Statistics on the use of cardiac electronic devices and interventional electrophysiological procedures in Africa from 2011 to 2016: report of the Pan African Society of Cardiology (PASCAR) Cardiac Arrhythmias and Pacing Task Forces.

Aims: To provide comprehensive information on the access and use of cardiac implantable electronic devices (CIED) and catheter ablation procedures in Africa. Methods and results: The Pan-African Society of Cardiology (PASCAR) collected data on invasive management of cardiac arrhythmias from 2011 to 2016 from 31 African countries. A specific template was completed by physicians, and additional information obtained from industry. Information on health care systems, demographics, economics, procedure rates, and specific training programs was collected. Considerable heterogeneity in the access to arrhythmia care was observed across Africa. Eight of the 31 countries surveyed (26%) did not perform pacemaker implantations. The median pacemaker implantation rate was 2.66 per million population per country (range: 0.14-233 per million population). Implantable cardioverter-defibrillator and cardiac resynchronization therapy were performed in 12/31 (39%) and 15/31 (48%) countries respectively, mostly by visiting teams. Electrophysiological studies, including complex catheter ablations were performed in all countries from Maghreb, but only one sub-Saharan African country (South Africa). Marked variation in cost (up to 1000-fold) was observed across countries with an inverse correlation between implant rates and the procedure fees standardized to the gross domestic product per capita. Lack of economic resources and facilities, high cost of procedures, deficiency of trained physicians, and non-existent fellowship programs were the main drivers of under-utilization of interventional cardiac arrhythmia care. Conclusion: There is limited access to CIED and ablation procedures in Africa. A quarter of countries did not have pacemaker implantation services, and catheter ablations were only available in one country in sub-Saharan Africa.

Regional fractionation and dominant frequency in persistent atrial fibrillation: effects of left atrial ablation and evidence of spatial relationship.

AIMS: The aim was to study regional fractionation and dominant frequency (DF) to determine if any relationship exists between the two parameters and also to assess the impact of limited left atrial ablation. METHODS AND RESULTS: Patients undergoing catheter ablation of persistent AF using three-dimensional navigation were studied. Regional left atrial electrograms were analysed in the frequency domain by assessing DF and organization index (OI), and for degree of fractionation [using complex fractionated electrograms (CFE)-mean] before and after circumferential pulmonary vein and left atrial roof ablation. Twenty-three patients with persistent AF were studied. After ablation, global CFE-mean increased [100 ± 5 to 147 ± 11 ms (P= 0.0003)], DF decreased [6.1 ± 0.2 to 5.3 ± 0.2 Hz (P= 0.0003)], and OI was unchanged [0.27 ± 0.01 to 0.26 ± 0.02, (P= 0.70)]. Comparing sites close to and distant from ablation lines, percentage change in CFE-mean was 94 ± 10 vs. 37 ± 6% (P< 0.0001), DF change was -13 ± 3 vs.-12 ± 2% (P= 0.98), and OI change was 3 ± 6 vs. 10 ± 5% (P= 0.75), respectively. There was modest correlation between CFE-mean and DF points prior to ablation (r = -0.33, P< 0.0001) which was reduced following left atrial ablation (r = -0.24, P= 0.005). CONCLUSIONS: Left atrial ablation reduces global left atrial DF and decreases the degree of fractionation. Complex fractionated electrograms-mean and DF appear to share only modest spatial correlation and are affected to different extents by ablation, suggesting that they are either separate entities or reflect different components of the same substrate.

Increase in organization index predicts atrial fibrillation termination with flecainide post-ablation: spectral analysis of intracardiac electrograms.

AIMS: The mechanism of the action of flecainide in the termination of human atrial fibrillation (AF) is not fully understood. We studied the acute effects of flecainide on AF electrograms in the time and frequency domain to identify factors associated with AF termination. METHODS AND RESULTS: Patients who were still in AF at the end of catheter ablation for AF were given intravenous flecainide. Dominant frequency (DF) and organization index (OI) were obtained by fast Fourier transform of electrograms from the coronary sinus catheter over 10 s in AF, before and after flecainide infusion. Mean AF cycle length (CL) was also calculated. Twenty-six patients were studied (16 paroxysmal AF and 10 persistent AF). Seven converted to sinus rhythm (SR) with flecainide. In all patients, mean CL increased from 211 +/- 44 to 321 +/- 85 ms (P < 0.001). Mean DF decreased from 5.2 +/- 1.03 to 3.6 +/- 1.04 Hz (P < 0.001). Mean OI was 0.33 +/- 0.13 before and 0.32 +/- 0.11 after flecainide (P = 0.90). Comparing patients who converted to SR with those who did not, OI post-flecainide was 0.41 +/- 0.12 vs. 0.29 +/- 0.10 (P = 0.013), and the relative change in OI was 29 +/- 33 vs. -3.9 +/- 27% (P = 0.016), respectively. No significant difference was noted in the change in CL and DF in the two groups. CONCLUSION: Increase in OI, independent of changes to CL and DF, appears critical to AF termination with flecainide. Increase in OI holds promise as a sensitive predictor of AF termination.