Separation and quantitation of ventricular myosin heavy-chain from human atrial myocardium.

A discrepancy observed in electrophoretic mobility of human atrial and ventricular myosin heavy chains permitted the determination of these protein isoforms in myocardial biopsies. In ventricular biopsies we found only the heavy chain specific to this tissue whereas in atrial specimens we sometimes detected an extra heavy chain comigrating with the ventricular species. The peptide mapping of such preparations revealed peptides unique to ventricular heavy chain. Patients suffering from pressure overload expressed ventricular heavy chain at a higher frequency than those suffering from coronary heart disease (66% VS.29%), but this disparity was not found statistically significant (0.1 greater than P greater than 0.05).