Responding to increased calls for better ways of diagnosing unexplained syncope, a Spanish research team has come up with a protocol involving selective use of electrophysiologic studies (EPSs), tilt-table tests (TTTs), and implantable loop recorders (ILRs). They say their strategy shows that "relatively simple clinical criteria" can guide physicians toward appropriate testing and ultimately a positive diagnosis in more than 70% of cases. Other experts are not convinced that the proposed protocol will produce accurate results.

The debate over syncope diagnosis centers on the value of conventional syncope tests, namely EPSs and TTTs, relative to ILRs. In recent studies, including the EaSyAS trial presented at the 2002 European Society of Cardiology meeting, ILRs have proved superior to conventional testing in determining an underlying cause of syncope.

However, as Dr Roberto Garcia-Civera (Hospital Clinico Universitario, Valencia, Spain) and colleagues point out, there are drawbacks to ILR use that make them less desirable for widespread application. “We decided not to systematically implant an ILR in patients with isolated syncope, because we believed that the benign nature, the low recurrence rate, and the uniform type of response in these cases do not justify an invasive approach and the additional cost of an ILR,” study coauthor Dr Ricardo Ruiz-Granell said. “We must wait until a new syncope, which could be the last one in the malignant subgroup; and it is expensive to implant an ILR in every patient.”