Pacemaker following adult cardiac surgery DR M HASANZADEH MUMS NOV 2014

MEDICATIONS — A VARIETY OF DRUGS CAN IMPAIR AV CONDUCTION, DIGITALIS,VERAPAMIL, DILTIAZEM, AMIODARONE, ADENOSINE, BETA- BLOCKERS, 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) VERAPAMILDILTIAZEMAMIODARONEPROCAINAMIDEDISOPYRAMIDE Iatrogenic heart block.etiology

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.

CABG ONLY 0.9 % AVR(+CABG ) 6 % MVR(+CABG) 7.6 % VALVE REPAIR(+CABG) 1.2 % GVR(+CABG) 0 % DOUBLE VALVE(+CABG) 16.3 % OTHER SURGERY 13.9 % TOTAL 2.2 % INCIDENCE OF PPM IMPLANTATION IN RELATION TO TYPE OF SURGERY (2011 STUDY)

AVR ; 13% % 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% Other surgery

ALL % CABG % VALVE SURGERY 3-6 % AVR 4.1 % MVR % CHD 25%(1971)-4%(1995) HEART TRANSPLANT 0-5% TVR or repair plus other surgery,up to 28%. POST OPERATIVE PPM PREVALENCE.

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. HEART BLOCK AFTER CABG

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. Preoperative risk predictors of PPM insertion.

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. OUTCOME

ECG POINTS: RBBB 2 LBBB 1 P-R>200 1 MULTI VALVE SURGERY: TRICUSPID INCLUDED 2 TRICUSPID NOT INCLUDED 1 OTHERS: AGE>70 1 PRIOR VALVE SURGERY 1 KOPLAN B SCORING TO PREDICT PPM AFTER SURGERY

SCORE POINTS PPM RISK% RISK SCORE

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. What to do to minimize the risk of PPM

Variables considered to place PPM : Conduction disturbances: High degree AVB –SSS-symptomatic bradycardia-slow AF- bifasicular block. Start TPM time Persistent arrhythmias in time Surgery type Complications longer stay. Indication and estimated time for PPM implantation

The mean days varies from 5 to 7 (3-31). 6 days for wide QRS escape and 9 days for narrow QRS escape. TIME TO IMPLANT