Travis Richardson

Comparative Outcomes of Transvenous Extraction of Sprint Fidelis and Riata Defibrillator Leads: A Single Center Experience

The FDA has issued class I advisories for Medtronic Sprint Fidelis® and St. Jude Medical RiataTM ICD lead families. Transvenous RiataTM ICD lead extraction is typically considered higher risk than Fidelis® extraction, based on longer duration from implant, presence of externalized conductors and lack of silicone backfill in the SVC and RV coils. However, published data comparing procedural outcomes between these leads are limited.

Prospective Randomized Evaluation of Implantable Cardioverter‐Defibrillator Programming in Patients With a Left Ventricular Assist Device

Background Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy‐programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra‐conservative ICD programming strategy in patients with LVAD affects ICD shocks. Methods and Results Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra‐conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra‐conservative group 16% of patients experienced at least one shock compared with 21% in the control group (P=0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT‐ON but this was not statistically significant: 10% of patients with CRT‐ON (n=21) versus 38% with CRT‐OFF (n=20) received shocks (P=0.08). Conclusions An ultra‐conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703.

Cardiac sympathectomy for the management of ventricular arrhythmias refractory to catheter ablation

BACKGROUND Catheter ablation is now a mainstay of therapy for ventricular arrhythmias (VAs). However, there are scenarios where either physiological or anatomical factors make ablation less likely to be successful. OBJECTIVE The purpose of this study was to demonstrate that cardiac sympathetic denervation (CSD) may be an alternate therapy for patients with difficult-to-ablate VAs. METHODS We identified all patients referred for CSD at a single center for indications other than long QT syndrome and catecholaminergic polymorphic ventricular tachycardia who had failed catheter ablation. Medical records were reviewed for medical history, procedural details, and follow-up. RESULTS Seven cases of CSD were identified in patients who had failed prior catheter ablation or had disease not amenable to ablation. All patients had VAs refractory to antiarrhythmic drugs, with a median arrhythmia burden of 1 episode of sustained VA per month. There were no acute complications of sympathectomy. One of 7 patients (14%) underwent heart transplant. No patient had sustained VA after sympathectomy at a median follow-up of 7 months. CONCLUSION Because of anatomical and physiological constraints, many VAs remain refractory to catheter ablation and remain a significant challenge for the electrophysiologist. While CSD has been described as a therapy for long QT syndrome and catecholaminergic polymorphic ventricular tachycardia, data regarding its use in other cardiac conditions are sparse. This series illustrates that CSD may be a viable treatment option for patients with a variety of etiologies of VAs.

Non-pulmonary vein mediated atrial fibrillation: A novel sub-phenotype

Background Atrial fibrillation (AF) is a mechanistically heterogeneous disorder, and the ability to identify sub-phenotypes (“endophenotypes”) of AF would assist in the delivery of personalized medicine. We used the clinical response to pulmonary vein isolation (PVI) to identify a sub-group of patients with non-PV mediated AF and sought to define the clinical associations. Methods Subjects enrolled in the Vanderbilt AF Ablation Registry who underwent a repeat AF ablation due to arrhythmia recurrence were analyzed on the basis of PV reconnection. Subjects who had no PV reconnection were defined as “non-PV mediated AF”. A comparison group of subjects were identified who had AF that was treated with PVI-only and experienced no arrhythmia recurrence >12 months. They were considered a group enriched for “PV-mediated AF”. Univariate and multivariable binary logistic regression analysis was performed to investigate clinical associations between the PV and non-PV mediated AF groups. Results Two hundred and twenty nine subjects underwent repeat AF ablation and thirty three (14%) had no PV reconnection. They were compared with 91 subjects identified as having PV-mediated AF. Subjects with non-PV mediated AF were older (64 years [IQR 60,71] vs. 60 [52,67], P = 0.01), more likely to have non-paroxysmal AF (82% [N = 27] vs. 35% [N = 32], P<0.001), and had a larger left atrium (LA) (4.2cm [3.6,4.8] vs. 4.0 [3.3,4.4], P = 0.04). In univariate analysis, age (per decade: OR 1.56 [95% CI: 1.04 to 2.33], P = 0.03), LA size (per cm: OR 1.8 [1.06 to 3.21], P = 0.03) and non-paroxysmal AF (OR 8.3 [3.10 to 22.19], P<0.001) were all significantly associated with non-PV mediated AF. However, in multivariable analysis only non-paroxysmal AF was independently associated with non-PV mediated AF (OR 7.47 [95% CI 2.62 to 21.29], P<0.001), when adjusted for age (per decade: OR 1.25 [0.81 to 1.94], P = 0.31), male gender (OR 0.48 [0.18 to 1.28], P = 0.14), and LA size (per 1cm: 1.24 [0.65 to 2.33], P = 0.52). Conclusions Non-paroxysmal AF was the only clinical variable found to be independently associated with non-PV mediated AF. We demonstrated that analysis of AF ablation outcomes data can serve as a tool to successfully identify a sub-phenotype of subjects who have non-PV mediated AF. Clinical trial registration ClinicalTrials.gov ID # NCT02404415.

Implantable Cardioverter-defibrillator Therapy in the Patient with a Left Ventricular Assist Device: Still a Black Box

The use of implantable cardioverter-defibrillators (ICDs) has become a cornerstone in the therapy of patients with New York Heart Association (NYHA) classes II and III congestive heart failure, as randomized controlled trials have soundly established the lifesaving value of these devices. However, in patients with severe class IV NYHA symptoms or class D disease, the relative risk of sudden cardiac death compared with death from progressive pump failure decreases dramatically, and ICD therapy is not recommended in these individuals.

Acute Mitral Regurgitation After Removal of an Impella Device

Acute mitral regurgitation is a very rare complication of an Impella device. We report a case of a 52-year-old man who had an Impella CP device placed for cardiogenic shock and developed acute mitral regurgitation after removal of the Impella. This was managed with the placement of TandemHeart device.

IATROGENIC MITRAL REGURGITATION: A RARE COMPLICATION OF IMPELLA DEVICE MANAGED WITH TANDEM HEART

Mitral regurgitation (MR) after Impella® placement is a rare, catastrophic complication. A 52 year old man presented with anterior ST elevation myocardial infarction (MI) and had an unsuccessful percutaneous coronary intervention. Impella CP® was placed for support and he was transferred to our

ADULT STILL’S DISEASE PRESENTING WITH PERICARDIAL TAMPONADE

Adult-Still’s Disease (ASD) is a rare condition characterized by fevers, pharyngitis, arthralgias, and evanescent rash; cardiac involvement is rare. : A 19-year-old man presented with two weeks of fever, sore throat, chest pain, arthralgias, and maculopapular rash during fever (Fig 1A).

Reversible myocardial perfusion abnormalities in nonischemic dilated cardiomyopathy

A 77-year-old man developed dyspnea on exertion. Ten years previously he had similar symptoms. There was 4-chamber cardiac enlargement with normal ventricular function on cardiac magnetic resonance imaging (CMR). Exercise treadmill testing revealed no ischemia on the ECG. He declined medical therapy and took over the counter supplements. His symptoms resolved, but there was a recent decline in left ventricular ejection fraction (LVEF) to 35-45%. A regadeonoson myocardial perfusion scan was obtained to evaluate the possibility of myocardial ischemia. These images revealed perfusion abnormalities in the anterior wall, apex, and lateral wall that were reversible on resting images, consistent with ischemia (Figure 1). There was a fixed perfusion defect in the inferior wall that persisted in spite of attenuation correction. The calculated LVEF was 38%. Despite the strikingly abnormal nuclear perfusion images, coronary angiography revealed only minimal coronary atherosclerosis (Figure 2). Radionuclide myocardial perfusion imaging plays a major role in the evaluation of patients who have LV dysfunction and possible ischemic heart disease. In contrast, the patient we illustrate here had a nonischemic dilated cardiomyopathy (NIDCM). The reversible perfusion abnormalities were consistent with myocardial ischemia, and the fixed inferior perfusion defect was likely due to myocardial fibrosis or soft tissue attenuation. The reversible findings were likely due to absolute and relative subendocardial hypoperfusion. It has previously been demonstrated that patients with NIDCM may have abnormalities in transmural myocardial blood flow (MBF) on positron emission tomography (PET) both at rest, and especially with coronary vasodilation. Recent studies of NIDCM utilizing CMR and [C] acetate PET have shown that the main limitation in myocardial perfusion reserve (MPR) is in the subendocardium, and this is directly related to abnormal myocardial energy supply/demand relations. Both the MPR and oxidative metabolism can improve after longterm anti-failure therapy.

ISOLATED MYOCARDIAL RECURRENCE OF ACUTE MYELOGENOUS LEUKEMIA DIAGNOSED BY PERCUTANEOUS ENDOMYOCARDIAL BIOPSY

While primary malignancies of the heart are rare, secondary cardiac involvement in patients with cancer is relatively common and should be considered when these patients develop cardiovascular symptoms. A 63-year-old man presented with dyspnea on exertion. He had a history of myelodysplastic