Cardiomyopathy

Takotsubo cardiomyopathy (also known as stress cardiomyopathy, or “broken heart syndrome”) is a type of non-ischemic cardiomyopathy in which there is transient regional systolic dysfunction of the left ventricle. Patients present with symptoms of acute coronary syndrome, including chest pressure and shortness of breath. Electrocardiogram (ECG) may show ST-segment elevations. Coronary angiography can help in differentiating this condition from myocardial infarction. Echocardiogram can confirm the diagnosis by demonstrating characteristic apical wall motion abnormalities. Management includes the removal of inciting stressors and beta blockers.

Dilated cardiomyopathy (DCM) is the most common type of non-ischemic cardiomyopathy and a common cause of heart failure (HF). The cause may be idiopathic, familial, or secondary to a variety of underlying conditions. The disease is characterized by the enlargement of 1 or both ventricles and reduced systolic function. Patients typically present with symptoms of HF such as shortness of breath, fatigue, weakness, and peripheral edema. Blood tests, ECG, X-rays, echocardiography, and other cardiac studies and procedures are typically done to obtain the diagnosis. Treatment includes medications used to reduce volume overload (e.g., diuretics) and manage HF (e.g., beta-blockers). Devices such as pacemakers and cardioverter-defibrillators may also be needed. In severe cases, a heart transplant is required. Complications include thromboembolic events and sudden cardiac death.

Restrictive cardiomyopathy (RCM) is a fairly uncommon condition characterized by progressive stiffening of the cardiac muscle, which causes impaired relaxation and refilling of the heart during diastole, resulting in diastolic dysfunction and eventual heart failure. It most often occurs secondary to scarring, damage, and/or infiltration of the heart muscle, with amyloidosis being the most common cause. Infrequently, it may be idiopathic or inherited. Signs and symptoms include shortness of breath, low exercise tolerance, fatigue, and peripheral edema. Diagnosis is made through clinical suspicion and confirmed through ECG, X-ray, echocardiography, and cardiac MRI. Treatment includes medications for heart failure, implantable devices such as pacemakers and cardioverter–defibrillators, and heart transplantation in refractory cases.

Arrhythmogenic right ventricular cardiomyopathy is an inherited disorder of the heart muscle that affects the right ventricle (RV); it can cause rhythm disturbances and sudden cardiac death (SCD). The disorder results from mutations in the genes that encode desmosomal proteins involved in cell-to-cell adhesion. Symptomatic patients develop palpitations, arrhythmias leading to syncope, dyspnea, or chest pain. Diagnosis is based on clinical, ECG, echocardiographic, and imaging findings. Management aims to prevent SCD and symptom-causing arrhythmias. Treatment includes implantable cardioverter-defibrillator (ICD) placement, radiofrequency ablation to correct arrhythmias, and antiarrhythmic medications if possible. Prevention of disease progression with lifestyle changes is important, and cardiac transplantation may be necessary after 15 years.

Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). The list of causes is extensive, ranging from familial disorders to underlying diseases and infections. Patients often present with chest pain, dyspnea, palpitations, and/or syncope. Some patients may be completely asymptomatic, while others may present with sudden cardiac death as the first sign of an underlying condition. Diagnosis is made through the use of ECG and cardiac imaging such as echocardiography and cardiac MRI. Management involves medications typically used to treat heart failure, as well as implantable devices. In severe cases, heart transplantation may be necessary.

Hypertrophic cardiomyopathy (HCM) is the most commonly inherited cardiomyopathy, which is characterized by an asymmetric increase in thickness (hypertrophy) of the left ventricular wall, diastolic dysfunction, and often left ventricular outflow tract obstruction. Hypertrophic cardiomyopathy is caused by various gene mutations affecting the contractile components of the heart, known as sarcomeres. Inheritance of HCM is typically autosomal dominant, although sporadic mutations also occur. Patients may be asymptomatic, present with dyspnea and chest pain or suffer sudden cardiac death without prior symptoms. Diagnosis is made based on ECG, echocardiography, stress test, and cardiac MRI. Symptomatic HCM is typically treated with beta-blockers as the 1st-line therapy. Additional management depends on the presence of left ventricular outflow tract obstruction.