Radionuclide absolute left ventricular volumes during exercise: Validation in normals by Fick measurements

ABSTRACTS

THE

SEQUENCE

OF

J.A.

Abildskov,

M.J.

Burgess,

Lake

City,

MD, MD;

ta

largely

refractory suction

R.L.

is

but

and

established

Using

is

regional

coexisting

covery

times

and

All

opposite moved

cardial

RS

showed

of

action local

in

late

activation. tracks

of

AS.

the

from

greater

to

apex

reflecting

corresponds

evidence

of

to

+

44

in

early

in

the

direct

that

effects

slope

in dog

RS

of

in

the

that and

of is

known

is

In

RNA,

fore

with

ted and

the for

1.01;

CO

five

.86,

to

been

developed alone.

AGE

IN

ON

THE

COMPONENTS

NORMAL

OF

ATRIOVENTRICULAR

MAN

Dhirendra N. Das, MD; Jerome L. Fleg, FlD, FACC; Edward G. Lakatta, MD, Gerontology Research Center, National Institute on Aging, NIH, Baltimore, MD. It is not known whether the age-related increase in PR interval is due to slowed conduction proximal (PH) or distal to the His bundle (HV) or both. Using a microprocessor-assisted high resolution ECG (Marquette MAC-I) to signal average 512 cardiac cycles, we recorded high frequency, low amplitude ECG signals from the body surface of 63 normal volunteers ages 21 to 79 (G = 46.1t17.0 yr) from the Baltimore Longitudinal Study on Aging. All subjects were clinically free of heart disease, had a normal resting ECG, and negative maximal treadmill exercise test. His bundle potentials were identified in 53 individuals; the 10 persons in whom a His spike could not be identified did not differ in age or resting heart rate (HR) from those with His potentials, but had shorter PR intervals (131.5k15.3 vs 155.8k18.5 msec, pc.001). In those subjects with demonstrable His activity, the following relationships were found with age (in years): PR

=

139.6

msec

+

0.35

age,

r

=

.32,

pc.02

PH

=

101.1

msec

+

0.31

age,

r

=

.33,

pc.02

HV

=

38.3

msec

HR

=

72.6

beats/min

+

0.04

age, -0.01

r age,

=

.09, r

=

=

NS

-.19,

p

p

=

NS

Conclusions: 1. The success rate of recordinq surface His ootentials varies directly with the PR interval. 2. HV interval does not change with adult age. 3. The prolongation of PR interval seen with advancing age is due to conduction delay proximal to the His bundle.

1.0; .65

SV

L/min,

The

.77.

Nine an

LV

but

RAD

RAO

method the

ml,

.9C,

ESV 4.7X,

FP

RNA

studies

the

nongeometric

and

were

r value

validated

the

has

from

count

is be

re-

for

technique

can

were

estimate

1.01;

LVEF

A

be-

correla-

of

I)

V=

supine

minutes

of

average

be

RAfl silhou-

and

22.4

to

completely

relationship

completely on

counts

namely

ten

.70;

configurations was

of

LVV,

determinations

volume-to-count

configuration

A,

a

biplane

.93,

balvol-

total by

error

ml,

on that

determined

and

Conclusions:

allows

of

area,

standard

yielded

.97.

measurement

R,

shown

determined

EDV

mea-

count-

experiments

standard 11.6

a

underwent

reproducibility

of

on

indwelling,

and

.8l,

resolution.

supported

results

method

which 2)

experimentally,

OF

LVV

relied

nongeometric

was

patients

date,

has

silhouettes

have

(LVA)

been

To

RNA

strictly

the

catheter

Reproducibility

data

ticrystal

25

correlation,

evaluate

parameters

most

Vc

further

angiograms

The

samples.

a

ratio,

WI vol-

angiography

develop

relationship

Uni-

recently

(FP)

purpose,

respectively:

15.9 ml,

method.

EFFECT

study

regression

.98,

for

this

has

spatial

the

MO:

ventricular

poor

between

LV

pass

dimensions

to is

from

left

blood

based

this

and

This

LVA.

between follows

RNA

related

pigtail

biplane

to to

For

relationship

.6?ZA'+ FP

FP

This

traced

FROM

Milwaukee,

angiographic

due

volumes

counts.

analogous

peated

human

heart.

CONDUCTION

with

directly

maximum

as

epicardial

is opposite

findings of

exlarg-

endocardial

suggest

LVV

of first

designed

relationship.

loons

ettes

differences of

RS

AS

maps. by

of

from

Dymond,

radionuclide

radionuclide

was

D.

techniques

counting

errors

Vc=.32(R-6)'.35.

of

direction

suggested

study

volume

to

of

VOLUME

Ctr,

of

equilibrium

volume

and

Medical

measurement

requires

introduces

VENTRICULAR

MD,

Sinai

nongeometric

of

planimetry

ume epi-

differ-

derivative

time

features

DD

recovery

small same

is

and

patterns

Schmidt,

gated

which

This

to

suggest

local

(RNA)

using

measurement on

D.H.

Wisconsin-Mt

with

surement

precordial of

with

endocardial

these

of

(LVV)

which

ef-

normal

results

indirect, while

bound-

(DD)

Opposing

briefer

re-

maps

greater

the

eval-

bound-

from

durations

be

multiple

Findings

AS.

slopes

during

Although

This

by

reported

LEFT

ANGIOGRAPNY.

scintigraphic

ume

different

MS,

of

The

OF

RADIONUCLIDE

Grenier,

versity

repolarizacan

of

magnitude

expected

lo-

R.

MEASUREMENT

PASS

potential

transition

time.

en-

short

NONGEOMETRIC FIRST

limited

to

THURSDAY, APRIL 29, 1982 AM GUANTITATWE TECHNIGUES IN RADIONUCLIDE ANGIOGRAPHY 8:30- 10:00

gradients

of

of

by

is compatible

activation

first

wave

Daof

successive

patterns

that

base

maps

long these

reflects

acti-

indicate

distributions

T

with

recovery

potentials

RS

with

potential

RS

from

DD

Salt

measures

surface

individual

is determined

Endocardial

action

MD;

define.

ventricles

map

followed

durations

of

boundaries

serial DD

is opposite and

human

from

inferiorly

pected er

DD

thorax

recovery

ences

Green,

and

by

body

derivative but

polarity

usually

and

all

We calculated upper

in

particular of

removes

subjects.

RS

of

of

a

with

characteristics

includes

Calculation

to

Results

both

sensitivity

features

durations

to

gradients

RS

of

importance

equal

difficult

determined

uated.

fectively

has more

apex-base

AS.

right

Utah,

distributions

and

-

of

records.

RS

aries.

University

potential

recovery.

aries.

L.S.

animals

cal

major

VENTRICLES MD;

experimental

microelectrode

do-epicardial

maps

PhD.,

(RS)

periods,

and

HUMAN

Ishikawa,

Lux,

(AS) from

and

tion

IN

T.

sequence

sequence

is

FACC;

Utah.

Repolarization vation

REPOLARIZATION

unique

determined

for

the

mul-

views.

ABSOLUTE LEFT VENTRICULAR VOLUMES DURING RADIONUCLIDE EXERCISE : VALIDATION IN NORMALS BY FICK MEASUREMENTS. W. Wyns, .I. Melin, Y. Dehouck, R. Vanbutsele, M. Steels, L. Piret, J.M. Detry. University of Louvain, Brussels, Belgium, Radionuclide (Rn) absolute left ventricular volumes (LVV) measured at rest correlate well with the angiographic volumes. During exercise (Ex) however, no reference (Rf) values are available. In order to validate Ex isotopic data, eight healthy males had simultaneous Fick stroke volume (SV) measurements and gated blood pool studies (LAO 45") at rest (supine and upright) and during 60" upright Ex at three consecutive workloads (mean heart rate was 110, 147, 181 beats/min). Radionuclide (Rn) left ventricular volumes (LW) were calculated from end-diastolic (ED) and end-systolic (ES) counts corrected in each subject for background (perisystolic region of interest), decay and attenuation (e-pd) : b was .15 cm-l and d was the depth of the center of LV. The activity of a blood sample was used to calculate LVV from LV counts; LW were further corrected for hemoconcentration during Ex. Rf LW were calculated from the Fick SV and Rn ejection fraction. Mean Rf EDV at rest and during Ex was 164 ml (from 110 to 222 ml) and mean Rf ESV was 48 ml (from 7 to 89 ml). Rf and Rn LVV were closely correlated (r=.96, n=80, SEE= 15 ml) but Rn LW were significantly (p<.OOl) underestimated : Rn LVV = .78 Rf LVV + 1.7 ml. The correlation between Rn and Rf was better for ESV (r=.88, n=40, SEE=6 ml) than for EDV (r=.65, x-1=40,SEE=20 ml). Thus, our data acquired over a wide range of physiological LVV show that in normal men, Ex LW can reliably be measured from radionuclide studies.

March 1982

The American Journal of CARDIOLOGY

Volume 49

1031