cardiomyopathy Flashcards
cardiomyopathy
a heterogeneous group of diseases of the myocardium associated with mechanical &/or electrical dysfunction that usually (but not invariably) exhibit inappropriate ventricular hypertrophy or dilatation and are due to a variety of causes that frequently are genetic
Cardiomyopathies either are confined to the heart or are a part of ??
generalized systemic disorders, often leading to cardiovascular death or progressive heart failure-related disability
Cardiomyopathy: 3 Categories + 2
DILATED
HYPERTROPHIC
RESTRICTIVE
ARRHYTHMOGENIC RV (don’t know as much)
ISCHEMIC – not focused upon in this lecture (most common in developed world, CAD)
Dilated cardiomyopathy
Congestive, DCM, IDC
most common cause of cardiomyopathy in the world
Dilatation and impaired contraction of the left or both ventricles.
hypokinetic left ventricle, and systolic dysfunction
Hypertrophic cardiomyopathy (IHSS, HCM, HOCM, ASH)
Left and/or right ventricular hypertrophy, often asymmetrical, which usually involves the inter ventricular septum
with or without left ventricular obstruction
Restrictive (Infiltrative)
cardiomyopathy
Restricted filling and reduced diastolic size of either or both ventricles with normal or near-normal systolic function.
Arrhythmogenic right ventricular cardiomyopathy (ARVD)
Progressive fibro-fatty replacement of the right ventricle
Dilated Cardiomyopathy: Background
CONGESTIVE presentations
Can be *inherited*
True cause: *unknown*
CHAMBER ENLARGEMENT
IMPAIRED SYSTOLIC FUNCTION:
right, left, or biventricular
Myocyte injury and fibrosisWide spectrum of causes of Dilated Cardiomyopathy (DCM)
Idiopathic (typically viral) Genetic ( 20-30%) Inflammatory (infectious and noninfectious) Toxic (etOH most common, chemo agents) Metabolic Neuromuscular Major ischemic episode
DCM Incidence / Prognosis
Prevalence is 36/100,000 population
3rd most common cause of heart failure
Middle age, men > women
Annual mortality: 12% !
Most frequent cause of heart transplantation
DCM accounts for approximately 10,000 deaths and 46,000 hospitalizations per year in the US
Complete recovery is rare
DCM primary vs secondary
Primary (idiopathic) is a disease of unknown etiology that principally affects the myocardium leading to LV dilation and systolic dysfunction
Secondary causes include ischemia, alcoholic, peripartum, post-infectious, viral
DCM causes2
Toxin induced:
alcohol
anthracycline
cobalt
catecholamine
Radiation
Infectious:
viral / HIV
parasitic
Metabolic:
starvation
thiamine deficiency
(beriberi)
thyrotoxicosis
Sarcoidosis
Hemochromatosis
Peripartum/postpartum
cardiomyopathy
Genetic
heart failure dx
done clinically, no definitive lab tests
DCM: Symptoms/Signs of heart failure
Pulmonary congestion (left heart failure) dyspnea (rest, excertional, nocturnal), orthopnea
Systemic congestion (right heart failure) edema, nausea, abdominal pain, nocturne
Cardiac exam reveals -> S3, S4 and murmur of TR and/or MR
Low CO
Hypotension, tachycardia, tachypnea
Fatigue and weakness
DCM: arrhythmia
Atrial fibrillation, conduction delays, complex PVC’s, sudden death
DCM dx
CXR (enlarged heart, CHF)
EKG (tachycardia, A-V block, LBBB, NSSTT changes, PVC’s)
Echo (left ventricular dilation, global hypo kinesis, low EF)
Myocardial biopsy, rare
Cardiac catheterization (R/O CAD): -if age >40, ischemic history, high risk profile, abnormal ECG
DCM tx
(*lifestyle*) Limit activity based on functional status Salt restriction Fluid restriction Initiate medical therapy
DCM med therapy
Diuretics (don’t increase longevity, improve symptoms, except loop-spironolactone)
the following improve mortality:
Beta Blockers, ACE/ARB
Hydralazine/nitrate combination if cannot tolerate ACE/ARB
Spironolactone if EF less than 35% with Class III/VI HF
Anticoagulation prn (EF less than 30%, history of LV thrombus or embolic events)
Implantable defibrillators if EF less than 35% on optimal medical therapy
DCM more invasive tx
Cardiac transplantation: -DCM is most common indication for cardiac transplantation Survival after transplant is 80% one year 70% 5 years
Left Ventricular Reduction Procedures
LV-reshaping
Hypertrophic Cardiomyopathy (HCM): Background
Genetic disease characterized by hypertrophy of the left ventricle with marked variable clinical manifestations morphologic and hemodynamic abnormalities
Prevalence 2:1000 (more than DCM?), younger pts
concentric or localized
the heart on HCM
Small LV cavity, septal hypertrophy which can be asymmetric (ASH), systolic anterior motion of the mitral valve leaflet (SAM), +/- obstruction of left ventricular outflow with low stroke volume, but elevated EF
HCM manifestations
Hyperdynamic systolic function
LVH and LV outflow obstruction
Diastolic dysfunction
Leads to pulmonary congestion
HCM Dynamic LV outflow tract obstruction
Outflow tract gradient (>30 mm Hg), considered severe if >50 mm Hg (occurs in 25-30% of cases leading to name hypertrophic obstructive cardiomyopathy)
the original “classic” feature
we now know that it is absent in about half of the patients, and the severity of the obstruction varies greatly in those who do have it
HCM complications
Dynamic LV outflow tract obstruction Diastolic dysfunction Impaired diastolic filling, filling pressure Myocardial ischemia Mitral regurgitation Arrhythmias
HCM The causes of obstruction:
- narrowed left ventricular outflow tract due to hypertrophied interventricular septum
- anterior displacement of the mitral valve leaflets during systole (SAM- systolic anterior motion of the mitral valve).
why heart hypertrophies
heart tries to squeeze harder against restriction of outflow tract
HCM: The severity of obstruction increases with:
- any maneuver that increases the force of contraction (exercise, positive inotropic agents)
- any maneuver that decreases filling of the ventricle (dehydration, squatting–>standing, tachycardia, valsava)
nomenclature HCM
Idiopathic Hypertrophic Subaortic Stenosis (IHSS)
Hypertrophic Obstructive Cardiomyopathy (HOCM)
Assymetric Septal Hypertrophy (ASH)
Muscular Subaortic Stenosis (MSS)
Hypertrophic Cardiomyopathy (WHO)
most common presentation HCM
hypertrophy of inter ventricular septum
HCM clinical presentation
Asymptomatic:
Echo finding only
Symptomatic: Dyspnea in 90% Angina pectoris in 75% Fatigue, pre-syncope, syncope, risk of SCD Palpitation, PND, CHF, dizziness Atrial fibrillation, thromboembolism SUDDEN CARDIAC DEATH
HCM Presentation (2)
- Ischemic chest pain*: secondary to increased myocardial oxygen demand
- not necessarily from CAD (coronary aa not able to be filled due to hypertrophy)
- SYNCOPE: LV outflow decreased
- Exertional Syncope: increasing LV demand increases the level of obstruction
Major Findings in HCM
- EJECTION MURMUR at LSB (systolic, sounds like mitral regurg)
- EKG: LVH, abnormal Q’s
- Valsalva: decreased LV volume
- INCREASES the murmur
- Standing: same as above
*Squatting: Increased LV volume DECREASES the murmur (preload increases)
HCM PE
systolic murmur best heard between the apex and
left sternal border
- increases in intensity with maneuvers that
decrease preload (Valsalva maneuver)
does not radiate to the carotid arteries
HCM dx
CXR – mostly normal
routine blood-work – unremarkable
EKG – usually shows marked LVH
Echocardiogram – is the diagnostic test of choice
HCM – EKG Findings
Abnormal in 85-90% of cases LVH, Strain pattern Abnormal ST-T’s, giant T wave inversions Abnormal Q’s, Bundle Branch Block Left atrial enlargment Ventricular arrhthymias
ECHO findings HCM (don’t know in detail)
Left ventricular hypertrophy >1.3 cm (usually >1.5 cm)
Septal to posterior wall ratio >1.3:1
Mitral regurgitation
Systolic anterior motion of the mitral valve (SAM)
Premature midsystolic closure of the aortic valve
Asymmetric septal hypertrophy (ASH)
Diastolic dysfunction
Left ventricular outflow tract obstruction (LVOT)
HCM: MORE ECHO
LVH usually develops between 5-15 years of age in HCM
A normal ECHO in a young child does not R/O the diagnosis
Serial ECHOs are recommended up to the age of 20 yr where there is a family history of HCM
HOCM
Clinical presentation from infancy to old age
Variable clinical course 25 % of cohort achieve normal longevity
Annual mortality 3% in referral centers probably closer to 1% for all patients
Course may be punctuated by adverse clinical events: sudden cardiac death, embolic stroke, and consequences of heart failure
Sustained V-Tach and V-Fib: most likely mechanism of syncope/ sudden death
HOCM2
Risk of SCD higher in children, may be as high as 6% per year, majority have progressive hypertrophy
Accounts for 36% of deaths in athletes younger than 35 years
Clinical deterioration usually is slow
Poor prognosis in males, young age of onset, family Hx of SCD, Hx of syncope, exercise induced hypotension (worst)
Progression to DCM occurs in 10-15%
Risk Factors for Sudden Cardiac Death: HCM
Young age (younger than 35 years) “Malignant” family history of sudden death Aborted sudden cardiac death Sustained VT or SVT Non-sustained VT on holter monitoring Atrial fibrillation Dilated left ventricle NYHA classes III or IV
HCM management
-careful family history focused on sudden cardiac death
-exercise testing to determine the presence of exercise-induced LVOT gradient
-counseling regarding avoidance of strenuous exercise, avoidance of dehydration
-all first-degree family members should be periodically screened with an echocardiogram – yearly between ages 12-18, every 5 years thereafter
-consider genetic testing
HCM tx
Beta-adrenergic blockers (atenolol, metoprolol, sotalol, etc)
Calcium channel blockers (amlodipine, diltiazem, etc)
Anti-arrhythmics – Amiodarone, disopyramide
Pacemakers (ICD) / Defibrillators (AICD)
*Myomectomy (resection of septum)
*Alcohol septal ablation (controlled MI through septal perforator perfusing basal septum) wall thinning decreases in LVOTO
Transplantation
HCM tx: B-blockers
- first-line therapy, clinical improvement >50%
- negative inotropic effect decreases outflow gradient
decreased myocardial demand results in reduced
ischemia
prolonged diastolic filling time results in improved LV
filling as well as improved coronary perfusion - may have an antiarrhythmic effectplease NOTE that in hypertrophic cardiomyopathy, as
opposed to dilated cardiomyopathy, we are using beta-
blockers for their negative inotropic effect
Septal
Myectomy
drip etOH next to septum, part of septum dies, reducing hypertrophy
HCM Course of Illness
Usually, signs and symptoms increase with
age
*Leading cause of death: sudden death in
asymptomatic patients
Restrictive Cardiomyopathy (RCM): Background
*Rare in West: can affect both ventricles
*Systolic function usually normal
especially early in the
disease process
Small ventricular cavity size
Diastolic dysfunction (can’t fill)
Elevated ventricular filling pressures
LA is huge compared to LV; dilates in response to pressure
RCM more background
Hallmark: abnormal diastolic function
Rigid ventricular wall with impaired ventricular filling
Bear some functional resemblance to constrictive pericarditis
Importance lies in its differentiation from operable constrictive pericarditis
Much less common then DCM or HCM outside the tropics, but frequent cause of death in Africa, India, South and Central America and Asia primarily because of the high incidence of endomyocardial fibrosis in those regions
Classification of Restrictive Cardiomyopathy
Myocardial
*Non-infiltrative*: Idiopathic Familial Hypertrophic Scleroderma*
Infiltrative:
Amyloid (most common)
Sarcoid
Gaucher’s
Storage disease:
Hemochromatosis*
Glycogen storage disease
Fabry’s
Endomyocardial: Endomyocardial fibrosis Hypereosinophilic syndrome Carcinoid Metastatic malignancy Radiation Chemotherapy toxicity
Physiology of RCM
Rigid myocardium–>inc. diastolic ventricular pressure–>Venous congestion–>Jugular venous distention
Hepatomegaly
Ascites
Rigid myocardium–>dec. ventricular filling–>dec. CO–>weakness, fatigue
RCM: Clinical Manifestations
Symptoms of right and left heart failure
Jugular Venous Pulse
Echo-Doppler:
Abnormal mitral inflow pattern
Prominent E wave (rapid diastolic filling)
Reduced deceleration time ( LA pressure)
RCM (2): Presentation
- Again: CHF…S3
- EKG: can be normal or nonspecific
- ECHO: to exclude other CHF causes
* thick walls, reduced systolic fxn
* Doppler study: can demonstrate diastolic abnormality - Right heart cath: commonly necessary
- can help with endomyocardial biopsy
Consider RCM in any patient with ??
predominantly R-sided heart failure without evidence of either cardiomegaly or systolic dysfunction
RCM dx
tx??
possibly biopsy
Treatment: CHF therapy (same as DCM)
- No Clear medical therapy
- Treat reversible causes
- Transplant maybe only option
slide 56
overview
Arrhythmogenic RV Cardiomyopathy
Characterized by fibroadipose replacement of segments of the free wall of the right ventricle
(fibrosis of RV causing significant ventricular arrhythmias)
Familial and progressive
Predominately found in young adults
Cause of young adult sudden death
ICD implantation in ALL patients who are symptomatic with arrhythmias
ICD implantation vs anti-arrhythmic meds in asymptomatic patients
FIRST AID
pg 296
amyloidosis
pt has heart failure, EKG is low voltage: amyloid infiltrates decrease e-conduction
FA: dilated cardiomyopathy
Most common cardiomyopathy (90% of cases). Often idiopathic or familial.
ABCCCD:
Other etiologies include chronic Alcohol abuse
wet Beriberi
Coxsackie B virus myocarditis
chronic Cocaine use
Chagas disease
Doxorubicin toxicity, hemochromatosis, sarcoidosis, peripartum cardiomyopathy
FA: DCM findings
HF, S3, systolic regurgitant murmur, dilated heart on echocardiogram, balloon appearance of heart on CXR
FA: DCM tx
Na+ restriction ACE inhibitors β-blockers diuretics digoxin ICD (defibrillator) heart transplant
FA: DCM pathophys
Systolic dysfunction ensues. Eccentric hypertrophy (sarcomeres added in series)
case: HOCM
dx with ECHO:
significant gradients
outflow obstruction
what to do? defibrillator in heart no more competitive sports B-blocker stay hydrated genetic testing for rest of fam monitor every 6 mos may tolerate sx if want to continue competitive sports
FA: HCM
60–70% of cases are familial, autosomal dominant (commonly a β-myosin heavy-chain mutation). Can be associated with Friedreich ataxia. Causes syncope during exercise and may lead to sudden death in young athletes due to ventricular arrhythmia.
FA: HCM findings
S4, systolic murmur. May see mitral regurgitation due to impaired mitral valve closure.
FA: HCM tx
cessation of high-intensity athletics
use of β-blocker or non-dihydropyridine Ca2+ channel blockers (e.g., verapamil)
ICD if patient is high risk.
FA: HCM pathophys
Diastolic dysfunction ensues.
Marked ventricular hypertrophy, often septal
predominance. Myofibrillar disarray and
fibrosis.
Obstructive hypertrophic cardiomyopathy
(subset)—asymmetric septal hypertrophy and systolic anterior motion of mitral valve outflow obstruction dyspnea, possible syncope.
FA: RCM/infiltrative cardiomyopathy major causes
sarcoidosis, amyloidosis, postradiation fibrosis, endocardial fibroelastosis (thick fibroelastic tissue in endocardium
of young children),
Löffler syndrome:(endomyocardial fibrosis with a prominent eosinophilic infiltrate), and hemochromatosis (dilated cardiomyopathy can also occur).
FA: RCM pathophys
Diastolic dysfunction ensues. Can have low- voltage ECG despite thick myocardium (especially amyloid)
