cardiomyopathy Flashcards
what is cardiomyopathy
an abnormality of heart function secondary to changes in the structure of the heart muscle
- can result in no symptoms, mild, moderate, or severe symptoms of heart failure
what are the three types of cardiomyopathy
- dilated
- hypertrophic
- restrictive
what is the leading cause of “congestive heart failure”
dilated cardiomyopathy
does ventricular dysfunction caused by coronary disease (ischemic cardiomyopathy) fall under cardiomyopathy
No, may look the same, but has a different cause
name some causes of dilated cardiomyopathy
- ideiopathic
- infectious - cocksackie, adenovirus
- alcoholism
- uncontrolled tachycardia
- chemotherapy
- cocaine
- peripartum/post-partum (3rd trimester-6 months post)
what are the diagnostic criteria for idiopathic dilated cardiomyopathy
- EF < 45% or FS (fractional shortening) <25%
- LVEDD (end diastolic dimension) > 117% of predicted
make sure idiopathic: always ask about alcohol and cocaine use
define idiopathic cardiomyopathy
- disease of unknown etiology that principally affects myocardium
-
LV dilated and systolic dysfunction
- increased heart size and weight
- ventricular dilation, usually normal wall thickness
- can be post-viral or unknown genetic
what patient population is most affected by idiopathic cardiomyopathy
- blacks: whites 2:1
- men:women 3:1
alcoholic cardiomyopathy accounts for what percentage of clinical DCM
1/3
what is the risk for SVT in patients who drink > 6 drinks/day
2.6x
peripartum cardiomyopathy affects what patient population the most
- twin pregnancies
- multiparas: women who has given birth 2 or more times
- > 30 y.o
- african american
*subsequent pregnancies discouraged
what are the non-pharmalogical treatment recommendations for dilated cardiomyopathy
- limit activity based on functional status
- salt restriction of 2 g (Na+) or 5g NaCl
- fluid restriction for significantly low Na+ levels
what is the primary pharmacological treatment option for dilated cardiomyopathy
- ACE inhibitors
- reduce afterload by vasodilation, BP reduction
- underdosing is common error
- most start with Captopril (50 mg/d in 3 divided doses)
- Diuretics
- watch K+ levels
what are some other pharmalogical treatment options you can give a patient with dilated cardiomyopathy
- Digoxin: inotropic agent
- B-blockers: if symptoms persist
- anticoagulation for EF < 30%, h/o clots
- antiarrhythmics
Putting it all together, what medication treatment should a patient with dilated cardiomyopathy put on when they are discharged home? (compensated DCM)
- ACE -I afterload reduction
- diuretics
- B-blockers: reduce contractility
What is the purpose of putting someone with dilated cardiomyopathy on a beta blocker?
- in heart failure, there is massive catecholamine release and constant stimulation of heart -> causes B-receptor desentisization
- B-receptor blockers enable B-receptors to recover and let them become more efficient
- may help prevent cardiac remodeling
What are the only two B-blockers approved for treatment of chronic compensated heart failure
Metroprolol and Carvedilol
what is the treatment for uncompensated dilated cardiomyopathy
- inotropes
- diuretics
- ACE-I
- mechanical support
- transplantation
Patients with dilated cardiomyopathy are are increased risk for ventricular arrhythmias and sudden cardiac death. Patients who have a LVEF < 30% can be considered for what medical treatment
- cardiac defibrillator
*regardless of symptom status
patients with LVEF < 35%, BBB (QRS >0.12 s) and persistant heart failure sypmtoms may benefit from
cardiac resynchronization therapy via a biventricular pacemaker
what is hypertrophic cardiomyopathy
disease of cardiac muscle characterized by severe myocardial hypertrophy, in absence of a cause for secondary hypertrophy
- LV is hypercontractile and during systole ejects all of its blood, with high wall stress
- small LV cavity
hypertrophic cardiomyopathy is familial, and inherited in 60% of cases, what is the genetic trait
- autosomal dominant
symptoms of hypertrophic cardiomyopathy are similar to what other cardiac condition
- vavlular Aortic stenosis
- symptoms: dyspnea, syncope, angina, palpitations
how is murmur in hypertrophic cardiomyopathy differ from vavular AS?
- murmur is similar but LOUDER if patient STANDS or VALSALVAS
treatment for hypertrophic cardiomyopathy
- calcium channel blockers
- beta-blockers
how does hypertrophic cardiomyopathy lead to myocardial ischemia
- increased muscle mass and filling pressure increases O2 demand
- decrease in vasodilatory reserve
- systolic compression of arteries
what are the two most common symptoms in patients with hypertrophic cardiomyopathy
- dyspnea (90%)
- angina pectoris (75%)
- fatigue, syncope
- **increased risk of Sudden cardiac death in children and adolescents
how do the following impact HCM murmur?
- postextrasystolic beat
- squatting
- isometric handgrip exercises
- postextrasystolic beat: increase contractility and increase preload: murmur is louder
- squatting: softer
- isometric handgrip exercises: increase afterload; murmur is softer
what are the principe pathways of disease progression in hypertrophic cardiomyopathy
- progression of symptoms
- AFIB
- sudden death
- end stage with systolic dysfunction
when is surgery for hypertrophic cardiomyopathy considered
- gradient > 50 mmHg at rest
- class III or IV heart failure
treatment options
** non-surgical alcohol septal ablation or surgical myomectomy
what is the hallmark of restrictive cardiomyopathy
abnormal diastolic function
what is restrictive cardiomyopathy
- rigid ventricular wall with impaired diastolic ventricular filling
- **can’t correct with surgery
- least common form of cardiomyopathy
what are the classifiations for restrictive cardiomyopathy
- idiopathic
- myocardial
- noninfiltrative
- infiltrative
- amyloid
- sarcoid
- storage disease
- hemochromatosis
- endomyocardial
symptoms of restrictive cardiomyopathy are consistent with
right and left heart failure
- * jugular venous pulse prominent
diagnosis of restrictive cardiomyopathy is confirmed by
endomyocardial biopsy
how can you differentiate between restrictive and constrictive pericarditis
- **History
- constrictive
- h/o TB, trauma
- restrictive
- amyloidosis, hemochromatosis
- mixed
- mediastinal radiation, cardiac surgery
- constrictive
what is the most common cause of restrictive cardiomyopathy in the USA
amyloidosis
- amyloid of myocardial biopsy could be due to primary amyloidosis or secondary to multiple myeloma and hypergammaglobulinemia
hemochromatosis is characterized by
iron overload
clinical presentation
- cirrhosis, DM, hyperpigmentation, cardiac dysfunction
- CHF-leading cause of death
hemochromatosis
treatment for hemochromatosis
- phlebotomy
- chelation therapy
- **cardiac function may normalize
treatment of restrictive cardiomyopathy
- NO satisfactory medical therapy
- drug therapy use with caution
- diuretics for extremely high filling pressures
- Inotropic agents are NOT indicated
- drug therapy use with caution
what two conditions account for the highest percentrage of transplants
- CAD
- cardiomyopathy (majority DCM)
what EKG changes are commonly seen in dilated cardiomyopathy
- sinus tachycardia
- L BBB
what EKG changes are commonly seen in hypertrophic cardiomyopathy
- LVH
- septal Q waves
what conditon causes sudden cardiac death in young athletes
hypertrophic cardiomyopathy
