The development of a new, simple electrocardiographic method for the estimation of the latest activated left ventricular site

Background Current cardiac resynchronization therapy (CRT) works by pacing the latest activated left ventricular (LV) site. The estimation of the location of the latest activated LV site (LALVS) may be important to determine the optimal position of the LV electrode during CRT or to predict the patient response to the current CRT technique devised to pace the LALVS usually present in patients with left bundle branch block (LBBB) pattern. Methods We used a modified 12-lead ECG algorithm originally devised and used by other authors* for a different purpose, to identify the segment of origin of ventricular tachycardia in the 16-segment American Heart Association LV model by analyzing the QRS axis in the limb and chest leads. We hypothesized that modifying this ECG algorithm by using the secondary ST vector axis instead of the QRS axis in the limb and chest leads, we can apply this ECG method to estimate the LALVS instead of the site of origin of the ventricular tachycardia. The resultant secondary ST vector is directed 180o away from the LALVS. Using this ECG method we determined the LALVS in 22 patients with LBBB and 20 patients with nonspecific intraventricular conduction disturbance (NICD) patterns and heart failure. To validate the ECG method, we also estimated the LALVS by echocardiography using 3D parametric imaging and 2D speckle tracking. Results The LALVS determined by the electrocardiographic method and echocardiogrpahy in the 16-segment model matched (was in the same or adjacent segment) in 38/42 (90.5%) patients and among these patients complete matching (the LALVSs were in the same segment) was found in 16/38 (42%) and partial matching (the LALVSs were in adjacent segments) in 22/38 (58%) patients. When the LBBB and NICD groups were separated to patients with ≥150 ms and <150 ms QRS duration subgroups, the LALVSs of the ≥150 ms subgroup were almost exclusively in the anterolateral (or anterior) or inferolateral areas and those of the <150 ms subgroup were in the above mentioned areas or sometimes at other sites located remote from these areas. Conclusions The novel, simple surface electrocardiographic method could as reliably estimate the approximate location of LALVS as echocardiography. The possible explanation for the effectivity of CRT in patients with sinus rhythm with intraventricular conduction disturbance and ≥150 ms QRS duration is that their LALVS is at the same most distant areas (anterolateral, anterior, inferolateral) from the initial septal activation site where the LV electrodes are positioned during application of the current CRT technique. FUNDunding Acknowledgement Type of funding sources: None.

Safety of Amiodarone in Ventricular Arrhythmia in Patients Admitted in Bangabandhu Sheikh Mujib Medical University

Background: Amiodarone is the most effective antiarrhythmic medications available today for the treatment of both atrial and ventricular arrhythmias. It is an iodinated benzofuran derivative with demonstrated efficacy against a range of cardiac arrhythmias, including atrial fibrillation, paroxysmal supraventricular tachycardias, and life-threatening ventricular arrhythmias. Objective: To evaluation the status of amiodarone with therapeutic dose in Bangladeshi population. Materials and Methods: The quasi experimental study was conducted in the Department of Cardiology in Bangabandhu Sheikh Mujib Medical University (BSMMU), Shahbagh, Dhaka during April, 2019 to March, 2020 Patients got admitted in the Department of Cardiology, BSMMU, consecutive patients who had been treated with amiodarone for arrhythmia were included in this study. Patients without an amiodarone prescription were assumed and patients who will not give informed written consent were excluded in this study. Results: The most common adverse event was bradycardia or conduction disturbance (9.0%) followed by 4(2.2%) thyroid toxicity, 3(1.7%) hepatic toxicity, 2(1.1%) eye toxicity and 1(0.6%) pulmonary toxicity. In multi variable logistic regression, bradycardia or conduction disturbance, amiodarone daily dose (≥300 mg) and duration of amiodarone (>4 month) was found to be significantly (p<0.05) associated with adverse effects of amiodarone. Conclusion: The most common adverse event was bradycardia or conduction disturbance followed by thyroid toxicity, hepatic toxicity, eye toxicity and pulmonary toxicity. Bradycardia or conduction disturbance, amiodarone daily dose (≥300 mg) and duration of amiodarone (>4 month) was found to be significantly associated with adverse effects of amiodarone. University Heart Journal Vol. 17, No. 2, Jul 2021; 118-121

Conduction disturbances after TAVR - a 1-year follow-up

Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter aortic valve replacement (TAVR) is an established procedure to treat patients (pts) with symptomatic severe aortic stenosis. Although conduction disturbances remain the most frequent complication, there is a lack of consensus on their management, which leads to significant differences in permanent pacemaker (PPM) implantation rates between centers. Purpose To evaluate new conduction disturbances and PPM implantation in pts undergoing TAVR, peri-procedure and up to 1 year. Methods We retrospectively analyzed all pts who underwent TAVR at a tertiary center from October 2014 to November 2019; pts with a previous PPM were excluded (n = 30). Clinical and ECG data were collected at presentation and up to 1 year after implantation, including systematic interrogation of implanted PPM. Results 340 pts underwent TAVR (57% female, mean age 80 ± 8years). CoreValve Evolut R was the most used valve (41% of pts), followed by CoreValve Evolut Pro (21%) and Acurate Neo (13%). Of the 77% pts who were in sinus rhythm pre-TAVR, 79% had normal atrioventricular (AV) conduction and 20% 1st degree AV block (AVB); 60% had no intraventricular (IV) conduction disturbance, 9% left bundle branch block (LBBB), 7% right bundle branch block (RBBB) and 7% RBBB plus fascicular block. After TAVR, 50.9% of pts exhibited new conduction disturbances. Regarding AV conduction, 12.4% of pts developed advanced AVB and 20% of pts without previous disturbances developed 1st degree AVB. Concerning IV conduction, the most frequent disturbance was de novo LBBB (n = 109, 32,2%) which resolved in 56% of cases after 6 months. Among pts with previous RBBB, 42% developed advanced AVB; the presence of previous RBBB was the major risk factor for advanced AVB [OR = 8.5 (95% CI 4.1-17.5; p &lt; 0.001)] and PPM implantation [OR = 5.2 (95% CI 2.7-10.0; p &lt; 0.001)], followed by previous 1st degree AVB [OR = 2.3 (95% CI 1.2-4.4; p = 0.016) for PPM implantation]; previous FA or LBBB were not associated with advanced AVB or PPM implantation. Overall, 19% of pts implanted a PPM post-TAVR (n = 63). The main reason was advanced AVB (60%), followed by LBBB plus 1st degree AVB (22%), isolated LBBB (5%) and alternating bundle branch block (ABBB) (5%). At first PPM evaluation, pts with advanced AVB had a median percentage of ventricular pacing (VP) of 80% (52% had VP &gt;90% and 14% &lt;1%) and one year after-TAVR the median percentage of VP was 83%. Concerning pts with LBBB plus 1st degree AVB, median VP at first assessment was 4% (38% had &lt; 1% of VP). In pts with isolated LBBB or ABBB, median VP at first evaluation was 13% and 11%, respectively. Conclusion LBBB was the most frequent de novo conduction disturbance after TAVR, with more than half of the cases resolving in the first 6 months. RBBB, on the other hand, was the major risk factor for advanced AVB and PPM implantation. Advanced AVB was associated with a high percentage of VP at 1-year follow-up, unlike pts with milder degrees of conduction delay.

Intraprocedural high degree atrioventricular block after transcatheter aortic valve replacement in patients with native versus bioprosthetic aortic valves

Funding Acknowledgements Type of funding sources: None. Introduction One of the most frequent intraprocedural complication of patients undergoing transcatheter aortic valve replacement (TAVR) is high degree atrioventricular block (HDAVB). The incidence varies from 5-20% depending on the type of valve, previous surgical valve replacement (SVR) and basal conduction disturbances. Purpose The purpose of this study was to evaluate the incidence of intraprocedural HDAVB in patients undergoing TAVR in native valves versus patients with previous SVR derived for valve-in-valve TAVR (VIV-TAVR). Methods Data was collected from all the patients undergoing TAVI in a single center from December 2007 to July 2019. The primary endpoint was to compare the incidence of HDAVB in patients undergoing TAVR versus patients undergoing VIV-TAVI. The secondary endpoint was to describe the differences in the baseline characteristics of patients that presented with HDAVB vs patients without HDAVB. Results A total of 661 patients were derived for TAVR and separated into 2 groups for analysis. 596 patients with native valves treated with TAVR and 65 patients with previous SVR treated with VIV-TAVI. The primary outcome was present in 87 patients (14,6%) in the TAVR group vs 1 patient (1,54%) in the VIV-TAVR group (p: 0,0033). Patients with HDAVB (n = 88) had a mean age of 83,1 ± 6,26 years. The baseline EKG showed a conduction disturbance in 47,6% of the cases (50% of right bundle branch block; 21,8% of first degree AVB; 15,09% of left bundle branch block and 35,85% of left anterior fascicular block). A new permanent pacemaker was implanted in 77 (87,5%) patients. Patients without HDAVB (n = 573) had a mean age of 82,5 ± 6,14 years. The baseline EKG showed a conduction disturbance in 28,91% of the cases (22,73% of Right bundle branch block; 25,68% of first degree AVB; 31,70% of left bundle branch block and 21,25% of left anterior fascicular block). A new permanent pacemaker was implanted in 59 (10,30%) patients. Conclusions There is a very low incidence of intraprocedural HDAVB in patients undergoing VIV-TAVR compared to the rest of TAVR procedures (1,54% vs 14,6% p:0,0033). Moreover, the only predictors that associated with the development of HDAVB where previous right bundle branch block and left anterior fasicular hemiblock. The development of intraprocedural HDAVB is associated with the need of a new permanent pacemaker. Table 1: Basal CharacteristicsNo HDAVBHDAVBp VALUEAge, yrs82,683,10,453Basal conduction disturbance28,91 %47,62 %&lt;0,0001PPM implantation10,3 %85,2 %&lt;0,0001Basal characteristicsAbstract Figure. Clinical characteristics by groups