The Characteristics of Diastolic Pressure-Volume Relationships in Primary Myocardial Disease

Utilizing the pressure-volume relationship, the indices of left ventricular diastolic compliance, SV/EDP-DP, dV/dP, and dV/VdP, ventricular stiffness index, I/P(dV/dP), and myocardial stiffness index, I/S(dD/dS) were evaluated of seven patients with normal left ventricle, eleven patients with hypertrophic and seven with congestive type of primary myocardial disease. Myocardial stiffness index was obtained from the equation of S = aekD, where S is a wall stress, a; a constant, D; a length of short axis, K; a stiffness constant. The mean values and standard errors of the means of SV/EDP DP, dV/dP, dV/VdP, I/P(dV/dP), and I/S(dD/dS) for normal group are 16.7 +/- 8.7 (ml/mmHg), 16.03 +/- 6.98 (ml/mmHg), 0.1259 +/- 0.0447 (mmHg-1), 0.0059 +/- 0.0032 (ml-1) and 0.603 +/- 0.153 (cm-1), for hypertrophic type are 10.5 +/- 5.5 (ml/mmHg), 7.23 +/- 7.42 (ml/mmHg), 0.0599 +/- 0.0736 (mmHg-1), 0.0174 +/- 0.0097 (ml-1) and 1.3555 +/- 0.3395 (cm-1), and for congestive type are 17.5 +/- 3.4 (ml/mmHg), 3.91 +/- 2.13 (ml/mmHg), 0.0250 +/- 0.0239 (mmHg-1), 0.0308 +/- 0.0126 (ml-1), and 3.287 +/- 1.272 (cm-1). There were highly significant differences between normal and primary myocardial disease in each indices except SV/EDP-DP. I/P(dV/dP), and I/S(dD/dS) had highly significant differences between hypertrophic and congestive type, the latter is stiffer than the former. The compliance index was not sensitive enough to separate two types of primary myocardial disease.