Cardiomyopathy Flashcards
Dilated cardiomyopathy etiology
Most common one. LV dilation and low EF must be present for diagnosis
Most cases are idiopathic but known secondary causes include:
1) alcohol
2) myocarditis
3) postpartum status
4) drugs (doxorubicin, AZT, cocaine)
5) endocrinopathies (thyroid dysfunction, acromegaly, pheochromocytoma)
6) Infection (coxsackie, HIV, Chagas, parasites)
7) Genetic
8) Nutritional (wet beriberi)
Most common causes of secondary dilated cardiomyopathy are ischemia ischemia and HTN**
History and Physical for Dilated cardiomyopathy
Often presents with gradual development of CHF symtpoms
Exam often reveals displacement of LV impulse, JVD, an S3/S4 gallop or mitral/tricuspid regurgitation
S3** (signifies rapid ventricular filling in setting of fluid overload)
Diagnosis of Dilated cardiomyopathy
1) Echo is diagnostic
2) ECG may show nonspecific ST-T changes, a low voltage QRS, sinus tachy and ectopy. LBBB is common
3) CXR shows an enlarged, balloon-like heart and pulmonary congestion
Tx of dilated cardiomyopathy
1) Address underlying cause
2) Treat symptoms of CHF with diuretics, ACEIs/ARBs, and B blockers. Digoxin is second line. AVOID CCBs in HF.
3) Consider anticoagulation to lower thrombus risk if AF or an IV thrombus is present
4) Consider an ICD if EF is below 35%
Dilated cardiomyopathy basic characteristics
1) Major abnormality = impaired contractility
2) LV cavity size (end diastolic) = much increased
3) LV cavity size (end systolic) = Much increased
4) EF greatly reduced
5) Wall thickness is reduced, but variable
Hypertrophic cardiomyopathy basic characteristics
1) Major abnormality = impaired relaxation
2) LV cavity size (end diastolic) = Reduced
3) LV cavity size (end systolic) = Much reduced
4) EF is high or normal
5) Wall thickness is much increased
Restrictive cardiomyopathy basic characteristics
1) Major abnormality = impaired elasticity
2) LV cavity size (end diastolic) = Increased
3) LV cavity size (end systolic) = Increased
4) EF is low or normal
5) Wall thickness is increased but variable
Woman with HTN and prior MI has an exam notable for a displaced PMI, an S3, a nonelevated JVP and bibasilar rales. Next best step in dx?
This patient has evidence of dilated cardiomyopathy
An Echo is the best next step
What is the most common cause of death in young athletes in the US?
HOCM
What does an S4 gallop tell us?
Stiff, noncompliant ventricle and increased “atrial kick” and may be linked to hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy
Impaired LV relaxation and filling (nonsystolic dysfunction) due to thickened ventricular walls. Hypertrophy frequently involves the IV septum, leading to LV outflow obstruction and impaired ejection of blood
Congenital form is HOCM (hypertrophic obstructive cardiomyopathy) - inherited as autosomal dominant trait in 50% of HOCM patients
Other causes of marked hypertrophy include HTN and aortic stenosis
History and physical in hypertrophic cardiomyopathy
1) Patients may be asymptomatic but may also present with syncope, dyspnea, palpitations, angina or sudden cardiac death
2) Exam often reveals a sustained apical impulse, an S4 gallop, and a systolic ejection crescendo-decrescendo murmur that increases with reduced preload (Valsalva, standing) and decreases with increased preload (passive leg raise)
Diagnosis of hypertrophic cardiomyopathy
1) Echo is diagnostic and shows an asymmetrically thickened septum and dynamic obstruction of blood flow
2) ECG may show signs of LVH
3) CXR may reveal LA enlargement secondary to mitral regurg
Tx of hypertrophic cardiomyopathy
1) B-blockers are initial therapy for symptomatic relief; CCBs are second line agents
2) Surgical options for HOCM include dual-chamber pacing, partial excision or alcohol ablation of the myocardial septum, ICD placement, and mitral valve replacement
3) Patients should avoid intense athletic competition and training
Restrictive cardiomyopathy
Defined as reduced elasticity of myocardium leading to impaired diastolic filling without significant systolic dysfunction (normal or near normal EF). It is caused by infiltrative disease (amyloidosis, sarcoidosis, hemochromatosis) or by scarring and fibrosis (secondary to radiation)