Importance of Systematic Diagnostic Testing in Idiopathic Ventricular Fibrillation

BACKGROUND Idiopathic ventricular fibrillation (iVF) is a diagnosis of exclusion. Systematic diagnostic testing is important to exclude alternative causes for VF. The early use of high yield testing, including cardiac magnetic resonance (CMR), exercise testing, and sodium channel blocker provocation, has been increasingly recognized. OBJECTIVES The purpose of this study was to investigate the importance and consistency of systematic diagnostic testing in iVF. METHODS This study included 423 iVF patients from 11 large secondary and tertiary hospitals in the Netherlands. Clinical characteristics and diagnostic testing data were ascertained. RESULTS IVF patients experienced the index event at a median age of 40 years (IQR: 28-52 years), and 61% were men. The median follow-up time was 6 years (IQR: 2-12 years). Over the years, high yield diagnostic tests were increasingly performed (mean 68% in 2000-2010 vs 75% in 2011-2021; P< 0.001). During follow-up, 38 patients (9%) originally labeled as iVF received an alternative diagnosis. Patients inwhomhigh-yield diagnostic tests were consistently performed during the initial work-up received an alternative diagnosis less frequently during follow-up (HR: 0.439; 95% CI: 0.219-0.878; P = 0.020). Patients who received an alternative diagnosis during follow-up had a worse prognosis in terms of cardiac death (P = 0.012) with a trend toward more implantable cardioverter-defibrillator therapy (P = 0.055). CONCLUSIONS Although adherence to (near) complete diagnostic testing in this population of iVF patients increased over the years, patients with iVF still undergo varying levels of diagnostic evaluation. The latter leads to initial underdiagnosis of alternative conditions and is associated with a worse prognosis. Our results underscore the importance of early systematic diagnostic assessment in patients with apparent iVF. (J Am Coll Cardiol EP 2023;9:345-355) (c) 2023 by the American College of Cardiology Foundation.

Automated summary

This study aimed to investigate the importance and consistency of systematic diagnostic testing in iVF. The findings showed that performing high yield diagnostic tests can reduce the frequency of alternative diagnoses in iVF patients during follow-up and improve their prognosis.