This document discusses how pressure-volume (PV) indices can help evaluate diastolic dysfunction (DD), which occurs in about 50% of heart failure cases. PV exams provide load-dependent indices like Tau and -dp/dt min, as well as load-independent indices like stiffness constant β and R value to assess DD. Visual representations of Tau and dp/dt min on PV loops can directly compare diastolic function at baseline and with diastolic dysfunction.

1. PRESSURE-VOLUME (PV) INDICES IN
ASSESSMENT OF DIASTOLIC
DYSFUNCTION(DD)

2. PV CAN HELP TO EVALUATE DD
PV research has been focused on left ventricular (LV)
systolic function, understudied is diastolic function
DD occurs in ≈50% of heart failure cases
DD is characterized by increased stiffening of the LV
despite seemingly normal systolic function HFpEF (heart
failure with preserved ejection fraction)
Exercise intolerance is a hallmark feature of HFpEF
PV exams can help to evaluate DD based on
hemodynamic load dependent and independent indices

3. WHILE NOT DISCUSSING
SYSTOLIC PORTION
PV EVALUATION OF DD INCLUDES
ASSESSMENT OF INDICES
PV LOAD-DEPENDENT
PV LOAD-INDEPENDENT

4. PRESSURE-VOLUME EVALUATION OF DD
EXAMPLE OF LOAD DEPENDENT INDICES
Tau (in millisecond) ms
Time to peak filling (ms)
-dp/dt min (mmHg/sec)
Ratio (-dp/dt max vs. dp/dt
min)
LVEDP (mmHg)
Diastolic indices (mouse) Baseline (e.g.)
Mean ± SD
Diastolic
dysfunction
Heart rate 605 ± 50 similar
Tau Weiss (msec) 4.6 ± 0.78 ↑↑
-dp/dt min -9297.84 ± 3474.8 ↓
Ratio (-dp/dt max vs. dp/dt min) 1.05 Ratio ↑
LVEDP (mmHg) 3.28 ±0.585 ↑

5. Visual representation of Tau start
and end on PV loop (BASELINE)
Tau start
Tau end
∙ ∙∙∙∙∙
∙ ∙∙∙∙∙
∙∙∙∙∙∙
∙
∙∙∙∙∙
Visual representation of Tau start
and end on PV loop ( BASELINE vs.
post-TAC(B)
Tau start
Tau end
ABILITY TO DIRECTLY COMPARE DIASTOLIC VALUES DURING
PRESSURE-VOLUME
RECORDINGS

6. dp/dt
min
Visual representation of dp/dt min
on PV loop (BASELINE)
ABILITY TO DIRECTLY COMPARE DIASTOLIC VALUES DURING PRESSURE-VOLUME
RECORDING
∙∙∙∙∙
∙∙∙∙∙
Visual representation of dp/dt min on
PV loop (BASELINE vs. post-TAC(B)
∙∙
dp/dt
min

7. PRESSURE-VOLUME EVALUATION OF DD
LOAD INDEPENDENT INDICES
Diastolic indices (mouse load independent ) Baseline
Mean ± SD
Diastolic
dysfunction
Stiffness constant (β) 0.037±0.009 ↑↑
R value 0.7 and more 0.7 and more
•Stiffness constant β
•R value
•Weight normalized end diastolic elastance (mmHg/µl/weight)

8. Pressure-volume evaluation of diastolic dysfunction
(load independent) PMID: 16014610

9. 0
1
2
3
4
5
6
7
25 45 65
EDP(mmHg)
EDV (µl)
End Diastolic P-V relationship
(EDPVR)
Baseline DD
Basic PV software's uses e.g. exponential model fit (PMID: 1601461)
P= α* exp(β*V)
Example: EDP = 0.003123*exp(0.109596*EDV)
β is referred as chamber stiffness coefficient
α scaling and stiffness coefficient
ABILITY TO DIRECTLY COMPARE DIASTOLIC VALUES DURING ANALYSIS OF
PRESSURE-VOLUME RECORDINGS
User can e.g. calculate EDP
based on selected EDV using
provided formulas to create
visual curvilinear displays or
(and) to compare
relationship using stat.
software