Heart disease. Gross specimen of the sectioned left ventricle of a heart after a heart attack (myocardial infarction) and with an enlarged left ventricle (ventricular hypertrophy). A heart attack occurs when the blood flow to the heart is interrupted, causing the tissue deprived of blood to die (pale, bottom). Ventricular hypertrophy is the enlargement of the wall of the ventricle (lower chamber, left). It can be due to thickening of the muscle because of an increased workload caused by heart valve disease or high blood pressure. However, it may be due to dilation of the heart after the muscle is weakened by a heart attack or congestive heart failure.