Cardiomyopathies Flashcards
Types of cardiomyopathy
Dilated, hypertrophic, and restrictive cardiomyopathy
Most common type of cardiomyopathy
DCM
What is DCM characterized by?
Ventricular contraction is reduced (contractile dysfunction), left ventricle dilation. RV may also be dilated.
African American male, aged 40 years old presents with symptoms of low output HF including dyspnea upon exertion, orthopnea, S3 heart sound, peripheral edema. Also has conduction disturbance. Diagnosis?
DCM
Etiologies of DCM
Idiopathic, Ischemic, Stress-induced, infectious, genetic, LV non-compaction, peripartum, toxic causes, inflammatory diseases
Infectious causes of DCM
Viral, HIV, Chagas, and Lyme disease
Toxic causes of DCM
Alcohol, cocaine, meds, trace elements
Stress-induced DCM aka
Broken heart syndrome, Transient left ventricular apical ballooning, and Takotsubo Cardiomyopathy
What is stress induced DCM triggered by
Acute medical illness or intense emotional or physical stress
What is the most common cause of myocarditis?
Viral DCM
What organisms are associated with causing viral DCM?
Parovirus B19, human herpesvirus 6, influenza virus, adenovirus, echovirus, ctyamegalovirus, HIV, cosackieirus
What is the leading cause of DCM in Central and South America?
Chagas Disease
Chagas disease occurs due to..
protozoan infection due to Trypanosoma cruzi
Of Lyme Disease and Chagas disease, which one is more chronic vs. self limited and mild?
Chagas- chronic symptoms. Lyme- self limited and mild
What kind of abnormality is present in Lyme disease?
Usually manifests as a conduction abnormality in which the cardiac muscle is dysfunctional.
Mode of inheritance in DCM
Autosomal dominant usually. Autosomal recessive, X-linked, mitochondrial inheritance have also been described.
Autoimmune cause of DCM in…..
30% of patients
Left-ventricular Non-compaction aka
Isolated Ventricular Non-Compaction, Left Ventricular Hypertrabeculation, Spongy Myocardium
How might alcohol cause DCM?
Alcohol causes oxygen free radical damage and defects in cardiac protein synthesis which is toxic to cardiac myocytes
What are the mechanisms by which cocaine might cause DCM?
Direct toxic effect, cocaine-induced hyperadrenergic state, and parenteral cocaine abusers- might cause infection
How might trace elements cause DCM?
Accumulation of cobalt, arsenic or deficiency of selenium
Which DCM related etiology is associated with pregnancy?
Peripartum- occurs late pregnancy and early postpartum. 4 criteria- hx failure in last month of pregnancy or within 5 months of delivery, absence of other identifiable cause of HF, absence of recognizable heart disease prior to last, and LV systolic dysfunction less than 45% ejection fraction
How does Angiotensin II affect preload and afterload?
Causes aldosterone secretion which causes increased preload, and constriction of vascular smooth muscle which causes increased afterload
What is the gold standard for DCM?
Endomyocardial biopsy
Diagnosis of DCM
Elevated cardiac markers, serological tests for viral, parasitic etiologies, markers of inflammation, Echocardiography, endomyocardial biopsy, cardiac cathetirization-r/o ischemic disease, and nuclear and magnetic resonance imaging
Management of DCM
Education, Meds include ACE-Inhibitors, Aldosterone inhibitors, anticoagulation, BB, and Diuretic Therapy, and mechanical- implantable cardiac defibrillator or biventricular pacemaker
How often should first degree relatives of DCM patients be screened?
every 3-5 years
Cardinal feature of HCM
Myocyte-myofibril disarray
Hypertrophic cardiomyopathy aka
I-HAM. Idiopathic hypertrophic subaortic stenosis, Hypertrophic obstructive cardiomyopathy, Asymmetric septal hypertrophy, and Muscular subaortic stenosis
Dyspnea, atrial fibrillation, and HTN. Patient presents with massive asymmetric hypertrophy, diastolic left ventricular dysfunction, small internal diamteter of left ventricle. S2 split due to aortic valve closing early, harsh crescendo systolic murmur. Aortic outflow obstruction and MR present. SAM also present. What do you suspect?
HCM
Pattern of LVH in HCM
TYpe I- classic septal hypertrophy (Anterior segment of the ventricular septum). Type II- Hypertrophy of anterior and posterior segments of the septum. Type III- extensive thickening. Type IV- Isolated apical hypertrophy.
HOCM
Hypertrophic Obstructive Cardiomyopathy- HCM with SAM- Hypertrophic Cardiomyopathy with systolic anterior motion of the mitral valve
Three ages of presentation in this disorder- adolescents, like young athletes wtih syncope during athletic event No PE abnormalities. Also ages 40 and 60.
HCM
DDX of hypertrophic Cardiomyopathy
Hypertensive heart disease- hypertrophy pattern is different, and valvular heart disease
Clinical presentation of HCM
Dyspnea, effort-related chest discomfort, syncope, sudden cardiac death, atrial fibrillatin, hypertension
Imaging study of choice for diagnosis of HCM
Echocardiography
Diagnosis of HCM
Electrocardiography, Cardiac catheterization, echocardiography- LV hypertrophy, LA enlargement, mitral regurgitation, septal hypertrophy
Types of HCM Tx
Avoidance of volume depletion, activity restriction, Meds, Mechanical and surgical
Why do you want to avoid volume depletion in HCM?
Tends to decrease SV, and increases the left ventricular outflow gradient. May lead to hypotension, lightheadedness, or syncope
Meds in Tx of HCM
BB (decreases chronotropy and inotropy), Calcium Antagonists (Improves diastolic filling, decreases chronotropy), Anti-arrythmic drugs
Most commonly used CCB in HCM
Verapamil
Most commonly used anti-arrythmic drug in HCM
Amiodarone
Mechanical tx in HCM
Implantable Cardioverter Defibrillator Therapy to prevent sudden cardiac death
Surgical tx of HCM
Alcohol ablation of the septum, myectomy, and heart transplant
HCM may be caused by mutations such as-
encoding proteins of the cardiac sarcomere- MYH7 (Beta myosin heavy chain), MYBPC3 (cardiac myosin-binding protein C), TNNT2 (Cardiac troponin T)
Least common CM outside of tropic area
Restrictive CM
What are RCM characterized by?
Walls of ventricles become stiff, but not necessarily thickened. They are non-dilated, with impaired ventricular filling. Also, bi-atrial enlargement. Normal systolic function.
RCM general classification
Secondary restrictive physiology, nonfiltrative, infiltrative, storage diseases, endomyocardial disease, radiation/drug toxicity
Noninfiltrative causes of RCM
Idiopathic, familial, hypertrophic, and diabetic
Infiltrative causes of RCM
Amyloidosis, Sarcoidosis, Fatty infiltration, Gaucher disease, and Hurler Syndrome
Storage disease causes of RCM
Hemochromatosis, Fabry Disease, GLycogen Storage disease
Endomyocardial disease causes of RCM
Endomyocardial fibrosis and hypereosinophilic syndrome, Churg-Strauss Syndrome, radiation, and toxic drugs
What age group is more affected by Idiopathic RCM?
older adults
Test of choice for amyloidosis RCM?
Echocardiography
What toxic drugs may cause RCM?
Methysergin (Vascular headaches), Ergotamine (Migraine headaches)
Diagnosis of RCM
Labs, CXR- enlarged RV, EKG- RV hypertrophy, atrial arrhythmias, echo- ventricular doppler filling patterns, cardiac catheterization
Gold standard to diagnose RCM
Cardiac catheterization- R and L heart pressure during inspiration and endomyocardial biopsy
Tx for RCM
To slow heart rate- BB
To control atrial fibrillation- antiarryhthmics, and anticoagulation
To improve diastolic relaxation- CCB, BB, ACE-I
Diuretics, spironolactone, control systemic BP, avoid digitalis
Cardiac Transplantation
Patient presents with fatigue and weakness, pulmonary hypertension, dyspnea, peripheral edema, ascites, arrhythmias. Echo reveals that ventricles are not dilated, but the atria are enlarged. There is a diastolic filling problem in the ventricles due to the rigid walls, leading to decreased preload and EDV. What do you suspect?
RCM
Ground glass appearance on echo would make you suspect what cause for Restrictive CM?
Amyloidosis RCM
Patient comes in with dyspnea, atrial fibrillation, and HTN. He is a young athletic patient that had a syncopal episode. ECG shows you LV hypertrophy, echo shows you abnormal systolic anterior leaflet motion of the mitral valve which is causing obstruction of blood from the LV to aorta. So you have aortic outflow obstruction and also MR. You are suspicious of HCM. What maneuvers could you do in the office to help with your diagnosis?
Decrease volume in LV would cause increased obsturction–>increased murmur intensity. Decreased venous return to heart caused by upright position to sitting, squatting, supine position, valsalva, nitroglycerin or other vasodilator. To decrease intensity, increase volume in LV by going from standing to squatting, handgrip, after passive elevation of legs.
Are ACE-I or diuretics indicated in HCM patients?
NO. AVOID volume depletion! Already have decreased volumes in LV due to hypertrophy. Stick to BB, CCB, and anti-arrhythmia drugs in tx of HTN
HCM patient in ER who is at risk of sudden cardiac death most likely due to…
abnormal arrhythmai- often degenerate into VF (atrial arrhythmia, SVT, WPW syndrome). That’s why often treated wtih amiodarone (along with BB and CCB)
Which cardiomyopathy cause diastolic vs. systolic problem?
HCM and RCM- diastolic filling problem. DCM- systolic contraction problem
Which sides of the heart are most effected in CM?
DCM and HCM- left side of heart. RCM- right side more affected
