Acute cardiac tamponade during atrial flutter ablation: improved hemodynamics after positive pressure ventilation: a case report.

INTRODUCTION: Acute cardiac tamponade is a rare event during any type of interventional or surgical procedure. It can occur during electrophysiology procedures due to radiofrequency ablation, lead or catheter manipulation, transseptal puncture, laser lead extractions, or left atrial appendage occlusion device positioning. Cardiac tamponade is difficult to study in a prospective manner, and case reports and case series are important contributions to understanding the best options for patient care. An 87-year-old Caucasian male patient breathing spontaneously developed acute tamponade during an atrial flutter ablation. Pericardial drain insertion was difficult, and hypotension failed to respond to epinephrine boluses. The patient became hypoxemic and hypercarbic, requiring intubation. Unexpectedly, the blood pressure markedly increased postintubation and remained in a normal range until the pericardium was drained. CONCLUSION: Spontaneous ventilation is considered important to maintain venous return to the right heart during cardiac tamponade. However, spontaneous ventilation reduces venous return to the left heart and worsens the paradoxical pulse in tamponade. Intravenous vasopressors are thought to be ineffective during cardiac tamponade. Our patient maintained pulmonary blood flow as indicated by end-tidal carbon dioxide measurements but had no measurable systemic blood pressure during spontaneous ventilation. Our case demonstrates that tracheal intubation and positive pressure ventilation can transiently improve left heart venous return, systemic perfusion, and drug delivery to the systemic circulation.

Look before you place: A bizarre ECG artifact due to lead placement.

The Electrocardiogram (ECG) is a readily available non-invasive test used in the evaluation of a patient with angina. ECG artifacts are common and stem from a number of different reasons including lead placement and must be identified to appropriately manage patients. We present the case of an elderly patient for whom an ECG was performed to evaluate chest pain showing an abnormal waveform concerning for an ST elevation myocardial infarction (STEMI). Closer inspection of the ECG revealed a characteristic pattern documented in the literature known as Aslanger's Sign seen when an ECG lead is placed over an artery.

Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience.

BACKGROUND: The ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks. METHODS: We describe our first multicenter experience of 255 consecutive patients (235 females, 25.94 ± 3.84 years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n = 204, 80%) or POTS (n = 51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected. RESULTS: Normal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months, all patients presented stable SR. At a mean of 4.07 ± 1.8 years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest > 5 s. CONCLUSIONS: Preliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

Inappropriate Implantable Cardioverter-Defibrillator Therapy With the Use of an Underbody Electrosurgery Dispersive Electrode.

Perioperative management of implantable cardioverter-defibrillators is an important part of anesthetic care. Society recommendations and expert consensus statements exist to aid clinicians, and they have identified the umbilicus as an important landmark in decision-making. Implantable cardioverter-defibrillator antitachycardia therapy may not need to be deactivated for infraumbilical surgery because electromagnetic interference is unlikely to occur. The authors present two cases in which inappropriate antitachycardia therapy occurred intraoperatively with use of an underbody dispersive electrode, even though both surgeries were infraumbilical. The authors also present two cadaver models to demonstrate how monopolar electrosurgery below the umbilicus is sensed using both traditional and underbody dispersive electrosurgical return electrodes.

An Incessant Tachycardia: What Is the Mechanism?

A 39-year-old man presented with lifelong palpitations, a mildly reduced left ventricular ejection fraction, and incessant tachycardia. Electrocardiography revealed a regular, one-to-one supraventricular tachycardia with superiorly directed P-waves and a long R-P interval. The differential diagnosis of the tachycardia, response to invasive electrophysiologic maneuvers, and treatment with catheter ablation are discussed.

The Storm Before the Calm: Ablation of Premature Ventricular Complex Trigger for Incessant Ventricular Fibrillation.

Ventricular tachycardia storm is associated with high mortality rates and is often refractory to treatment. Historically, few options for treatment have existed in cases when antiarrhythmic drugs fail. We report the case of a patient with incessant ventricular fibrillation (VF) in the postinfarction period that was triggered by premature ventricular contractions (PVCs) that persisted despite normal electrolytes, exclusion of ongoing ischemia, infusions of antiarrhythmic drugs, general anesthesia, full circulatory support with extracorporeal membranous oxygenation, and cardiac sympathetic denervation. Given that the VF appeared to be triggered consistently by a unifocal, short-coupled PVC (consistent with Purkinje fiber-mediated VF), we performed catheter ablation, after which point, the patient experienced no further PVCs or ventricular arrhythmia. This case serves as a reminder of three key teaching points. First, not all VF is created equal, with some cases being chiefly the result of a vulnerable substrate and others being best accounted for by frequent triggers. Second, examining the available electrocardiographic data and appropriately interpreting them can guide the selection of therapies up to and including catheter ablation for treatment-refractory VF. Third, full circulatory support greatly facilitates successful electroanatomic mapping and catheter ablation of unstable ventricular arrhythmias.

Cardiac Tumor Masquerading as ST Elevation Myocardial Infarction: A Case Report and Literature Review.

Cardiac tumors are rare, with primary tumors much rarer than secondary. They can present with a variety of symptoms, including cardiogenic shock, arrhythmias, tamponade, and systemic embolism. There have been cases reported of patients having cardiac tumors presenting with ST elevations. While the exact pathophysiological mechanism for ST changes in patient with tumors is not known, proposed theories include tumor emboli to coronary artery, external compression of coronary arteries, stretching of cardiac muscle fibers, inflammatory reactions, and electrolyte transfer from necrotic tumor tissue to adjacent myocardium. We present a case in which the patient had no prior history of malignancy that are presented with cough, shortness of breath, lower extremity edema, ST elevation on electrocardiogram, and was found to have epithelioid tumor in his left ventricle. This case raises awareness of wide differential for ST changes on electrocardiogram besides myocardial infarction, especially in patients who do not present with classic ischemic symptoms.

Body Mass Index, Sex, and Incident Atrial Fibrillation in Diabetes: The ACCORD Trial.

OBJECTIVES: This study sought to characterize the relationship between obesity and the risk of atrial fibrillation (AF) in diabetes. BACKGROUND: Obesity is associated with increased risk of AF in the general population, but there is evidence that this relationship may differ in those with diabetes. METHODS: Cox proportional hazards models were used to examine the association between body mass index (BMI) and incident AF on study electrocardiogram in participants from the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial. RESULTS: Among 10,074 ACCORD participants (age 62.7 ± 6.6 years, 38.7% women, 62.2% white), 8.4% were normal weight, 29.0% were overweight, 53.1% were obese, and 9.5% were severely obese. Participants with obesity and severe obesity had increased risks of AF compared with normal weight (hazard ratio [HR]: 1.91; 95% confidence interval [CI]: 1.03 to 3.93; and HR: 3.69; 95% CI: 1.79 to 8.22, respectively). There was a 51% increased risk of AF per SD (5.4 U) BMI increase. However, there was a sex and BMI interaction-in men, obesity and severe obesity were associated with a substantially increased AF risk (HR: 3.19; 95% CI: 1.27 to 7.31; and HR: 4.79; 95% CI: 2.11 to 11.93, respectively), whereas there was no statistically significant association in women. CONCLUSIONS: In those with diabetes, obesity and severe obesity are associated with increased risk of AF, but there is an interaction between sex and BMI, such that elevated BMI appears to confer a much greater risk of AF in men than in women. Further studies exploring the differential effects of BMI on AF risk in men and women are needed.

Effect of Intensive Glycemic and Blood Pressure Control on QT Prolongation in Diabetes: The ACCORD Trial.

Compared with standard glycemic control, intensive glycemic control caused increased mortality in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. Preliminary data from several studies suggest that intensive glycemic control is associated with QT prolongation, which may lead to ventricular arrhythmias as a possible explanation of this increased mortality. We sought to assess the effects of intensive glycemic control and intensive blood pressure control on the risk of incident QT prolongation. Cox proportional hazards models were used to compare the risk of incident QT prolongation (>460 ms in women or >450 ms in men) in the intensive versus standard glycemic control arms. Over a combined 48,634 person-years of follow-up (mean 4.9), 634 participants (6.4%) developed a prolonged QTc. Participants in the intensive glycemic control arm did not have an increased risk of QT prolongation. Similarly, a strategy of intensive blood pressure control did not result in a significant change in risk of prolonged QTc. Sensitivity analyses using alternative QT correction formulas (Hodges and Bazett) yielded overall similar findings. In conclusion, the increased mortality observed in the intensive glycemic control arm in the ACCORD trial is not likely to be explained by QT prolongation leading to lethal ventricular arrhythmias.

Effect of Intensive Blood Pressure Lowering on Incident Atrial Fibrillation: A Systematic Review and Meta-Analysis.

The effect of intensive versus standard blood pressure (BP) lowering on the risk of atrial fibrillation (AF) is uncertain. Intensive BP lowering is associated with a lower risk of AF among patients with hypertension. We searched PubMed, EMBASE, and CENTRAL (inception to June 5, 2020) for randomized controlled trials evaluating the effect of intensive versus standard (target systolic BP < 140 mmHg) BP lowering on incident AF. We assessed heterogeneity using the I2 statistic then used fixed-effects meta-analysis models to report pooled treatment effects and 95% confidence intervals. We also tested for publication bias by three funnel plot-based methods. The quality of each study was assessed with the Cochrane Risk of Bias tool. We assessed 16 candidate studies for eligibility from 2,312 published articles, but only three randomized clinical trials were eligible for inclusion and included a combined 12,219 participants with hypertension: Cardio-Sis (Studio Italiano Sugli Effetti Cardiovascolari del Controllo della Pressione Arteriosa Sistolica), ACCORD-BP (Action to Control Cardiovascular Risk in Diabetes Blood Pressure trial), and SPRINT (Systolic Blood Pressure Intervention Trial). The target systolic BP in the intensive BP arm was <120 mmHg for participants in SPRINT and ACCORD-BP, but <130 mmHg for participants in Cardio-Sis. Participants randomized to intensive BP lowering had significantly lower risk of incident AF compared with those randomized to standard BP lowering (AF incidence 2.2% vs. 3.0%, respectively; pooled hazard ratio (95% confidence interval): 0.74 (0.59 - 0.93)). Intensive BP lowering is associated with a significantly lower risk of incident AF in patients with hypertension. These findings add to the current evidence supporting the benefits of intensive BP control.

The association of QT interval components with atrial fibrillation.

BACKGROUND: Although abnormalities of the QT interval are associated with atrial fibrillation (AF), it is unclear whether ventricular depolarization (QRS duration) or repolarization (JT interval) is a more important marker of AF risk. METHODS: This analysis included 4,181 (95% white; 59% women) participants from the Cardiovascular Health Study (CHS) who were free of baseline AF and major intraventricular delay. A linear scale was used to compute heart rate adjusted QT (QTa), QRS (QRSa ), and JT (JTa ) intervals. Prolonged QTa , QRSa , and JTa were defined by values greater than the sex-specific 95th percentile for each measurement. AF events were ascertained during the annual study electrocardiograms and from hospitalization discharge data. Cox regression was used to compute hazard ratios (HR) and 95% confidence intervals (CI) for the associations of prolonged QTa , QRSa , and JTa with AF, separately. RESULTS: Over a mean follow-up of 12.1 years, a total of 1,236 (30%) AF events were detected. An increased risk of AF (HR = 1.50. 95% CI = 1.20, 1.88) was observed with prolonged QTa . When we examined the association between individual components of the QTa interval and AF, the risk of AF was limited to prolonged JTa (HR = 1.31, 95% CI = 1.04, 1.65) and not prolonged QRSa (HR = 1.00, 95% CI = 0.77, 1.30). Similar results were obtained per 1-SD increase in QTa (HR = 1.07, 95% CI = 1.01, 1.13), QRSa (HR = 0.99, 95% CI = 0.94, 1.06), and JTa (HR = 1.07, 95% CI = 1.01, 1.13). CONCLUSIONS: The JT interval is a more important marker of AF risk in the QT interval among persons who do not have ventricular conduction delays.

Short-term safety and efficacy of left atrial appendage closure with the WATCHMAN device in patients with small left atrial appendage ostia.

INTRODUCTION: Left atrial appendage (LAA) closure with the WATCHMAN device, according to FDA labelling, is recommended in patients with a maximal LAA ostial width between 17 and 31 mm. The safety and efficacy of LAA closure in patients with a maximal LAA ostial width < 17 mm has not been evaluated. The goal of this study was to determine the acute and short-term safety and efficacy of LAA closure with the WATCHMAN device in patients with a maximal LAA ostial width < 17 mm. METHODS AND RESULTS: Thirty-two consecutive patients with a maximal LAA ostial width < 17 mm as determined by a screening transesophageal echocardiogram (TEE) underwent LAA closure with the WATCHMAN device between March 2015 and November 2016 at five medical centers, and were included in this study. Mean age, body mass index (BMI), and CHA2 DS2 -VASC score were 70.8 ± 8.6 years, 29.3 ± 6.5 kg/m2 , and 3.9 ±1.2, respectively. At the screening TEE, mean maximal LAA ostial width and depth were 15.6 ± 0.6 mm (range 14-16) and 23.2 ± 4.5 mm (range 13-31), respectively. Successful LAA closure with the WATCHMAN device was achieved in 31 of 32 patients (97%), with no major complications. TEE performed 45 days after LAA closure demonstrated no peridevice leak > 5 mm and no device related thrombi. Warfarin was discontinued in all 31 patients 45 days after LAA closure. CONCLUSIONS: LAA closure with the WATCHMAN device can be successfully and safely achieved in patients with a maximal LAA ostial width < 17 mm.

PR-Interval Components and Atrial Fibrillation Risk (from the Atherosclerosis Risk in Communities Study).

Reports on the association between the PR-interval and atrial fibrillation (AF) are conflicting. We hypothesized that inconsistencies stem from that fact that the PR-interval represents a composite of several distinct components. We examined the associations of the PR-interval and its components (P-wave onset to P-wave peak duration, P-wave peak to P-wave end duration, and PR-segment) with incident AF in 14,924 participants (mean age 54 ± 5.8 years; 26% black; 55% women) from the Atherosclerosis Risk In Communities study. The PR-interval and its components were automatically measured at baseline (1987 to 1989) from standard 12-lead electrocardiograms. PR-interval >200 ms was considered prolonged and values above the ninety-fifth percentile defined abnormal PR-interval components. AF was ascertained during follow-up through December 31, 2010. Over a median follow-up of 21.2 years, 1,985 participants (13%) developed AF. Prolonged PR-interval was associated with an increased risk of AF (hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.02 to 1.40). However, PR-interval components showed varying levels of association with AF (P-wave onset to P-wave peak duration: HR 1.57, 95% CI 1.31 to 1.88; P-wave peak to P-wave end duration: HR 1.20, 95% CI 0.99 to 1.46; and PR-segment: HR 1.05, 95% CI 0.85 to 1.29). In addition, the components of the PR-interval had weak-to-moderate correlation with each other (correlation r ranged from -0.44 to 0.06). In conclusion, our findings suggest the PR-interval represents a composite of distinct components that are not uniformly associated with AF. Without considering the contribution of each component, inconsistent associations between the PR-interval and AF are inevitable.

Angiographic Efficacy of the Atriclip Left Atrial Appendage Exclusion Device Placed by Minimally Invasive Thoracoscopic Approach.

OBJECTIVES: This study sought to assess long-term left atrial appendage (LAA) closure efficacy of the Atriclip applied via totally thoracoscopic (TT) approach with computed tomographic angiography. BACKGROUND: LAA closure is associated with a low risk for atrial fibrillation-related embolic stroke. The Atriclip exclusion device allows epicardial LAA closure, avoiding the need for post-operative oral anticoagulation. Previous data with Atriclip during open chest procedures show a high efficacy rate of closure >95%. METHODS: Three-dimensional volumetric 2-phase computed tomographic angiography ≥90 days post-implantation was independently assessed by chest radiology for complete LAA closure on all consented subjects identified retrospectively as having had a TT-placed Atriclip at Vanderbilt University Medical Center from June 13, 2011, to October 6, 2015. RESULTS: Complete LAA closure (defined by complete exclusion of the LAA with no exposed trabeculations, and clip within 1 cm from the left circumflex artery) was found in 61 of 65 subjects (93.9%). Four cases had incomplete closure (6.2%). Two clips were placed too distally, leaving a large stump with exposed trabeculae. Two clips failed to address a secondary LAA lobe. No major complications were associated with TT placement of the Atriclip. Follow-up over 183 patient-years revealed 1 stroke in a patient with complete LAA closure and no thrombus (hypertensive cerebrovascular accident). CONCLUSIONS: Angiographic LAA closure efficacy with a TT-placed Atriclip is high (93.9%). The clinical significance of a remnant stump is unknown. Confirmation of complete LAA occlusion should be made before cessation of systemic anticoagulation.