Dr. Abraham discusses sinus node dysfunction and atrioventricular block. Key points include: - The sinus node is usually located in the right atrium and receives blood supply from the right coronary artery or left circumflex artery. - Symptoms of sinus node dysfunction range from asymptomatic ECG changes to tachycardia, bradycardia, and tachy-brady syndrome. - Treatment options include pharmacotherapy with drugs like atropine or theophylline for short term use, and pacemaker implantation for long term treatment of sinus node disease. - The atrioventricular node receives innervation from the arteries of Koch and shows minimal autonomic innervation. AV block can be first,

1. Dr. Abraham

6.  Identify
 Classify
 Rectify

7.  Location
 SA nodal artery – RCA>LCx
 S & PS

8.  Asymptomatic – ECG changes
 Symptomatic – tachy
brady
tachy – brady
 Overdrive suppression
 SA disease – brady
pause
arrest
exit block
chronotropic incompetence

13.  <85% predicted heart rate
 <100
 <2 SD of expected

14.  Block sympathetics – 0.2mg/kg propranolol
 Block para – 0.04mg/kg atropine
 Intrinsic heart rate –
117.2-(0.53*age)

16.  Type I second-degree SA block results from
progressive prolongation of SA node
conduction with intermittent failure of the
impulses originating in the sinus node to
conduct to the surrounding atrial tissue.
Second-degree SA block appears on the ECG
as an intermittent absence of P waves
“WENKEBACH”

18.  no change in SA node conduction before the
pause

20.  Complete or third-degree SA block results in
no P waves on the ECG

22.  ECG – holter
loop study
event monitors
 Chronotropic incompetence
 IHR
 Invasive testing – SNRT
SACT

23.  Exclude extrinsic causes
 Short term – pharmacotherapy – atropine
theophylline
isoproterenol
 Long term – pacemaker – SA disease
Carotid
hypersensitivity

24.  OF KOCH
 AV nodal , septal perforators
 S & PS
 HIS and further down – minimal autonomic
innervation

28.  1ST DEGREE
Mobitz type I “wenkebach”
 2ND DEGREE
Mobitz type II
 3RD DEGREE

33. DEFINITE DIAGNOSIS – “HIS” ELECTROGRAM

37.  Exculde functional causes
Transcutaneous
Temporary
 Pacing Transjugular
Permanent

40.  1 – A, V, D, S, O
 2 – A, V, D, S, O
 3 – I, T, D, O
 4 – R
 5 – P, S, D, O

41.  Of the procedure
 Twiddler syndrome
 Pacemaker syndrome – fatigue
neck pulsation
palpitation
dizziness
raised JVP
cannon waves
CCF

42.  Class I - those for which there is evidence or
consensus of opinion that therapy is useful
and effective
 Class II - there is conflicting evidence or a
divergence of opinion about the efficacy of a
procedure or treatment
 II A - weight of evidence or opinion favors
treatment
 II B - efficacy is less well established by the
evidence or opinion of experts
 Class III - evidence or weight of opinion
indicates that the therapy is not efficacious
or useful and may be harmful