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ARRYTHMIAS AND ACUTE
MYOCARDIAL INFARCTION
DR. ZIAD NOFAL
CARCIOLOGIST
DAMASCUS
HOSPITAL
‫بطء القلب الجيبي‬
‫‪‬‬
‫‪‬‬
‫‪‬‬
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‫نسبة الحدوث ‪%20-15‬‬
‫تشاهد بشكل شائع في االحتشاء السفلي‬
‫غالبا ما تكون عابرة‬
‫قد تنجم عن نقص التروية‬
‫تسرع القلب الجيبي‬
‫‪‬‬
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‫نسبة الحدوث ‪%40-30‬‬
‫تعد عالمة سوء انذار‬
‫المعالجة‬
Treatment I
•
Initial treatment should consist of synchronized DC
cardioversion with an initial monophasic shock of 200 J
for AF and 50 J for atrial flutter, preceded by brief
anesthesia or conscious sedation whenever possible.
• For episodes of AF with hemodynamic compromise that
do not respond to electrical cardioversion or that recur
after a brief period of sinus rhythm, the use of
intravenous amiodarone or, in patients with left
ventricular dysfunction and heart failure, intravenous
digoxin is indicated.
Treatment II
• Intravenous beta adrenergic blockade (this approach is
preferred unless contraindicated). Options include
metoprolol (2.5 to 5.0 mg every two to five minutes to a
total of 15 mg over 10 to 15 minutes), or atenolol (2.5 to
5.0 mg over two minutes to a total of 10 mg in 10 to 15
minutes).
• When beta blockers are contraindicated , intravenous
diltiazem (20 mg [or 0.25 mg/kg] over two minutes
followed by an infusion of 10 mg/hour), or intravenous
verapamil (2.5 to 10 mg over two minutes; may repeat a
5 to 10 mg dose after fifteen to thirty minutes).
Q1
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Risk factors for stroke in patients with AF include all of
the following
except:
a.Age >75 years
b.Dyslipidemia
c.HTN
d.Heart failure
e.Stroke or transient ischemic attack
ACC /AHA guidlines2014
JUNCTIONAL T.

Nonparoxysmal
junctional
tachycardia is typically transient,
occurring within the first 48
hours
of
infarction
and
developing
and
terminating
gradually.
No
specific
antiarrhythmic
therapy
is
indicated .
PSVT
TREATMENT
• Carotid sinus massage.
• Intravenous adenosine (6 mg over one to two
seconds; if no response, 12 mg one to two minutes
later; may repeat 12 mg dose if needed).
•
Intravenous beta blockade with metoprolol (2.5 to
5.0 mg every two to five minutes to a total of 15 mg
over 10 to 15 minutes), or atenolol (2.5 to 5.0 mg over
two minutes to a total of 10 mg in 10 to 15 minutes).
• Intravenous diltiazem (20 mg [or 0.25 mg/kg] over
two minutes followed by an infusion of 10 mg/hour).
• Intravenous digoxin (8 to 15 microg/kg, or 0.6 to 1.0
mg in a patient weighing 70 kg). A delay of at least
one hour may occur before the onset of
pharmacological effects with digoxin.
Paroxysmal Supraventricular
Tachycardia


Refers to supraventricular tachycardia other
than afib, aflutter and MAT
Usually due to reentry—AVNRT or AVRT
Q2
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Which of the following antiarrhythmic
agents may promote AF?
a.Adenosine
b.Quinidine
c.Propafenone
d.Amiodarone
e.Atenolol
BLOOD SUPPLY I

Blood supply – In order to fully understand the relationship
between myocardial infarction and dysrhythmia, it is helpful to
review the vascular supply of the different components of the
conduction system (show figure 2) :

SA node – Supplied by the right coronary artery (RCA) in 60
percent of people; by the left circumflex artery (LCX) in 40 percent.

AV node – Supplied by the RCA in 90 percent (AV nodal branch);
by the LCX in 10 percent of people.

His bundle – Supplied by the RCA (AV nodal branch) with a
minor contribution from the septal perforators of the left anterior
descending artery (LAD).
BLOOD SUPPLY II


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Main or proximal left bundle branch – The LAD coronary artery
provides most of the blood supply for the left bundle branch, particularly for
the initial portion. There may be some collateral flow from the RCA and LCX
systems.
Left posterior fascicle – The proximal part of the left posterior fascicle
is supplied by the AV nodal artery and, at times, by septal branches from
the LAD. The distal portion has a dual blood supply from both anterior and
posterior septal perforating arteries.
Left anterior fascicle – The left anterior and mid-septal fascicles are
supplied by septal perforators of the LAD and, in about one-half of subjects,
by the AV nodal artery.
Right bundle branch – The right bundle branch receives most of its
blood supply from septal perforators from the LAD coronary artery,
particularly in its initial course. It also receives some collateral supply from
either the RCA or LCX coronary systems, depending upon the dominance of
the coronary system.
J/R

The admission ECG can predict the occurrence
of high degree (second or third) degree AV block
in patients presenting with an inferior MI. One
study of 1336 patients receiving thrombolytic
therapy for an inferior MI reported that a ratio of
J point/R wave amplitude > or =0.5 in two
inferior leads was associated with an 11.8
percent incidence of high degree AV block
compared to 6.7 percent when the J point/R
wave amplitude was < or =0.5 .
RISK SCORE

A risk score was developed from the MILIS
data to predict the development of CHB. One
point was assigned for the new development
of PR prolongation, second degree AV block,
left anterior or posterior fascicular block, LBBB,
and RBBB. The risk of progression to CHB was:
• 1.2 to 6.8 percent with a point score of 0.
• 7.8 to 10 percent with a score of 1.
• 25 to 30 percent with a score of 2.
• 36 percent with a score of 3 or more.
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