11. Cardiomyopathies, myocarditis, pericardititis, endocarditis

What do cardiomyopathies primarily affect?

The structure and function of the heart muscle

How can cardiomyopathies impact the heart?

By causing significant mechanical and electrical dysfunction

What are cardiomyopathies?

Disorders of the heart muscle involving changes in myocardial wall thickness and heart chamber size.

What distinguishes primary cardiomyopathies from secondary cardiomyopathies?

Primary cardiomyopathies are intrinsic to the heart muscle and not related to other systemic diseases, while secondary cardiomyopathies are part of a broader systemic disorder but distinct from heart issues caused by ischemic disease, valvular abnormalities, or hypertension.

What is the classification of cardiomyopathies based on?

Cardiomyopathies are typically classified based on their structural and functional impacts on the heart:

• Dilated Cardiomyopathy (DCM)

• Hypertrophic Cardiomyopathy (HCM)

• Restrictive Cardiomyopathy (RCM)

• Arrhythmogenic Right Ventricular Dysplasia (ARVD)

Name three types of cardiomyopathies based on their classification.

Cardiomyopathies are typically classified based on their structural and functional impacts on the heart:

• Dilated Cardiomyopathy (DCM)

• Hypertrophic Cardiomyopathy (HCM)

• Restrictive Cardiomyopathy (RCM)

• Arrhythmogenic Right Ventricular Dysplasia (ARVD)

Dilated Cardiomyopathy (DCM)

What is the most common type of cardiomyopathy?

• Incidence and Prevalence: It is the most common type, with an incidence of 6 per 100,000 people per year, showing a male predominance.

What is the incidence of Dilated Cardiomyopathy per year?

• Incidence and Prevalence: It is the most common type, with an incidence of 6 per 100,000 people per year, showing a male predominance.

What is the main characteristic of Dilated Cardiomyopathy?

• Characteristics: Marked by progressive dilation of the ventricles often accompanied by ventricular hypertrophy.

What functional impact does Dilated Cardiomyopathy have on the heart?

• Functional Impact: Leads to systolic dysfunction, where the dilated heart struggles to pump blood efficiently.

Causes of dilated cardiomyopathy?

Idiopathic

Secondary Causes

What is the cause of Dilated Cardiomyopathy in about 50% of cases?

• Idiopathic: In about 50% of cases, no specific cause is identified.

What are some secondary causes of Dilated Cardiomyopathy?

• Secondary Causes: Can include viral myocarditis (e.g., Coxsackie virus), exposure to toxins such as alcohol, cocaine, and anthracyclines (e.g., doxorubicin, daunorubicin), nutritional deficiencies like thiamine deficiency (beriberi), malnutrition, genetic factors, and peripartum cardiomyopathy.

Pathophysiology of Dilated Cardiomyopathy

• Structural Damage:

• Compensatory Mechanisms:

  • Frank-Starling Law:

  • Progression to Dilation:

• Outcome:

What is the response triggered by initial structural damage to the myocardium?

• Structural Damage: Initial damage to the myocardium triggers compensatory mechanisms aimed at maintaining cardiac output.

What is the Frank-Starling Law?

The myocardium responds by increasing the left ventricular end-diastolic volume and developing eccentric hypertrophy to maintain stroke volume and cardiac output temporarily.

What happens during the progression to Dilation?

The heart begins to dilate, increasing the distance between myofibrils and reducing myocardial contractility.

What is the outcome of the progressive decrease in contractility?

A reduction in ejection fraction leading to heart failure.

Left ventricular failure (LVF) leads to:

Forward Failure

Backward Failure

Right Heart Failure

What is left ventricular failure (LVF)?

LVF is a serious condition where the left ventricle of the heart is unable to pump blood effectively.

How is left ventricular failure (LVF) categorized in terms of clinical consequences?

LVF can lead to forward failure, backward failure, and secondary right heart failure, each reflecting different aspects of deteriorating function and effects on the body.

What is Forward Failure?

Forward Failure occurs when the left ventricle fails to pump sufficient blood into the systemic circulation.

What are the consequences of diminished blood flow in the body?

Renal Dysfunction, Cerebral Dysfunction, Cold Extremities

What can poor kidney perfusion lead to?

Acute kidney injury and chronic kidney disease

What symptoms can reduced cerebral perfusion cause?

Dizziness, confusion, and cognitive impairments

Why do cold extremities occur?

Due to decreased blood flow to peripheral areas of the body

What is backward failure?

Backward failure occurs due to the inability of the left ventricle to receive and eject the blood coming from the lungs, leading to a buildup or "backup" of blood in the pulmonary circulation.

What are the consequences of increased pressure in the pulmonary circulation?

Pulmonary Congestion and Edema

How does pulmonary congestion and edema affect gas exchange?

Fluid leaks into the alveolar and interstitial spaces, impairing gas exchange.

What is Right Heart Failure?

A secondary consequence of chronic left ventricular failure, where increased pressure in the pulmonary circulation strains the right ventricle.

What are the consequences of diminished blood flow in the body?

• Consequences: The right ventricle struggles to pump blood effectively into the overloaded pulmonary arteries, leading to:

  • Systemic Circulation Congestion: Manifests as peripheral edema (swelling of ankles and feet), abdominal edema (ascites), and other signs of fluid overload such as jugular venous distention.

How does the right ventricle struggling to pump blood effectively manifest in the body?

• Consequences: The right ventricle struggles to pump blood effectively into the overloaded pulmonary arteries, leading to:

  • Systemic Circulation Congestion: Manifests as peripheral edema (swelling of ankles and feet), abdominal edema (ascites), and other signs of fluid overload such as jugular venous distention.

Pathological and Clinical Features of Dilated Cardiomyopathy

• Heart Enlargement:

• Valvular Changes:

• Coronary Arteries:

• Ventricular Changes:

• Microscopic Changes:

What is a common characteristic of heart enlargement in cardiomyopathy?

The heart is typically enlarged, often 2-3 times heavier than normal, primarily due to the dilation of all chambers.

What valvular changes are typically seen in cardiomyopathy patients?

There are usually no primary valvular diseases; however, valvular regurgitation (especially mitral regurgitation) may occur secondary to the dilation of the heart.

Are coronary arteries usually affected by atherosclerosis in non-ischemic cardiomyopathy?

Generally free from significant atherosclerosis if the cause is non-ischemic cardiomyopathy.

What is eccentric hypertrophy of the left ventricle characterized by?

An increase in the size of the ventricular cavity with normal or decreased wall thickness.

What are some microscopic changes seen in the myocardium due to structural damage?

Enlarged muscle cells with atypical nuclei, signs of interstitial and endocardial fibrosis, absence of inflammatory infiltrate, and potential formation of mural thrombi.

What are the early signs of DCM?

Exertional dyspnea, palpitations, and chest pressure.

What are the late signs of DCM?

Fatigue, angina pectoris, and signs of fluid overload like ankle edema and ascites.

Physical Examination of DCM

• Mitral or Tricuspid Valve Regurgitation:

• S3 Gallop:

• Left Ventricular Impulse Displacement:

• Jugular Venous Distention (JVD):

• Rales (Crackles):

• Palpitations:

• Peripheral and Abdominal Edema:

What is the cause of Mitral or Tricuspid Valve Regurgitation?

• Mitral or Tricuspid Valve Regurgitation: Detected as a systolic murmur during auscultation. This occurs due to dilation of the ventricles, which can lead to improper closure of the valves.

When is the S3 Gallop sound heard in the cardiac cycle?

• S3 Gallop: This is a low-frequency sound heard shortly after S2 (the "dub" of "lub-dub") during the rapid filling phase of the ventricle and is indicative of increased ventricular filling pressures, often associated with heart failure.

What can a laterally displaced point of maximal impulse (PMI) indicate?

• Left Ventricular Impulse Displacement: A laterally displaced point of maximal impulse (PMI) can indicate left ventricular hypertrophy or dilation.

What does Jugular Venous Distention (JVD) suggest?

• Jugular Venous Distention (JVD): Suggestive of elevated right atrial pressure, commonly seen in heart failure.

What do crackles (rales) heard over both lung fields indicate?

• Rales (Crackles): Heard over both lung fields, indicating fluid accumulation within the lung interstitium, a sign of pulmonary edema.

How might patients describe palpitations?

• Palpitations: Patients may report feeling their heart beating irregularly or rapidly.

Diagnostics of DCM

• Laboratory Tests:

  • BNP (Brain Natriuretic Peptide):

  • Troponins and CK-MB:

• Electrocardiogram (ECG):

  • Conduction Disorders:

  • Arrhythmias:

  • Reduced QRS Amplitude:

  • Axis Changes:

• Echocardiography:

  • Ventricular and Atrial Dilation:

  • Decreased Ejection Fraction:

  • Wall Motion Abnormalities:

• Chest X-Ray:

  • Cardiomegaly:

  • Pulmonary Edema:

What does peripheral and abdominal edema indicate?

• Peripheral and Abdominal Edema: Fluid accumulation in the extremities and abdomen, indicating systemic congestion often seen in right heart failure.

• Laboratory Tests:

• Laboratory Tests:

  • BNP (Brain Natriuretic Peptide):

  • Troponins and CK-MB:

What does an elevated BNP level indicate in laboratory tests?

• BNP (Brain Natriuretic Peptide): Elevated levels are indicative of heart failure as BNP is released in response to ventricular volume expansion and pressure overload.

When should Troponins and CK-MB markers be significantly elevated in laboratory tests?

• Troponins and CK-MB: These markers of myocardial injury should not be significantly elevated unless there is concurrent myocardial infarction.

• Electrocardiogram (ECG)

• Electrocardiogram (ECG):

  • Conduction Disorders:

  • Arrhythmias:

  • Reduced QRS Amplitude:

  • Axis Changes:

What are some examples of conduction disorders that may be seen on an ECG in cardiac pathology?

• Conduction Disorders: Such as atrioventricular (AV) block or left bundle branch block, which might suggest a genetic or inflammatory etiology and generally carry a poorer prognosis.

• Arrhythmias:

  .

• Including atrial fibrillation, which may arise due to tissue fibrosis and abnormal electrical re-entry.

How can reduced QRS amplitude on an ECG be interpreted in terms of cardiac tissue mass?

• Reduced QRS Amplitude: Indicates decreased contractile cardiac tissue mass.

What can deviations in the cardiac axis on an ECG indicate in relation to the heart's structure?

• Axis Changes: Deviations in the cardiac axis can occur due to structural changes in the heart from dilation.

• Echocardiography

• Echocardiography:

  • Ventricular and Atrial Dilation:

  • Decreased Ejection Fraction:

  • Wall Motion Abnormalities:

What does echocardiography allow for the direct visualization of?

• Ventricular and Atrial Dilation: Direct visualization of chamber sizes.

What does decreased ejection fraction quantify?

• Decreased Ejection Fraction: Quantifies the reduction in the left ventricular pumping capacity.

What do wall motion abnormalities, such as hypokinesis, indicate during the cardiac cycle?

• Wall Motion Abnormalities: Such as hypokinesis, which indicates reduced wall movement during the cardiac cycle.

• Chest X-Ray:

• Chest X-Ray:

  • Cardiomegaly:

  • Pulmonary Edema:

What is Cardiomegaly?

• Cardiomegaly: General enlargement of the heart, particularly of the left side, often with a balloon-like appearance.

What is Pulmonary Edema?

• Pulmonary Edema: Fluid in the alveolar and interstitial lung spaces, indicative of left-sided heart failure decompensation.

Treatment Strategies for DCM

1. Lifestyle Modifications:

   • Avoid Alcohol and Cardiotoxic Agents:

   • Manage Infections:

2. Heart Failure Management:

   • Sodium Restriction:

   • ACE Inhibitors:

   • Beta-Blockers:

   • Diuretics:

   • Digoxin:

   • Aldosterone Receptor Antagonists:

3. Anticoagulation:

   • Warfarin or Other Anticoagulants:

4. Device Implantation:

   • Implantable Cardioverter Defibrillator (ICD):

5. Heart Transplantation:

1. Lifestyle Modifications:

1. Lifestyle Modifications:

   • Avoid Alcohol and Cardiotoxic Agents:

   • Manage Infections:

What lifestyle modifications can help prevent further deterioration of cardiac function?

• Avoid Alcohol and Cardiotoxic Agents: These substances can exacerbate myocardial damage and should be avoided to prevent further deterioration of cardiac function.

Why is it important to manage infections promptly for individuals with heart issues?

• Manage Infections: Prompt treatment of infections to avoid additional stress on the heart.

1. Heart Failure Management:

1. Heart Failure Management:

   • Sodium Restriction:

   • ACE Inhibitors:

   • Beta-Blockers:

   • Diuretics:

   • Digoxin:

   • Aldosterone Receptor Antagonists:

How does sodium restriction help manage blood pressure and fluid retention?

• Sodium Restriction: Helps to reduce fluid retention and manage blood pressure.

How do ACE Inhibitors benefit heart function?

• ACE Inhibitors: Aid in vasodilation, reducing the heart's workload and improving survival.

What is the role of Beta-Blockers in heart health?

• Beta-Blockers: Decrease heart rate and blood pressure, reducing the heart's oxygen demand and also beneficial in arrhythmia control.

What is the primary purpose of diuretics?

• Diuretics: Used to remove excess fluid from the body, relieving symptoms such as swelling and shortness of breath.

How does digoxin benefit the heart?

• Digoxin: Helps strengthen heart muscle contractions and can control heart rate.

What are the main effects of Aldosterone Receptor Antagonists?

• Aldosterone Receptor Antagonists: Reduce fluid retention and provide cardioprotective effects.

1. Anticoagulation:

1. Anticoagulation:

   • Warfarin or Other Anticoagulants:

What is the purpose of anticoagulation in cases of intraventricular thrombus or atrial fibrillation?

• Warfarin or Other Anticoagulants: Necessary in cases of intraventricular thrombus or atrial fibrillation to prevent thromboembolic events such as stroke.

Why is an Implantable Cardioverter Defibrillator (ICD) recommended for patients with an ejection fraction of less than 35%?

1. Device Implantation:

   • Implantable Cardioverter Defibrillator (ICD): Recommended for patients with an ejection fraction of less than 35% to prevent sudden cardiac death due to life-threatening arrhythmias like ventricular fibrillation.

1. Heart Transplantation:

When is heart transplantation considered?

• Considered when all other treatments have failed and the patient’s condition continues to deteriorate, or in young patients with severe disease.

Complications of DCM

1. Progressive Left Ventricular Failure:

2. Systemic Thromboembolism:

3. Arrhythmias:

4. Sudden Cardiac Death:

5. Prognosis:

What can Progressive Left Ventricular Failure lead to?

• Can lead to cor bilaterale (bilateral heart failure), where both the left and right sides of the heart fail.

What complications can Systemic Thromboembolism cause?

• May cause stroke, pulmonary embolism, or acute mesenteric ischemia due to blood clots traveling to different parts of the body.

What are Ventricular Tachycardia and Ventricular Fibrillation?

• Ventricular Tachycardia and Ventricular Fibrillation: Severe types of arrhythmia that can lead to sudden cardiac death if not promptly treated.

Why is Sudden Cardiac Death a significant risk in patients with cardiomyopathy?

• A significant risk in patients with cardiomyopathy, particularly those with severe left ventricular dysfunction and arrhythmias.

What is the prognosis for patients diagnosed with cardiomyopathy?

• Approximately 50% of patients may die within two years of diagnosis, primarily due to progressive cardiac failure or arrhythmias.

HYPERTROPHIC CARDIOMYOPATHY

Etiology of Hypertrophic Cardiomyopathy

Pathophysiology

Pathological Changes

Clinical Symptoms

Physical Examination Findings

Diagnostics

What is hypertrophic cardiomyopathy (HCM) characterized by?

Excessive thickening of the heart muscle, particularly the ventricles, without an obvious cause such as high blood pressure or aortic stenosis.

Etiology of Hypertrophic Cardiomyopathy

• Primary Hypertrophic Cardiomyopathy

• Secondary Causes

• Primary Hypertrophic Cardiomyopathy

Why is hypertrophic cardiomyopathy (HCM) considered a significant health concern?

Due to its implications, including sudden cardiac death, especially in young athletes.

What is Primary Hypertrophic Cardiomyopathy characterized by?

It is characterized by being the most common hereditary heart disease.

Which pattern of inheritance does Primary Hypertrophic Cardiomyopathy follow?

It follows an autosomal dominant pattern of inheritance with variable penetrance.

Where are the genetic mutations responsible for Primary Hypertrophic Cardiomyopathy typically found?

The genetic mutations are typically found in the genes that encode sarcomeric proteins.

What are some of the commonly involved proteins in Primary Hypertrophic Cardiomyopathy?

Commonly involved proteins include myosin heavy chain, myosin binding protein C, cardiac troponins, and tropomyosins.

What percentage of cases of Primary Hypertrophic Cardiomyopathy are primary, with no other underlying cardiovascular condition?

Approximately 60-90% of cases are primary.

• Secondary Causes

What are some examples of secondary causes of cardiac hypertrophy?

• These include conditions that traditionally cause cardiac hypertrophy such as chronic hypertension and aortic stenosis. Other systemic diseases like Fabry disease and amyloidosis can also lead to hypertrophic changes in the heart muscle.

How can conditions like Fabry disease and amyloidosis contribute to hypertrophic changes in the heart muscle?

• Secondary Causes:

  • These include conditions that traditionally cause cardiac hypertrophy such as chronic hypertension and aortic stenosis. Other systemic diseases like Fabry disease and amyloidosis can also lead to hypertrophic changes in the heart muscle.

Pathophysiology

• Concentric Hypertrophy:

• Diastolic Dysfunction:

• Left Ventricular Outflow Tract Obstruction:

What is the characteristic hypertrophy seen in HCM?

• Concentric Hypertrophy:

  • HCM is most often characterized by concentric hypertrophy, particularly of the left ventricular septum. This abnormal thickening can lead to a reduction in the size of the ventricular cavity.

  • The septal hypertrophy can cause mechanical obstruction to blood flow out of the heart (left ventricular outflow tract obstruction), especially during systole.

How can septal hypertrophy in HCM affect blood flow out of the heart?

• The septal hypertrophy can cause mechanical obstruction to blood flow out of the heart (left ventricular outflow tract obstruction), especially during systole.