Effective identification of patients at increased risk of malignant cardiac
arrhythmia presently represents a clinically important unmet need. Existing
guidelines for the selection of candidates for the prophylactic implantation of
cardioverters-defibrillators (ICD) are based solely on the reduction of ventricular
haemodynamic performance. Although this guidance is based on statistical results
of previously conducted randomized clinical trials, available experience shows that it
does not serve clinical needs efficiently. The majority of patients who are implanted
with ICDs for prophylactic reasons never utilize the device during its technical longevity
whilst, at the same time, many patients who succumb to sudden cardiac death do
not have ventricular haemodynamic performance particularly compromised. Recent
results also showed that the previous statistical findings of ICD efficacy are not fully
reproducible in patients with non-ischemic heart disease and that the reduction of
sudden cardiac death after myocardial infarction by external automatic defibrillation
vests is lower than expected.
Advances in cardiac electrophysiology are needed for better understanding of the
mechanisms that are the basis of different arrhythmic abnormalities. Increased
understanding of these mechanisms will allow them to be more effectively classified
so that optimum therapeutic options can be offered. Likewise, better understanding of
the underlying electrophysiology processes is needed so that novel and more focused
randomized clinical trials can be designed. Compared to invasive electrophysiological
studies, noninvasive cardiac electrophysiology offers the possibility of screening
larger number of patients as well as healthy subjects investigated under different
provocations and conditions. To advance the field, broad spectrum of studies is
needed together with meta-analyses and reviews facilitating research interactions.