Cardiomyopathy Flashcards
Disorders characterized by morphologically and functionally abnormal myocardium in the absence of any other disease that is sufficient, by itself, to cause the observed phenotype
Cardiomyopathy
Excludes cardiac dysfunction caused by structural heart disease: CAD, primary valve disease, HTN
Cardiomyopathy involves which part of the heart and causes dysfunction of systole, diastole, or both?
LV
diagnostic modalities of Cardiomyopathy include:
- echo
- nuclear imaging
- coronary angiography w/ L ventriculography
- Cardiac MRI
resulting dysfunction can be transient or permanent
how does Systolic dysfunction happen?
decrease in myocardial contractility nd reduction in LVEF
Eventually fails and HF develops
what Compensatory mechanisms in systolic dysfunction aim to maintain cardiac output:
- LV enlargement resulting in higher stroke volume
- Frank-Starling relationship (↑stretch = ↑contractility)
how does Diastolic dysfunction happen?
cardiac dysfunction d/t abnormal LV relaxation and filling
Accompanied by elevated filling pressures
T/F: diastolic dysfunction can happen with or w/o systolic dysfunction
T
Always present if systolic dysfunction occurs
Why is diastolic dysfunction often underestimeated/missed?
more difficult to quantify on echo
An inflammatory, infiltrative process involving the myocardium caused by infectious and noninfectious conditions
Myocarditis
May be acute, subacute, or chronic
what can Myocarditis lead to?
- necrosis and/or degeneration of myocytes
- myocardial dysfunction and dilated cardiomyopathy
Pathogenesis of Myocarditis
Varies depending on the underlying cause (which is often undetermined)
- Host-mediated: direct cytotoxic effect of the causative agent
- Autoimmune-mediated: secondary immune response
Myocardial damage occurs in 2 main phases:
- Acute phase:
- First 2 weeks
- Myocyte death is a direct result of the causative agent, leading to cell-mediated cell toxicity - Chronic phase:
- After 2 weeks
- A result of an inappropriate, overactive immune response
what are the MC infectious causes of myocarditis
- adenovirus
- coxsackie B virus
- cytomegalovirus
- COVID
what are the MC cardiotoxin causes of myocarditis
- alcohol
- anthracyclines
- cocaine
Epidemiology of Myocarditis
- Frequency is poorly defined d/t variability of clinical presentation
- MC 20-50 y/o
- Men have a slightly higher mortality rate
myocarditis presentation
- days-weeks after acute febrile illness / respiratory infection - No known underlying cardiac pathology
- SOB, pleural/pericardial chest pain, +/- fever, chills—Could also present with HF
- gradual or abrupt with decreased cardiac output, shock, and severely depressed LV systolic function
- Palpitations, syncope, or sudden death may also occur d/t arrhythmias
PE of myocarditis
- pericardial friction rub, tachycardia, S3 or S4, murmur of mitral or tricuspid regurg if ventricular dilation is severe
- HF → volume overload
initial testing for myocarditis
- EKG → sinus tachycardia, dysrhythmias, ventricular ectopy (PVCs), ST-T changes
- Cardiac biomarkers → elevated troponin levels common (esp. in rapid onset myocarditis)
- CXR → typically nonspecific, but may see cardiomegaly, pulmonary edema, pleural effusion
other testing for myocarditis (not initial)
- Labs: CRP, ESR (elevated), CBC (eosinophilia), +/- rheumatologic workup, serum viral antibody titers, BNP (in setting of HF)
- TTE: critical!
- cardiac MRI (CMR)
- suggests myocarditis, but sensitivity and specificity are limited and time-dependent
what testing allows visualization of the myocardium, assessment of ventricular function, helps r/o / assess other pathology (regurg)
TTE
what testing helps assess extent of inflammation, myocyte necrosis and scarring, ventricular size / shape changes, wall motion abnormalities, and pericardial effusion
cardiac MRI (CMR)
Endomyocardial biopsy (EMB) should only be obtained if ?
there is a high probability that results will change patient management
tx for infectious myocarditis
- Consult Cardiology!
- tx directed toward presentation
- LVEF <40% → ACE-I, BB
- NSAIDs (possibly Colchicine) for myopericardial CP
- Arrhythmia management
- Trials using immunosuppressive therapies, corticosteroids, IVIG, and antivirals have not shown benefit
noninfectious myocarditis MCC by?
medications, illicit drugs, and toxic substances
Majority of cardiomyopathies are what type?
dilated
what is the #1 reason for heart transplant
dilated cardiomyopathy
dilated cardiomyopathy is MC in what race/ethnicity
Black pts
3x than white pts
Once sx of dilated cardiomyopathy manifest, mortality is ?% at 5 years
50%
dilated cardiomyopathy is characterized by?
- dilation and impaired contraction of one or both ventricles, predominantly the LV
- Defined by LVEF <40% w/o CAD or valvular disease
causes of dilated cardiomyopathy
idiopathic
- Excessive alcohol consumption
- Infectious
- Genetic
- Systemic Disorders
- Peripartum
- Endocrinopathies
- Tachycardia induced
- Arrhythmia associated
infectious causes of dilated cardiomyopathy
- Viral - Parvo B19, herpes, coxsackievirus, influenza, adenovirus, CMV, HIV
- Bacterial - TB, Meningococcal, Pneumococcal
- Chagas Disease
- Caused by protozoan infection, Trypanosoma cruzi
- Leading cause of DCM in Central and South America - Lyme Disease
- Usually manifests as conduction abnormality
- May cause myocardial dysfunction due to myocarditis
Systemic Disorders that cause dilated cardiomyopathy
Sarcoidosis, SLE, Celiac, Scleroderma, RA
how do genetics cause dilated cardiomyopathy?
- Autosomal dominant predominantly
- Involve antibodies to a variety of cardiac proteins
- Inherited syndromes, such as muscular dystrophies, hemochromatosis, thalassemias
Endocrine Disorders that cause dilated cardiomyopathy
Thyroid dysfunction, pheochromocytoma, Cushing’s or GH excess or deficiency
Arrhythmia Associated that cause dilated cardiomyopathy
PVC-mediated (>15% burden)
RV-paced rhythm
how does Peripartum CM cause dilated cardiomyopathy?
- Rare cause
- Unclear etiology
- Occurs late in pregnancy or early postpartum
- Presents as CHF or SCA
- Typically normalizes after 2 to 3 months of therapy
how does Tachycardia cause dilated cardiomyopathy?
- Afib, SVT, AVNRT
- HR correlates with LV dysfunction
- Causes reduced myocyte contractility
- LV dysfunction can occur without dilatation
DCM etiology mnemonic
ABCCCD - a bunch (of stuff) can cause cardiac dilation
- alcohol abuse
- beriberi (wet)
- coxsackie B myocarditis
- chronic cocaine use
- chagas’ disease
- doxorubicin toxicity
presentation of dilated cardiomyopathy
- Gradual HF development
- PE: rales, elevated JVP, S3 gallop, murmur of mitral or tricuspid regurg, peripheral edema, ascites - Arrhythmias
- Tachycardia, pulsus alternans, LBBB - Sudden death possible
how to diagnose DCM
- If dyspnea is present, BNP or NT-proBNP are necessary to determine prognosis and disease severity
-
Echo
- Excludes valvular disease and confirms ventricular dilation, reduced LV systolic function (and RV systolic dysfunction if applicable), or pulmonary HTN - Possibly radionuclide ventriculography (MUGA), cardiac MRI
tx for DCM
- Treat underlying source if known, which commonly resolves LV dysfunction
- CHF management
- Prevention of SCA
- Heart transplant
- Characterized by nondilated ventricle with impaired filling
- Caused fibrosis/infiltration of the ventricular wall
- Causes diastolic dysfunction
- Ventricles predominantly non-hypertrophied on echo, with moderate to severe biatrial enlargement
what type of cardiomyopathy?
Restrictive Cardiomyopathy (RCM)
causes of restrictive cardiomyopathy
- Infiltrative disorders
- Amyloidosis, sarcoidosis, fatty infiltration - Storage diseases
- Hemochromatosis, Fabry disease - Radiation, chemo, carcinoid heart disease, hypereosinophilic syndrome
how to diagnose RCM
Echo or cardiac MRI will assist in diagnosis
Endomyocardial biopsy may be considered
tx for RCM
Treat underlying cause if known
Reduce pulmonary and systemic congestion
with diuretics
- Caused by mutations of sarcomere genes; genetic disposition
- Characterized by LV hypertrophy
which cardiomyopathy is this?
hypertrophic cardiomyopathy
what parts of the heart are involved in hypertrophic cardiomyopathy?
- Occasionally RV involved
- NOT caused by pathologic loading conditions, such as HTN and valvular disease (AS)
- Interventricular septum is MC involved
- Leads to diastolic dysfunction
Hypertrophic Cardiomyopathy
may lead to ?
LV outflow obstruction, myocardial ischemia and/or mitral regurgitation
pt presents with
- Fatigue, chest pain, CHF, syncope, SCA
- Carotid pulsus bisferiens d/t mimicked aortic stenosis
- Mid-systolic, harsh, 3rd and 4th ICS, louder with valsalva, quieter with squatting
what does this pt have?
Hypertrophic Cardiomyopathy
Increased risk for arrhythmias (afib, SVT, and VT/VF) and SCA
diagnostics for Hypertrophic Cardiomyopathy
- EKG may demonstrate LVH pattern
- Echo is the diagnostic modality of choice
— LV wall >1.5 cm thick
management for Hypertrophic Cardiomyopathy
- Avoid volume depletion
- Activity restriction
- BB or Verapamil (helps relax contractility)
- Avoid diuretics and vasodilators - Septal myectomy or alcohol septal ablation
- Screening of 1st degree relatives
- Annual echo until age 20 and then Q5 yrs
Most common cause of HF in the U.S
Ischemic Cardiomyopathy
Results from death/damage/hibernation of myocardium d/t reduced O₂
Ischemic Cardiomyopathy is typically results from what condition, but can be from any source of ischemia?
CAD
Cocaine, vasospasm, thrombus
what type of cardiomyopathy
- Characterized by systolic dysfunction - Can be transient or permanent
- Predominantly affects LV, but can involve the RV or both ventricles
- CHF (edema, dyspnea, JVD)
Ischemic Cardiomyopathy
diagnostics for Ischemic Cardiomyopathy
- Possible Q waves on EKG
- CXR - pulmonary edema
- Echo → decreased LVEF, regional wall motion abnormality
- Coronary angiography recommended, esp LV dysfunction cause unknown
management for Ischemic Cardiomyopathy
- Revascularization (PCI or CABG)! For acute ischemia/infarction
- Consider nuclear viability study to determine if myocardial dysfunction is due to scarring or hibernating myocardium
- CHF management
-
Prevention of SCA:
- External wearable defibrillator
- Implanted cardioverter - defibrillator - Cardiac rehab
- Characterized by ventricular arrhythmias and a specific myocardial pathology
- RV free wall myocardium is replaced by fibrous/fatty tissue, producing RV dilation –> RV function abnormal
what type of cardiomyopathy?
Arrhythmogenic Right Ventricular Cardiomyopathy
young adults; More prevalent in Europe; rare in US
presentation and management for Arrhythmogenic Right Ventricular Cardiomyopathy
- chest pain, palpitations, syncope, SCA
- Diagnose w/ echo and cardiac MRI
- Management
- Manage systemic congestion with diuretics
- Manage ventricular arrhythmias with antiarrhythmics, ablation or ICD
- Rare congenital cardiomyopathy; 0.05% of echoes
- Altered myocardial wall due to intrauterine
arrest of compaction of the loose interwoven meshwork
what type of cardiomyopathy?
Left Ventricular Noncompaction
presentation and tx for Left Ventricular Noncompaction
- Presentation: CHF, thromboembolism, and ventricular arrhythmias occur
- dx: Cardiac MRI
- tx: cardiac transplant
- Causes an ACS (even STEMI) in the absence of critical CAD, due to a high catecholamine surge
- A result of intense psychological or physical stress
- Primarily occurs in postmenopausal women
what type of cardiomyopathy
Stress-Induced Cardiomyopathy
AKA broken heart syndrome and Takotsubo cardiomyopathy
dx and tx Stress-Induced Cardiomyopathy
- dx: LV apical ballooning on echo or LV angiography (systolic dysfunction of the apex and/or mid segments)
- tx: Almost all recover in a few wks
— BB at least 1 yr
