New diagnostic test for calcium release deficiency syndrome shows promise

A new diagnostic test involving the analysis of cardiac repolarization responses on an electrocardiogram (ECG) after brief tachycardia and a subsequent pause shows promise in effectively identifying calcium release deficiency syndrome (CRDS), a previously undetectable genetic arrhythmia, according to a study.

This test could significantly improve the clinical evaluation of unexplained cardiac arrests and enhance patient outcomes if confirmed by larger studies.

The study involved individuals with CRDS, patients with suspected supraventricular tachycardia, survivors of unexplained cardiac arrest (UCA), individuals with genotype-positive catecholaminergic polymorphic ventricular tachycardia (CPVT), and genetic mouse models.

The intervention involved inducing brief tachycardia followed by a pause, either spontaneously or through cardiac pacing. The primary measures were changes in the QT interval and T-wave amplitude on the ECG.

Results indicated that among 10 CRDS patients, the median change in T-wave amplitude post-pause was significantly higher than in the 45 suspected supraventricular tachycardia controls, 10 UCA controls, and 3 CPVT controls (P < 0.001). CRDS patients exhibited a minimum T-wave amplitude change of 0.250 mV, compared to a maximum of 0.160 mV in controls, allowing for 100% discrimination. Although the QT interval change was also longer in CRDS cases (P = 0.002), there was some overlap between cases and controls.

The authors concluded that if confirmed by larger studies, this simple ECG maneuver may become a crucial tool in the clinical evaluation of unexplained cardiac arrests, by identifying CRDS in at-risk patients.

Reference
Ni M, Dadon Z, Ormerod JOM, et al. A Clinical Diagnostic Test for Calcium Release Deficiency Syndrome. JAMA. 2024;doi: 10.1001/jama.2024.8599. Epub ahead of print. PMID: 38900490.