In hypertrophy the heart muscle becomes thicker. This can have different causes. Left ventricular hypertrophy results from an increase in left ventricular workload, e.g., during hypertension or aortic valve stenosis. Right ventricular hypertrophy results from an increase in right ventricular workload, e.g., emphysema or pulmonary embolization.
These causes are fundamentally different from [[Miscellaneous#Hypertrophic_Obstructive_Cardiomyopathy|hypertrophic obstructive cardiomyopathy (HCM)]], which is a congenital misalignment of cardiomyocytes resulting in hypertrophy.
Left and right ventricular hypertrophy can be distinguished on the ECG: