Læknablaðið : fylgirit - 15.06.2002, Síða 25

POSTERS / ICELAND 2002: EMERGENCY MEDICINE BETWEEN CONTINENTS
dynamic stability are required. During the last months 46 episodes
of AF underwent electrical cardioversion in the ED setting, 28
males, 18 females, mean age 66.3.12 of the cases were elective, 26
semi-elective and 8 urgent. 23 (50%) of the cases had IHD, 23
(50%) - hypertension, 10 (22%) - CHF and 10 (22%) - DM. For
premedication we used in group I (23 patients) Propofol 1.5 mg/kg
and in group II (23 patients) Ketalar 1 mg/kg with Midazolam 0.015
mg/kg. All patients had reasonable sedation and satisfactory anes-
thesia for the procedure. The electrical dose range was 50-360 j - In
44 cases a biphasic defibrillator was used and the remaining two
cases were cardioverted with a monophasic defibrillator. 41/46
(89%) episodes were successfully converted to sinus rhythm.
Coniplicutions/Side effects: Minor side effects were seen in 21/46
pts. 6/23 patients (26%) from group II developed a transient con-
fusional state but with total amnesia for the procedure. In 15/23 pts.
from group I, a significant reduction in blood pressure (> 20 % of
base line) was seen with full recovery during the first 60 min. either
spontaneously or by fluid infusion. The majority of these pts. had
underlying heart disease such CHF or IHD. One pt. from group I
developed prolonged asystole (3 min) immediately after the proce-
dure and underwent short successful CPR but had a prolonged
hypotensive state (for 2 hours) which was treated with fluids and
dopamine. He was admitted to the hospital for observation and
discharged the next day.
Conclusions: Both methods of premedication are quite effective for
electrical cardioversion in various types of AF with a low rate of
complications in patients without significant underlying heart
disease but Ketalar is favorable for pts.with significant IHD and /or
CHF although larger cohorts of pts. are needed for statistical
significance and towards this goal our study is still ongoing.
P 25 - Cardiovascular Emergencies
Elective and urgent electrical cardioversion of atrial fibrillation
(AF) in the emergency department - its safety and efficacy
comparison between monophasic and biphasic defibrillators
Darawshe A, Feldman A, Malatskey L, Seligmann L, Chiporen L, Antoneli
D, Freedberg N
HaEmek Medical Center, Afula, Israel
Atrial fibrillation (AF) is the most common sustained cardiac
arrhythmia and is a frequent cause of presentation to the Emer-
gency Department (ED). Electrical cardioversion to sinus rhythm
is frequently necessary in both chronic and acute AF, especially if
medical therapy fails to convert the rhythm to sinus, or if early
conversion is essential. Since 1994 the implantable cardioverter
defibrillator (ICD) industry has replaced monophasic wave forms
with biphasic wave forms. Transthoracic cardioversion with bipha-
sic wave forms is less well studied.
The aim of our study is to compare the success rate, safety and
complications of cardioversion of atrial fibrillation between bipha-
sic and the standard monophasic defibrillator (D ).
During 1996-2000 496 episodes of atrial fibrillation were treated
with electrical monophasic technique cardioversion. In the last year
50 episodes of AF underwent electrical cardioversion in our ED
with a biphasic defibrillator. No statistically significant differences
were found between the two study populations in the mean age,
sex, and clinical characteristics. 446/496 (90%) of episodes were
successfully converted to sinus with the monophasic D compared to
a 48/50 (96%) success rate with the biphasic D. 24% of the success-
fully converted episodes by monophasic technique needed more
than 2 attempts and maximal electrical dose (360 j) compared to
6.2% of the successfully converted episodes by the biphasic tech-
nique.
Side effects and complications: In the monophasic group there were
13/496 (2.6%) who developed significant complications during or
immediately after the cardioversion compared to 1/50 (2%) in the
biphasic group. Although our study with the biphasic technique is
still ongoing we conclude that electrical cardioversion performed in
various types of AF can be carried out safely in the ED setting by
either the monophasic or biphasic method but with higher efficacy
and lower energy doses with the second technique.
P 26 - Cardiovascular Emergencies
Does variation in lead placement affect electrocardiographic
morphology?
Lateef F
Dept of Emergency Medicine, Singapore General Hospital, Singapore
Introduction: The exact placement of electrodes for electrocardio-
graphy (ECG) depends on the interpretation and conscientious-
ness of the person performing it (e.g. nurses, technicians, medical
students). Technical variability represents the largest source of
error for variations in amplitude and wave form of the chest lead
ECG. Precordial leads are commonly placed either too high, too
low or horizontally displaced from their anatomically defined sites.
Will this affect interpretation by doctors as well as their decision
perlaining to thrombolytic therapy, intervention and other aspects
of patient management? In this context, comparison of serial ECGs
may also be affected.
Objectives: To assess if changes in position of precordial leads
placement affect the 12-lead ECG morphologically.
Methods: Adult volunteers, with no history of ischemic heart
disease, had the following performed:
1. A standard 12-lead ECG with surface precordial lead place-
ment.
2. A 12-lead ECG as in 1. above, but with all the precordial leads
(ie.Vl to V6) shifted 2cm upwards.
3. A 12-lead ECG as in 1, but with the precordial leads shifted 2 cm
downwards.
Measurements were done using a standard rule. All 3 ECGs for
each volunteer were compared manually, and the differences
documented (e.g. changes in QRS amplitude and morphology, ST
segment-T wave abnormalities)
Results: Out of a total of 60 volunteers, age range from 18 to 71
years, 33 (55.0%) had no changes when the three ECGs were
compared. The other 27 (45.0%) had the following changes: R
wave amplitude change (23 persons), S wave amplitude change
(23), T wave changes (5), QRS morphological change (3) and ST-
segment change (2). There were no specific trends noted in the
pattern of change.
Conclusion: There are changes in the ECG morphology with the
deliberate displacement of precordial leads. This may suggest the
need for standardization, or the use of a device to assist in lead
placement, which can ensure accuracy and quality control.
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