Cardiomyopathy Dr.mirdamadi Cardiologist, fellowship of echocardiograpy
Definition: Group of diseases that primarily affect the heart muscle and are not the result of congenital, acquired, valvular, hypertensive , coronary arterial or pericardial abnormalities
Classification: Dilated primary myocardial involvement Restrictive secondary myocardial involvement: Hypertrophic ( infective, Metabolic, Connective tissue disorders Infiltration, toxin, peripartum)
1/3 of CHF is due to DCM • LV and/or RV systolic function is impaired leading to progressive cardiac dilation • No cause detected in many cases, but familial (1/4-1/3 of cases) or secondary cause like infectious, metabolic or toxic agents present.
Reversible form may be found with alcohol abuse, pregnancy, thyroid disease, cocaine use and chronic uncontrolled tachycardia.
Clinical features symptoms of left and right sided CHF. some patients have LV dilation for months or even years before becoming symptomatic vague chest pain (typical angina is unusual and suggestive of IHD) syncope due to arrhythmias systemic embolism
Physical examination Narrow pulse pressure and elevated JVP in advanced disease S3 S4 MR TR
Laboratory examination CXR : cardiomegaly , pulmonary congestion ECG : Sinus tachycardia or AF , Ventricular arrhythmias, Non specific changes Echocardiography : LV dilation , systolic dysfunction Angiography : to exclude IHD
Endomyocardial biopsy : is not necessary in idiopathic or familial DCM but may be helpful in the recognition of secondary CMP like amyloidosis and myocarditis
most patient has progressive course patients > 55 years die within 4 years of the onset of symptoms Spontaneous improvement in about one- quarter of patient death is due to progressive HF or ventricular arrhythmia or brady arrhythmia
large quantities (>90g/d) of alcohol over many years cause DCM Risk of developing CMP is partially genetically patient with severe CHF have a poor prognosis (< 1/4 of such patients survive 3 years)
Second presentation of alcoholic cardiotoxicity is recurrent supraventricular or ventricular tachyarrhythmia’s Holiday heart syndrome: AF, Atrial flutter or frequeut PVC after a drinking binge.
Cardiac dilation and CHF may develop during the last trimester of pregnancy or within 6 months of delivery. Mortality rate is 10%. Patient who recover from peripartum CMP should be encouraged to avoid further pregnancy .
A variety of drugs may damage the myocardium acutely (myocarditis) or they may lead to chronic damage (like DCM) Anthracycline derivatives : Doxorubicin cardiotoxicity may occur acutely but more commonly develops 3 months after the last dose. TCA – antidepressants, phenothiazines , lithium Cocaine abuse (SCD , myocarditis , DCM, acute MI )
ARVD is a familial CMP with progressive fibrofatty replacement of the RV and to a much lesser degree LV. Patients may present by RV failure or ventricular tachycardia
Others Neuromuscular disease Tako – tsubo (stress) CMP Non compaction CMP
characterized by LV hypertrophy without obvious cause It is 1 in 500 of general population two features af HCM : asymmetric LV hypertrophy , Dynamic LVOT obstruction
There is a bizarre and disorganized arrangement of myocytes with variable degree of fibrosis. About a half of patients have a positive family history compatible with autosomal dominant transmission
Screening by echocardiography of first- degree relatives between the age 12 and 20 should be done every 12-24 months unless diagnosis evaluated by genetic testing
Clinical features Clinical course is variable , from asymptomatic to SCD SCD frequently occur in children and young adult during or after physical exertion. HCM is the most common cause of SCD in young competitive athletes Other symptom : dyspnea , syncope , angina and fatigue.
Physical examination Double or triple apical precordial impulse Fourth heart sound Harsh , diamond – shaped systolic murmur in LSB due to LVOT obstruction Holosystolic and blowing systolic murmur at apex due to MR
Hemodynamic Obstruction in LVOT is dynamic (not fixed) and is due to narrowing of the LVOT by systolic anterior motion (SAM) of mitral valve against the hypertrophied septum.
Hemodynamic Three mechanisms are involved dynamic obstruction : 1) increased LV contractility (exercise) 2) decreased ventricular preload (strain phase of valsalva maneuver , standing ) 3) decreased ventricular after load
Squatting , sustained handgrip position with leg raising , expansion of volume in pregnancy decreased obstruction
Laboratory evaluation ECG : LVH and deep broad Q waves (mistake as a MI) CXR : Cardiomegaly Echocardiography : septal hypertrophy ( septum>=1.3 times of posterior wall ) SAM of mitral valve with MR.
Apical HCM Apical hypertrophy Giant negative T wave on the ECG Spade – shaped LV cavity
Management Competitive sports and very strenuous activities should be proscribed dehydration should be avoided.
B- blockers ameliorate angina and syncope in1/3-1/4 of patients Varapamil and diltiazem may reduce the stiffness of LV Amiodaron reduced risk of SCD and arrhythmia Digitalis,diuretics,nitrates, dihydropyridine calcium blockers, vasodilators and B- agonists are best avoided.
Surgical myotomy / myectomy of septum and ethanol injections into the septal artey are the invasive treatment. • ICD should be considered in high- risk patients
Hallmark of the RCM is abnormal diastole function. Myocardial fibrosis,hypertrophy or infiltration caused rigid LV walls
Amyloidosis, hemochromatosis, glycogen storage disease, endomyocardial fibrosis, sarcoidosis, hypereosinophilic disease, sceleroderma, following mediastinal irradiation
Inability of the ventricles to fill, caused decrease cardiac out put • exercise intolerance and dyspnea • elevated systemic venous pressure cause edema ascitis and elevated JVP
Laboratory examinations • in infiltrative disease ECG often shows low – voltage, nonspecific ST/T change and various arrhythmias. • Echocardiography , CT and MRI showed thickened LV walls with normal LV systolic function and dilated atria.
Management is usually disappointing except for hemochromatosis and fabry’s disease.
myocarditis is most commonly the result of infectious process, frequently complicated by autoimmunity. myocarditis may also result from hypersensitivity to drugs (TCA , antibiotics,antipsychotics) or may be caused by irradiation, chemicals or physical agents.
Most common cause is viruses especially coxsakievirus B adenovirus hepatitis C and HIV
Patients with viral myocarditis may give a history of upper respiratory febrile illness or a flu like syndrome , and viral nasopharyngitis or tonsillitis may be evident.
Clinical manifestation • clinical spectrum ranges from an asymptomatic state to fulminant condition with arrhythmias, acute CHF and death.