Safety and effectiveness of intravenous procainamide in patients with frequent ventricular ectopics during cardiac magnetic resonance scanning: a way to ensure high quality imaging
Authors: Nikolaidou C , Leal-Pelado J , Kouskouras K , Vassilikos VP , Karvounis H , Karamitsos TD 
Published: February 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Cardiac magnetic resonance (CMR) imaging in patients with frequent ventricular arrhythmias provides significant diagnostic and prognostic information but is challenging due to artefacts. In patients with occasional ventricular premature contractions (VPCs), arrhythmia rejection algorithms can be used to acquire good quality cine images at the expense of longer breath-hold times. However, arrhythmia sorting in not practical in cases of frequent VPCs; other options include triggered data acquisition which compromises image quality or use of low temporal and spatial resolution ‘real-time’ imaging.

Purpose
The aim of our study was to examine the safety and effectiveness of the class Ia antiarrhythmic medication procainamide for suppressing ventricular ectopy and acquiring high quality CMR images.

Methods
50 consecutive patients (mean age 48 ± 16 years; 52% female) with a high burden of VPCs during CMR scanning were included in the study. Procainamide was administered on the scanner table prior to CMR scanning at intermittent intravenous bolus doses of 50 mg every minute, until suppression of VPCs was achieved or a maximum dose of 10 mg/kg was reached. Blood pressure was measured every minute and there was continuous monitoring of heart rate and ECG trace. CMR studies were performed on a 1,5T Magnetom Avanto scanner using a standard cardiac protocol.

Results
The average dose of procainamide administered was 567 ± 197 mg (range 200-1000 mg). Procainamide successfully suppressed VPCs in 82% of patients (20 patients with complete suppression and 21 with significant reduction); 7 patients had minimal suppression of VPCs, while there was no effect of procainamide in only 2 patients. Baseline blood pressure (BP) was mildly reduced (mean change systolic BP -12 ± 9 mmHg; diastolic BP -4 ± 9 mmHg) but none of the patients developed symptomatic hypotension. Baseline heart rate (HR) was relatively unchanged (baseline 75 ± 11 beats per minute (bpm) – peak procainamide HR 74 ± 12 bpm (mean HR change -1 ± 6 bpm). None of the patients developed pathological ECG changes. CMR scan had normal findings in 42% of the patients, 26% had non-ischemic cardiomyopathy, in 16% the most likely diagnosis was VPC-related cardiomyopathy, 14% had previous myocarditis, and 1 patient had dual pathology (dilated cardiomyopathy with previous myocardial infarction). Mean left ventricular ejection fraction was 55% ± 9%.

Conclusion
We propose the bolus intravenous administration of procainamide prior to CMR scanning as a safe and effective alternative approach for suppressing VPCs and acquiring high quality images in patients with frequent ventricular arrhythmias and normal or only mildly impaired left ventricular function. Further studies are needed to assess its safety and effectiveness in larger patient cohorts, including also patients with ventricular systolic impairment.