CVS

Diseases of the myocardium

Diseases that primarily effect the heart muscles, as myocarditis and cardiomyopathy.

Acute myocarditis

Acute inflammation of the cardiac muscle.

Myocardial Damage

Direct viral invasion of the myocyte leads to myocardial damage. Auto immune response directed against the myocyte leads to further damage.

Causes

I - Infectious agents a. Viruses: Coxacki B, HIV, Echovirus..etc. b. Bacterial; Staphylococcus, enterococcus, diphtheria toxin..etc. c. Protozoal d. Spirochetal e. Ricketsial f. Metazoal II - Drugs and chemical agents III - Radiation

Clinical manifestations

Usually the patient gives history of a recent upper respiratory tract infection, or a flu like illness. The presentation is variable and ranges from an asymptomatic state to a severe fulminant condition.

ECG Changes& Biomarkers

Sinus tachycardia ST T wave changes especially if the pericardium is involved. Cardiac Troponin and CPK may be elevated.


Physical examination
Fever Tachycardia Peripheral edema Small pulse volume Muffled heart sounds
A third heart sound A murmur of mitral regurgitation

Treatment

preferably complete bed rest, till the ECG changes return to normal. If there is evidence of heart failure, then treat with the usual measures (salt restriction, diuretics, ACE inhibitors) Anti-arrhythmic drugs are given if arrhythmias develop.

Prognosis

Frequently the disease passed unnoticed as upper respiratory tract infection.Some patients develop ventricular dysfunction to present months –years later as DCM.

Cardiomyopathies

Diseases that involve the myocardium directly and are not the result of hypertensive, congenital, valvular or arterial abnormalities

Causes

A - Primary causes 1. Idiopathic 2. Familial 3. Eosinophilic endomyocardial disease 4. Endomyocardial fibrosis B - Secondary causes

Secondary causes

1. Infective. 2. Metabolic. 3. Storage diseases. 4. Deficiency diseases. 5. Connective tissue diseases.
6. Infiltration & granulomas. 7. Neuromuscular. 8. Sensitivity & toxic reactions. 9. Peripartum heart disease.

Types according to clinical presentation

Dilated cardiomyopathy Hypertrophic cardiomyopathy Restrictive cardiomyopathy

Dilated cardiomyopathy

In this condition there is impaired ventricular contraction ( Systolic dysfunction) . It involves both ventricles, but usually starts in the left ventricle. It leads to left sided and later congestive heart failure.

Dilated cardiomyopathy

It is a disease of middle age people Males are affected more often than females in a ratio of 2:1 The cause is usually unknown, but it may be the end result of myocardial damage produced by a variety of causes, toxic metabolic, infectious..etc. In 20% of cases it is inherited as autosomal dominant. It runs a progressive course, but reversible forms are found with alcohol abuse, pregnancy, thyroid disease..etc.

Clinical features I

1. Symptoms of congestive heart failure Exertional dyspnea Fatigue Orthopnea Paroxysmal nocturnal dyspnea Peripheral edema

Clinical features II

2. Vague chest pain (not similar to angina) 3. Arrhythmias different types but usually of ventricular origin. may lead to sudden death. 4. Systemic embolization Patient may present with CVA, limb gangrene..etc. It is due to dislodgement of mural thrombi from the dilated and poorly contractile ventricles.

Physical examination

1.Features of congestive heart failure Elevated JVP Peripheral edema Bilateral basal crepitations Tender hepatomegaly
2. Cardiac examination Cardiomegaly Soft heart sounds S3 and/or S4 gallop Murmurs of mitral and tricuspid valvular regurgitations.

Investigations I

1. Chest X-ray Generalized cardiomegaly, mostly L.V. pattern. Pulmonary venous congestion. Pulmonary edema.

Investigations II

2.ElectrocardiographyArrhythmias: mostly sinus tachycardia, atrial fibrillation, ventricular ectopics…etc.Low voltageConduction defects.

ECG in Dilated cardiomyopathy

Normal echocardiography

Investigations III

3.Echocardiography L.V.dilatation. Mitral, tricuspid valve regurgitation Reduced ejection fraction(<55%). Not specific.

Investigations IV

4. Cardiac catheterization Is of limited value in establishing the diagnosis.

Investigations V

5. Transvenous endomyocardial biopsy Not necessary Useful to detect some forms of secondary types as infiltrative diseases

Prognosis

Most patients follow a downhill course Fifty fife % die within 3-5 years of the diagnosis. Death is usually due to CVA or a ventricular tachy dysrrythmia.

Treatment

1. Rest 2. Salt restriction 3. Anti-failure drugs: - ACE inhibitors - Angiotensine II receptor blockers - Beta- blockers - Diuretics - Digitalis
4. Anticoagulants: - Low mol. Wt. Heparine - heparin - oral anticoagulants 5. Immunsuppressive drugs: - Azothioprine - Cyclosporine 6. Implantable cardioverter defibrillator 7. Cardiac transplantation

Hypertrophic cardiomyopathy

Characterized by inappropriate and elaborate ventricular hypertrophy. Preferentially the interventricular septum is affected resulting in asymmetric septal hypertrophy (ASH). ASH will result in narrowing of the subaortic area and eventually it will impede the outflow tract. So it is also called Hypertrophic Obstructive Cardiomyopathy (HOCM).

These heamodynamic abnormalities produce abnormal movement of the lateral leaflet of the mitral valve.This movement is called Systolic Anterior Motion (SAM), which results in mitral regurgitation. The ventricles are stiff and non-compliant, so ventricular filling is impeded, hence the dysfunction is diastolic.

HOCM Septal hypertrophy. Outflow tract obstruction.

Clinical manifestations
A familial disease, 50% of cases is transmitted as autosomal dominant trait. It is found in 1:500 of the general population. The course is variable, may be assymptomatic and run a benign course, or might present with sudden death


Clinical presentation

Symptoms

Ventricular hypertrophy ---- small ventricular cavity small ventricular volume----low cardiac output --- dyspnea and fatigue. Angina pectoris, due to increased O2 demand by the hypertrophied muscle. Dynamic Left ventricular outflow obstruction -- Syncopal attacks or near syncope (dizzy spells).

Physical examination

Rapidly rising carotid arterial pulse Double(or triple) apical precordial impulse. A 4th. Heart sound. Most important is a harsh systolic murmur in the left sternal border due to the subaortic obstruction.

Laboratory evaluationElectrocardiography

Marked LV hypertrophy.Q-waves due to old myocardial infarction.Arrhythmias – Atrial and ventricular, better elicited by Holter monitor

Chest X -ray

Usually normal Later increase cardiac size is noticed

Echocardiography

Important for the diagnosis LV hypertrophy Small LV cavity Systolic anterior motion (SAM) of the mitral valve leaflet.

Hypertrophic cardiomyopathy echocardiography

Treatment
Avoid competitive exercise to decrease the incidence of sudden death. Beta-blockers: used to relieve angina, decrease the incidence of syncopeal attacks. they will not affect survival. Amiodarone: useful antiarrythmiac drug. It prevents supraventricular and ventricular arrhythmias. It decreases the incidence of sudden death.


Implantable cardioverter defibrillator ICDpatients surviving cardiac arrestpatients with high risk of ventricular tachyarrythmiasSurgery – MyomectomyImprove symptoms in 75% of patients who are severely symptomatic and unresponsive to medical therapy

Restrictive cardiomyopathy

The hallmark of this disease is excessive rigidity of the ventricular wall. This impedes ventricular filling in diastole ( Diastolic dysfunction ) . This will lead to atrial hypertrophy dilatation atrial fibrillation Intra-atrial thrombosis systemic embolism which may lead to death.

Clinical manifestations

Most important features are exercise intolerance and dyspnea(low CO).Elevated JVP, Kussmal’s sign might be positive. Dependant edemaAscitisPulsatile, and tender hepatomegaly.

ECG Low voltage Nonspecific ST-T changes Various arrhythmia Echocardiography Diastolic dysfunction Reduced ventricular volume.

Treatment

Prognosis is bad. Treatment is usually symptomatic. Chronic anticoagulation may prevent thromboembolic complications. Cardiac transplantation is the only definitive treatment.