#Low_Voltage_ECG : ✍️Definition: The QRS is said to be low voltage when: 👉The amplitudes of all the QRS complexes in the limb leads are < 5 mm; OR 👉The amplitudes of all the QRS complexes in the precordial leads are < 10 mm ✍️Mechanisms Low voltage is produced by… The “damping” effect of increased layers of fluid, fat or air between the heart and the recording electrode. Loss of viable myocardium. Diffuse infiltration or myxoedematous involvement of the heart. ✍️Causes Specific causes of low voltage include: 👉Fluid: Pericardial effusion; Pleural effusion 👉Fat: Obesity 👉Air: Emphysema; Pneumothorax 👉Infiltrative / Connective Tissue Disorders: Myxoedema; infiltrative myocardial diseases — i.e. restrictive cardiomyopathy due to amyloidosis, sarcoidosis, haemochromatosis; constrictive pericarditis; and scleroderma. 👉Loss of viable myocardium: Previous massive MI; end-stage dilated cardiomyopathy ✍️Most important cause: Massive pericardial effusion with triad of: Low voltage Tachycardia Electrical alternans Patients with this triad need to be immediately assessed for clinical or echocardiographic evidence of tamponade #ECG_note #تعال_استفيد