The impact of mechanical oesophageal deviation on posterior wall pulmonary vein reconnection.

AIMS: During atrial fibrillation ablation, oesophageal heating typically prompts reduction or termination of radiofrequency energy delivery. We previously demonstrated oesophageal temperature rises are associated with posterior left atrial pulmonary vein reconnection (PVR) during redo procedures. In this study, we assessed whether mechanical oesophageal deviation (MED) during an index procedure minimizes posterior wall PVRs during redo procedures. METHODS AND RESULTS: Patients in whom we performed a first-ever procedure followed by a clinically driven redo procedure were divided based on both the use of MED for oesophageal protection and the ablation catheter employed (force or non-force sensing) in the first procedure. The PVR sites were compared between MED using a force-sensing catheter (MEDForce), or no MED with a non-force (ControlNoForce) or force (ControlForce) sensing catheter. Despite similar clinical characteristics, the MEDForce redo procedure rate (9.2%, 26/282 patients) was significantly less than the ControlNoForce (17.2%, 126/734 patients; P = 0.002) and ControlForce (17.5%, 20/114 patients; P = 0.024) groups. During the redo procedure, the posterior PVR rate with MEDForce (2%, 1/50 PV pairs) was significantly less than with either ControlNoForce (17.7%, 44/249 PV pairs; P = 0.004) or ControlForce (22.5%, 9/40 PV pairs; P = 0.003), or aggregate Controls (18.3%, 53/289 PV pairs; P = 0.006). However, the anterior PVR rate with MEDForce (8%, 4/50 PV pairs) was not significantly different than Controls (aggregate Controls-3.5%, 10/289 PV pairs, P = 0.136; ControlNoForce-2.4%, 6/249 PV pairs, P = 0.067; ControlForce-10%, 4/40 PV pairs, P = 1.0). CONCLUSION: Oesophageal deviation improves the durability of the posterior wall ablation lesion set during AF ablation.

Esophageal Deviation During Atrial Fibrillation Ablation: Clinical Experience With a Dedicated Esophageal Balloon Retractor.

OBJECTIVES: The goal of this study was to determine the safety and feasibility of a novel esophageal balloon retractor (DV8) for MED during PVI. BACKGROUND: The authors previously showed that mechanical esophageal deviation (MED) is feasible using an off-the-shelf metal stylet to allow uninterrupted ablation along the posterior left atrium during pulmonary vein isolation (PVI). Although it is an attractive strategy to avoid esophageal thermal injury, this technique was hampered by both the propensity for oropharyngeal trauma from the stiff stylet and the limited lateral esophageal displacement. METHODS: In 200 consecutive patients undergoing atrial fibrillation ablation, the DV8 balloon retractor was used for MED; contrast was instilled into the esophagus to accurately delineate the trailing esophageal edge. Deviation was performed to maximize the distance from the trailing esophageal edge to the closest point of the ablation line (MEDEffective) and correlated to occurrences of luminal esophageal temperature elevation. RESULTS: In patients undergoing MED during a first-ever PVI of 304 vein pairs, the MEDEffective during right and left PVI were 21.2 ± 8.7 mm and 15.5 ± 6.8 mm, respectively. Deviation of at least 5 mm of MEDEffective was achievable in 97.7%. Luminal esophageal temperature increases universally occurred (100%) at MEDEffective <5 mm, less often (28%) at MEDEffective 5 to 20 mm, and rarely (1.9%) at MEDEffective >20 mm. There were no esophageal complications, but 2 patients experienced oropharyngeal bleeding due to trauma related to device placement. CONCLUSIONS: MED with the balloon retractor safely moved the esophagus away from the site of energy delivery during atrial fibrillation ablation.

Cardiovascular Abnormalities in Carbon Monoxide Poisoning.

Acute carbon monoxide (CO) poisoning is the most common cause of poisoning and poisoning-related death in the United States. It manifests as broad spectrum of symptoms ranging from mild headache, nausea, and fatigue to dizziness, syncope, coma, seizures resulting in cardiovascular collapse, respiratory failure, and death. Cardiovascular complications of CO poisoning has been well reported and include myocardial stunning, left ventricular dysfunction, pulmonary edema, and arrhythmias. Acute myocardial ischemia has also been reported from increased thrombogenicity due to CO poisoning. Myocardial toxicity from CO exposure is associated with increased short-term and long-term mortality. Carboxyhemoglobin (COHb) levels do not correlate well with the clinical severity of CO poisoning. Supplemental oxygen remains the cornerstone of therapy for CO poisoning. Hyperbaric oxygen therapy increases CO elimination and has been used with wide variability in patients with evidence of neurological and myocardial injury from CO poisoning, but its benefit in limiting or reversing cardiac injury is unknown. We present a comprehensive review of literature on cardiovascular manifestations of CO poisoning and propose a diagnostic algorithm for managing patients with CO poisoning.

Right ventricular apical versus non-apical implantable cardioverter defibrillator lead: A systematic review and meta-analysis.

INTRODUCTION: We aimed to study the effect of right ventricular implantable cardioverter defibrillator (ICD) lead positioning on clinical outcomes in patients undergoing ICD placement. METHODS: A systematic literature search was performed using PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to identify clinical trials comparing outcomes in patients with ICD leads in apical and non-apical positions. The primary outcome of our study was death at 1-year follow-up. Secondary outcomes studied were "death at 3years", "total number of shocks", "appropriate shocks", "inappropriate shocks" and "cut-to-suture time". RESULTS: We analyzed a total of 3731 patients (2852 in apical and 879 in non-apical ICD groups) enrolled in 4 clinical trials. No significant difference was observed between the apical and non-apical ICD groups in all-cause mortality at 1year (OR 0.88; 95% CI 0.51-1.49, p=0.63; I2=5.32%). Similarly, no differences were seen between the two groups in death at 3years (OR=0.76; 95% CI 0.56-1.04, p=0.08; I2=0%), total number of shocks (OR 0.99; 95% CI 0.81-1.22, p=0.95; I2=0%), appropriate shocks (OR 1.00; 95% CI 0.79-1.27, p=0.99; I2=0%), inappropriate shocks (OR 0.98; 95% CI 0.70-1.37, p=0.91; I2=0%) and cut-to-suture time (Standard mean difference=-0.03; 95% CI -0.20 to 0.14, p=0.73; I2=0%). No publication bias was seen. CONCLUSION: Non-apical RV ICD lead implantation is non-inferior to traditional RV apical position with no significant differences in mortality, total number of shocks, appropriate shocks, inappropriate shocks and procedural time.

Milestones: a rapid assessment method for the Clinical Competency Committee.

INTRODUCTION: Educational milestones are now used to assess the developmental progress of all U.S. graduate medical residents during training. Twice annually, each program's Clinical Competency Committee (CCC) makes these determinations and reports its findings to the Accreditation Council for Graduate Medical Education (ACGME). The ideal way to conduct the CCC is not known. After finding that deliberations reliant upon the new milestones were time intensive, our internal medicine residency program tested an approach designed to produce rapid but accurate assessments. MATERIAL AND METHODS: For this study, we modified our usual CCC process to include pre-meeting faculty ratings of resident milestones progress with in-meeting reconciliation of their ratings. Data were considered largely via standard report and presented in a pre-arranged pattern. Participants were surveyed regarding their perceptions of data management strategies and use of milestones. Reliability of competence assessments was estimated by comparing pre-/post-intervention class rank lists produced by individual committee members with a master class rank list produced by the collective CCC after full deliberation. RESULTS: Use of the study CCC approach reduced committee deliberation time from 25 min to 9 min per resident (p < 0.001). Committee members believed milestones improved their ability to identify and assess expected elements of competency development (p = 0.026). Individual committee member assessments of trainee progress agreed well with collective CCC assessments. CONCLUSIONS: Modification of the clinical competency process to include pre-meeting competence ratings with in-meeting reconciliation of these ratings led to shorter deliberation times, improved evaluator satisfaction and resulted in reliable milestone assessments.

Hemodynamic Support for Ventricular Tachycardia Ablation.

This review discusses the role of hemodynamic support for catheter ablation of unstable ventricular tachycardia, using commercially available mechanical circulatory support devices (intra-aortic balloon pump, Impella, TandemHeart, extracorporeal membrane oxygenation) and analyzes the published clinical experience of the safety and efficacy of these devices during ventricular tachycardia ablation. Appropriate selection of patients, device-specific characteristics, and hemodynamic monitoring is also discussed.

Implantation of the Subcutaneous Implantable Cardioverter-Defibrillator: An Evaluation of 4 Implantation Techniques.

BACKGROUND: Alternative techniques to the traditional 3-incision subcutaneous implantation of the subcutaneous implantable cardioverter-defibrillator may offer procedural and cosmetic advantages. We evaluate 4 different implant techniques of the subcutaneous implantable cardioverter-defibrillator. METHODS AND RESULTS: Patients implanted with subcutaneous implantable cardioverter-defibrillators from 2 hospitals between 2009 and 2016 were included. Four implantation techniques were used depending on physician preference and patient characteristics. The 2- and 3-incision techniques both place the pulse generator subcutaneously, but the 2-incision technique omits the superior parasternal incision for lead positioning. Submuscular implantation places the pulse generator underneath the serratus anterior muscle and subfascial implantation underneath the fascial layer on the anterior side of the serratus anterior muscle. Reported outcomes include perioperative parameters, defibrillation testing, and clinical follow-up. A total of 246 patients were included with a median age of 47 years and 37% female. Fifty-four patients were implanted with the 3-incision technique, 118 with the 2-incision technique, 38 with submuscular, and 37 with subfascial. Defibrillation test efficacy and shock lead impedance during testing did not differ among the groups; respectively, P=0.46 and P=0.18. The 2-incision technique resulted in the shortest procedure duration and time-to-hospital discharge compared with the other techniques (P<0.001). A total of 18 complications occurred, but there were no significant differences between the groups (P=0.21). All infections occurred in subcutaneous implants (3-incision, n=3; 2-incision, n=4). In the 2-incision group, there were no lead displacements. CONCLUSIONS: The presented implantation techniques are feasible alternatives to the standard 3-incision subcutaneous implantation, and the 2-incision technique resulted in shortest procedure duration.

The Extent of Mechanical Esophageal Deviation to Avoid Esophageal Heating During Catheter Ablation of Atrial Fibrillation.

OBJECTIVES: This study sought to determine the extent of lateral esophageal displacement required during mechanical esophageal deviation (MED) and to eliminate luminal esophageal temperature elevation (LETElev) during pulmonary vein (PV) isolation. BACKGROUND: MED is a conceptually attractive strategy of minimizing esophageal injury while allowing uninterrupted energy delivery along the posterior left atrium during PV isolation. METHODS: MED was performed using a malleable metal stylet within a plastic tube placed within the esophagus. Barium was instilled to characterize the trailing esophageal edge. For each MED attempt, the MEDEffective, defined as the distance from the trailing esophageal edge-to-ablation line, was correlated to occurrences of LETElev. RESULTS: In 114 consecutive patients/221 PV pairs undergoing MED (age 62.1 ± 11 years, 75% men, 62%/38% paroxysmal/persistent AF), esophageal stretching invariably occurred such that the esophageal edge trailed behind the plastic tube. MEDEffective distances of 0 mm to 10 mm, 10 mm to 15 mm, 15 mm to 20 mm or >20 mm were achieved in 60 (27.1%), 64 (29%), 48 (21.7%), and 49 (22.2%) attempts, respectively. Overall, LET elevation >38°C occurred in 81 of 221 (36.7%) PV pairs. The incidence of LETElev among the 4 groups was 73.3%, 35.9%, 25%, and 4.1%, respectively. MEDEffective distances were 9.1 ± 6.5 mm and 18 ± 7.6 mm in patients with and without LETElev, respectively (p < 0.0001). Three patients (2.6%) experienced clinically significant MED-related trauma, albeit only with a stiffer stylet. CONCLUSIONS: Mechanical esophageal deviation >20 mm from the PV ablation line prevents significant esophageal heating during PV isolation, but this level of displacement was difficult to safely achieve with this off-the-shelf mechanical stylet approach.

Gastrointestinal complications associated with catheter ablation for atrial fibrillation.

Atrial fibrillation is the most common arrhythmia in the United States. With the ageing population, the incidence and prevalence of atrial fibrillation are on the rise. Catheter ablation of atrial fibrillation is a widely accepted treatment modality in patients with drug refractory symptomatic paroxysmal or persistent atrial fibrillation. The close proximity to the left atrium posterior wall makes the thermosensitive esophagus a potential site of injury during catheter ablation of AF leading to various gastrointestinal complications. The major gastrointestinal complications associated with catheter ablation include atrioesophageal fistula, gastroparesis, esophageal thermal lesions and esophageal ulcers. Multiple studies, case reports and series have described these complications with various catheter ablation techniques such as radiofrequency, cryoenergy and high frequency focused ultrasound energy ablation. This review addresses the gastrointestinal complications after AF ablation procedures and aims to provide the clinicians with an overview of clinical presentation, etiology, pathogenesis, prevention and management of these conditions.

Safety and efficacy of oral factor-Xa inhibitors versus Vitamin K antagonist in patients with non-valvular atrial fibrillation: Meta-analysis of phase II and III randomized controlled trials.

BACKGROUND: Aim of our study was to assess the safety and efficacy on factor-Xa inhibitors (FXIs) in patients with non-valvular atrial fibrillation (NVAF) as compared to Vitamin K antagonist (VKA). METHODS: Phase II and III randomized controlled trials that reported clinical safety and efficacy of FXI in patients with NVAF were identified from MEDLINE, Embase, and Cochrane Central Register of Controlled Trials through December 10, 2015. The primary safety outcome of our study was composite of stroke and systemic embolic event. Secondary outcomes studied were individual endpoints of primary safety outcome, major bleeding, clinically relevant non-major bleed (CRNMB), and all-cause mortality. RESULTS: We included 11 RCTs with a total of 59,164 participants, of which 34,231 patients received oral FXI and 24,933 patients were on VKA with a mean follow-up of 369days. There was a significant reduction in primary outcome with FXI compared to VKA, 1,112 (3.4%) versus 816 (3.6%) events, respectively (OR 0.82; 95% CI 0.68-0.99). Use of FXI significantly reduced major bleeding events compared to VKA, OR 0.74, 95% CI 0.58-0.96, test for heterogeneity (I(2)=74%). Incidence of CRNMB was not different between FXI and VKA groups, OR 0.84, 95% CI 0.68-1.04. There was a significant reduction in all-cause mortality in FXI group compared to VKA group, OR 0.88, 95% CI 0.83-0.94 with no significant heterogeneity. CONCLUSION: Use of FXI was associated with a significant reduction in major bleeding events and all-cause mortality without increased risk of stroke or SEE compared to VKA.

Multimarker risk stratification approach and cardiovascular outcomes in patients with stable coronary artery disease undergoing elective percutaneous coronary intervention.

AIMS: We studied the utility of multimarker risk stratification approach to predict cardiovascular outcomes in patients with stable coronary artery disease, undergoing elective percutaneous coronary intervention (PCI). METHODS: We prospectively evaluated 302 consecutive patients with stable coronary artery disease and normal CPK-MB and cardiac troponin T levels, and who underwent elective PCI at our institution. The following cardiac biomarkers were measured before and between 12 and 24h post-procedure: CK-MB, cardiac troponin T, hs-CRP, and NT-ProBNP. Patients were followed up for a minimum of 6 months. RESULTS: Post-PCI, CPK-MB levels were elevated but below myocardial infarction (MI) range in 70 patients (23%), and in the MI range in 6 patients (2%). Troponin T levels were detectable but below the 99th percentile (microleak) in 32 patients (10.6%) and elevated above the 99th percentile (periprocedural MI) in 104 patients (34.4%). At 9 months' follow-up, 1% died, 2% had stable angina, 10.3% had non-fatal MI, and 87.7% remained asymptomatic. There was no significant difference in clinical events among groups stratified by elevation of one biomarker or multiple biomarkers. CONCLUSION: Single or multiple biomarker strategy in patients with normal baseline biomarkers failed to predict major cardiac events after PCI over medium-term follow-up.

Prosthetic Valve Thrombosis: Diagnosis and Management.

St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, prosthetic valve thrombosis is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy. Transthoracic echocardiography (TTE) is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics. Fluoroscopy is an alternate imaging modality for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or transesophageal echocardiography. A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. We discuss a case of a 91-year-old man with thrombosis of bileaflet mechanical mitral prosthesis that was demonstrated on real-time fluoroscopy (not evident on TTE). An algorithmic approach to diagnosis and management of prosthetic heart valve thrombosis is outlined.

The Conundrum of "Warfarin Hypersensitivity": Prolonged Partial Thromboplastin Time From Factor IX Propeptide Mutation.

Carboxylation of glutamic acid residues of vitamin K dependent clotting factors (II, VII, IX, and X) is essential to their biological functioning. Binding of these factors to γ-glutamyl carboxylase enzyme for carboxylation reaction is mediated by wild-type propeptide, a small sequence of amino acids that precede the actual polypeptide. Missense mutations at certain residue severely decrease the affinity of mutated propeptide for the enzyme. Such mutations are reported to occur at codon-10 of factor IX propeptide, a clinically silent metabolic event in normal conditions. However in the presence of warfarin, such mutations and resultant decrease affinity of factor IX propeptide for the enzyme that causes severe selective decrease in factor IX activity. This can potentially leads to life-threatening bleeding complications and known as one of the causes of warfarin hypersensitivity. It is imperative to recognize such cases early on to avoid additional warfarin therapy. Recurrent bleeding episodes, subtherapeutic to therapeutic range international normalized ratio values with relatively prolong partial thromboplastin time should raise the suspicion of underlying factor IX propeptide mutations.

Sudden Cardiac Arrest in a Patient With Apical Hypertrophic Cardiomyopathy: Case Report and a Brief Review of Literature.

Apical hypertrophic cardiomyopathy (HCM) is a phenotypic variant of nonobstructive HCM, in which hypertrophy of the myocardium predominantly involves the left ventricular apex. It is common in Japanese and other Asian populations but is rare in the United States. Apical HCM has a relatively benign prognosis in terms of cardiovascular mortality; however, morbid events such as ventricular aneurysms, apical thrombi, diastolic dysfunction, atrial fibrillation, and myocardial infarction are not uncommon. We report a case of an 18-year-old white man who presented to our hospital after an out-of-hospital cardiac arrest. The patient had a witnessed collapse while playing basketball in the field. He was found to be pulseless and unresponsive by his coach, and cardiopulmonary resuscitation was immediately started. Upon arrival of emergency medical services, an automated external defibrillator advised shock and he was defibrillated thrice. Return of spontaneous circulation was achieved in 15 minutes. He was intubated for airway protection and was brought to the hospital. Therapeutic hypothermia was initiated. He demonstrated good neurological status after active rewarming. Subsequent cardiac magnetic resonance imaging was suggestive of apical HCM with right ventricular involvement. The patient underwent an implantable cardioverter defibrillator placement for secondary prevention and was subsequently discharged. In conclusion, apical HCM can rarely be associated with adverse cardiovascular events. The diagnosis may be missed on transthoracic 2-dimensional cardiac echocardiogram, and cardiac magnetic resonance imaging should be considered to exclude apical HCM in young patients who present after sudden cardiac arrest.

Epidemiology and outcomes of peripartum cardiomyopathy in the United States: findings from the Nationwide Inpatient Sample.

AIMS: Peripartum cardiomyopathy (PPCM) is defined as systolic heart failure within the last month of pregnancy or 5 months after delivery in the absence of any identifiable cause of heart failure. We aimed to investigate the prevalence of PPCM and predictors of in-hospital mortality in patients with PPCM. METHODS: We analyzed patients with diagnosis of PPCM from the Nationwide Inpatient Sample database using the Ninth Revision of International Classification of Diseases (ICD-9) from 2009 to 2010. We categorized PPCM (n = 4871) into three groups of presentation based on their ICD-9 codes: antepartum (674.53; n = 189), peripartum (674.51, 674.52; n = 887) and postpartum (674.54; n = 3741). RESULTS: PPCM was more common in African-Americans (43.9%) as compared with white (40.8%), Hispanic (8.7%) and Asian (2.7%) women. Hypertensive disorders were classified as pre-existing hypertension (31.6%), gestational hypertension (3.7%), preeclampsia (9.9%), eclampsia (2.4%) and preeclampsia/eclampsia superimposed on hypertension (3.1%). Among different ethnicities, pre-existing hypertension (1 : 2.3) and diabetes (1 : 10.4) were more prevalent in African-Americans, whereas preeclampsia (1 : 4.3) and premature labor (1 : 5.4) were more common in Asians. In-hospital mortality rate was 1.8%, with 2.1% in the postpartum and 0.5% in the peripartum group. Asians had the highest mortality (8.3%). In multimodel regression analysis, Asians [odds ratio (OR) 9.68, 95% confidence interval (CI) 1.11-83.9, P = 0.03] and length of stay (OR 1.06, 95% CI 1.03-1.10, P < 0.01) were associated with increased mortality, whereas white women were associated with reduced mortality (OR 0.10, 95% CI 0.02-0.59, P = 0.01). CONCLUSION: Although PPCM was prevalent in African-Americans, Asians had higher in-hospital mortality, increased prevalence of preeclampsia and premature labor. Also, mortality rate was significantly higher in the postpartum group.

Etiology of Syncope in Patients Hospitalized With Syncope and Predictors of Mortality and Readmission for Syncope at 17-Month Follow-Up: A Prospective Study.

We investigated the etiologies of syncope and risk factors for mortality and rehospitalization for syncope at 17-month follow-up in a prospective study of 242 consecutive patients, mean age 69 years, hospitalized for syncope. The etiologies of syncope included the following: vasovagal syncope in 49 patients (20%), volume depletion in 39 patients (16%), orthostatic hypotension in 13 patients (5%), primary cardiac arrhythmias in 25 patients (10.3%), structural cardiac disease in 6 patients (2%), and drug overdose in 5 patients (2%). The etiology of syncope could not be determined in 84 patients (35%). Of the 242 patients, 6 (2%) were rehospitalized for syncope and 12 (5%) died. Stepwise logistic regression analysis showed that the significant independent prognostic factors for rehospitalization for syncope were drug overdose [odds ratio (OR): 11.506; 95% confidence interval (CI): 1.083-22.261]. Stepwise logistic regression analysis showed that significant independent prognostic factors for time to mortality were undetermined etiology of syncope (OR: 4.665; 95% CI: 1.002, 21.727), San Francisco Syncope Score (OR: 3.537; 95% CI: 1.472-8.496), hypertension (OR: 0.099; 95% CI: 0.019-0.504), and glomerular filtration rate (OR: 0.964; 95% CI: 0.937-0.993).

Syncope: Approaches to Diagnosis and Management.

Syncope is defined as a transient loss of consciousness due to cerebral hypoperfusion followed by spontaneous recovery. Common causes of syncope include vasovagal syncope, situational syncope, orthostatic hypotension, carotid sinus hypersensitivity, left- and right-sided obstructive cardiac lesions, and cardiac arrhythmias. History and physical examination often provide valuable clues about the underlying etiology of syncope. Admission decisions in the emergency department can be guided by various risk prediction scores. Evaluation of a patient with syncope involves a large battery of diagnostic tests that include a 12-lead electrocardiogram, Holter monitoring, echocardiogram, tilt table testing, ischemia evaluation, electrophysiologic studies, and other imaging tests. Despite the availability of these advanced diagnostic tests, a significant proportion of patients with syncope remain undiagnosed. Therapy should be tailored based on the underlying etiology of syncope.