Direct Current Cardioversion of Atrial Arrhythmias in Adults With Cardiac Amyloidosis

Abstract

BACKGROUND Arrhythmias, conduction abnormalities, and intracardiac thrombus are common in patients with cardiac amyloidosis (CA). Outcomes of direct-current cardioversion (DCCV) for atrial arrhythmias in patients with CA are unknown. OBJECTIVES This study sought to examine DCCV procedural outcomes in patients with CA. METHODS Patients with CA scheduled for DCCV for atrial arrhythmias from January 2000 through December 2012 were identified and matched 2:1 with control patients by age, sex, type of atrial arrhythmia, and date of DCCV. RESULTS CA patients (n = 58, mean age 69 ± 9 years, 81% male) were included. CA patients had a significantly higher cardioversion cancellation rate (28% vs. 7%; p < 0.001) compared with control patients, mainly due to intracardiac thrombus identified on transesophageal echocardiogram (13 of 16 [81%] vs. 2 of 8 [25%]; p = 0.02); 4 of 13 of the CA patients (31%) with intracardiac thrombus on transesophageal echocardiogram received adequate anticoagulation ≥3 weeks and another 2 of 13 (15%) had arrhythmia duration <48 h. DCCV success rate (90% vs. 94%; p = 0.4) was not different. Procedural complications were more frequent in CA versus control patients (6 of 42 [14%] vs. 2 of 106 [2%]; p = 0.007); complications in CA included ventricular arrhythmias in 2 and severe bradyarrhythmias requiring pacemaker implantation in 2. The only complication in the control group was self-limited bradyarrhythmias. CONCLUSIONS Patients with CA undergoing DCCV had a significantly high cancellation rate mainly due to a high incidence of intracardiac thrombus even among patients who received adequate anticoagulation. Although the success rate of restoring sinus rhythm was high, tachyarrhythmias and bradyarrhythmias complicating DCCV were significantly more frequent in CA patients compared with control patients. (J Am Coll Cardiol 2019;73:589–97)

DSMA Renal Scan in Cardiac Amyloidosis

“…10 Anticoagulation has been suggested for prophylaxis, but one study found a high rate of atrial clots prior to cardioversion despite adequate anticoagulation. 12 One autopsy series found atrial thrombi in 33% of patients with cardiac amyloidosis and thromboembolism in 20% of these patients. 13 The thromboembolism was fatal in 83% of cases.…”

Long-Term Electrocardiographic Follow-Up of a Patient with Light-Chain Cardiac Amyloidosis

“…However, it has been reported that while direct current cardioversion for atrial arrhythmias in patients with cardiac amyloidosis improved cardiac function, the complication rate of bradycardic and tachyarrhythmias events were high 21 . In addition, regarding pacemaker implantation, there are many unsolved problems such as the timing of implantation, pacing site and mode 22 .…”

Cardiac Care of Patients with Cardiac Amyloidosis

“…Rhythm Control in CA. A recent study described direct current cardioversion procedural outcomes in patients with CA [47]. Although the success rate of restoration of the sinus rhythm was high, tachyarrhythmias and bradyarrhythmias complicating direct current cardioversion were significantly more frequent in CA patients compared with control patients (14 vs. 0%).…”

“…Importantly, intracardiac thrombus was detected in 28% of CA patients referred for transesophageal guided direct cardioversion, including patients who did not require transesophageal guidance per guidelines (either had a therapeutic level of anticoagulation for >3 weeks or arrhythmia onset <48 h before the planned cardioversion) [47]. Thus, transesophageal echocardiography should strongly be considered before direct cardioversion in all patients with CA, regardless of the duration of arrhythmia or the therapeutic level of anticoagulation [47, 53].…”