Electrocardiogram (ECG) indicating ventricular tachycardia in a case of cardiomyopathy. Electrocardiography records electrical activity in heart; certain patterns are characteristic of disease conditions. The ink pattern is recorded on a strip of moving paper from electrodes placed on the skin of all four limbs and the chest wall; a total of 12 electrodes are typically used. Ventricular tachycardia means an increase in ventricular contraction above the normal rate - the left & right ventricles are the heart's large pumping chambers. Cardiomyopathy is a term used to describe any chronic disorder affecting the heart muscle. Causes of cardiomyopathy are obscure.