The Morphology of the Aging Heart

Jagdish Butany, MBBS, MS, FRCPC and Manmeet S. Ahluwalia, MBBS, Department of Pathology, Toronto General Hospital, University Health Network, Toronto, ON.

With advancing age, the cardiovascular system undergoes subtle but progressive changes that result in altered function. The endocardium becomes thicker and opaque, left ventricular (LV) wall thickness increases and there is increased interstitial fibrosis in the myocardium. Although myocyte size increases, the number of myocytes decreases, as does the number of cells in the conduction system. The decrease in the filling rate of LV in early diastole is accompanied by a greater rate of filling in late diastole augmented by atrial contraction. Maximum achievable heart rate and ejection fraction (with exercise) decreases. All these changes make increasing age a significant independent risk factor for heart failure, the most common reason for hospitalisation in patients older than 65 years.
Key words: aging, cardiovascular disease, myocardium, fibrosis, heart failure.