Dilated cardiomyopathy: definition, risk factors, diagnosis, treatment and prognosis

Kamilė Burbaitė1, Justina Ramanavičiūtė1

1Lithuanian University of Health Sciences, Medical Academy, Faculty of Medicine


Dilated cardiomyopathy – disease, which occurs with symptoms caused by a weakened heart muscle. The reasons are various, but the majority cases are related with genetic predisposition to the disease, mostly type of inheritance is autosomal dominant, but could be linked with X chromosome related diseases. The disease could be without any symptoms for a lot of years, however, over time it usually manifests itself in symptoms of decompensated heart failure, such as an increased heart rate, shortness of breath, swelling of the legs, exercise intolerance and others. The main symptom of the disease is left ventricular dilatation and a decrease in the left ventricular ejection fraction, which is equal to or less than 40%. Diagnosis of this disease is based on a thorough medical history, physical examination, measurement of natriuretic peptide level, two-way echocardiographic examination using Doppler, and chest radiograph. Significant increase in N-terminal pro-type B-natriuretic peptide and its precursor N-terminal pro-type B natriuretic peptide (BNP > 35 pg/mL, NT-proBNP >125 pg/mL), which confirms the preliminary diagnosis of heart failure and identifies patients who require additional cardiac examination. Such patients undergo a two-way echocardiographic examination to assess left ventricular ejection fraction and diameter.  As an alternative, cardiac MRI may be performed. A linear and lateral chest radiograph is also important in diagnosis, during which cardiac enlargement and signs of venous stasis can be detected and assessed. An ECG is performed to monitor left ventricular hypertrophy. The two most important criteria in diagnosis can be used to determine dilated cardiomyopathy: 1) left ventricular dilation, which is determined by echocardiographic examination of the heart; 2) systolic dysfunction, decreased myocardial contractile force. A displacement fraction of less than 50% is considered systolic dysfunction. Treatment strategy – treatment focuses on the root cause of the disease, it is also important to pay attention to the stages of heart failure. The recommended pharmacological treatment consists of ACE inhibitors, angiotensin receptor blockers or angiotensin receptor non-prilisin inhibitors, as well as β-blockers and aldosterone antagonists in most patients with diuretic overload. Patients who continue to have symptoms vasodilators, ivabradine and digoxin may be prescripted. The prognosis is associated with decreasing left ventricular ejection fraction and increased terminal diastolic and terminal systolic volumes, increasing left ventricular mass limiting physiological development according to Doppler indices.

Keywords: cardiomyopathy, heart failure, prognosis.