July 1, 2018Open Access
Localized Structural Alterations Underlying a Subset of Unexplained Sudden Cardiac Death
Key Result
Detailed electrophysiological mapping revealed localized structural alterations in 62.5% of patients with previously unexplained sudden cardiac death, which colocated with VF drivers.
Study Design
Type
Observational (n=24)
Structured PICO
Does detailed electrophysiological mapping identify localized structural alterations underlying idiopathic ventricular fibrillation?
P
Population
24 patients (mean age 29±13 years) who survived idiopathic ventricular fibrillation (unexplained sudden cardiac death).
I
Intervention
Multielectrode body surface recordings and endocardial/epicardial catheter mapping, followed by catheter ablation in 18 patients
O
Outcome
Presence of localized structural alterations, colocation with VF drivers, and arrhythmia-free outcome after catheter ablationsurrogate
Detailed electrophysiological mapping reveals that localized structural alterations, predominantly in the epicardium, underlie a significant subset of previously unexplained sudden cardiac death and can be targeted by catheter ablation.
Limitations
- Limited number of patients
- Body surface mapping used reconstruction algorithms subject to uncertainties
- Electrophysiological criteria based on studies with a relative paucity of presumed healthy patients
- Narrower electrogram duration possibly resulted in underestimation of abnormal areas
- Lack of a control group without ablation
Abstract
Background: Sudden cardiac death because of ventricular fibrillation (VF) is commonly unexplained in younger victims. Detailed electrophysiological mapping in such patients has not been reported. Methods: We evaluated 24 patients (29±13 years) who survived idiopathic VF. First, we used multielectrode body surface recordings to identify the drivers maintaining VF. Then, we analyzed electrograms in the driver regions using endocardial and epicardial catheter mapping during sinus rhythm. Established electrogram criteria were used to identify the presence of structural alterations. Results: VF occurred spontaneously in 3 patients and was induced in 16, whereas VF was noninducible in 5. VF mapping demonstrated reentrant and focal activities (87% versus 13%, respectively) in all. The activities were dominant in one ventricle in 9 patients, whereas they had biventricular distribution in others. During sinus rhythm areas of abnormal electrograms were identified in 15/24 patients (62.5%) revealing localized structural alterations: in the right ventricle in 11, the left ventricle in 1, and both in 3. They covered a limited surface (13±6 cm 2 ) representing 5±3% of the total surface and were recorded predominantly on the epicardium. Seventy-six percent of these areas were colocated with VF drivers ( P <0.001). In the 9 patients without structural alteration, we observed a high incidence of Purkinje triggers (7/9 versus 4/15, P =0.033). Catheter ablation resulted in arrhythmia-free outcome in 15/18 patients at 17±11 months follow-up. Conclusions: This study shows that localized structural alterations underlie a significant subset of previously unexplained sudden cardiac death. In the other subset, Purkinje electrical pathology seems as a dominant mechanism.
Cite This Study
Haı̈ssaguerre et al. (Sun,) conducted a observational in Idiopathic ventricular fibrillation (n=24). Electrophysiological mapping and catheter ablation was evaluated on Presence of localized structural alterations (abnormal electrograms). Detailed electrophysiological mapping revealed localized structural alterations in 62.5% of patients with previously unexplained sudden cardiac death, which colocated with VF drivers.