Indications for pacing In Special conditions Dr. Ahmed Taha Hussein M.Sc.Cardiology Electrophysiology specialist Assistant lecturer Zagazig university
Jul 10, 2015
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