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