Cardiomyopathy Flashcards
gold standard to determine physical properties vetnricles
cardiac magnetic resonance image (CMR)
Genetics ARVD/C
- autosomal dominant
(rare from recessive in families from Greece) - most common in individuals < 35
two most common types cardiomyopathy
- familial hypertrophic cardiomyopathy (HMC)
2. arrhythmogenic R ventricular dysplasia/cardiomyopathy (ARVD/C)
Heard sounds possible observable in ARVD/C
- s4
- wide split s2
- s3
- s4
* major clue to dx
category of cardiomyopathy
based on pathological features of heart tissue
Signs ARVD/C
arrhythmias
syncope
chest pain
palpitations
sudden cardiac death (second leading cause behind MHC)
Genetic testing HCM
- identify mutation in proband (pt starting point for genetic testing, i.e. first in family diagnosed)
- test at risk relatives
- mutation status CANNOT determine
- age of onset
- severity of symptoms - mutation status CAN
- determine who is at risk and who needs close surveillance
Genetic testing ARVD/C
- 8 genes known to be assoc.
- testing for at risk individuals routinely performed once mutation is identified in proband
- 1st degree relative family members of proband should undergo initial screening with the onset of puberty and follow up exams every 2-3 years
Leading cause of death in young athletes
HMC
-can be asymptomatic until sudden death
Management ARVD/C
same as HCM
Goal: prevent arrhythmias, syncope, sudden cardiac death
- pharm
- anti-coagulant
- implantable defibrillator
- avoid endurance training
- heart transplant
S4 heart sound
can be heard in HMC and sometime in ARVD/C
- low pitched sound immediately before S1
- S1= lub (closing AV valves)
- (S2=dub, closing semilunar valves) - S4 caused by stiffening of the walls of ventricles
- blood flow turbulent as atria contract to force blood into ventricle
screening HCM
- electrocardiogram
- echocardiogram
- cardiac magnetic resonance imaging (CMR(
- gold standard to determine physical properties of L ventricular wall
Diagnosis HMC
difficult
- personal and family hx
- fatigue, arrhythmias, palpitations, presyncope, syncope, chest pain
- any of these in someone < 35 - family hx of sudden cardiac death, or unexplained death in 1st degree relative
- family hx of heart failure, hypertrophic cardiomyopathy, heart transplant, stroke, blood clots
Genetics HMC
- autosomal dominant
- over 20 genes involved, genes that encode sarcomere proteins
- MYH7, MYBPC3, TNNT2, TNNI3 involved 1
Clinically observable phases in ARVD/C
- concealed phase
- Symptomatic arryhtmias
- R ventricular failure
- complete pump failure
- left ventricular involved can occur in any one of these phases
- sudden cardiac death can occur in any one phase
Arrythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C)
- replacement of normal heart muscle in R ventricle by fibrous, fatty tissue
- weakened muscle, impaired contractibility
Dx ARVD/C components
- assesss structural alterations
- level of heart dysfunction
- tissue characterization
- family hx
PE ARVD/D
- normal in 50%
- EXTRA HEART SOUND
- S4
- Wide-plit S2
- presence S3 or S4 - characteristic ECG in 90% affected pt.
- dilation R ventricle can cause asymmetry in chest wall
- male, normally btwn. 19-40
Defining characteristic HMC
- a portion (usually L ventricle) if hypertrophied
- functional impairment of cardiac muscle
Second leading cause sudden cardiac death
ARVD/C
Genes involved in HMC
over 20 genes discovered, most common are
- MYH7
- MYBPC3
- TNNT2
- TNNI3
^genes encoding sarcomere proteins
*some mutations are more malignant than others
Tx/Management HCM
Primary goal: prevent arrhythmia, syncope, and sudden cardiac death
- pharmacologic therapy
- implantable defibrillators
- anti-coagulants to prevent thromboembolism if in afib
- avoid endurance training
- heart transplant
6 suspecting signs HMC
- fatigue
- heart palpitations
- presyncope
- syncope
- chest pain
- S4 heart sound**
cardiomyopathy
def: condition where there is dysfunction of the heart muscle
- increased risk for arrhythmia and sudden cardiac death
Sarcomere
basic unit of muscle
