Introduction Post ablation of the accessory pathway (AP), the patient is observed in the catheterization laboratory for a variable period for resumption of pathway conduction. Aim of the study was to determine whether the administration of intravenous adenosine at 10 minutes after ablation of accessory pathway (AP) would have the same diagnostic accuracy as waiting for 30 minutes in predicting the resumption of AP conduction. Methods: This was a prospective interventional study conducted in two centers. Post ablation of the AP, intravenous adenosine was administered at 10 minutes to look for dormant pathway conduction. The response was recorded as positive (presence of pathway conduction), negative (absence), or indeterminate (not able to demonstrate AV and VA block and inability to ascertain AP conduction). Results: The study included 110 procedures performed in 109 patients. Adenosine administration at 10 minutes showed positive result in 3 cases (2.7%), negative result in 99 cases (90%) and indeterminate result in 8 cases (7.3%). Reconnection of accessory pathway at 30 minutes post ablation was seen in 8 cases (7.3%). Of these 8 cases, 10minutes adenosine administration showed positive test in 3 patients and negative test in 5 patients. Adenosine test at 10 minutes has a sensitivity, specificity, positive predictive value, and negative predictive value of 37.5%, 100%, 100% and 94.9% in identifying the recurrence of accessory pathway conduction at 30 minutes, respectively. Conclusion: Absence of pathway conduction on administration of adenosine 10 minutes post ablation does not help predict the absence of resumption of conduction thereafter.

Manuscript Title: Atrial paced beat rocks the boat of a broad QRS tachycardia causing AVVA response. What is the mechanism?Key words: Atriofascicular pathway, BBRVT, dual AV nodal physiology

Title Page Manuscript Title:Simultaneous atrial and ventricular pacing during narrow complex tachycardia – The Janus Response. Which one is true?

A document by Anand Manickavasagam. Click on the document to view its contents.

Introduction: Knowledge of factors causing pacing-induced cardiomyopathy (PICM) is incomplete. We sought to estimate the incidence and predisposing factors for PICM in South Asian population and evaluate if the risk they portend adds up. Methods: Consecutive patients with preserved LVEF undergoing pacemaker (PM) implantation between 2012 and 2018 were analysed. Results: A total of 749 patients (68.4% male; mean age 59.2 ± 14.08 years) were included in the analysis. PICM developed in 74 (9.9 %) patients over a median follow up of 2.2 years (IQR 1.1-3.2). Pre-implant LVEF, paced QRS duration and RV pacing burden were independent predictors of PICM. Using 90% specificity cut-off values for LVEF and paced QRS, and the value separating lowest tertile of RV pacing from the higher tertiles, three risk factors were identified: (i) baseline LVEF < 55%, (ii) paced QRS duration > 160 msec, and (iii) RV pacing burden > 33%. Patients with two or more risk factors were at the highest risk (OR 11.62, 95% CI 4.62 - 29.21, p-value < 0.001) for developing PICM while those with one risk factor had an intermediate risk (OR 3.89, 95% CI 1.62 - 9.34, p-value 0.002) when compared to those without any risk factors. Conclusion: Low-normal baseline LVEF, wider paced QRS and higher RV pacing burden independently predicted the development of PICM. The presence of ≥2 factors increased the odds of PICM, twelve-fold. Striving to get a narrower paced QRS, the only modifiable of the three risk factors, will help mitigate the development of PICM.

A document by Anand Manickavasagam. Click on the document to view its contents.