Effect of pressure loading, volume loading and surgery on left ventricular chamber and myocardial stiffness in congenital heart disease, with a reevaluation of normal pediatric values

• Published in: Journal of the American College of Cardiology Vol. 8; no. 2; pp. 371 - 378
• Main Authors: Sandor, George G.S., Puterman, Martin L., Patterson, Michael W.H., Tipple, Marion A., Vince, Dennis J.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.08.1986; Elsevier Science
• Subjects: Adolescent; Adult; Biological and medical sciences; Blood Pressure; Cardiology. Vascular system; Child; Child, Preschool; Congenital heart diseases. Malformations of the aorta, pulmonary vessels and vena cava; Diastole; Elasticity; Heart; Heart Defects, Congenital - physiopathology; Heart Defects, Congenital - surgery; Heart Ventricles - physiopathology; Hemodynamics; Humans; Medical sciences; Stroke Volume; Human; Heart; Corrective surgery; Cardiac performance; Congenital; Heart disease; Cardiovascular disease; Child; Left ventricle; Hypertrophy
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/S0735-1097(86)80053-5

This study assessed the effect of pressure load, volume load and surgery on left ventricular chamber stiffness (b) and myocardial stiffness (k). A normal range for chamber stiffness and myocardial stiffness was also established. A total of 44 patients were studied: 8 were control subjects, 12 had volume load and 24 had pressure load. At cardiac catheterization simultaneous high fidelity pressures (P) and left ventricular volumes (V) were obtained in one diastolic cycle. From the relation P = aVb, operant chamber stiffness (b) was estimated for each patient. Similarly, the relation between stress (σ) and radius (B) was approximated by σ = cBfand the myocardial stiffness (k) derived for each patient. Mean values for chamber or myocardial stiffness for the diagnostic groups were not significantly different but differed within the operative groups. Mean values for b and k were greater in the post-open heart surgery group than in the post-closed heart surgery or nonsurgical group. Although the mean values for chamber stiffness and myocardial stiffness for the diagnostic groups were not different, there were more abnormal patients in the pressure load group (9 of 24) than in the volume load group (2 of 8) when the normal range was obtained from the control group. Thus, left ventricular operant chamber and myocardial stiffness are often preserved with volume loading, less frequently with pressure loading and rarely after open heart surgery.