Repetitive firing during synchronized ventricular stimulation

College In 6 patients,

RV

the

outflow

tract,

The

mean difference

portion M2.,

\Gas paced

at a rate of 100jmin.

mid-portion, between

2 ml./beat/M2., 3 msec.,

between

mid-portion

parameters

outflow

2 mm.

Hg,

respectively. and

inflow

It is therefore

of ventricular

more,

the

output

be slightly

in patients of

A system cardiogram.

This

a digital the

system

The

computer

Electro-

Field

computer

monitoring

will

allow data

has

electro-

exhibit

baseline

artifact

distortion,

The

QRS

every

complexes

patient

absence

with

points

on the P-R

the slope

parallel

line between

is the baseline tudes

and

artifacts

0.02

sec. intervals,

similar

intervals.

artifact

distorts

are

averaged

“average

onsets

for measuring and When and

defined

limits,

P-R

are excluded.

at

segment

amplitudes

at

or other

from each 6 sec. made

from

this

of measurements

by

computer has been documented by comparison measurements from paper records by physicians. Measurements printed

and provide

retained

that

the

If value

time

change

initial

a template

and compared

analyses. critical

from

with of

are printed

VOLUME17, JANUARY1966

those

with

from

which

all measurements

cycle

index)

during

although

the

pulsatile

total bypass system,

(12) The

in vitro,

work

(as

up to

phase,

al-

upon the arterial

pressure variable.

augment

in phase

was also ob-

the systolic

again

the

the carotid

was lowered

depended

of

was in(6) The

(9) Left ventricular

figure

total

approximately

and flow curves

massage.

was also lowered (11)

The

pressure

system attained

system also operated becoming

(13) Plasma

was 109 mg.‘%

an assist-

hemoglobin,

total

after

6 hr.

cycles.

Repetitive Firing During Synchronized Stimulation,

Ventricular

AGUSTIN CASTELLANOS, JR.,

M.D.,

F.A.c.c., LOUIS LEMBERG,M.D., F.A.C.C. and BAROUH V.

BERKOVITS, E.E.,

of Medicine,

University Fla.

Miami,

Fourteen

patients

with

slow idioventricular

the

through

Miami

or

electrodes

cavity.

to two synchronized

A-V

were studied.

bipolar

catheter

ventricular

of

complete

rhythms ordinary

tetrapolar

right

nected

from

The

to 240y0

(8) A change

with cardiac

are

and serve as the new

(3)

phase lag between

as a pulsatile

structed

a

was increased

flow through

300%.

values

the actual

also

(2)

arteries

was also altered.

(10) The end-diastolic

could

was

was increased

by tension-time

by 40%,

as follows:

of normal.

flow was increased

pressure

of control

are

succeeding

exceeding

2000/,

(5) The

total

the

arteries

time base of the flow curve

was increased

though

in

vascular

to any arterial

of normal.

in these vessels.

paced

interval

of values

measurement

is recognized,

interval

time

50%

200%

artery

The

the system so that too

in the coronary

and flow curves

(7) The

flow

be summarized

approximately

considerably.

or 36,000

amplitudes

Accuracy

pressure

(4) The

determined

segment

6 complexes

may

ing system postoperatively.

of the two complexes

measurements

complex.”

If these lines

base line fluctuation

the data,

is com-

the Q, R, and S ampli-

ST-T

307,.

tree.

and

corresponding

segments.

or other

durations,

arrhythmia.

these points

within

QRS

from

is identified,

another

base line fluctuations The

which

limits

head is never applied

flow per cycle

creased

and

and (3) aid in peripheral

to approximately coronary

systems.

arterio-arterial

to (1) lower work load on pressure

peak flow in the coronary

served

freedom

of lines joining

and ST-T

to one

to

measured

of an

of two complexes

pared

increased

arteries

to

of blood

results

peak

the digitized and

physiologic

The computer The

sec.

for measurement relative

the slope of the line connecting

are

6

for Increasing

CALLAGHAN, M.D.

to achieve

increase

arteries;

(1) The The

artificial

is designed

(2)

heart;

peak carotid

is a valu-

care

to scan

signals

and

pumping

the

lag between

constancy,

onset

phased

pressure

immediate

and

the intensive

is programed

select two adjacent

system

circuit.

and in stress electrocardiography. electrocardiographic

present

normal.

of electrocardiographic in monitoring

for various

great a pressure

CACERES, M.D., LARRY K.

includes

PHILLIP B.

recent years, servomechanisms have been

Over used

perfusion.

to

with heart disease.

to analyze

are signi-

change.”

pital, Denver, Colo.

to cardiac

D. C.

which

developed

Servomechanism

Flow,

appears

Monitoring

magnitude

A Computerized

coronary

Further-

C. LEINBACH, ANDREW PRESTO

Washington,

asset

but

deter-

ROSNER, M.D., Instrumentation

W.

analysis

systole

heart

the

CESAR A.

JACMON, M.D., R. Station,

of atria1

Analysis

cardiogram,

in man.

of lesser

“No significant

1

the site of artificial

performance

in the normal

greater

Computer

that

is not a fundamental

contribution

is small

S.

for the same

12 ml./beat/M2.,

and 1 msec. None was

concluded

of the heart

Differences

fied by a statement,

and DAVID H. WATIUNS, M.D., Denver General Hos-

difference

significant.

stimulation minant

mean

template.

Coronary

0.3 kg.-M./min./ tract

was 1.1 L.,/min./M2.,

statistically

able

at

tract.

tract and mid-

The

mm. Hg, 0.4 kg.-M./min./M2.

been

inflow

for CI, SI, FA, VP and ET was 0.6 L./min./

M2. and

and

and

119

News

The artificial

a preselected

rate while cycle.

Testing

the second stimuli

block

specially

latter

and

They were

introduced were

pacemakers

such a way that one was used to stimulate ventricular

School

coninto conin

the heart at

one scanned

were delivered

the after

College every third or fourth driving in excitability lus followed

every driving

seen in 3 patients to the peak occurred This

of the

T

never

under

vulnerable

msec.

in the patients

initiation

phase.

in whom

in patients

possible

areas

refractory

Ventricle

in the descend-

stimuli

heart

repeti-

block.

work of Hoffman

of vulnerability

In

et al.,

seemed

to

be

early and the other late in the

Following

P-A.

can induce

Induced

Auxiliary

Heart

Failure

CHAPTAL, M.D., T. AKUTSU, PH.D.

Avco-Everett

and

ADRIAN

Research

in

A. R.

M.D.,

KANTROWITZ,

Laboratory,

Everett,

Our most recent U-shaped placed

mechanical

flexible

plastic

scending

bulb

it is connected

with

consists

between

the proximal the unit.

anastomosis, during

pressed air controlled We have studied 25 dogs with coronary

heart

average

of

diastole

failure

and

hypovolemic work

while

Results pressure,

induced In

increased

of com-

the unit (indicated

by

flow.

reduces

left

ventricular

from

25 to 50

flow by 700/,, thus

and peripheral operated a

flow

aortic

of 45%

circulation.

in 20 dogs in left decrease

in left ventricular

and left atria1 pressure)

in

pressure

by

of normal work by an

coronary

aortic

left

and coronary

the device

arterial

effects in

series

change

shock,

coronary

increases

the

by bleeding,

this

by an average

raising

with

failure

with

by application

left ventricular

Hg and augmenting better

flow through

insufficiency,

reduced

30%

and

electronically.

significant

ventricular

ensuring

compelling

embolization.

20y,-without

the aorta is artery

are synchronized

mitral

dogs, the device

arch;

in

and de-

the unit’s hemodynamic

ligation,

microsphere

Located

brachiocephalic

Its contractions

left ventricle

During

the aortic

the

of a

no inside valves

to the ascending

aorta paralleling

transected

heart

ventricle

in a firm case of the same contour.

the chest,

mm.

(3)

the natural

Left

ventricular

in

diastolic

were as follows:

systolic pressure

(1) Arterial

diastolic

dogs’ condition

pressure

of the Heart

thesis, DENTOX A. BLOODWELL,

Houston,

for Advanced

Using

M.D.

valvular widely

operation

of choice

cardiac

and

GRADY

replacement

for patients

disease.

Among

although

some disadvantages

the

Starr-Edwards

and

embolic

phenomena

couraging

to have

or fatal cerebral Within

embolism.

been serious survive

valve which

SCDK

double-caged

All patients

class m or Iv. Single

ments

were made

mortality).

valve replacement was the low incidence

and

of 123

patients,

prostheses

were

to be in func-

or mitral

replace-

bvith 8 deaths

(17

IV patients

had

class

(no deaths).

patients.

and 2 had triple

Of particular

of systemic

a confirmed

embolus

in several

of the fatal

farction

were demonstrated SCDK

after

in

patient

operation,

cases small

at autopsy.

valve

signifi-

embolism

Not a single surviving

though

available

flow

(4 deaths),

cance

prosthesis

aortic

used a re-

of thrombosis

ball

Seven

replacement

ion the Cutter

with

improved

series

in 113 patients

valve

had

we have

were considered

tional

the surviving

and dis-

operation

provides

and lower incidence a consecutive

cent

and distressing

embolus.

In

inserted.

thrombo-

in both the early

it has been frustrating

the past four months

characteristics

with blood

Moreover,

a patient

with

valves.

and then suffer a sudden disabling

designed

Cutter

have

Indeed,

results,

noted

interference

after operation

and late follow-up complications.

been

Magovern-Cromie

the left ventricle.

acpros-

the ball and seat

satisfactory

have

of these valves produce

flow through

as the

advanced

the numerous

employ

given

few years

with

most

has

HALLMAN,

with prosthetic

used in the past

have

double

L.

of Medicine,

theses used, the ones which

per

ProsROBERT

College

principle

cently

Valvular

an Improved

University

excision

has been

the

and the

Texas.

Total

quired

(6) In some

to recovery,

COOLEY, M.D., F.A.c.c.,

M.D., F.A.c.c.,Baylor

to

by 40%.

stable until sacrifice.

Total Valve Replacement Disease

rcturncd

by 50%.

lead

remaining

(2) Left of 47%.

was reduced

flow was increased

these improvements

peak.

by an average

(4) Left atria1 pressure

cases,

D.

systolic

work war reduced

valve replacement

Mass.

work

exceeded

normal.

Both

Effects of a Mechanical

KANTROWITZ, M.D.,

repetitive

period.

Hemodynamic Dogs,

at the

fell in the vul-

with complete

One occurred

relative

be measured.

group,

falling

with the experimental

present.

20 to 40

of the T wave.

tive firing two

duration

occurred

the stimuli

1 of the latter

It seems that pacemaker keeping

threshold.

between

it could

firing took place with impulses ing portion

once.

intensities

the

responses

when

In

times

ranged

multiple

of pacing

nerable

with

pressure ventricular

(5) Aortic

extrasystolcs

fibrillation

four

was

fell close

2.4 and 6.7 v. The

phase

In 2 other patients

Multiple

observed

between

firing

impulses

ventricular was

were

varied

of the

wave.

and

phenomenon

Voltage

one. Repetitive

when the testing

twice

which

beat to avoid the changes

which could occur if each testing stimu-

News

al-

foci of in-

In our opin-

is the most satisfactory

for valve replacement.

Results of Shunt Procedures

in Fallot’s Tetralogy G. DAOUD,

in Patients Under

Four Years of Age,

M.D., G. I. NAGAO,

M.D., S. KAPLAN, M.D. and J. A.

HELMSWORTH, M.D., University cinnati,

Complete fants

of Cincinnati,

Cin-

Ohio. repair

is associated

of Fallot’s with

tetralogy

a prohibitive

in small surgical

in-

mor-

THE AMERICANJOURNAL OF CARDIOLOGY