours is time to return to baseline after AMI
troponins
takes 3 hours for these to come up so most likely won’t wait this long to get them to cath lab so look at other signs/symptoms
troponins stay elevated for 1-2 weeks
systemic (left-sided) HTN heart disease
criteria for diagnosis
Criteria for Diagnosis
1. Left ventricular hypertrophy (usually concentric) in the absence of other cardiovascular pathology that may have induce it.
2. A history or pathologic evidence of systemic hypertension
(BP > 140/90 mm Hg)
May present clinically with CHF or atrial arrythmias
HTN heart disease
Pulmonary right sided
Cor Pulmonale results from pulmonary disorders that cause chronic severe pulmonary hypertension.
Occurs with:
Pulmonary Parenchyma Disorders
Chronic Obstructive Pulmonary Disease (COPD)
Diffuse Interstitial Lung Disease
Pulmonary Vessel Disorders
Recurrent Pulmonary Embolism
Primary Pulmonary Hypertension
Chest Movement Disorders
Kyphoscoliosis
Right ventricle –> dilated and has thickened free wall and hypertrophied trabeculae
Cardiac valve dysfunction
causes what>
Stenosis***: failure of valve to open completely impeding forward flow
Almost always due to a primary valve cusp abnormality and virtually always a chronic disease
Insufficiency*** (regurgitation or incompetence): failure of a valve to close allowing reverse flow
- ->From intrinsic disease of valve cusp or an acquired structural abnormality of the supporting anatomic structures - ->In addition to chronic disease, acute insufficiency syndromes may occur (e.g., rupture of a papillary muscle) - ->Functional regurgitation – normal valve leaflets but problem with supporting structures (e.g. dilated annulus from ventricular dilatation)
“Pure” when only stenosis or insufficiency present
“Mixed” when both present in same valve
acquired stenoses of the aortic and mitral valves accounts for 2/3 of all valvular diseases
aortic stenosis
Calcification of anatomically normal and congenitally bicuspid aortic valves
aortic insufficiency
Dilatation of the ascending aorta due to hypertension and aging
mitral stenosis
rheumatic heart disease
mitral insufficiency
Myxomatous degeneration (mitral valve prolapse)
senile calcific aortic stenosis
Calcific Aortic Stenosis
Most common of all valvular abnormalities*
Consequence of calcification* owing to progressive and advanced age
Pathologic Features
Nodular masses of calcium are heaped up within the sinuses of Valsalva (arrow).
can close completely but not open - more problem with stenosis
Clinical features
Clinical symptoms do not occur until 7th (60s) to 9th (80s) decades**
Pressure hypertrophy results from flow obstruction and patient develops significant left ventricular concentric hypertrophy***
Left ventricular cardiac mass tends to be ischemic and leads to:
Congestive heart failure (die within 2 yrs)
Syncope (die within 3 years)
Angina pectoris (die within 5 yrs)
Calcific stenosis of congenitally bicuspid aortic valve
Congenital bicuspid aortic valve occurs in ~ 2% population
Two cusps frequently not equal size: larger cusp may have a raphe” (seam) – result of incomplete separation during development
Bicuspid valves more susceptible to progressive degenerative calcification; develop significant calcification earlier ***
Develop clinical symptoms and signs of cardiac dysfunction earlier, 5th and 6th decades (7th to 9th decades with tricuspid aortic valves)
May have coexisting abnormalities of aortic wall
mitral annular calcification
what population does this occur in ?
fibrous tissue that leaflets attach to … is the annulus
Occurs in three types of patients
Women over 60 years of age
Individuals with myxomatous mitral valves
Patients with elevated left ventricular pressure
– e.g., hypertension
Generally does not affect valvular function
Occasionally associated with arrythmias –>
if this calcifies conduction system–> end up with arrythmias
Most diagnosed because:
Large calcium deposits are incidentally detected
on radiography done for other reasons
Myxomatous Degeneration of the Mitral Valve (Mitral Valve Prolapse
presentation?
occurs in what population?
serious complications ?
One or both mitral valve leaflets are “floppy” and prolapse into the left atrium during systole (midsystolic click +/- regurgitant murmur)
Affects ~2-3% adults in US, most often young women (7F:1M)
Seen in Marfan syndrome (fibrillin-1/elastic fibers)
Vast majority patients clinically asymptomatic, but small subset (3%) may develop one of four serious complications:
1 Infective endocarditis
2 Mitral insufficiency
3 Stroke or other systemic infarct
4 Arrhythmias (both atrial and ventricular, rare sudden death)
Atypical chest pain
Mitral valve prolapse diagnosis by echocardiography
valves are stretchy and look like “parachute” - translucent valves (less collagen)
presentation:
young women
mid-systolic click (valve closing extra hard, plus leaflet hitting wall of atrium) - cause regurg jet lesion
can show up in psychiatrists office (anxiety, etc. ?)
valvular problem predisposes patients to….
predisposed to endocarditis
