Cardiomyopathies Flashcards
What are Cardiomyopathies?
Cardiomyopathy is a disease of the heart muscle that makes it harder for heart to pump blood to rest of your body, can lead to heart failure.
What are the 3 main types of Cardiomyopathy?
Dilated
Restrictive
Hypertrophic
What happens in Dilated Cardiomyopathy?
Ventricular chamber enlargement & systolic dysfunction with normal left ventricular wall thickness. 4cm ventricular dilation at autopsy
What are the causes of Dilated Cardiomyopathy?
Causes (Familial) 25% Autosomal dominant Causes (Secondary) Primary without family history - idiopathic Myocarditis Causes (secondary) Alcoholism Heart valve disease Autoimmune disorders After child birth Ingestion of drugs Thyroid disease Mitochondrial disorders
What is the abnormal Physiology in Dilated Cardiomyopathy?
Enlargement of the left ventricle
lower ejection fraction and increase in the ventricular wall stress and end systolic volumes.
Early compensatory mechanisms include an increase in heart rate and tone of the peripheral vascular system.
neurohumoral activation of the renin-angiotensin aldosterone system and an increase in circulating levels of catecholamines.
levels of natriuretic peptides are also increased.
Eventually these compensatory mechanisms become overwhelmed and the heart fails.
What is the presentation of Dilated Cardiomyopathy?
Dyspnoea, displaced apex beat, S3 or systolic murmur fatigue, angina, pulmonary congestion low cardiac output
What investigations can be done to help diagnose dilated cardiomyopathy?
Genetic Testing Viral serology ECG Chest X ray Cardiac catheterisation Cardiac MRI/CT Scan Exercise stress test Echocardiography
What is the treatment for dilated cardiomyopathy?
Counseling
Diet modification - fluid + Na restriction
Treatment of underlying cause.
Treat symptoms of heart failure and possibly orthotopic heart transplantation.
What happens in Hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disease.
It is defined by an increase in left ventricular wall thickness that is not solely explained by abnormal loading conditions.
This hypertrophy can occur in any region of the left ventricle but frequently involves the interventricular septum, which results in an obstruction of flow through the left ventricular (LV) outflow tract.
What are the causes of Hypertrophic cardiomyopathy?
Familial HCM occurs as an autosomal dominant Mendelian-inherited disease in approximately 50% of cases.
Most patients with HCM are asymptomatic. Unfortunately, the first clinical manifestation of the disease in such individuals may be sudden death, likely from ventricular tachycardia or fibrillation
What happens in terms of cardiac output in hypertrophic cardiomyopathy?
Most patients with HCM have abnormal diastolic function, which impairs ventricular filling and increases filling pressure, despite a normal or small ventricular cavity.
These patients have abnormal calcium kinetics and subendocardial ischemia, which are related to the profound hypertrophy and myopathic process.
What is the presentation of hypertrophic cardiomyopathy?
Sudden cardiac death Double carotid artery impulse, S3 gallop,
Syncope ejection systolic murmur
Presyncope
Congestive heart failure
Dizziness
Palpitations
Angina
What investigations can be done to help diagnose cardiomyopathy?
Hemoglobin level: Anemia exacerbates chest pain and dyspnea
Brain natriuretic peptide (BNP), troponin T levels: Elevated BNP, NT-proBNP, and troponin T levels are associated with a higher risk of cardiovascular events, heart failure, and death
Echocardiography
Chest Xray
Cardiac MRI
What is the management for hypertrophic cardiomyopathy?
HCM with symptoms; Beta blocker, Verapamil if there are side effects; Add disopyramide; mechanical therapy; Pacemaker, Septal myectomy/ablation.
What happens in restrictive cardiomyopathy?
Restrictive ventricular filling pattern
It is characterized by diastolic dysfunction with restrictive ventricular physiology, whereas systolic function often remains normal. Atrial enlargement occurs due to impaired ventricular filling during diastole, but the volume and wall thickness of the ventricles are usually normal.
What are the causes of restrictive cardiomyopathy?
RCM accounts for approximately 5% of all cases of diagnosed cardiomyopathies
It may be idiopathic, familial (has been related to troponin I or desmin mutations, the latter often in association with a skeletal myopathy), or associated with various systemic disorders, such as haemochromatosis, amyloidosis, sarcoidosis, Fabry’s disease, carcinoid syndrome, scleroderma, anthracycline toxicity, or previous radiation.
What leads to restrictive cardiomyopathy?
Increased stiffness of the myocardium due to familial or other secondary causes e.g amyloidosis
Infiltrative cardiomyopathies are characterized by deposition of abnormal substances (ie, amyloid proteins, noncaseating granulomas, iron) within the heart tissue.
Infiltration causes the ventricular walls to stiffen, leading to diastolic dysfunction.
Restrictive physiology predominates in the early stages, causing conduction abnormalities and diastolic heart failure.
Adverse remodelling may lead to systolic dysfunction and ventricular arrhythmias in advanced cases.
What happens in the abnormal physiology of restrictive cardiomyopathy?
Increased stiffness of the myocardium causes ventricular pressures to rise precipitously with small increases in volume.
Thus, accentuated filling occurs in early diastole and terminates abruptly at the end of the rapid filling phase.
Patients typically have reduced compliance (increased diastolic stiffness), and the left ventricle cannot fill adequately at normal filling pressures
Reduced left ventricular filling volume leads to a reduced cardiac output.
What is the presentation of restrictive cardiomyopathy?
comfortable in the sitting position because of fluid in the abdomen or lungs, and they frequently have ascites and pitting edema of the lower extremities.
The liver is usually enlarged and full of fluid, which may be painful.
Weight loss and cardiac cachexia are not uncommon.
Easy bruising, periorbital purpura, macroglossia, and other systemic findings, such as carpal tunnel syndrome, should be an indication for the clinician to consider amyloidosis.
Increased jugular venous pressure is present.
The pulse volume is decreased, consistent
What investigations can be done to investigate restrictive cardiomyopathy?
CBC, Serology, Amylodosis check, Chest Xray ,ECG ,Echocardiography, Catheterisation, MRI/Biopsy
What is the management for restrictive cardiomyopathy?
Heart failure medication
Guideline-directed medical therapy for heart failure, including angiotensin-converting enzyme inhibitors or angiotensin receptor II blockers, diuretics and aldosterone inhibitors should be initiated in patients with reduced LV
Antiarrhythmic Therapy
Immunosuppression- Steroids
Pacemaker
Cardiac transplantation
