New diastolic filling parameters for evaluation of left ventricular hypertrophies by equilibrium gated studies

Detection of abnormal ventricular compliance is of clinical importance and is most commonly found in left ventricular hypertrophy (LVH). The use of peak filling rate alone provides a very poor separation of patients (Pts) with LVH. The authors have studied 13 normal (N1) and 50 Pts with LVH of various etiologies. All had ejection fraction > 55%, and 23 had cardiac catheterization. The method used by the authors was as follows: The LV time activity curve was replaced by weighted sum of 7 Fourier harmonics, expanded to 512 points. Rates were normalized and expressed as % stroke volume/sec. The following parameters were used: (A) Peak Filling Rate; (B) Duration from nadir of curve to (A); (C) Average Early Filling Rate within early 1/4 of diastole (normalized to heart rate); (D) same as (C) but within early 1/5; (E) linear discriminant function (df) containing values of (C) and (D) (df = (D + .59 x C)/100). Specificity kept by study design at 100%. The results were as follows: averages (Nl vs LVH +- SD): (A) 545 +- 61 vs 527 +- 172 NS; (B) 148 +- 11 vs 264 +- 120 p<.001; (C) 293 +- 36 vs 153 +- 56 p<.001;more » (D) 235 +- 35 vs 121 +- 45 p<.001; (E) 4.08 +- 0.55 vs 2.12 +- .076 p<.001; Sensitivity: A=48%; B-88%; C=98%; D=96%; E=98%. Ranking based on Fisher's discriminant measure, indicates top ranking for E (1.77) then C (1.72), D (1.44), B (.88). Besides parameter (E) no other combination of two PAR was found to be superior to single PAR (C). The authors conclude that average early filling rates within normalized early diatolic intervals are simple (can be used even as single PAR) and very sensitive for the evaluation of compliance abnormality in LVH.« less