Cardiomyopathy

Kinza Ali

Introduction

Cardiomyopathies are a group of diseases primarily involving the myocardium and is characterized by myocardial dysfunction that is not the result of hypertension, coronary atherosclerosis, valvular dysfunction, or pericardial abnormalities.

Introduction

The main types of cardiomyopathy are: Dilated cardiomyopathy (Congestive, ACM,

IDC)▪ Ventricular enlargement and systolic dysfunction

Hypertrophic cardiomyopathy (IHSSic , HOCM)▪ Inappropriate myocardial hypertrophy in the

absence of Hypertension or aortic stenosis Restrictive cardiomyopathy(infiltrative)▪ Abnormal filling and diastolic dysfunction

Dilated Cardiomyopathy (DCM)

Most common type of cardiomyopathy Generally occurs between ages of 20 to 60

years More common in men Heart begins to dilate or stretch and become

thinner increased ventricular chamber size

Systolic dysfunction Reduced CO increased EDV weakness

and shortness of breath biventricular CHF

Pathophysiology

Etiology

Most commonly Idiopathic Toxic: due to cocaine, amphetamines, and

some chemotherapy drugs (doxorubicin, daunorubicin)

Ischemic: caused by CAD and MI, leave scars in the heart muscle

Infectious: HIV, viral myocarditis due to coxasackie B or echovirus

Alcoholic: happens 10 years after sustained, heavy alcohol consuption

Pregnancy

Symptoms

Signs of CHF Dyspnea on exertion, orthopnea,

paraoxysmal nocturnal dyspnea Palpitations Fatigue Restingtachycardia Mitral regurgitation

Normal DCM

Ejection fraction (>55%)LV Diastolic Dimension (<55mm)LV wall thicknessAtrial sizeValvular regurgitationCommon first Symptoms

<30%>60mmDecreasedIncreasedMitralExertion intolerace

Hypertrophic cardiomyopathy

Most common cause of death in young people

Occurs when muscle thickens abnormally ( usually LV)=impaired diastolic function the ventricles fill with less blood because the

thickened walls are less compliant and take up too much space, and the heart has too much muscle to be able to support its own energy needs

Diastolic failure, increased ejection fraction Sudden death due to ventricular arrhythmias

Pathophysiology

Two types of HCM: obstructive and non obstructive. Septum thickens and bulges into the left

ventricle, blocks flow of blood into aorta. Thick but not abnormal thick that any

part of it crowds the ventricles Noncompliant chamber= decrease

diastolic filling=increased ED pressure=increase pulmonary venous pressure

Etiology

50% of cases are familial Mutations in one of 4 genes encoding

proteins of cardiac sarcomere accounts for majority of familial cases -MHC, Cardiac troponin, myosin binding protein

C, alpha-tropomyosin Genetic IHSS (1:500 young athletes

affected) Autosomal dominant Beta-MHC

Often Idiopathic

Symptoms

Dyspnea Syncope (usually seen with exercise) Angina Palpitations Sudden death: may be the only

manifestation S4: atria contracts, fluid going into

harder surface Diagnose it with ECG (atrial

enlargement, V hypertrophy), echo, histology, etc.

Restrictive Cardiomyopathy

Less common, tends to mostly affect older adults

Myocardial infiltration causing decreased compliance and rigidity

The ventricles become stiff and rigid because of scar tissue formation

Atria enlargement

Heart failure/arrthymias

Pathophysiology

Etiology

Main causes include: Post-Radiation therapy Collagen Vascular disease Amyloidosis: insoluble proteins deposit within

tissues Hemacuromatosis

Symptoms

Presents with symptoms of progressive left sided and right sided heart failure: Edema, ascites, hepatomegaly,

distended neck veins may be present Fatigue, weakness Congestive heart failure

Treatment

Manage any conditions that cause or contribute to the cardiomyopathy

Diet, physical activity, and lifestyle changes

Diuretics: remove excess fluid and sodium from the body

ACE inhibitors: lowers blood pressure and reduces stress on heart

Beta blockers: slows heart rate by reducing the speed of the heart contraction. Also lowers BP.

Treatment

Digoxin (avoid in amyloidosis) Antiarrhythmics (amiodorone) Calcium channel blockers: slows

rapid heartbeart by reducing the force and rate of heart contractions, decrease BP.

Anticoagulants

Case study A 39 year old school teacher, presented on account of progressive dyspnea associated with orthopnea, palpitations and bilateral leg swelling. There was no previous remarkable illness or hospital admission. She had a history of daily ingestion of alcohol for 8 years. On examination she was in respiratory distress, had bilateral basal crepitation, an irregular pulse, elevated jugular venous pulse, a displaced non heaving apex with left parasternal heave, and a non radiating apical pansystolic murmur. She also had a tender hepatomegaly, and bilateral pitting pedal edema. A chest radiograph showed upper lobe diversion, bilateral hilar opacities and a multi chamber cardiomegaly. A 12 lead surface electrocardiogram (ECG) showed atrial supraventricular and ventricular ectopics, and echocardiography showed, four chamber dilatation with poor systolic function and absent a waves.

References

http://www.nhlbi.nih.gov/health/health-topics/topics/cm/signs.html

http://circheartfailure.ahajournals.org/content/6/2/e19.extract

http://medind.nic.in/jal/t04/i4/jalt04i4p157.pdf

http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/dilated-restrictive-cardiomyopathy/