BackgroundLinear accelerator–based stereotactic radiosurgery delivered to cardiac arrhythmogenic foci could be a promising catheter‐free ablation modality. We tested the feasibility of in vivo atrioventricular (AV) node ablation in swine using stereotactic radiosurgery.Methods and ResultsFive Large White breed swine (weight 40–75 kg; 4 females) were studied. Single‐chamber St Jude pacemakers were implanted in each pig. The pigs were placed under general anesthesia, and coronary/cardiac computed tomography simulation scans were performed to localize the AV node. Cone beam computed tomography was used for target positioning. Stereotactic radiosurgery doses ranging from 35 to 40 Gy were delivered by a linear accelerator to the AV node, and the pigs were followed up with weekly pacemaker interrogations to observe for potential electrocardiographic changes. Once changes were observed, the pigs were euthanized, and pathology specimens of various tissues, including the AV node and tissues surrounding the AV node, were taken to study the effects of radiation. All 5 pigs had disturbances of AV conduction with progressive transition into complete heart block. Macroscopic inspection did not reveal damage to the myocardium, and pigs had preserved systolic function on echocardiography. Immunostaining revealed fibrosis in the target region of the AV node, whereas no fibrosis was detected in the nontargeted regions.ConclusionsCatheter‐free radioablation using linear accelerator–based stereotactic radiosurgery is feasible in an intact swine model.

Background: There is paucity of data regarding radiofrequency ablation for ventricular tachycardia (VT) in patients with cardiogenic shock and concomitant VT refractory to antiarrhythmic drugs on mechanical support. Methods: Patients undergoing VT ablation at our center were enrolled in a prospectively maintained registry and screened for the current study (2010–2017). Results: All 21 consecutive patients with cardiogenic shock and concomitant refractory ventricular arrhythmia undergoing bailout ablation due to inability to wean off mechanical support were included. Median age was 61 years, 86% were men, median left ventricular ejection fraction was 20%, 81% had ischemic cardiomyopathy, and PAINESD score was 18±5. The type of mechanical support in place before the procedure was intra-aortic balloon pump in 14 patients (67%), Impella CP in 2, extracorporeal membrane oxygenation in 2, extracorporeal membrane oxygenation and intra-aortic balloon pump in 2, and extracorporeal membrane oxygenation and Impella CP in 1. Endocardial voltage maps showed myocardial scar in 19 patients (90%). The clinical VTs were inducible in 13 patients (62%), whereas 6 patients had premature ventricular contraction–induced ventricular fibrillation/VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 with inducible clinical VTs. Substrate modification was performed in 15 patients with scar (79%). After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully, but 6 (29%) died during the index admission from persistent cardiogenic shock. Patients who had ventricular arrhythmia and cardiogenic shock on presentation had a trend toward lower in-hospital mortality compared with those who presented with cardiogenic shock and later developed ventricular arrhythmia. Conclusions: Bailout ablation for refractory ventricular arrhythmia in cardiogenic shock allowed successful weaning from mechanical support in a large proportion of patients. Mortality remains high, but the majority of patients were discharged home and survived beyond 1 year.

Background: Systems to improve ST-segment–elevation myocardial infarction (STEMI) care have traditionally focused on improving door-to-balloon time. However, prompt guideline-directed medical therapy and transradial primary percutaneous coronary intervention (PCI) are also associated with reduced STEMI mortality. The incremental prognostic value of each facet of STEMI care on clinical outcomes within a STEMI system of care is unknown. Methods and Results: We implemented systems-based strategies at our hospital to improve 3 STEMI care metrics: (1) prompt guideline-directed medical therapy before sheath insertion for PCI, (2) use of transradial primary PCI, and (3) door-to-balloon time. We assessed the incremental association of metrics achieved with in-hospital adverse events and 30-day mortality. Of 1272 consecutive patients with STEMI treated with PCI at our hospital (January 1, 2011, to December 31, 2016), the percentage with achievement of zero, 1, 2, or 3 STEMI care metrics was 7.1%, 24.1%, 43.8%, and 25.1%; and 30-day mortality was 15.6%, 8.6%, 3.6%, and 3.2%, respectively (log-rank P <0.001). After adjusting for known clinical predictors of STEMI in-hospital mortality, achievement of at least 2 STEMI care metrics was associated with significantly reduced in-hospital mortality (odds ratio, 0.39; 95% CI, 0.16–0.96; P =0.041). Each metric provided incremental prognostic value when modeled in stepwise order of their occurrence in clinical practice (final model C statistic, 0.677; P <0.001). Conclusions: Prompt guideline-directed medical therapy before sheath insertion for PCI, transradial primary PCI, and door-to-balloon time add incremental prognostic value in STEMI care. Expanding STEMI systems of care from a singular focus on door-to-balloon time to a comprehensive focus on multifaceted STEMI care offers an opportunity to further improve STEMI outcomes.

COVID19 has resulted in many challenges in patient care especially high-risk populations such as heart transplant patients. Patients with heart transplant experience a significantly higher mortality rate with COVID19 infection, and management is based on extrapolation from clinical trials done on non-transplant patients, and from clinical experience. Here we report four cases of heart transplant patients who presented in late 2020 with COVID19 infection. Patients presented with symptoms similar to those seen in the general population. All four patients were admitted to the hospital, and they were all treated with dexamethasone. In addition, two patients received remdesivir. Immunosuppressive medications were adjusted to maintain adequate levels of immunosuppression, but at the same time allowing for an adequate immune response against the infection. All patients were discharged alive from the hospital. We then performed a literature review on studies that included heart transplant patients who developed the infection, and suggest a standardized management approach accordingly.

Although there is no formal database of adults with congenital heart disease (CHD) in the United States, the prevalence and incidence of CHD can be estimated and extrapolated from data in the Canadian providence.1 As such, the prevalence of CHD in the United States has been estimated in 2010 to be around 2.4 million people (1.4 million adults and 1 million children), with an incidence of between four and 10 per 1,000. Forty-five per cent of these adults have mild disease, 37 % have moderate disease, and 14 % have severe disease. 1-3 Furthermore, the prevalence of patients living with CHD has been increasing secondary to the improvements in surgical techniques and medical management over the past few decades. Mortality secondary to CHD is highest during infancy and childhood declining gradually with age to reach a steady state between 15 and 65 years. It is higher in men than women. 4One of the most important causes of morbidity in patients with CHD is the development of cardiac arrhythmias, in particular tachyarrhythmias.These result from multiple surgical scars, haemodynamic abnormalities and structural defects that create arrhythmogenic substrates. 5 In fact, about 11 % of patients with CHD develop atrial arrhythmias (intra-atrial reentrant tachycardia [IART] and AF), with the risk being higher in patients with right-sided heart lesions. 6 The most common arrhythmia in patients with CHD is IART that occurs secondary to reentrant circuits in the right atrium. AF is a less common cause of atrial arrhythmia in CHD, but its prevalence is increasing in these patients because of improved survival to older age. AbstractWith improved surgical techniques and medical management for patients with congenital heart diseases, more patients are living longer and well into adulthood. This improved survival comes with a price of increased morbidity, mainly secondary to increased risk of tachyarrhythmias. One of the major arrhythmias commonly encountered in this subset of cardiac patients is AF. Similar to the general population, the risk of AF increases with advancing age, and is mainly secondary to the abnormal anatomy, abnormal pressure and volume parameters in the hearts of these patients and to the increased scarring and inflammation seen in the left atrium following multiple surgical procedures. Catheter ablation for AF has been shown to be a very effective treatment modality in patients with refractory AF.However, data and guidelines regarding catheter ablation in patients with congenital heart disease are not well established. This review will shed light on the procedural techniques, success rates and complications of AF catheter ablation in patients with different types of CHD, including atrial septal defects, tetralogy of Fallot, persistent left superior vena cava, heterotaxy syndrome and atrial isomerism, and Ebstein anomaly. KeywordsAtrial fibrillation, catheter ablation, congenital heart disease, atrial septal defect, tetralogy of Fallot, persistent left superior vena cava, Ebstein anomaly, atrial isomerism Discl...

Background - Many centers continue to routinely perform trans-esophageal echocardiograms (TEE) prior to atrial fibrillation (AF) ablation procedures in patients treated with direct oral anticoagulants (DOAC). One study suggested that the procedures could be done without TEE but employed intracardiac echo (ICE) imaging of the appendage from the right ventricular outflow. This study aimed to assess the safety of ablation for AF without TEE screening or ICE imaging of the appendage in DOAC compliant patients. Methods - All patients undergoing AF ablation at the Cleveland Clinic (2011-2018) were enrolled in a prospectively maintained data registry. All consecutive patients presenting with AF or atrial flutter (AFL) on DOAC were included. Peri-procedural thromboembolic complications were assessed. Results - A total of 900 patients were included. Their median CHA2DS2-VASc score was 2 (interquartile range 1-3). All were on DOACs (333 Rivaroxaban, 285 Dabigatran, 281 Apixaban, and 1 Edoxaban). Thrombo-embolic complications occurred in 4 patients (0.3%): 2 ischemic strokes; 1 transient ischemic attack without residual deficit and 1 splenic infarct; all with no further complications. Bleeding complications occurred in 5 patients (0.4%): 2 pericardial effusions (1 intra-operative, 1 after 30 days, both drained), 3 groin hematomas (1 of them due to needing heparin for venous thrombosis, none required interventions). No patients required emergent surgeries. Conclusions - In DOAC compliant patients who present for ablation in AF/AFL, the procedures could be performed without TEE screening or ICE imaging of the appendage; with low risk of complications.

Atrial fibrillation (AF) and cardiometabolic syndrome (CMS) have been linked to inflammation and fibrosis. However, it is still unknown which inflammatory cytokines contribute to the pathogenesis of AF. Furthermore, cardiometabolic syndrome (CMS) risk factors such as obesity, hypertension, insulin resistance/glucose intolerance are also associated with inflammation and increased level of cytokines and adipokines. We hypothesized that the inflammatory immune response is exacerbated in patients with both AF and CMS compared to either AF or CMS alone. We investigated inflammatory cytokines and fibrotic markers as well as cytokine genetic profiles in patients with lone AF and CMS. CMS, lone AF patients, patients with both lone AF and CMS, and control patients were recruited. Genetic polymorphisms in inflammatory and fibrotic markers were assessed. Serum levels of connective tissue growth factor (CTGF) were tested along with other inflammatory markers including platelet-to-lymphocyte ratio (PLR), monocyte-to-HDL ratio (MHR) in three groups of AF+CMS, AF, and CMS patients. There was a trend in the CTGF levels for statistical significance between the AF and AF+CMS group (P = 0.084). Genotyping showed high percentages of patients in all groups with high secretor genotypes of Interleukin-6 (IL-6) (P = 0.037). Genotyping of IFN-γ and IL-10 at high level showed an increase in expression in the AF + CMS group compared to AF and CMS alone suggesting an imbalance between the inflammatory and anti-inflammatory cytokines which is exacerbated by AF. Serum cytokine inflammatory cytokine levels showed that IL-4, IL-5, IL-10, IL-17F, and IL-22 were significant between the AF, AF+CMS, and CMS patients. Combination of both CMS and AF may be associated with a higher degree of inflammation than what is seen in either CMS or AF alone. Thus, the identification of a biomarker capable of identifying metabolic syndrome associated with disease will help in identification of a therapeutic target in treating this devastating disease.

Objectives: We aimed to study adoption of transradial primary percutaneous coronary intervention (TR-PPCI) for ST elevation myocardial infarction (STEMI) ("radial first" approach) and its association with door-to-balloon time (D2BT).