Cardiomyopathy● Cardiomyopathies are diseases of heart muscle that are associated with cardiac dysfunction. ● Heart failure due to cardiomyopathy represents a major health problem ● Cause is unknown● Occurs in only 10-20 per 100,000● Results in 30,000 deaths/year● Cardiomyopathies are classified traditionally according to morphological and functional criteria into four categories:

1. hypertrophic cardiomyopathy 2. dilated cardiomyopathy 3. arrhythmogenic right ventricular dysplasia 4. restrictive cardiomyopathy

Signs and symptoms are dependent upon the typeDilated

Dyspnea Fatigue Left sided heart failure Cardiomyopathy Mitral regurgitation (S1 and S2 sounds heard)Hypertropic Syncope Ankle edema Orthopnea Angina Restrictive Exercise intolerance Dyspnea Fatigue Right sided heart failure S3 and S4

Hypertrophic Cardiomyopathy (HCM) The term cardiomyopathy is purely descriptive, meaning disease of the heart muscle Hypertrophic cardiomyopathy (HCM) is a disease in

which the heart muscle (myocardium) becomes abnormally thick — or hypertrophied. Heart septum usually doesn’t enlarge until adolescents This thickened heart muscle can make it harder for the heart to pump blood. HCM may also affect the heart's electrical system Affects 1 in 500 people Risks : Autosomal Dominant Mutation of one out of a number of genes Pathology: enlarging of heart muscle without

increase chamber size, decreases outflow Usually ++ heart murmur Famous for being leading cause of sudden cardiac death in young athletesPedigree

autosomnal dominant passed on from affected males and females The disease does not skip generations In most people,

HCM doesn't cause severe problems and they're able to live a normal life. In a small number of people with HCM, the thickened heart muscle can cause symptoms such as :

- shortness of breath, - problems in the heart's electrical system

resulting in life-threatening - arrhythmias

- sudden cardiac death. HCM is the most common cause of heart-related sudden death in people under 30

Primary disease of cardiac muscleHistologic evidence of myocardial cellular disarray

Characteristics LVH (often marked in the septum) Reduced diastolic compliance Subvalvular pressure gradient Ventricular arrhythmias May have Systolic Anterior Motion (SAM) of the mitral valve

Blood is ejected into the LV outflow tract at high velocity which creates Venturi effect. This pulls the anterior leaflet of the mitral valve toward the septum during systole. This creates dynamic outflow tract obstruction and mitral regurgitation.

The myocardial disarray Microscopic examination of the heart muscle shows that it is abnormal. The normal

alignment of muscle cells is absent and this abnormality is called myocardial disarray. This disarray can contribute to an irregular heartbeat (arrhythmia) in some people.

Variants of HCMMost common location: subaortic , septal, and ant. wall.Asymmetric hypertrophy (septum and ant. wall): 70 %. Basal septal hypertrophy: 15- 20 %. Concentric LVH: 8-10 %. Apical or lateral wall : (< 2 % (25 % in Japan/Asia) ) characteristic :

- giant T-wave inversion laterally & - spade-like left ventricular cavity: more benign.

Pathophysiology of HCM Dynamic LV outflow tract obstruction Diastolic dysfunction Myocardial ischemia Mitral regurgitation ArrhythmiasPathophysiology

Left ventricular outflow tract gradient ↑ with decreased preload, decreased afterload, or increased contractility. Venturi effect

anterior mitral valve leaflets & chordae sucked into outflow tract →↑ obstruction, eccentric jet of MR in mid-late systole.

Symptoms of HCM : Some patients don’t have symptoms Symptoms include

Shortness of breath Fatigue Fainting Irregular heart beat Uncomfortable awareness of heart beat Chest pain Sudden Cardiac Death (SCD)

Physical examinationManeuvers that ↓ end-diastolic volume (↓ venous return & afterload, ↑ contractility) Vasodilators Inotropes Dehydration Valsalva Amyl nitrite Exercise → ↑ HCM murmur

Echocardiographic still frames from the parasternal long-axis. The left images were obtained prior to surgical myectomy, while the right images were obtained after myectomy in the same patient. The bottom images are magnified views of the left ventricular outflow tract. Note the surgical "bite" from the septum and enlargement of

the outflow tract. Ao = aortic root, LA = left atrium, LV = left ventricle.Differential diagnosisHCM Can be asymmetric Wall thickness > 15 mm LA: > 40 mm LVEDD : < 45 mm Diastolic function: always abnormalAthletic heart Concentric & regresses < 15 mm < 40 mm > 45 mm Normal Diagnosed HCM Echocardiography (ultrasound of heart) Electrocardiogram Exercise Test Cures and treatments for HCM? Medication (Beta-Blockers and Calcium Channel Blockers) Medication slows heart rate which improves heart functions Surgery of heart ICD (Implantable Cardioverter Defibrillator) Catheter Septal Ablation Alcohol kills heart muscle Therefore, enlarged septum shrinks to normal size, which improves heart functions Management The first step in developing a treatment plan is to demonstrate whether or not a dynamic

left ventricular outflow tract obstruction is present. Physical examination should reveal a dynamic outflow tract murmur often accompanied by

a bifid carotid impulse. The treatment of hypertrophic obstructive cardiomyopathy has been divided into

pharmacologic therapy versus more invasive procedures (dual-chamber pacing, catheter-based septal ablation, and septal myectomy)

Pharmacologic Therapythe goal of medications in hypertrophic cardiomyopathy is to blunt these catecholamine-induced phenomena

Drugs, which suppress contractility (negative inotropic agents) and suppress heart rate (negative chronotropic agents), have been the mainstays of therapy.

Drugs of choice- Beta-adrenergic receptor blockers - calcium entry blockers - disopyramide have been

Since most patients have symptoms only with exertion, the resting gradient should not be used as assessment of efficacy of medical therapy. The calcium channel blockers are a good alternativeif a beta-blocker cannot be tolerated.

The gold standard for symptomatic relief in patients with hypertrophic obstructive cardiomyopathy is septal myectomy.

HCM Patients Without Obstruction The activation of the local (myocardial tissue) renin-angiotensin cascade (RAS) has been

reported in HCM and other hypertrophic ventricles. Inhibition of the tissue RAS via intracoronary infusions of ACE inhibitor can improve

diastolic properties. However, systemic administration has not been widely studied. Caution must be taken prior to commencing therapy with antagonists of RAS

- ACE inhibitor- angiotensin receptor blocker, etc

that the patients have no resting or inducible outflow gradient. The afterload reduction that is produced by these agents can exacerbate the obstructivetendency, and counteract any gains made in diastolic function. Drugs, which slow or blunt the heart rate, can facilitate left ventricular filling by maintaining

an adequate diastolic filling period. Additionally, low-dose diuretics can be useful adjuncts in non-obstructive HCM.

A novel surgical technique has beendeveloped for patients with severely limiting dyspnea and apical HCM. Debulking of the apical myocardium results in a larger ventricular cavity and improved operating compliance at end-diastole

Prevention of Sudden Death in HCM Patients who have been resuscitated from cardiac arrest or have sustained ventricular

tachycardia are clearly at increased risk. secondary prevention of sudden death with implantable defibrillator appears to be

efficacious Primary prevention of sudden is much more difficult. HCM with one or more first-degree

relatives who have had SCD would appear to be a great risk. Those with the most severe forms of hypertrophy have also been reported to harbor increased risk.

Other factors such as nonsustained ventricular tachycardia, syncope in young patients, perfusion defects,hypotensive response to exercise, etc., ave also been studied in HCM. The approach to place ICDs in patients with prior cardiac arrest, sustained ventricular tachycardia, or a significant family history of sudden death should be

considered.DILATED CARDIOMYOPATHY Contractility decreases and ventricles dilate. Affects systolic function. Etiology

- viral myocarditis - toxins - alcohol - pregnancy - ischemia

Clinical manifestations same as with LVFDiagnosed : - ECHO - endomyocardial biopsy - ECG - chest x-ray - blood chemistriesManagement : same as with LVF - therapy dysrhythmias - heart transplant

Restrictive Cardiomyopathy Ventricle walls are rigid and do not stretch normally during filling.

Cardiac output decreases. Affects diastolic function.

Etiology - Amylodiosis - Sarcoidosis

Clinical manifestations - fatigue - activity intolerance - dyspnea - and other symptoms of LVF

Diagnosed

same as other cardiomyopathies Management

similar to hypertropic cardiomyopathy - Therapy dysrhythmias - Also tx underlying cause