Video-assisted thoracoscopic cardiac denervation of refractory ventricular arrhythmias and electrical storms.

Video-assisted thoracoscopic cardiac denervation of refractory ventricular arrhythmias and electrical storms

235Anatomic guided ablation of the right ganglionated plexus is enough for cardiac autonomic denervation in patients with significant bradyarrhythmias

Background In patients with significant bradyarrhytmias, cardiac denervation is an alternative therapeutic approach. Previous reports proposed different methods (as high frequency ednocardial stimulation of ganglionated plexus and specific atrial electrogram identification) and targets (right and left atrial ganglionated plexus) for adequate denervation. There is no consensus on the best way to perform these procedures, in spite the right atrial ganglia plexus (GP) ablation seeming to be the most contributive to its success. Purpose To assess the results of a purely anatomic approach for ablation of just the right atrial plexus in patients with severe vagal bradyarrhytmias. Methods We enrolled patients referred for ablation of cardiac parasympathetic ganglia, with or without atrial fibrillation ablation. We performed eletroanatomic mapping of the right and left atria and used an irrigated tip catheter for ablation, aiming at the anterior right GP at the right pulmonary veins antrum along with ablation at the superior vena cava junction and the inferior right GP at the posterior aspect of the right inferior pulmonary vein along with ablation of the right aspect of the interatrial septum, between the posterior wall and coronary sinus ostium (Figure 1). We assessed the PW and Wenckenback cycle lengths (CL) pre and post procedure in patients with sinus arrest or AV block, respectively, and the patients had new 24h holter readings at least 30 days from the index procedure. Results We enrolled 12 patients: 9 males (75%), median age of 49,5 years (IQR 36-61,75). All patients had structurally normal hearts. 7 patients had only ablation of the parasympathetic ganglia and 5 patients had simultaneous pulmonary vein isolation for previously documented atrial fibrillation. 7 patients (58,3%) had sinus bradycardia (2 patients had sinus arrest with pauses of 8 and 13 seconds), 2 patients with cardioinhibitory syncope (with pauses of 23 and 28 seconds) and 3 patients had transient high degree AV block. The ablation procedure led to a median sinus rate acceleration of 15 bpm (IQR 3-29), a median decrease of 320 ms in PW (IQR 23,75-609,5) in patients with sinus arrest and a decrease of 80 ms in wenckenback CL (IQR 60-200) in patients with AV block. With a median follow up of 133,50 days (IQR 36-61,75), no patient had recurrence of symptoms or conduction disturbances. Conclusions In selected patients with severe functional paroxysmal bradyarrhytmias, cardiac denervation using an ablation strategy purely based on anatomic aspects and targeting only the right GP, seems to be an effective therapeutic approach. Abstract Figure 1: Abl of right ganglionated plex

P2733Prognostic value of cardiac dysautonomia in AL amyloidosis

Introduction Cardiac involvement is the major prognostic factor in patients with light chain amyloidosis (AL). Cardiac dysautonomia can occur early in amyloidosis and can be assess by Iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy. Its prognostic value has been shown in TTR amyloidosis but is unknown in AL amyloidosis. We aimed to evaluate the prognosis impact of cardiac dysautonomia in patients with AL amyloidosis. Methods We carried out a prospective study in consecutive patients with biopsy-proven AL amyloidosis. All patients underwent clinical examination, EKG, echocardiography, cardiac MRI and biological tests. The 2012 Mayo clinic prognostic classification was calculated by using blood levels of NT-proBNP, cardiac T troponin and the differential of free light chains as recommended. The sympathetic cardiac innervation was assessed by using 123I-MIBGscintigraphy and measurement of the heart-to-mediastinum uptake ratio (late H/M) in the anterior view of the chest. A cardiac denervation was defined by late H/M <1.8 4h after injection of 3 MBq/kg of 123I-MIBG. The primary end-point was all-cause mortality during follow-up. Results Fifty consecutive patients with AL amyloidosis were included. The median age was 68 years old [58–73]. By using both echocardiography and MRI, cardiac involvement was diagnosed in 33 patients (66%) and thirteen of these patients were NYHA class III or IV. By using Mayo clinic classification, patients were I, II, III and IV classes in 9 (18%), 14 (28%), 16 (32%) and 11 (22%) cases respectively. According to echocardiographic data, the median wall thickness of left ventricle was 13 mm [12–15]. The late H/M was 1.51 [1.33–1.67]. Cardiac denervation was found in 44 patients (88%). The 6 patients (12%) with a normal late H/M had no cardiac amyloidosis involvement. During a median follow-up of 24 months, 9 patients (18%) died. The area under the ROC curve of late H/M for predicting death was 0.74 (CI 95% 0.58–0.86). According to this curve, the best threshold was 1.44 and 7 of the 9 patients who died had late H/M ≤1.44. The figure shows the 2 year-survival according to late H/M. Late H/M ≤1.44 predicted all-cause death irrespective of the Mayo clinic classification: HR 8.0 (CI 95% 2.1–63) after adjustment on the Mayo clinic score (p=0.005). In addition, unplanned hospitalization for heart failure occurred in 8 patients with late H/M ≤1.44 versus 3 patients with late H/M >1.44 (p=0.03). Survival according to late H/M Conclusion Late H/M ≤1.44 is predictive of adverse outcomes in patients with AL amyloidosis, independently of the Mayo Clinic prognostic classification.

The effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on mice myocardial morphology

ABSTRACT: Studies have demonstrated sympathetic cardiac denervation in the MPTP mouse model. MPTP toxicity causes sympathetic nerve damage and depletion of heart norepinephrine. Previous evaluations of impairments in heart innervation have been based on imaging, electrophysiological and biochemical methods. However, these studies lacked information that can be obtained from morphoquantitative analyses. Thus, this study aimed to apply a design-based stereological method for evaluating the morphoquantitative alterations of myocardium following treatment with the neurotoxin MPTP in the C57/BL mouse. Our results showed that MPTP reduced the number of cardiomyocytes in the left ventricle.