Download cardiac surgery — av block may be associated with replacement of a

Pacemaker following adult cardiac
surgery
DR M HASANZADEH
MUMS
NOV 2014
Iatrogenic heart block.etiology
MEDICATIONS — A VARIETY OF DRUGS CAN IMPAIR AV CONDUCTION,
DIGITALIS ,VERAPAMIL, DILTIAZEM, AMIODARONE, ADENOSINE, BETABLOCKERS, PROCAINAMIDE, DISOPYRAMIDE
CARDIAC SURGERY — AV BLOCK MAY BE ASSOCIATED WITH REPLACEMENT
OF A CALCIFIED AORTIC OR MITRAL VALVE, CLOSURE OF A VENTRICULAR SEPTAL
DEFECT, OR OTHER SURGICAL PROCEDURES
CATHETER ABLATION FOR ARRHYTHMIAS
TRANSCATHETER CLOSURE OF VSD
ALCOHOL (ETHANOL) SEPTAL ABLATION
TRANSCATHETER AORTIC VALVE IMPLANTATION (TAVI)
The conduction defects with cardiac surgery
are located at the sinus node,AV node,his
purkinje system.
May be due to injury of conduction system
or ischemia or specific coronary disorders.
May be temporary or irreversible.
INCIDENCE OF PPM IMPLANTATION IN
RELATION TO TYPE OF SURGERY
(2011 STUDY)
CABG ONLY
AVR(+CABG )
MVR(+CABG)
VALVE REPAIR(+CABG)
GVR(+CABG)
DOUBLE VALVE(+CABG)
OTHER SURGERY
TOTAL
0.9 %
6 %
7.6 %
1.2 %
0 %
16.3 %
13.9 %
2.2 %
Other surgery
AVR ;
13% 1960----6% recent studies.
TAVI ;
11.8—33 %
MVR ;
4.8 %
REDO ;
4 fold increase
MYXOMAS ;
2.6—18.8 %
CHD ; VSD ; 2.5%---ASD ; 2.2 %---COMPLEX LESIONS ???
ASCENDING AO SURGERY; 5-14%
POST OPERATIVE PPM PREVALENCE.
ALL
1.3-1.4%
CABG
0.4-2 %
VALVE SURGERY
3-6 %
AVR
4.1 %
MVR
2.6-4.2 %
CHD
25%(1971)-4%(1995)
HEART TRANSPLANT
0-5%
TVR or repair plus other surgery,up to 28%.
HEART BLOCK AFTER CABG
CABG less damaging conduction system.
45% incidence of TPM at the end of surgery.
Patients who discharged with PPM is significantly lower.(5-6.8%).
For ONCAB and OFFCAB the incidence is nearly the same.
(6.8 versus 5-5.6).
LBBB before surgery is a more potent predictor of post op PM need
than RBBB.
AF and bifasicular block are other predictors.
Preoperative risk predictors of PPM
insertion.
ABSENCE OF PREOP SINUS RHYTHM.
FEMALE GENDER
ADVANCED AGE>65Y
AORTIC ANNULUS CALCIFICATION.
ENDOCARDITIS.
UNSTABLE ANGINA.
COMROMISED SEPTAL FLOW.
VENTRICULAR DILATION.
RENAL FAILURE.
HYPOTENSION.
SOME MEDICATIONS.
FASICULAR BLOCKS (RBBB FOR VALVULAR AND LBBB FOR
CABG).
FIRST DEGREE AVB.
OUTCOME
Block may be recover in the short term ,
intermediate and long term after surgery.
30% in those with narrow escape QRS and 18% in
those with wide QRS.
KOPLAN B SCORING TO PREDICT PPM
AFTER SURGERY
ECG POINTS:
RBBB
2
LBBB
1
P-R>200 1
MULTI VALVE SURGERY:
TRICUSPID INCLUDED
TRICUSPID NOT INCLUDED
OTHERS:
AGE>70
PRIOR VALVE SURGERY
2
1
1
1
RISK SCORE
SCORE POINTS
6
5
4
3
2
1
0
PPM RISK%
50
36
21
12
8.7
5.2
1.9
What to do to minimize the risk of PPM
Solve the pre op non sinus rhythm as possible.
Improve metabolic status as possible.
Minimally invasive approach.
Do valve repair instead of replacement.
Do an optimal myocardial protection.
Minimize hypothermia time.
Reduce CPB and aortic CXL time.
Interrupted sutures in valve replacement.
Indication and estimated time for PPM
implantation
Variables considered to place PPM:
Conduction disturbances:
High degree AVB –SSS-symptomatic bradycardia-slow AFbifasicular block.
Start TPM time
Persistent arrhythmias in time
Surgery type
Complications longer stay.
TIME TO IMPLANT
The mean days varies from 5 to 7 (3-31).
6 days for wide QRS escape and 9 days for narrow QRS escape.