Cardiomyopathies

By:Dawit Ayele(MD,Internist)

a group of diseases that affect the heart muscle itself and are not the result of hypertension , congenital, valvular , coronary, or pericardial abnormalities

Definition

based on LV cavity size, wall thickness, and systolic contraction

dilated (myocyte necrosis, profound dilation, and systolic dysfunction),

hypertrophic(disproportionate septal thickening, obstructive or non-obstructive), or

restrictive (generalized wall thickening with both systolic and diastolic impairment)

Classification

Is mainly due to Prolonged, uninterrupted biomechanical overload

is characterized by eccentric hypertrophy(dilatation) , loss of cardiac contractile function(hypokinesis), and loss of cardiomyocytes due to apoptosis.

Dilated Cardiomyopathy

Prevalence is increasing

About 1 in 3 cases of CHF in the west is due to dilated cardiomyopathy

More common in middle aged men & African Americans than whites

Epidemiology

Idiopathic Familial/genetic- 20-40% mostly autosomal

dominant transmission infection, (viral esp) inflammation, Toxins-(alcohol,cocain) Pregnancy Thyroid disease Chronic uncontrolled tachycardia collagen vascular disease, and musculoskeletal disease

Causes

Of left & right sided CHF

Some present with left ventricular dilatation for months to yrs before diagnosis

Vague chest pain-but typical angina is unusual

Syncope 20 to arrhythmia or systemic embolism

Clinical Manifestations

Variable degrees of cardiac enlargement Advanced disease-narrow pulse pressure -Raised JVP -S3 & S4 sounds common -Mitral & tricuspid

regurgitation may occur

Physical Examination

CXR-enlargement of cardiac silhoutte -may show evidence of pulmonary

venous hypertension -may show interstitial & alveolar edema ECG- *Echocardiography Cardiac catheterization Coronary angiography Transvenous endomyocardial biopsy-

usu.not necessary

Lab examinations

Majority esp >55 yrs die within 3 yrs of onset of sxs Target: - Avoid toxins including alcohol

-Control CHF-standard Management

-Chronic anticoagulation –prevent embolism

-Sometimes pacemaker & use of implantable cardioverter defibrillator

-cardiac transplantation for refractory cases

Treatment

is a genetic disorder characterized by disproportionate hypertrophy of the left ventricle, and occasionally of the right ventricle

HYPERTROPHYIC CARDIOMYOPATY

Prevalence ◦1:500[0.2%] in general

population(may be the most common genetically transmitted cardiac disorder)

◦0.5% in non-selected Echo referral Most common cause of Sudden cardiac

death in the young in the USA Usually in third or fourth decades

Epidemiology

Etiology

- Genetic: Familial HCM-

Autosomal dominant(50%)

Sporadic due to spontaneous mutations

- Idiopathic

Pathology(Gross)

-marked in myocardial

mass-more LV involvement in

hypertrophy-small ventricular

cavities -dilated atria &

hypertrophy (vent. filling resistance )

- MV& elongation -anomalous papilary

ms. insertion.

Pathology(Gross)-variable pattern & extent

of hypertrophy(Maj.IVS and

anterolateral free wall)

-Eventual burned-out phase in 5-10% of patient◦ Resemble DCM

Thinning, dilation, systolic dysfunction

-Clinically silent remodeling with subtle regression of hypertrophy in some patient

Pathology (microscopic)

-Myocardial hypertrophy-Gross disorganization

of muscle bundles(whorled pattern)

-Cell to cell arrangement abnormality(disarray)

-Prominent fibrosis-interstitial connective

tissue elements.-Abnormal intramural

coronary arteries(80%)

◦ Asymptomatic in majority [90%] Sudden death can be the 1st event [esp. during

extreme exertion]◦ Variable pattern and severity of symptoms

Dyspnea most common [90%] Angina [75%] Fatigue, presyncope and syncope common [not

ominous in adult] Palpitation, PND and dizziness less common

◦ Exacerbating factors Exercise Erect posture [graying out spells]

Clinical feature ---Symptoms

Physical Examination - Normal except for an S4

Asymptomatic without – pressure gradient Mild hypertrophy Apical hypertrophy

- Usually prominent in presence of pressure gradient Characteristic carotid

pulse [“spike and dome”]

Prominent “a” wave Displaced, diffuse and

abnormally forceful AI

Narrow or paradoxical S2 split

S3 may be present [no prognostic value unlike in valvular AS]

Occasionally systolic ejection click

Systolic murmurs…midsystolic and hollosystolic [associated MR]◦ Correlate with SAM and pressure gradient◦ Labile intensity and duration◦ *Influenced by maneuvers

Diastolic murmurs…..apical rumbling and high pitched AR

Physical exam…

1-ECG 2-CXR(N/cardiomegaly+/-calcification) 3-Echocardiography 4-Other imaging-radionuclide scan,cardiac

MRI(when Echo is technically inadequate) 5-Cardiac catheterization(CAD,invasive Rx) 6-Biopsy 7-Genetic analysis?

Investigation

The subcostal view from the two dimensional echocardiogram shows extremely hypertrophied and

asymmetric septum which is 35 mm in thickness.

Septal hypertrophy

Concentric hypertrophy

Guiding principles:Three important goals Symptoms alleviation Complication prevention Death risk reduction

Majority require only medical treatment At least 50% with sever symptoms improveInvasive modalities required in only 5-

10% **Myotomy-myectomy[ gold standard..70-

90%]

Management

CLINICAL ALGORITHM

Condition & medics that better be avoided - physical exertion&competitive sports

- digitalis glycosides unless A-fib or systolic dysfunction

-B-adrenergic agonist -Nifedipine -excessive use of diuretics & dehydration

Management…

Restrictive cardiomyopathy

Abnormal diastolic function

Excessively rigid ventricular walls that impede filling

Unimpaired systolic function

*Has functional resemblance with constrictive pericarditis

*Is the least common of the main 3 CMPs

Hallmark of Constrictive Pericarditis

Myocardial-Non Infiltrative:*Idiopathic CMP Familial Scleroderma -Infiltrative:*Amyloidosis *Sarcoidosis -Storage disease Hemochromatosis..

Endomyocardial -*Endomyocardial fibrosis -*Radiation -*Toxic effects of anthracyclin -eosinophilic syndrome -metastatic cancers -Drugs(Serotonin,ergotamin,busulfan..)

Classification of types according to cause

Pathologic processes

- Myocardial fibrosis

- Infiltration

- Endomyocardial scarring

- Myocyte hypertrophy in idiopathic variety

Depends on which ventricle & AV valve show predominant involvement

Thromboembolic complication ~1/3 Sx-Exercise intolerance & dyspnea are

the most prominent sxs.(inability to CO by tachycardia w/o compromising vent filling)

-Exertional chest pain -Dependent edema,ascites &

enlarged tender & often pulsatile liverpersistently venous pressure.

General Clinical Features

Distended JVP-doesn’t fall normally - +/- kussmaul’s sign *apex pulse is usually palpable

Ht sounds may be distant

S3, S4 or both

Physical Exam

ECG

CXR to R/O ddx-eg-constrictive pericarditis

Echocardiography –

Cardiac catheterization –

Endomyocardial biopsy, computed tomography or magnetic resonance imaging & others help distinguish restrictive & constrictive disease

Investigations

Echocardiography of restrictive cardiomyopathy

Endomyocardial biopsy cardiac amyloidosis

No specific therapy other than symptomatic is available for the idiopathic form of RCM

Few secondary forms may benefit from targeted treatment regimens:

Hemochromatosis: deferoxamine has been helpful in reducing myocardial iron content

Chronic anticoagulation is often recommended to reduce the risk of embolization from the heart.

The prognosis in RCM is variable: usually it is one of relentless symptomatic progression and high mortality.

Treatment & prognosis

Thanks