Cardiomyopathies

Faculty of MedicineUniversity of BrawijayaMalang

Definition

“A heart muscle disease, often of unknown cause …”

Cardiomyopathy• Greek “kardia” heart + “myo” muscle

“patheia” suffering/disease

• 1980 WHO: “heart muscle disease of unknown cause”

• 1995 WHO/Task force: “diseases of the myocardium associated with cardiac dysfunction”

Classification

• etiology• gross anatomy• histology• genetics• biochemistry

• immunology• hemodynamics• functional• prognosis• treatment

WHO Classification

• Unknown cause(primary)– Dilated – Hypertrophic– Restrictive– unclassified

• Specific heart muscle disease (secondary)– Infective– Metabolic– Systemic disease– Heredofamilial– Sensitivity– Toxic

Br Heart J 1980; 44:672-673

Functional Classification

• Dilatated (congestive, DCM, IDC)– ventricular enlargement and syst dysfunction

• Hypertrophic (IHSS, HCM, HOCM)– inappropriate myocardial hypertrophy

in the absence of HTN (hypertension) or aortic stenosis

• Restrictive (infiltrative)– abnormal filling and diastolic function

Cardiomyopathies

Idiopathic DilatedIdiopathic Dilated

Konstam MA. Konstam MA. J Card Failure.J Card Failure. 2003. 2003.

HF-DilatedHF-Dilated

HypertensiveHypertensiveIschemicIschemic

HF-Non DilatedHF-Non Dilated

Hypertrophic CMHypertrophic CM

Characteristics of the three types of cardiomyopathy

Types LV wall LV cavity Systolic contrac-tility

Diastolic Compli-ance

Prognosis 10 year survival rate

Dilated Cardiomyo-pathy

Thin Large ↓ Normal to ↓* 30-40%

Hypertro-phic Cardio-myopathy

Thick Small ↑ ↓ 70%

Restrictive Cardiomyo-pathy

Normal to ↑ Normal Normal to ↓ ↓↓ 50% (idio-pathic type)

Contractility or compliance may be normal early in the disease state but may become abnormal subsequently

General approach to a patient with Cardiomyopathy

• Define the problem:– 1. Failure? – due to a low cardiac output state

(Dilated CM) or obstruction to LV filling (restrictive CM)

– 2. Arrhythmia? – due to supraventricular or ventricular arrhythmias.

– 3. Syncope?- due to obstruction in LV outflow tract (HOCM) and/or arrhythmias especially slow rates.

Dilated Dilated CardiomyopathyCardiomyopathy

Dilated Cardiomyopathy

• The heart is dilated and has impaired function

• The coronary arteries are normal.

Idiopathic Dilated CardiomyopathyObserved Survival of 104 Patients

104

72

56 5145

37 35 3124 19 16

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9 10

Years

Am J Cardiol 1981; 47:525

Incidence and Prognosis

• 3-10 cases per 100,000

• 20,000 new cases per year in the U.S.A.• death from progressive pump failure

1-year 25%2-year 35-40%5-year 40-80%

• stabilization observed in 20-50% of patient

• complete recovery is rare

Features for Diagnosis of Dilated Cardiomypathy

• Signs and symptoms of systolic heart failure

• Echocardiography shows dilated LV with global hypokinesia

• Normal coronary artery by angiography

• Presence of predisposing factors such as alcoholism, malnutrition etc

Etiologic classification of the Dilated Cardiomyopathy

I. Idiopathic

II. InflammatoryA. Infectious

A. Viral

B. Bacterial

C. Mycobacterial

D. Others: Parasitic, Rickettsial, Fungal

B. Non-infectiousA. Peripartal cardiomyopathy

B. Autoimmune disease

C. Hypersensitivity reaction

D. Tranplantation rejection

Etiologic classification of the Dilated Cardiomyopathy

III. Toxic agents

A. Alcohol

B. Methamphetamines/ Cocaine

C. Chemotherapeutic agents (Doxorubicin)

D. Cigarette smoking

E. Elemental compounds

D. Cathecolamines

Etiologic classification of the Dilated Cardiomyopathy

IV. Metabolic

A. Malnutrition

B. Endocrinologic: Thyrotoxicosis

C. Electrolyte abnormalities

D. Cigarette smoking

E. Elemental compounds

F. Cathecolamines

Etiologic classification of the Dilated Cardiomyopathy

V. Familial cardiomyopathy

A. Neuromyopathic

1. Progressive muscular dystrophy

2. Myotonic muscular dystrophy

3. Friedrich’s ataxia

B. Hereditary dilated Cardiomyopathy

Clinical features

• Progressive biventricular heart failure leads to symptoms– Fatigue– Paroxysmal nocturnal dyspnea, orthopnea,

dyspnea– Peripheral edema– Ascites

Clinical history

• History of specific exposure to etiologic agents (e.g alcohol, methamphetamine)

• Symptoms of left sided failure, then right sided heart failure

• Chest pain may be present in the absence of ischemic heart disease

Physical examination

• Similar to those of congestive heart failure

• Dilated heart, distended neck veins with functional MR murmur due mitral annular dilatation

History and Physical Examination

• Symptoms of heart failure– pulmonary congestion (left HF)

dyspnea (rest, exertional, nocturnal), orthpnea– systemic congestion (right HF)

edema, nausea, abdominal pain, nocturia– low cardiac output

fatigue and weakness

• hypotension, tachycardia, tachypnea, JVD (jugular venous distention)

Clinical features

• Other complications secondary to the progressive dilatation of the ventricles include:– Mural thrombi with systemic or pulmonary

embolization– Dilatation of the tricuspid and mitral valve rings

leading to functional valve regurgitation– Atrial fibrillation and other arrhythmias– Ventricular tachyarrhythmias and sudden death

Diagnostic tests

1. ECG: non-specific changes; may show LVH, occasionally LBBB

2. Chest X-ray: multichamber dilatation with congestive features

3. Echocardiography: multichamber dilatation, LV wall motion abnormalities usually global hypokinesia

4. Coronary angiography: normal coronary arteries

5. Angiography indicated only to rule out ischemic heart disease (“ischemic” cardiomyopathy)

Echocardiography

• Evaluation of dilated ventricles

• Evaluation of regurgitant valves

• Evaluation of thrombus

Normal echo

Management

• Search and treat any underlying cause ( e.g stop alcohol)• Treat heart failure (diuretics, ACE-inhibitor,

nitrates/hydralazine combination)• Treat any arrhythmias• Prevention of sudden death with placement of implantable

cardioverter defibrillator (ICD) is not recommended• Anticoagulate with warfarin to prevent mural thrombi• If cardiac failure does not respond to the above steps if

suitable candidate cardiac transplantation

Predicting Prognosis in IDC

Predictive Possible Not PredictiveClinical factors symptoms alcoholism age

peripartum durationfamily history viral illness

Hemodynamics LVEF LV sizeCardiac index atrial pressure

Dysarrhythmia LV cond delay AV block simple VPCcomplex VPC atrial fibrillation

Histology myofibril volume other findings

Neuroendocrine hyponatremiaplasma norepinephrineatrial natriuretic factor

VPC: ventricular premature contraction

Clinical Indications for Endomyocardial Biopsy

• Definite– monitoring of cardiac allograft rejection– monitoring of anthracycline cardiotoxicity

• Possible– detection and monitoring of myocarditis– diagnosis of secondary cardiomyopathies– differentiation between restrictive and

constrictive heart disease

Hypertrophic cardiomyopathy

Types of hypertrophic cardiomyopathy

• 1. Obstructive type. Synonym: idiopatthic hypertrophic subaortic stenosis

• 2. Non obstructive type

Features for diagnosis

• Dyspne or syncope• May have a family history of hypertrophic

cardiomyopathy in 50% of cases• Characteristic systolic ejection murmur at the

left sternal area which increases with valsalva maneuver (in obstructive type)

Features for diagnosis (continued)

• Marked hypertrophy of the left ventricle involving the interventricular septum and the LV outflow tract in the absence of other causes of hypertrophy

• Echocardiography shows interventricular septum to posterior LV wall ratio > 1.3:1.

Hypertrophic obstructive cardiomyopathy

• Characterized by asymmetrical hypertrophy of the cardiac septum – the cardiac septum is hypertrophied compared to the free wall of the left ventricle.

• The most common cause of heart-related sudden death in those under 30 years old.

• HOCM is inherited as an autosomally dominant trait with equal sex incidence

• The genetic abnormality is the subject of much current research, and it seems that different genes may be involved in different families

Hypertrophic obstructive cardiomyopathy

• The myocytes of the left ventricle are abnormally thick when examined microscopically left ventricular filling more difficult than normal and grossly disordered

Pathophysiology

• Systole– dynamic outflow tract gradient

• Diastole– impaired diastolic filling, filling pressure

• Myocardial ischemia muscle mass, filling pressure, O2 demand vasodilator reserve, capillary density– abnormal intramural coronary arteries– systolic compression of arteries

65% 35%

10%

www.kanter.com/hcm

Natural History

• annual mortality 3% in referral centersprobably closer to 1% for all patients

• risk of SCD higher in children may be as high as 6% per yearmajority have progressive hypertrophy

• clinical deterioration usually is slow

• progression to DCM occurs in 10-15%

Risk Factors for SCD (sudden cardiac death)

• Young age (<30 years)• “Malignant” family history of sudden death• Gene mutations prone to SCD (ex. Arg403Gln)• Aborted sudden cardiac death• Sustained VT or SVT• Recurrent syncope in the young• Nonsustained VT (Holter Monitoring)• Brady arrhythmias (occult conduction disease)

Br Heart J 1994; 72:S13

Clinical features

• Symptoms usually begins in the third and fourth decades of life.

• Four main symptoms:– Angina – due to the increased oxygen demands of the

hypertrophied muscle– Palpitations- atrial fibrillations and/or ventricular arrhythmias– Syncope and sudden death – due to LVOT obstruction by the

hypertrophied septum or to ventricular arrhythmia– Orthopnea/paroxysmal nocturnal dyspnea/dyspnea – due to

high end diastolic pressure pulmonary edema

Clinical features

• The signs to watch for are:– Jerky peripheral pulse– Double apical beat (bisferiens pulse)– Prominent “a” wave in jugular– Systolic thrill– Systolic murmur

Diagnosis and investigations

• Electrocardiography

• Continuous ambulatory electrocardiography (Holter)

• Echocardiography

Electrocardiography

• The EKG is usually abnormal

• T wave and ST segment abnormalities

• LVH (Left ventricular hypertrophy)

Holter

• Ventricular arrhythmias

Echocardiography

• The most useful investigation

• Characteristic echocardiography findings:– Increased mass of the left ventricle with

asymmetric hypertrophy of the septum– Abnormal systolic anterior motion of the

anterior leaflet of the mitral valve– Calcification of the mitral valve– Left ventricular outflow tract obstruction

Prognosis

• Children who are diagnosed at less than 14 years of age poor prognosis and high incidence of sudden death; 71% are asymptomatic

• Adults : better prognosis but have a higher mortality rate than general population

• Progressive cardiac failure with cardiac dilatation

•

Management

• Drug management– Avoid vasodilators because it worsen the gradient

obstruction. HOCM patient should not receive nitrates– Avoid drugs for systolic heart failure (3 D’s): Digoxin,

Ace-inhibitors (vaso-Dilators) and Diuretics are contra-indicated for the obstructive type of hypertrophic cardiomyopathy

– Beta-blockers are used, negative inotropic effect acts to decrease the contractility of the hypertrophied septum and reduce the outflow tract obstruction

Management

• Drug management– Anti-arrhythmia is given for ventricular and

atrial arrhythmias. – ICD (implantable cardioverter defibrillator)

should be placed for any patient at risk for sudden death

Management

• Dual chamber pacing– This reduces the outflow tract gradient by pacing the

RV apex and therefore altering the pattern of septal motion

• Surgery– Only used when all other treatments have failed– Myomectomy on the abnormal septum– Occluding the septal artery (new catheter technique to

infarct the septum)– Injecting a small amount of alcohol

Recommendations for Athletic Activity

• Avoid most competitive sports (whether or not symptoms and/or outflow gradient are present)

• Low-risk older patients (>30 yrs) may participate in athletic activity if all of the following are absent

Recommendations for Athletic Activity

• Low-risk older patients (>30 yrs) may participate in athletic activity if all of the following are absent– ventricular tachycardia on Holter monitoring– family history of sudden death due to HCM– history of syncope or episode of impaired consciousness– severe hemodynamic abnormalities, gradient 50 mmHg– exercise induced hypotension– moderate or severe mitral regurgitation– enlarged left atrium (50 mm)– paroxysmal atrial fibrillation– abnormal myocardial perfusion

Restrictive cardiomyopathy

Restrictive Cardiomyopathy

• Least common in developed countries• Much more common in third world countries in Africa

and South East Asia due to increased fibrosis of the endocardium secondary to infection

• The ventricular walls are excessively stiff and impede ventricular filling increased end diastolic pressure. The systolic function on the ventricle is often normal

Possible causes of restrictive cardiomyopathy

I. Infiltrative diseases

A. Amyloidosis

B. Hemochromatosis

C. Sarcoidosis

D. Glycogen storage disease (in pediatric age group)

I. Endocardial – Obliterative disease

A. Endomyocardial

B. Fibrosis

With eosinophilia (Loeffler’s syndrome)

With eosinophilia

Possible causes of restrictive cardiomyopathy

III. Interstitial disease

A. Idiopathic

B. Familial

C. Radiation-induced

D. Chronic allograft rejection

Clinical features of restrictive cardiomyopathy

• Most commonly present as right sided heart failure symptoms– Dyspnea, paroxysmal nocturnal dyspnea, and fatigue

due to poor cardiac output– Peripheral edema and ascites– Elevated jugular venous pressure with a positive

Kussmaul’s sign (increase in jugular venous pressure during inspiration)

– Up to one-third of patients: thromboembolic complications or conduction disturbances

Pathophysiology

• Diastolic dysfunction in diastolic heart failure: increasing stiffness of the myocardium causes severe diastolic non-compliance of both ventricles. Thus, LV and RV filling pressure are above normal causing pulmonary congestion and right-sided failure

• As the disease progresses, systolic function is also compromised

Restriction vs Constriction

History can provide important clues• Constrictive pericarditis

– history of TB, trauma, pericarditis, collagen vascular disorders

• Restrictive cardiomyopathy– amyloidosis, hemochromatosis

• Mixed– mediastinal radiation, cardiac surgery

Diagnostic tests

1. ECG: non specific changes, QRS voltages may be low because of the infiltrative process

2. Chest X-ray: may show dilated left atrium and right atrium; pulmonary venous congestion, pleural effusion

Diagnostic tests

3. Echocardiography:

May show LV hypertrophy and RV

hypertrophy but with no dilatation of

the ventricles. Both atria are frequently

dilated due to increase stiffness in the

ventricles. Doppler signs of diastolic

dysfunction suggestive of reduced

ventricular compliance

Diagnostic tests

4. Cardiac catheterization: frequently not necessary

5. Cardiac biopsy: Low yield but may be useful in selected diseases with specific treatment (e.g hemochromatosis, sarcoidosis)

Low voltage ECG’s with LV hypertrophy by echocardiography is suggestive of restrictive cardiomyopathy

Management

• Presentation is similar to that of constrictive pericarditis. Often a history of pericarditis, TB, radiation or surgery will favor constrictive pericarditis.

• The condition usually progresses towards death relatively quickly

• Most patients do not survive 10 years after diagnosis.

Treatment

• No satisfactory medical therapy• Drug therapy must be used with caution

– diuretics for extremely high filling prssures– vasodilators may decrease filling pressure– Ace-inhibitors and calcium channel blockers are of

uncertain benefit.– ? Calcium channel blockers to improve diastolic

compliance– digitalis and other inotropic agents are not indicated

Prognosis

• Poor prognosis for patients with amyloidosis

• Generally declining to zero survival at 4 years.

• For idiopathic restrictive cardiomyopathy, 10 year survival is about 50%