AimTo define the incidence, presentation, and outcomes of drug-induced Torsades de Pointes (TdP) with intravenous (IV) amiodarone.MethodsFrom January 2014 to August 2016 a total of 268 patients received IV amiodarone, 142 for ventricular tachycardia, 104 for atrial flutter/fibrillation, and 22 for incessant atrial tachycardia. A uniform dosing of amiodarone to yield 1 gm/day was used in all patients.ResultsFour of the 268 patients (M:F 1:3) with mean age of 51.25 + 9.17 years developed pause dependent TdP degenerating to VF, after a mean dose of 690 + 176.63 mg, infused over 12 + 5.88 h. The QTc that was 505 + 9.02 ms at the time of TdP normalized to 433.75 + 6.13 ms 48–72 h after stopping amiodarone. There was no immediate or late mortality, and patients are well at 5–10 months of follow-up. None of the patients tested positive for LQTS genes.ConclusionThe incidence of drug-induced TdP with IV amiodarone is about 1.5%. Risk factors include female sex, left ventricular dysfunction, electrolyte abnormalities, baseline prolonged QTc, concomitant beta-blocker, and digoxin therapy. Amiodarone induced TdP has favorable prognosis if recognized and treated promptly, and these patients should not receive amiodarone by any route in future.
Background
Right ventricular (RV) mid‐septal pacing has been proposed as an alternative to RV apical pacing. Fluoroscopic and electrocardiogram criteria are unreliable for predicting the RV mid‐septal lead position. This study aimed to define the optimal RV mid‐septal pacing site using RV angiography.
Methods
We randomized patients undergoing pacemaker implantation (PPM) to the RV angiography‐guided group (Group A) or conventional fluoroscopy‐guided group (Group F). In Group A, we performed an angiogram in right anterior oblique (RAO 30°), left anterior oblique (LAO 40°), and left lateral (LL) views. We made a 5‐segment grid in RAO 30° and LL views and a 3‐segment grid in LAO 40° on the angiographic silhouette to define the lead position. Computed tomography (CT) was used to validate the lead tip position in both groups.
Results
We enrolled 53 patients (Group A: 26, Group F: 27) with a mean age of 55.9 ± 12.2 years. CT images validated the lead position in the mid‐septum (Group A, 23 [88.5%]; Group F, 11 [40.7%], P = .0003) and anteroseptal (Group A, 3 [11.5%]; Group F, 5 [18.5%], P = .24). In Group F, the lead was in the anterior wall in 9 patients (33.3%) and the right ventricular outflow tract in 2 (7.4%) patients and none in these two positions in Group A. The lead tip in segment one on the angiographic 5‐segment grid in RAO 30° and LL views indicated a mid‐septal lead position on CT.
Conclusions
RV angiography is safe and may be used to confirm the mid‐septal lead position during PPM.
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