Cardiomypathy, Infectious, inflammatory Cardiac Disorders

Cardiomyopathy

Definition

• Cardiomyopathy: Disease of the heart muscle associated with cardiac dysfunction.

• Classified based on structural and functional abnormalities.

• 

Classifications

• Dilated Cardiomyopathy (DCM)

  • Most common form characterized by significant dilation of ventricles and systolic dysfunction.

  • Decreased ejection fraction and increased end-diastolic volume, leading to heart failure.

• Hypertrophic Cardiomyopathy (HCM)

  • Characterized by increased heart muscle size, particularly along the septum.

  • Leading cause of sudden death in adolescents and young adults, especially athletes.

• Restrictive (Constrictive) Cardiomyopathy (RCM)

  • Rigid ventricular walls resulting in impaired diastolic filling.

  • Symptoms similar to constrictive pericarditis.

• Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVC/D)

  • Inherited form characterized by replacement of myocardium with scar and adipose tissue.

• Unclassified Cardiomyopathy

  • Displays features of multiple types and caused by conditions like fibroelastosis and mitochondrial diseases.

Pathophysiology

• Impaired cardiac output leads to decreased stroke volume, activating sympathetic nervous system and the renin-angiotensin-aldosterone response.

• Resulting in increased systemic vascular resistance and fluid retention, increasing workload on the heart.

Clinical Implications

• Sodium is the major electrolyte involved; often leads to fluid overload and heart failure.

• Diagnosis often through echocardiogram (decreased ejection fraction).

Dilated Cardiomyopathy (DCM)

Characteristics

• Distinguished by ventricular dilation without hypertrophy.

• Leads to poor systolic function and high end-diastolic pressure, resulting in fluid overload and heart failure.

Causes

• Over 75 possible conditions can cause DCM.

• Idiopathic cases account for 20%-30% of nonischemic DCM cases.

Hypertrophic Cardiomyopathy (HCM)

Genetics and Risk

• Autosomal dominant inheritance.

• Increased muscle size leads to ischemia due to restricted blood flow.

Clinical Screening

• Annual ECG, physical exam, and echocardiograms advised for asymptomatic patients with positive genetic testing.

Symptoms and Complications

• Possible obstruction of left ventricular outflow tract (LVOT). Symptoms include dyspnea, syncope, and arrhythmias.

Management

• Medical management through hydration, beta-blockers, or surgical options like myectomy or alcohol septal ablation.

Restrictive Cardiomyopathy (RCM)

Characteristics

• Caused by rigid ventricular walls, leading to graduated increases in filling pressures and impaired diastolic function.

• Symptoms similar to constrictive pericarditis, including dyspnea and chest pain.

Causes

• May be either inherited or from systemic diseases. Diagnosis may require an endomyocardial biopsy.

Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVC/D)

Clinical Presentation

• Initially localized in the right ventricle; can progress to the left ventricle.

• Symptoms may include palpitations, syncope, sudden cardiac death.

Diagnosis and Management

• Diagnosis through ECG, echo, cardiac MRI, and family history. Genetic counseling recommended.

Unclassified Cardiomyopathies

• Characteristics are mixed from other types and relate to various underlying conditions.

Diagnosis of Cardiomyopathy

Procedures

• Effective diagnosis involves patient history, echocardiography, and ruling out other heart conditions.

• ECG findings may show arrhythmias and hypertrophy indicators.

Management

• Management includes identifying causes, correcting heart failure, and potentially implanted devices for arrhythmias.

Surgical Management

Heart Transplantation

• Considered when heart failure progresses beyond medical treatment.

• Challenges with donor availability and managing rejection versus infection.

Ventricular Assist Devices (VAD)

• Used for patients awaiting transplant or with advanced heart failure.

• Increased use in destination therapy for patients ineligible for transplant.

Total Artificial Hearts

• Designed to replace both ventricles; complications include bleeding and infection.

Infectious Diseases of the Heart

Types of Infections

• Infective Endocarditis

  • Infection of heart valve endothelium, diagnosed by blood cultures and echocardiography. Symptoms include fever and heart murmur.

• Myocarditis

  • Inflammation of myocardium; can result in dilation and heart failure. Symptoms may include flulike symptoms, fatigue, and dyspnea.

• Pericarditis

  • Inflammation of the pericardium, symptoms include chest pain and can lead to effusion or cardiac tamponade.

  • 

Diagnosis and Management

• Diagnosis often based on symptoms and echocardiography. Treatment includes IV antibiotics and may require surgical intervention for severe cases.