Regional variations in left ventricular myocyte diameter and nuclear length in post mortem population: implications in assessing myocyte hypertrophy

Cardiac hypertrophy can be appreciated microscopically by assessing for myocyte hypertrophy. Features of myocyte hypertrophy include increased myocyte diameter, together with increase in nuclear hyperchromicity, size and irregularity, and an increase in binucleated myocytes. There is limited literature to demonstrate whether these features are uniform within the myocardium in the post mortem setting. This study compared the myocyte diameter, myocyte nuclear length, and proportion binucleated myocytes between the free wall of the left ventricle and interventricular septum in 21 post mortem cases. It showed regional variation in myocyte hypertrophy parameters between the free walls of the left ventricle and intraventricular septum. Over 75% of cases showed significant differences in myocyte nuclear length and myocyte diameter (ANOVA one-way, p < 0.05), whereas binucleated myocyte nuclei did not show any significant difference. The result of this study has implication in sampling and assessing myocyte hypertrophy. Further studies are recommended to explore the reasons why this variation occurred and whether it is clinically significant.