“New” mode of action of antiarrhythmic agents

151

Abstracts cardiogenic

shock.

It also identifies

of greatest

value

of facilities

for effective

Malposition A

and fosters

of

Hypertrophic

the

M.D., Bethesda,

JR.,

Considerable

Stenosis,

ALLAN L. SIMON,

controversy

sure gradients.

JAMES H.

the

and

40

(87%)

angiographic

combination

of abnormalities.

a linear

radiolucent

tract during

annulus,

this

pressure

mitral

not

The

retract

normally

radiolucent

area

to the leading

of mitral

more

ferior septal

papillary restricts

that

during

the

Rubella

Asymmetric of the

abnormal

stress on

and

thereby

of the mitral

leaflets.

is held in the outflow

hypertrophied

cardiac

tract,

implications. expression

from the patent

DAN G. MCNAMARA,

cally an XX

DON B. SINGER, M.D. Houston,

Texas.

These

“New”

the heart

valves

VOI.UME 19, JANUARY 1967

valves.

in these patients

This

has

literature. had the

and

\vas clini-

an opportunity

to consider

and teratogenic

of Antiarrhythmic

on

that reduction

spontaneous

of latent

Agents,

4

cells

conduction.

potential

due

depolarization

may result

in conduction

due to their

was tested in experiments Purkinje

were recorded

stretch

fibers.

ability

1.0

at both ends

of phase 4 depolari-

by a low rate of stimulation on

the

of ouabain

preparation,

(10F6M).

amount

of depolarization,

ranging

from

simple

conduction

4 depolarization

and restored

brane

potential

normal.

mg./L.) (30-60

Sometimes

of transmembrane

mg./L.)

diastolic

resulted

potentials

Presumably,

beneficial

of phase

4 depolarization

oc-

mem-

in marked

of conduction. rarely

they caused further

duction.

block

suppressed

With low concentra-

this usually

or normalization

or the

disturbances

mg./L.)

phase

toward

on

to advanced

(5-60

and

hypoxia,

Depending

slowing

Procainamide

(5-20

on isolated

Transmembrane

simultaneously

Development

was induced

duction.

de-

However,

(diastolic)

in such instances

of canine

curred.

quinidine solely

phase 4 depolarization.

This possibility strands

e.g.,

to exert

of membrane

phase

N. Y.

suggests that these agents might improve

conduction suppress

thought

cardiac

pacemaker

disturbances

agents,

are

evidence

concentrations

in the medical

ru-

recovered

and had the additional

background

of Action

effects

heart

or more

present

pressant

and congestive

in three

‘Turner

in the first trimester.

antiarrhythmic

to thrive

mentioned

(XY

of maternal

A third patient

phenotype

procainamide,

with failure sclerosis

syndrome

SINGER, M.D., HAROLD STRAUSS. M.D.

Standard and

improvement

been only rarely

etiologic phenotypic

and BRIAN F. HOFFMAN, M.D., New York.

early

valvular Although

Mode

who presented

of the heart in each case revealed

will focus on some important

at the time of operation

of genetic

DONALD H.

5 infants

Examination

de-

for the disturbed

had the clinical

rubella

patients

concerns

failure.

cardiac

insult.

tions

in infancy

have

at autopsy.

Turner

the interplay

infusion

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

congenital

virus was subsequently

history of maternal

zation

SIMPSON, M.D.,

spongiosum.

to the periphery-.

had a history

ductus

from the heart

increased

JAMES W.

Another

the rubella

mechani-

Syndrome,

pro-

of baso-

in 3 the associated

of the male Turner

phenotype). bella;

which

One patient

potentials

Phenotypes

associated

of these patients

of the preparation.

in Turner

in the stratum

to be responsible

features

with idio-

Sclerosis

in their was

function.

that this mech-

stenosis.

there

the deposition

in each infant,

The discussion

in many patients

subaortic

and nodular

was displaced

there were other

role in producing

JAMES J. NORA, M.D., F.A.c.c.,

This report

substance

interventricular

It is proposed

to ejection

ValvuIar

by the in-

maldirection systole

excursion

anism plays an important

Multiple

usual

being

and

fibrosum

abnormalities

was

In addition,

is postulated:

leaflet

hypertrophic

While

to

produces

in midsystole.

cal obstruction

than

causes

tendineae

meets

present,

leaflet.

mass.

the posterior it

view leaflet.

muscles was abnormal,

sequence

the anterior

septum

when

anterolaterally

muscles

projected

in the frontal

mitral

hypertrophy

chordae

but

edge of the mitral

regurgitation,

muscle

following

ventricular

and

the

systole

directed

and

In

the anterior

did

ground

The stratum

with the

change.

and during

the axis of the papillary

pathic

across

in diastole,

jet

where

area extended

at a level corresponding

seen below the immobilized

Thus,

a char-

In the frontal

projections,

anteriorly.

the

features,

in

or lateral

corresponded

The

exhibited,

was identified

leaflet

The

were

systole 2 to 2.5 cm. below

site of the intraventricular left oblique

pres-

46 studies

to the usual

leaflet

philic

of fibroblasts

unusual

were reviewed

with IHSS;

addition

the aortic

hypertrophic

thickened

Microscopically

appearance.

liferation

(LV)

and intraventricular

acteristic

the LV outflow

the

ventricle

angiocardiograms

satisfactory

projection,

GAULT,

concerning

left

with idiopathic

(IHSS)

LV

exists

of

in 61 patients

technically

Systole:

in Idiopathic

of leaflets with no fusion at the com-

they were

fects did not appear

anatomy

stenosis

in detail

During

M.D. and

during systole in patients subaortic

Leaflet

Md.

angiographic

number

missures, gross

Obstruction

Subaortic

JOHN Ross,

M.D.,

in the design

monitoring.

of the Mitral

Component

normal

the measurements

economy

Higher

improved

con-

deterioration

and depression

of

con-

effects of suppression

were outweighed

by direct

152

Abstracts

depressant

effects

of this agent.

procainamide

prevented

depolarization

and

Pretreatment

development

concomitant

of

with

phase

conduction

4

abnor-

of an atria1 septal defect to sustain an adequate monary

pul-

arterial pressure and resistance and to main-

tain systemic flow.

malities. Thus,

contrary

to current

low concentrations abnormalities potential

belief, procainamide

may improve conduction

result

from

reduction

in membrane

due to phase 4 depoIarization

cells. If, as has been suggested, tion is a significant turbances

of procainamide

may

antiarrhythmic

rhythms,

then

factor

Left

Ventricle

Syndrome: Infants,

in its

Analysis

with Surgical

N. SINHA, M.D., STUART

SACHCHIDA

M.D., ROGER B.

COLE

chamber

formation

which

Eight

patients

aortic

atresia

and mitral

palliation

is uniformly aortic

and

mitral

stenosis;

and 4, mitral

root. Three

atresia;

7, severe

11, aortic

atresia with hypo-

fourths of the patients

congestive

heart failure within

life. Poor

systemic

peripheral

pulses even after digitalization,

blood

to

in this mal-

fatal in early infancy.

and

mitral

stenosis;

plastic aortic

at autopsy were reviewed

of surgical

had

of the

had

the first three days of

flow, evidenced

by weak was noted

in half the infants. In this malformation, quate

(a) adequate

the maintenance

of an ade-

flow is anatomically dependent

systemic

unobstructed

communication

patency

of an interatrial

and (b) adequate-sized

patent ductus

arteriosus;

and physiologically dependent

adequately

elevated pulmonary

provide continuing

upon:

on

vascular

(c)

an

resistance

to

systemic flow from the puImonary

artery. Five

patients,

in whom

significant

atria1

tained,

had

atrium.

At autopsy the foramen

pressures

gradients

venous

cardiography

Creation

a large

return,

may

decrease

the

the ductus.

constrictive

banding

with

autopsy

ductus

of all the

arteriosus

ap-

aorta in diameter.

to provide

sistance and thus decrease

left

interfering

of an atria1 septal defect

necessary

through

and

patent

the descending

usually

the

favoring

to the right side. Angio-

in 10 infants

hearts showed proximating

return

ob-

ovale in three fourths

of the infants was valve competent, pulmonary

were

alone,

though

free pulmonary

venous

pulmonary

vascular

re-

the systemic flow coursing

It is suggested

that operative

of the main pulmonary

arteries

distal to the ductus be done together with the creation

recordings

phonocardiogram

rived carotid

arterial tracing.

undertaken tion

WEISSLER,

tricular

ejection (PEP).

The

and

These

intervals

tilt (HUT)

externally

pre-ejection

and heart rate (HR)

10 stepwise

increments

effects of gravity

are Iinearly

expressed as maximal

change,

(rt2) 25’,

Q-SZ:

-59(+4)

-83(&4) msec.,

43”.

msec.,

lo”,

compared

change were,

msec.,

lo’,

38“;

32’;

PEP:

+27

lo”,

19O; HR:

When

re-

responses

angle of onset

of change, and angle of 50% of maximal LVET:

of

in each of 15 normal subjects.

hydrostatic

respectively,

de-

left ven-

and

lated to the sine of the angle of tilt. Mean (=tSE),

from

electro-

(Q-S,),

(LVET),

during

the

effects on the dura-

systole

time

determined

of

The present study was

to define gravitational

of electromechanical

head-up

Ill.

fast-speed

cardiogram,

Chicago,

study the problem

of Gravitational

REGIS W. STAFFORD, M.D.,

The systolic time intervals can be determined

were

left ventricular

as Indexes

Ohio.

simultaneous,

period

M.D., ALEXANDER

hypoplasia

Intervals

Stress in Man,

WILLARD S. HARRIS, M.D., ARNOLD M.

J. MUSTER, M.D. and MILTON H. PAUL, M.D., F.A.c.c.,

Cases of 30 infants with extreme

Time

Circulatory

Columbus,

dis-

this action

be an important

Data from Thirty

Considerations, RUSNAK,

conduction

Systolic

M.D., F.A.C.C. and JAMES V. WARREN, M.D., F.A.c.c.,

activity.

Hypoplastic of Autopsy

of automatic

phase 4 depolariza-

cause of cardiac

and re-entrant

in

when the

+26(&2)

beats/min.,

with regression

data re-

lating systolic time intervals to HR, derived from 210 normal

supine subjects,

shortened, HUT.

while

Q-S,

Changes

linearly

in

PEP was lengthened,

LVET

remained

during

PEP

and

unchanged LVET

were

related

to the sine of the angIe of tilt. In the supine

position similar

venous

pooling

alterations

of PEP and reduction to the known

with

of LVET

reduction

It is noteworthy

tourniquets

of systolic intervals.

produced

Prolongation

appear

to be related

of stroke volume

that HUT

by HUT.

did not alter these in-

tervals or heart rate in 3 patients

with severe con-

gestive heart failure. Determination sensitive

and

gravitational

Embolism,

time

approach

intervals

Artery

offers

on left ventric-

events in man. Blood

Flow in Acute

Pulmonary

PAUL D. STEIN, M.D., SHAKAEB ALSHABK-

HOUN, M.D., CHARLES HATEM, M.D., ALI A. SHAHRIARI, M.D., DWIGHT

E.

FLORENCE W.

HARKEN,

DEXTER, M.D., F.A.c.c., The

M.D., Boston,

coronary

F.A.C.C.

dogs.

and

embolism

blood flow (LCBF)

ured by an electromagnetic anesthetized

HAYNES,

PURPH.D., LEWIS

Mass.

effect of acute pulmonary

left circumflex chest

a

for demonstrating

effects (or their absence)

ular hemodynamic Coronary

of systolic

practical

(PE) on was meas-

flow meter in 11 openEmbolization

with

poly-

THE AMERICANJOURNAL OF CARDIOLOGY