Effects of hypertension on heart and kidney. Hypertension (high blood pressure) has caused renal atrophy and scarring, and left ventricular hypertrophy in the sectioned heart (right). In chronic hypertension the arteriole walls thicken. Resulting reduced renal blood flow causes chronic ischaemia and atrophy of the kidney tubules. Loss of functioning nephrons eventually leads to chronic renal failure and shrunken 'end-stage' kidneys as seen here. The heart's left ventricle wall has enlarged to allow for the increased work of pumping blood to the tissues when arterial pressure is high. Hypertension and ventricular hypertrophy are associated with heart failure.