Background Radiofrequency ablation (RFA) of ventricular tachycardia (VT) can fail due to inaccessibility to the VT substrate. Trans-arterial coronary ethanol ablation (TCEA) can be effective, but entails arterial instrumentation risk. We hypothesized that retrograde coronary venous ethanol ablation (RCVEA) can be an alternative bail-out approach to failed VT RFA. Methods and Results Out of 334 consecutive patients undergoing VT/PVC ablation, seven patients underwent RCVEA. Six of seven patients had failed RFA attempts (including epicardial in 3). Coronary venogram-guided venous mapping was performed using a 4F quadripolar catheter or an alligator-clip-connected angioplasty wire. Targeted veins included those with early pre-systolic potentials and pace-maps matching VT/PVC. An angioplasty balloon (1.5-2 × 6 mm) was used to deliver 1-4 cc of 98% ethanol into a septal branch of the anterior interventricular vein (AIV) in 5 patients with LV summit VT, a septal branch of the middle cardiac vein, and a postero-lateral coronary vein (n=1 each). The clinical VT was successfully ablated acutely in all patients. There were no complications of RCVEA, but one patient developed pericardial and pleural effusion attributed to pericardial instrumentation. On follow-up of 590 ±722 days, VT recurred in 4/7 patients, three of whom were successfully re-ablated with RFA. Conclusions RCVEA is safe and feasible as a bail-out approach to failed VT RFA, particularly those originating from the LV summit.

Background Radiofrequency (RF) ablation can alleviate drug-refractory inappropriate sinus tachycardia (IST). However, phrenic nerve (PN) injury and other complications limit its use. Objective We sought to characterize the maneuvers utilized to avoid PN injury and the long-term clinical outcomes. Methods Retrospective analysis of consecutive patients who underwent ablation for IST. Results RF ablation was carried out on 13 consecutive female patients with drug-refractory IST. Eleven patients exhibited PN capture at desired ablation sites. In one patient, PN capture was not continuous throughout the respiratory cycle and ventilation holding sufficed to avoid PN injury. In 10 patients, pericardial access (PA) and balloon (PB) insertion was required. Initially (n=4) a posterior PA was utilized, which was replaced by an anterior PA in the subsequent 6 cases. PA to optimal balloon positioning time was significantly lower in anterior vs. posterior PA (16.3±6 min vs. 58±21.3 min p=0.01), as was fluoroscopy time (15.66±16.72 min vs. 35.9±1.8 min, p=0.03). RF ablation successfully reduced sinus rate to less than 90 bpm in 13/13 patients. Procedure times and total radiofrequency times were not significantly different in anterior vs posterior PA. Major complications occurred in 2 patients, including unremitting pericardial bleeding requiring open-chested repair in one patient and sinus pauses mandating pacemaker implantation in another. Long-term symptom control after a follow-up of 811±42 days was successful in 84.6%. Conclusion Ventilation holding and/or pericardial balloon insertion are frequently warranted in IST ablation. Anterior PA appears to facilitate the procedure over posterior PA.

Inappropriate sinus tachycardia ablation/modification achieves acute success in the vast majority of patients. Complications are fairly common and diverse. However, symptomatic relief decreases substantially over longer follow-up periods, with a corresponding high recurrence rate.

Background: Approximately 2-3% of patients undergoing advanced heart failure therapies such as left ventricular assist devices (LVAD) and orthotropic heart transplantation (OHT) have chemotherapy-related cardiomyopathy, according to analyses of large databases such as United Network for Organ Sharing (UNOS) or Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registries. While these studies have shown similar survival outcomes post-interventions, these databases by definition exclude patients referred for advanced therapies but do not receive them, and thus there is little data on overall outcomes of such patients. Given the lack of nuance in the diagnoses in large registries and the possibility that many cancer treatment-related cardiomyopathy (CCMP) patients might be misclassified by the generic "non-ischemic" or "dilated" cardiomyopathies, we investigated the incidence and clinical outcomes of CCMP patients among advanced heart failure (HF) referrals at a single high volume institution. Methods: All referrals from 2013 to 2016 were evaluated for type of cardiomyopathy, with careful chart review. Outcomes such as LVAD, OHT and death were compared between CCMP and other cardiomyopathies. Results: Of 553 referrals for advanced HF, 19 (3.4%) were for CCMP. There was a higher percentage of patients receiving advanced therapies in the CCMP vs. non-ischemic cardiomyopathy (NICMP) and ischemic cardiomyopathy (ICMP) (42.1% vs 30.2% vs 33.6%, not significant). Of the CCMP patients, 3 had OHT directly, 2 had LVAD followed by OHT, and 3 had LVADs as bridge to candidacy or destination therapy. Fifty-eight percent of the CCMP did not receive LVAD or OHT compared to 69.8% and 66.3 of the NICMP and ICMP, respectively (p = 0.0388). Independent of type of advanced therapy, survival was significantly higher in the CCMP group compared to NICMP and ICMP (93.3% vs 84.8% vs 73.8%, respectively P = 0.0021 for 1 year, 93.3% vs 76.2% vs 58.3%, respectively, P = < 0.0001 for 3 year). Conclusions: In a single institution, CCMP accounts for more than 3% of all referrals for advanced HF therapies and almost 8% of NICMP. Contrary to concerns for previous cancer and sequelae of cancer treatment excluding patients for advanced therapies, a higher percentage of CCMP underwent advanced HF therapies and with similar outcomes. This is the first study to show that among patients referred for advanced therapies, CCMP patients do not have inferior outcomes compared to other cardiomyopathies regardless of the selected management strategy.

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BackgroundElevated defibrillation threshold (DFT) occurs in 2%‐6% of patients undergoing implantable cardioverter defibrillator (ICD) implantation. Adding a defibrillation coil in the coronary sinus (CS) or its branches can result in substantial reductions in the mean DFT. However, data regarding acute success and long‐term stability remain lacking. We report our experience with this bailout strategy.MethodsPatients with elevated DFT at implantation (safety margin at implantation <10 J) and those with failed ICD shocks for ventricular arrhythmias (VA) referred for high DFT underwent placement of an additional defibrillation coil in the CS. DFT testing was performed at the completion of the implantation procedure. External potentially reversible factors were excluded. High‐output devices were systematically used.ResultsFour patients with high DFT at implantation and two with several failed shock attempts underwent placement of a defibrillation coil in the CS. Mean age was 41.8 (23‐78). They presented a mean LVEF of 21% (15‐30), QRS‐complex duration of 109.8 milliseconds (87‐168), body surface area of 1.96 m2 (1.45‐2.58), and a mean R wave of 16.3 mV (8‐27). Defibrillation coil implantation in the CS (final shocking configuration of right ventricle as anode and left ventricle (LV) plus can as cathode) was associated with successful DFT testing in all. Three patients had a concomitant LV lead for biventricular pacing. During a mean follow‐up of 54.67 months (10‐118), two patients experienced successful ICD shocks for VA (one of them also presented inappropriate shocks because of the fast conducting atrial fibrillation).ConclusionsPositioning of a defibrillation coil in the CS can result in a substantial reduction in mean DFT and associates with optimal long‐term stability.

Background: The autonomic nervous system response to apnea and its mechanistic connection to atrial fibrillation (AF) are unclear. We hypothesize that sensory neurons within the ganglionated plexi (GP) play a role. We aimed to delineate the autonomic response to apnea and to test the effects of ablation of cardiac sensory neurons with resiniferatoxin (RTX), a neurotoxic TRPV1 (transient receptor potential vanilloid 1) agonist. Methods Sixteen dogs were anesthetized and ventilated. Apnea was induced by stopping ventilation until oxygen saturations decreased to 80%. Nerve recordings from bilateral vagal nerves, left stellate ganglion, and anterior right GP were obtained before and during apnea, before and after RTX injection in the anterior right GP (protocol 1, n=7). Atrial effective refractory period and AF inducibility on single extrastimulation were assessed before and during apnea, and before and after intrapericardial RTX administration (protocol 2, n=9). GPs underwent immunohistochemical staining for TRPV1. Results: Apnea increased anterior right GP activity, followed by clustered crescendo vagal bursts synchronized with heart rate and blood pressure oscillations. On further oxygen desaturation, a tonic increase in stellate ganglion activity and blood pressure ensued. Apnea-induced effective refractory period shortening from 110.20±31.3 ms to 90.6±29.1 ms ( P <0.001), and AF induction in 9/9 dogs versus 0/9 at baseline. After RTX administration, increases in GP and stellate ganglion activity and blood pressure during apnea were abolished, effective refractory period increased to 126.7±26.9 ms ( P =0.0001), and AF was not induced. Vagal bursts remained unchanged. GP cells showed cytoplasmic microvacuolization and apoptosis. Conclusions: Apnea increases GP activity, followed by vagal bursts and tonic stellate ganglion firing. RTX decreases sympathetic and GP nerve activity, abolishes apnea’s electrophysiological response, and AF inducibility. Sensory neurons play a role in apnea-induced AF.

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