NEW YORK (Reuters Health) – In patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), changes in Holter exam findings after diagnosis were associated with the risk of sustained ventricular arrhythmias within a year, researchers say.
“These findings…provide a new tool to dynamically monitor the risk of life-threatening cardiac arrhythmias in patients with ARVC during follow-up,” Dr. Hugh Calkins of Johns Hopkins University School of Medicine in Baltimore told Reuters Health by email. “Holters are available worldwide, are inexpensive, and the interpretation of the number of premature ventricular contractions (PVCs) is straightforward.”
As reported in JAMA Cardiology, Dr. Calkins and colleagues analyzed data on 169 patients with ARVC (mean age, 36.3; 56%, men) who had Holter monitoring results at diagnosis, plus at least two additional Holter results during follow-up.
The main outcomes were the association between prespecified variables retrieved at each Holter monitoring follow-up: overall PVC burden; presence of sudden PVC spikes; presence of nonsustained ventricular tachycardia (NSVT); and use of beta-blockers and class III antiarrhythmic drugs. Sustained ventricular arrhythmias occurring within 12 months after a Holter examination were also assessed.
During a median follow-up of 54 months, 723 Holter examinations were performed (median, 4 per patient), and 75 PVC spikes and 67 sustained ventricular arrhythmias were detected.
The PVC burden decreased significantly from the first to the second Holter examination (mean reduction, 2,906 PVCs per 24 hours). The authors suggest that this initial PVC burden reduction may be attributed to restriction of endurance and high-level endurance sports and/or initiation of drug treatment, which occurred in close to 75% of participants after the first assessment.
A model including 24-hour PVC burden (odds ratio,1.50); PVC spikes (OR, 6.20); and NSVT (OR, 2.29) at each Holter follow-up was associated with the occurrence of a sustained ventricular arrhythmia in the following 12 months.
Dr. Edmond Cronin, Associate Professor of Medicine at the Lewis Katz School of Medicine at Temple University in Philadelphia commented on the study in an email to Reuters Health. “These findings will help to risk-stratify patients with ARVC and help decide who would benefit from an ICD,” he said.
However, he noted, “the investigators used 24-hour Holter monitors. While standard in the past, current technology (ambulatory loop monitors) enables longer periods of monitoring. It is well known that PVC burden can vary dramatically day-to-day, and longer monitoring periods of 5-7 days give a more accurate PVC burden. Some of the variation in PVC burden observed in the study may just reflect day-to-day variability.”
“The number of PVCs dropped from the first to the second Holter,” he noted. “That is surprising, as ARVC is a progressive disease, and I would have expected that the number of PVCs would increase over time, not decrease. However, it may be due to the patients starting treatment after diagnosis.”
“Although most patients with frequent PVCs do not have ARVC, all patients with frequent PVCs should be assessed for this and other underlying conditions by a cardiologist,” he added. “As in any condition in which risk stratification is performed to decide whether to recommend a particular therapy or not, that risk stratification should be repeated at intervals, as risk factors change over time.”
SOURCE: https://bit.ly/35f84Zz JAMA Cardiology, online February 23, 2022.