Indications for pacingIn

Special conditionsDr. Ahmed Taha Hussein

M.Sc.CardiologyElectrophysiology specialist

Assistant lecturerZagazig university

Updates of the guidelines

Specific conditions▪ Acute myocardial infarction▪ Pacing after cardiac surgery,transcatheter aorticvalve implantation,and heart transplantation.▪ Pacing and cardiac resynchronization therapy inchildren and in congenital heart disease.▪ Pacing in hypertrophic cardiomyopathy.▪ Pacing in rare diseases.▪ Pacing in pregnancy.▪ Pacing for first-degree atrioventricular block(haemodynamic).

Acute myocardial infarction

▪ Incidence 3.2% after PCI and thrombolytics.▪ AWMI associated high degree AV block isalways below Hiss bundle , while IWMI usuallyabove Hiss bundle .▪ Usually resolve spontaneously within 2-7 days.▪ 9% need Permenant pacing later on.▪ Newely developed Intraventricular condcutiondefect usually associated with high mortality dueextensive myonecrosis ... CRT criteria.

Acute myocardial infarction

Post-cardiac surgery

▪ AV-block occurs in 1-4% cases :▪ In 8% after repeated surgery , 20 - 40% incalcific aortic valve and TV-replacement.▪ SN-dysfunction may occur in CABG, lateralatriotomy , trans-septal superior approaches tothe MV.▪ In clincial practice 5-7 days observation periodapplied before PPM.

TAVI▪ AV-block post TAVI reaches 14% , especiallywith CoreValve prosthesis .▪ Independant predictors : use of the CoreValveprosthesis and evidence of conduction systemdysfunction, either pre- existing RBBB or AVlock at the time of TAVI.▪ New-onset persistent LBBB is commonfollowing TAVI, but its significance is unclear.▪ Even TAVI patients meet the criteria for CRT ,experience is very limited.

Heart transplantation

▪ SN-dysfunction is common up to 8% fo cases.▪ Causes :surgical trauma, sinus node arterydamage, or ischaemia and prolonged cardiacischaemic times.▪ Av-block is less common and is probablyrelated to inadequate preservation.▪ Chronotropic incompetence is always presentfollowing standard orthotopic hearttransplantation.▪ Observation period several weeks , in clinicalconsensus 3 weeks .

ChildrenMay be early manifestationsis sudden cardiac death,Adam stokes attackes orheart failure.

Pacing site RV vs LVEpicardial vs endocardial

ChildrenSN-dysfunction CRT

The evidence islimited to casereports.Single site LVpacing (apex/midlateral wall)

Hypertrophic cardiomyopathy▪ uncommon in (HCM), but in context,can suggest specific aetiologies (forexample, PRKAG2 gene mutations,Anderson-Fabry disease andamyloidosis).▪ CRT may be considered inindividual cases in which there issome evidence for systolic ventricularimpairment.

RV apical pacing

Rare diseases

LQT- syndromesICD (with active pacing) is preferable in patients withsymptoms unresponsive

to ß-blocker therapy or pause-dependent ventriculararrhythmia according to current ICD guidelines.

Muscular dystrophiesEmery-Dreifuss MD

once bradycardia appeared , but thromboebolism arenot preventable by pacing.athy and mitochondrial diseases , pacing with ICDback-up is the recommended Other types ofdesmopapproach.

Pregnancy▪ Vaginal delivery carries no extra risks in amother with congenital complete heart block.▪ For women who have a stable, narrow,complex junctional escape rhythm, PMimplantation can be deferred until after delivery.

1st degree AV-blockProlonged PR interval lead ineffective atrial systole,and diastolic MR , increased PCWP and pulmonarycongestion.

DDD -- LV dysfunction

Functional Atrial undersensing --shift of P wave

ATP-atrial algorithmRate-adaptive pacing, which periodically assesses the underlyingintrinsic rate to pace just above it, elevation of the pacing rate afterspontaneous atrial ectopy, transient high-rate pacing after modeswitch episodes and increased post-exercise pacing to prevent anabrupt drop in heart rate.

Thank you