ORIGINAL ARTICLE Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures Alessia Gimelli 1 & Francesca Menichetti 2 & Ezio Soldati 2 & Riccardo Liga 2 & Andrea Vannozzi 2 & Paolo Marzullo 1,3 & Maria Grazia Bongiorni 2 Received: 21 June 2016 /Accepted: 5 July 2016 /Published online: 19 July 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Purpose To assess the relationship between regional myocar- dial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiologi- cal data in patients with ventricular arrhythmias (VA) submit- ted to invasive electrophysiological study and ablation procedure. Methods Sixteen subjects underwent invasive electrophysiolog- ical study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial per- fusion and sympathetic innervation by means of tomographic 99m Tc-tetrofosmin and 123 I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off- line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. Results CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable seg- ments, those showing an innervation/perfusion mismatch pre- sented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/ perfusion mismatch remained the most frequent ablation tar- gets (OR 5.6, 95 % CI 1.5–20.8; P = 0.009). Conclusions In patients with VA, intra-cavitary electrical ab- normalities frequently originate at the level of viable myocar- dial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target. Keywords Sympathetic innervation . Perfusion . Ventricular arrhythmias . Ablation . SPECT Introduction Ventricular arrhythmias (VA) represent the leading cause of death in cardiac patients, associated with considerable social and sanitary costs [1]. Structural heart diseases, such as ische- mic cardiomyopathy, are among the major predisposing fac- tors for a VA [i.e. re-entrant ventricular tachycardia (VT)] [1]. The development of VA, particularly in the presence of struc- tural heart disease, relies on the combined presence of a trig- gering mechanism that starts the arrhythmia and of an anatom- ic substrate that maintains the arrhythmic event [2]. While the most frequent anatomic substrate of a VA is identified by sections of scar tissue (i.e. an old myocardial infarction or the results of a myocarditis) interposed within bands of living myocardium, the triggering functional mechanism may vary. One of the most relevant factors that may trigger a VA is Alessia Gimelli and Francesca Menichetti shared first co-authorship. * Alessia Gimelli gimelli@ftgm.it 1 Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1, 56124 Pisa, Italy 2 Cardio-Thoracic and Vascular Department, University Hospital of Pisa, Pisa, Italy 3 CNR, Institute of Clinical Physiology, Pisa, Italy Eur J Nucl Med Mol Imaging (2016) 43:2383–2391 DOI 10.1007/s00259-016-3461-y