Effect of myocardial hypertrophy on systolic and diastolic function in children: insights from the force-frequency and relaxation-frequency relationships
Anirban Banerjee, MD, FACCa,
Alan M. Mendelsohn, MD, FACCa,
Timothy K. Knilans, MD, FACCa,
Richard A. Meyer, MD, FACCa and
David C. Schwartz, MD, FACCa
a Division of Cardiology, Children’s Hospital Medical Center, Cincinnati, Ohio, USA
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Figure 1 Time constant of relaxation measured at a constant heart rate of 120 beats per minute, by the zero asymptote method ( L), was prolonged in children with myocardial hypertrophy suggesting slower relaxation. Error bars represent standard deviation (*p < 0.001).
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Figure 2 Left-ventricular end-diastolic stress-strain relationship in a patient with myocardial hypertrophy, depicting a typical exponential curve fit (R2 = 0.99).
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Figure 3 The force-frequency relationship (dP/dtmax vs. heart rate) is depicted in the control (squares) and hypertrophy (circles) groups. The dP/dtmax increases with each increment in heart rate, producing a positive force-frequency relationship in each group. At each level of heart rate the mean dP/dtmax is not significantly different and the slope of the force-frequency relationship remains unchanged between the two groups. Error bars represent standard error of mean.
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