A simple method for the evaluation of pharmacologically induced variations of myocardial blood flow in man

Abstracts the effect was variable. In contrast, in all cases of valvar aortic stenosis and mitral incompetence studied the systolic murmur increased in loudness. The decrease in intensity of the systolic murmur in HOCM can be explained by the sudden increase in venous return leading to increased left ventricular filling and increase in end-diastolic volume. In addition, the raised arterial pressure and peripheral resistance would reduce the intraventricular gradient and, thus, the intensity of the murmur. Prompt squatting has thus proved to be an excellent and simple bedside test in this condition. Proper

Interpretation

of Lung

Scans in Diagnosing

D. POE, M.D., EARL K. DORE, M.D., LEONARD A. SWANSON,M.D. and GEORGEV. TAPLIN, M.D., Los Angeles, Calif.

Pulmonary

Embolism.

NORMAN

As pulmonary embolism becomes suspected clinically with increasing frequency, the need for a simple confirmatory test is obvious. Lung scanning now is widely available and has been advocated as a diagnostic test for pulmonary emboli. However, the presence of the so-called “false-positive” scan has cast some doubt on the accuracy of the procedure. Because the lung scan measures regional pulmonary blood flow, it technically is more a pulmonary function test than a diagnostic one. Alone it has no diagnostic significance except to localize areas of partial or total &hernia. Proper interpretation lies in the correlation of the scan with the clinical findings and the chest x-ray film. A number of physiologic and pathologic conditions can produce scans that mimic emboli. Physiologic alterations include the posture at the time of tracer injection, obesity, congestive heart failure or other causes of pulmonary hypertension, and certain vasoactive drugs. Pathologic alterations that can be distinguished from emboli, but not infarction, by the chest x-ray film include pneumonitis, tumors, bullae, tuberculosis and granulomatous diseases, pleural effusion and atelectasis. The latter two may be associated with emboli. Frequently emphysema, bronchiectasis, inactive tuberculosis and bronchial asthma produce major ischemic defects without obvious radiographic abnormality that are indistinguishable from emboli. Diagnosis of embolism when these disorders are present is hazardous. Experience with 800 cases of suspected pulmonary embolism has shown the scan to be as accurate as angiography for diagnosing emboli. Both technics become less specific when blockage occurs in subsegmental and smaller vessels. Scanning has the advantage of safety, convenience and economy, whereas angiography more accurately identifies the VOLUME21, JANUARY1968

113

occlusive site and is always mandatory if embolectomy is considered.

Improved Results in Surgical Treatment of the Complete Form of Persistent Common Atrioventricular Canal Using a New Surgical Repair. G. C. RASTELLI, M.D., PATRICK A. ONGLEY, M.D., F.A.C.C. and DWIGHT C. MCGOON, M.D., Rochester, Minn. Thirty-eight patients with the complete form of persistent common atrioventricular (A-V) canal were operated on from 1955 through 1967. Their ages ranged from 10 months to 51 years (median 6 yr.). The hospital mortality prior to 1964 was 60 per cent. In the last 4 years (10 cases), over-all mortality was 20 per cent. Factors responsible for the improved mortality were avoidance of A-V block, better understanding of the anatomic features based on a new description of the site and size of the interventricular communication and arrangement of A-V valves, better selection of patients, and a new surgical method. This method consists of (1) reconstruction of the anterior leaflet of the mitral valve by approximation of its components at the level of the cleft; (2) closure of the atria1 and ventricular septal defect with a single patch; and (3) attachment of the reconstructed anterior mitral leaflet (and in some cases the tricuspid septal leaflet) to the patch. The rationale of this repair, which was performed on seven occasions, is to preserve mobility and function of the A-V valves and to avoid obstruction to the left ventricular outflow tract. This experience suggests that when severe mitral incompetence is present preoperatively, prosthetic replacement of the valve is indicated. When only mild or moderate mitral incompetence exists preoperatively, it often persists after surgery; but these patients are symptom-free and leading thus far a normal life. A Simple Method for the Evaluation of Pharmacologically Induced Variations of Myocardial Blood Flow in Man. ATT~LIOREALE, M.D., Rome, Italy. When injected into the circulatory stream, suspensions of radio-albumin aggregates (MAA-1131) are retained by the capillary bed in a quantity proportional to the regional blood flow. This principle was applied to the study of myocardial blood flow in 20 patients undergoing diagnostic cardiac catheterization. Two identical doses of 200 to 400 ~Cccof MAA-Ilal were successively injected into the left ventricle or the aortic root. Each injection was

114

Abstracts

followed

by

precordia1

counting.

originating

from

myocardial

mass was accounted

from

the

right

thoracic

precordial

the second

dose of isotope

of variations

9 control

precordial

patients

count

-1

slight

count

(from -6

the

of MAA

expectedly

yield

count

in the

whom the

corrected twice

average

at in-

and showed (from

after sublingual

-1

whereas

than 83%.

preliminary

of evaluating

of 48%

results

by a very

of pharmacologic

of 14%

affords

promise

(from

+0.5

to

Dysfunction DAVIS

the

effect

on myocardial

Synergism

HENRY I. RUSSEK, Patients

with

little

M.D.,

F.A.c.c.,

severe

angina

or no response

adrenergic

receptor

pranolol

improves

whereas

the nitrates

ischemic

in Angina

blood

relief in intractable

Apparatus

M.D.,

pectoris

to the

blocking

in Children.

M.D.,

Cincin-

F.A.c.c.,

nati, Ohio. Although

several causes of mitral

insufficiency

in children,

this report

suggests

nonrheumatic

myocarditis

may

in papillary

dysfunction

observations

and mitral

result

insufficiency.

were based on 15 patients ‘These patients

a history of rheumatic

sized hearts.

These

or beta

Since

tend to increase

appeared

evident.

oxygen

rationale

pro-

were asymptomatic

joint

Moreover,

was apical,

since

Recognition are essential

strongly

To investigate undertaken

in 48 patients resistant

In addition

fashion under carefully therapy,

following

exercise

pectoris

dinitrate

controlled in pain patterns,

maximum

S-T

(ISD),

5

in random

circumstances.

and capacity segment

On

manifested

experience,

(II,

that

incompetence

the mur-

without

leaflet

of this syndrome

emphasizes

and prophylactic

during surgical

procedures

that

the

antibiotics when the pa-

endocarditis.

The

Evolution

of

Atrioventricular

Hemodynamics

Canal

with

of

Complete

CHANDRAKANT

Age.

V. SHAH, M.D., GREGORIO B. PATACSIL,

M.D.,

RODRIGUEZ-CORONEL,

E.

M.D.,

MARIA

ALBERTO SERRATTO,

and ALOIS R. HASTREITER, M.D., Chicago

Ill. The

large ventricular

the complete canal

exposes

septal

defect

form of common the pulmonary

flow, high pressure

associated

atrioventricular

with (A-V)

vascular

bed to a high

system from birth.

It can, there-

ischemic

fore, be used as a model from which to study the rate

for exer-

of development

of pulmonary

age. Twenty-three

cases of complete

depression

was 3.2 mm. with placebo,

leads

for months

and left ven-

confirmed

is not innocent

M.D., F.A.C.C.

alone.

40 to 80 mg. orally

46 of the 48 patients

improvement Average

isosorbide

singly or in combination

electrocardiographic

test) was

with severe angina

and propranolol,

were administered

striking

(two-step

to either agent administered

to placebo,

mg. sublingually

combined

was

a study of the pain

tolerance

persisted

with

of a useful synergism

these possibilities,

and exercise

T wave inver-

surface

catheterization

tient is at risk for bacterial

suggested.

experience relatively

could be

of its partner-vasoand tachycardia

and

diminished

abnormality.

out by the influence propranolol

Cardiac

mur was due to mitral

subsidiary

possibility

of amyl nitrite.

angiocardiography

canceled

with

The murmur

and

These changes

desirable

the nitrates-the

phenylephrine

III. aVF> Vs, V,). or even years.

occuand, in

was lengthened

in left ventricular

murmur

constriction

with

by a click.

position,

after inhalation

each of these agents seems to possess at least one uneffect which conceivably

with

sion was present

tricular

supply

for

was preceded

the

and in-

fever and with normal-

The systolic murmur

markedly

that

in whom

findings were a late systolic murmur

T waves.

without

greatly

frequently

nitrates

agents.

the

administration

N. Y.

have

been described

accentuated

of oxygen utilization,

myocardium,

an-

DAOUD, M.D.,

GEORGES

F.AX:.C. and SAMUEI. KAPI.AN)

varied

Pectoris.

New York,

the economy

more

treatment

pied the late part of systole, varied in duration

Propranolol-Nitrate

cise.

therapy

averaging

or more in all 46 patients

of the Mitral

some patients,

to

was only

with combined

of long-term

C. SCIIWARTZ,

verted

the possibility

technic

flow.

show

in exercise

alone

benefit on continued

over a period of six months

muscle

of isoproterenol

indicate

simple

interventions

the increment

Persisting

dominant

+156%). These

increase

or ISD

was more than three times this value,

to

nitroglycerin,

by an average

In 8 infusion

the

-9%).

repeated

of activity

increase

propranolol

circulatory

less than

after the injections

to +437&).

an average

no second

were

increased

with

and 0.4 with propranolol

The average

gina pectoris.

-24%,

decay

In 3 patients,

caused

in

to

time intervals

precordial

should

determinations

a progressive -8%).

24%,

over

bed for a few hours,

was somewhat

(from

In 6 instances creasing

obtained

of the ability

induced,

1.6 with propranolol,

and ISD combined. tolerance

in blood flow.

were count

ISD,

the

for by subtracting

twice the first precordial

modifications first

Because

Radioactivity

or underlying

that

by the capillary

approximately In

count

wall.

to be retained

absence

tissues overlying

1.9 with

THE

AMERICANJOURNAL

vascular

changes

common OF

with

A-V canal CARDIOLOGY