Cardiomyopathy, EKG Flashcards
What is the standard (old) classification system for cardiomyopathies?
- Dilated Cardiomyopathy (DCM)
- Hypertrophic Cardiomyopathy (HCM)
- Restrictive Cardiomyopathy (RCM)
- Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D)
What is the newer classification system of Cardiomyopathies?
Differentiates cases in which myocardial pathology occurs:
- Primary cardiomyopathy - in isolation from extracardiac illness
- Secondary Cardiomyopathy - occurs as a manifestation of a generalized, multisystem disorder
What are the subcategories of the newer cardiomyopathy classification system?
- Genetic
- Mixed
- Acquired
What are two distinct but similar disorders characterized by RCM as a consequence of dense endocardial scarring with associated thrombus formation, commonly resulting in reduction in ventricular cavity size?
- Endomyocardial fibrosis (Davies disease)
- Loeffler endocarditis
What is the most common phenotypic expression of cardiomyopathy?
- Dilated Cardiomyopathy (DCM)
- wide variety of primary and secondry processes affecting the myocardium
What are the pathologic findings in DCM?
- four-chamber cardiac enlargement (usually)
- histologic evidence
- myocyte hypertrophy
- interstitial fibrosis
What percentage of DCM are interited?
What is crucial in identifyig these etiologies?
- 20-35%
- detailed family history
When does endomyocardial biopsy have the highest yield?
- DCM
- fulminant presentations with rapidly progressive HF or significant electrical instability
- RCM
What precentage of DCM cases are classified as idiopathic/undiagnosed?
50%
What is the most common secondary cause of cardiomyopathy in the developing world?
Chronic overuse of alcohol
What are the pathophysiologic effects of acute cocaine intoxication leading to DCM?
- abrupt catecholamine surges
- severe hypertension
- increases in LV afterload and wall stress
What are the pathophysiologic effects of chronic cocaine intoxication that can lead to DCM?
- Chronic-cocaine related catecholamine stimulation
- alterations in G protein-related signaling (similar to pheochromocytoma) –> LV dysfunction
- Procoagulant effects + coronary vasospasm –> ischemic myocardial injury or infarction (even in the absence of coronary atherosclerosis)
What chemotherapeutic medications (class) are particularly associated with DCM?
Anthracyclines (doxorubicin, daunorubicin)
Who is at greatest risk for developing DCM from anthracyclines?
- High-dose (cumulative dose > 550 mg/m2
- extremes of age
- adjuvant radiation or comcomitant treatment with nonanthracyclines
- taxanes (paclitaxel and docetaxel)
- human epidermal growth factor receptor-2 (HER-2) antagonist (trastuzumab)
What are the recommendations/guidelines for chemotherapy induced LV dysfunction?
ACE and BB in all patient’s with reduced EF to prevent development of symptomatic HF
What trial demonstrated attenuated declines in LV systolic dysfunction and enhanced clinical outcomes in patients with hematologic malignancies receiving anthracycline-based therapy?
What medications were administered in the trial?
- OVERCOME (preventiOn of left Ventricular dysfunction with Enalapril and caRvedilol in patients submitted to intensive ChemOtherapy for the treatment of Malignant hEmopathies) trial
- Carvedilol and Enalapril
X-linked DCM leads to an absence or severe reduction of this?
dystrophin (protein found in skeletal muscle)
Mutations in genes for dystrophyin production are associated with these disease processes?
- X-linked DCM
- Muscular dysrophies (commonly complicated by DCM)
- Duchenne
- Becker
- X-linked cardioskeletal myopathy associated with mitochondrial dysfunction and cyclic neutorpenia
- typically present in male infants with HF
- mutation in the gene tafazzin encoding an acyltransferase
Barth Syndrome
Mutations in the gene tafazzin (enconding acyltransferases) can lead to these cardiomyopathies with associated arrhythmias and risk of sudden cardiac death?
- Barth Syndrome
- DCM
- Endocardial fibroelastosis
- LV noncompaction (LVNC)
Define a normal P wave on EKG?
- normal axis: 0-75 degress
- upright in leads I and II
Define a normal PR interval on EKG?
PR interval (120-200ms)
Define a normal QRS on EKG?
QRS complex (normal axis: -30 to 105 degrees; duration < 120ms)
Define a normal ST-segment on EKG?
ST segment (usually isoelectric with less than 1mm of elevation/depression in limb leads)
Define normal T waves on EKG?
T wave (upright in I, II, V3-V6) and normal configuration and duration
Define sinus arrhythmia on EKG?
- normal P wave axis (0-75 degrees; upright in leads I and II)
- P-P interval varies by > 10% or 0.16s
- Sinus arrhythmia
- LVH
- Acute pericarditis
- Sinus rhythm
- AV junctional rhythm/tachycardia
- PVC’s
- 3rd degree AV block
- Inferior MI
- Sinus arrhythmia
- Anterior or anteroseptal, age recent or probably acute
Define anterior or anteroseptal age recent or probably acute MI?
- Pathological Q waves
- must be greater than or equal to 30ms wide and 0.1mV deep in amplitude or QS complex) in anterior (V3-V4) or anteroseptal (V1-V3) leads; Q wave width may only be 20ms wide in V2-V3
- Evidence of acute or evolving myocardial injury
- ST elevation in two contiguous leads greater than or equal to 2 mm in men or 1.5mm in women in V2-V3 and/or 1 mm in other anterior or anteroseptal leads)
What is the ECG criteria for LAFB?
- LAD (-45 to - 90 degrees)
- Small q waves and big R waves ( = qR complexes) in I and aVL
- Small r waves and big S waves in ( = rS complexes) in II, III, aVF
- QRS duration normal or slightly prolonged (80-110ms)
- Prolonged R wave peak time in aVL > 45 ms
- Increased QRS voltage in limb leads
What is the DDx for dynamic LVOT obstruction?
- HCM
- Amyloidosis
- Hypertensive heart disease
- Apical and mid-LV infarction
- Reduced LV chamber size
