Sex-Related Differences in Ventricular Tachyarrhythmia Events in Patients With Implantable Cardioverter-Defibrillator and Prior Ventricular Tachyarrhythmias.

BACKGROUND: Data on the risk of ventricular tachycardia (VT), ventricular fibrillation (VF), and death by sex in patients with prior VT/VF are limited. OBJECTIVES: This study aimed to assess sex-related differences in implantable cardioverter-defibrillator (ICD)-treated VT/VF events and death in patients implanted for secondary prevention or primary prevention ICD indications who experienced VT/VF before enrollment in the RAID (Ranolazine Implantable Cardioverter-Defibrillator) trial. METHODS: Sex-related differences in the first and recurrent VT/VF requiring antitachycardia pacing or ICD shock and death were evaluated in 714 patients. RESULTS: There were 124 women (17%) and 590 men observed during a mean follow-up of 26.81 ± 14.52 months. Compared to men, women were at a significantly lower risk of VT/VF/death (HR: 0.67; P = 0.029), VT/VF (HR: 0.68; P = 0.049), VT/VF treated with antitachycardia pacing (HR: 0.59; P = 0.019), and VT/VF treated with ICD shock (HR: 0.54; P = 0.035). The risk of recurrent VT/VF was also significantly lower in women (HR: 0.35; P < 0.001). HR for death was similar to the other endpoints (HR: 0.61; P = 0.162). In comparison to men, women presented with faster VT rates (196 ± 32 beats/min vs 177 ± 30 beats/min, respectively; P = 0.002), and faster shock-requiring VT/VF rates (258 ± 56 beats/min vs 227 ± 57 beats/min, respectively; P = 0.30). There was a significant interaction for the risk of VT/VF by race (P = 0.013) with White women having significantly lower risk than White men (HR: 0.36; P < 0.001), whereas Black women had a similar risk to Black men (HR: 1.06; P = 0.851). CONCLUSIONS: Women with a history of prior VT/VF experienced a lower risk recurrent VT/VF requiring ICD therapy when compared to men. Black Women had a risk similar to men, whereas the lower risk for VT/VF in women was observed primarily in White women. (Ranolazine Implantable Cardioverter-Defibrillator Trial; NCT01215253).

Shared decision-making tool for thromboprophylaxis in atrial fibrillation - A feasibility study.

BACKGROUND: Appropriate thromboprophylaxis for patients with atrial fibrillation or atrial flutter (AF) remains a national challenge. METHODS: We hypothesized that a shared decision-making interaction facilitated by an Atrial Fibrillation Shared Decision Making Tool (AFSDM) would improve patient knowledge about atrial fibrillation, and the risks and benefits of various treatment options for stroke prevention; increase satisfaction with the decision-making process; improve the therapeutic alliance between patient and the clinical care team; and increase medication adherence. Using a pre- and post-visit study design, we enrolled 76 patients and completed 2 office visits and 1-month telephone follow-up for 65 patients being seen in our Arrhythmia Clinic over the 1-year period (July 2016 through June 2017). Our primary outcome measure was change in decisional conflict between the first and second clinical visit. RESULTS: Decisional conflict decreased from an average of 31 to 9. Mean change was 22.3 (95% CI, 25.7 - 37.1), corresponding to an effect size of 0.94 standard deviations. Satisfaction with decision increased from 4.0 to 4.5, measures of therapeutic alliance with the care team (Kim Alliance scale) increased from 100.1 to 103.1, and satisfaction with provider increased from 4.2 to 4.5 (P < .0001 for all measures). AF knowledge assessment scores increased from 8.4 to 9.1, and knowledge about personal stroke and bleeding risk increased from 1 to 1.5 (P < .0001). Finally, medication adherence improved as reflected by an increase in the Morisky Medication Adherence scale from 5.9 to 6.4 (P < .0001). CONCLUSIONS: A shared decision-making interaction, facilitated by an AFSDM can significantly improve multiple measures of decision-making quality, leading to improved medication adherence and patient satisfaction.

Atrial fibrillation decision support tool: Population perspective.

BACKGROUND: Appropriate thromboprophylaxis for patients with atrial fibrillation or atrial flutter (AF) remains a national challenge. The recent availability of direct oral anticoagulants (DOACs) with comparable efficacy and improved safety compared with warfarin alters the balance between risk factors for stroke and benefit of anticoagulation. Our objective was to examine the impact of DOACs as an alternative to warfarin on the net benefit of oral anticoagulant therapy (OAT) in a real-world population of AF patients. METHODS: This is a retrospective cohort study of patients with paroxysmal or persistent nonvalvular AF. We updated an Atrial Fibrillation Decision Support Tool (AFDST) to include DOACs as treatment options. The tool generates patient-specific recommendations based upon individual patient risk factor profiles for stroke and major bleeding using quality-adjusted life-years (QALYs) calculated for each treatment strategy by a decision analytic model. The setting included inpatient and ambulatory sites in an academic health center in the midwestern United States. The study involved 5,121 adults with nonvalvular AF seen for any ambulatory visit or inpatient hospitalization over the 1-year period (January through December 2016). Outcome measure was net clinical benefit in QALYs. RESULTS: When DOACs are a therapeutic option, the AFDST recommends OAT for 4,134 (81%) patients and no antithrombotic therapy or aspirin for 489 (9%). A strong recommendation for OAT could not be made in 498 (10%) patients. When warfarin is the only option, OAT is recommended for 3,228 (63%) patients and no antithrombotic therapy or aspirin for 973 (19%). A strong recommendation for OAT could not be made in 920 (18%) patients. In total, 1,508 QALYs could be gained if treatment were changed to that recommended by the AFDST. CONCLUSIONS: Availability of DOACs increases the proportion of patients for whom oral anticoagulation therapy is recommended in a real-world cohort of AF patients and increased projected QALYs by more than 1,500 when all patients are receiving thromboprophylaxis as recommended by the AFDST compared with current treatment.

Cardiac Sarcoidosis: The Impact of Age and Implanted Devices on Survival.

OBJECTIVE: To assess the clinical characteristics, diagnosis, and outcome of cardiac sarcoidosis in a single institution sarcoidosis clinic. METHODS: Patients with cardiac sarcoidosis were identified using refined World Association of Sarcoidosis and Other Granulomatous Diseases (WASOG) criteria of highly probable and probable. Patient demographics, local and systemic treatments, and clinical outcome were collected. RESULTS: Of the 1,815 patients evaluated over a 6-year period, 73 patients met the WASOG criteria for cardiac sarcoidosis. The median age at diagnosis was 46 years, with a median follow-up of 8.8 years. Reduced left ventricular ejection fraction (LVEF) was the most common manifestation (54.8%). Patients with arrhythmias experienced ventricular tachycardia or severe heart block, (35.6% and 19.2%, respectively) with or without reduced LVEF. A total of 45 (61.6%) patients underwent cardiac PET scan and/or MRI, with 41 (91.1%) having a positive study. During follow-up, 10 patients (13.7%) either underwent transplant (n = 3) or died (n = 7) from sarcoidosis. Kaplan-Meier survival curves revealed 5- and 10-year survival rates of 95.5% and 93.4%, respectively. Univariate factors of age at diagnosis < 46 years, implantation of pacemaker or defibrillator, mycophenolate treatment, or LVEF > 40% were associated with improved survival. Cox regression analysis demonstrated that age ≥ 46 years and lack of an implanted pacemaker or defibrillator were the only independent predictors of mortality. CONCLUSIONS: The new WASOG criteria were able to characterize cardiac involvement in our sarcoidosis clinic. Age and lack of pacemaker or defibrillator were the significant predictors of mortality for cardiac sarcoidosis, and reduced LVEF < 40% was associated with worse prognosis. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02356445; URL: www.clinicaltrials.gov.

Antibiotic-induced cardiac arrhythmias.

This review aims to clarify the underlying risk of arrhythmia associated with the use of macrolides and fluoroquinolones antibiotics. Torsades de pointes (TdP) is a rare potential side effect of fluoroquinolones and macrolide antibiotics. However, the widespread use of these antibiotics compounds the problem. These antibiotics prolong the phase 3 of the action potential and cause early after depolarization and dispersion of repolarization that precipitate TdP. The potency of these drugs, as potassium channel blockers, is very low, and differences between them are minimal. Underlying impaired cardiac repolarization is a prerequisite for arrhythmia induction. Impaired cardiac repolarization can be congenital in the young or acquired in adults. The most important risk factors are a prolonged baseline QTc interval or a combination with class III antiarrhythmic drugs. Modifiable risk factors, including hypokalemia, hypomagnesemia, drug interactions, and bradycardia, should be corrected. In the absence of a major risk factor, the incidence of TdP is very low. The use of these drugs in the appropriate settings of infection should not be altered because of the rare risk of TdP, except among cases with high-risk factors.

Atheroscerlotic heart disease in Bangladeshi immigrants: risk factors and angiographic findings.

BACKGROUND: The prevalence of coronary artery disease (CAD) among Bangladeshis greatly exceeds that of Caucasians. Bangladeshis also suffer from premature onset, clinically aggressive and angiographically extensive disease. The role of conventional CAD risk factors (CCRFs) has been questioned. We therefore sought to determine if the CCRFs of Bangladeshis differed from non-Bangladeshis. We also sought to determine whether CAD was more extensive in Bangladeshis and if Bangladeshi ethnicity was independently predictive of extensive i.e., 3-vessel CAD at angiography. METHODS: We reviewed the coronary angiograms and medical records of 75 Bangladeshis and 57 non-Bangladeshis presenting with myocardial infarction or angina pectoris. RESULTS: Bangladeshis were younger (56.1 vs. 62.4 years, p=.001), had a lower body-mass index (25.2 vs. 27.2 kg/m(2), p=.017) and were less likely to be current or recent smokers (40% vs. 58%, p=.041) than non-Bangladeshis. There were no statistically significant differences in the proportion of subjects in the 2 groups with respect to diabetes mellitus, dyslipidemia, hypertension or family history of CAD. Bangladeshis had twice the rate of 3-vessel CAD of non-Bangladeshis (53% vs. 26%, p=.002). Bangladeshi ethnicity was independently associated with >3X the likelihood of having 3-vessel CAD at angiography (p=.011). CONCLUSIONS: This study demonstrated that the CCRF burden of Bangladeshis with CAD is not excessive compared to that of non-Bangladeshis and is therefore unlikely to account for the excessive CAD risk found in this cohort. We also conclude that Bangladeshis have more angiographically extensive CAD than non-Bangladeshis and that Bangladeshi ethnicity is independently predictive of 3-vessel disease.

Care of the pacemaker/implantable cardioverter defibrillator patient in the ED.

As the population ages and the prevalence of cardiovascular disease increases, patients with pacemakers and implantable cardioverter defibrillators (ICDs) more commonly present to the emergency department. These patients can have complex medical issues related to and independent of their pacemaker/ICD that require careful management by the emergency physician. This article will review the major diagnostic and therapeutic considerations in the emergency care of patients with pacemakers and ICDs.

Atrial tachycardia arising from the coronary sinus musculature: electrophysiological characteristics and long-term outcomes of radiofrequency ablation.

OBJECTIVES: We sought to describe the electrophysiological features and long-term outcome after radiofrequency catheter ablation (RFCA) of atrial tachycardia (AT) arising from the coronary sinus (CS) musculature. BACKGROUND: Atrial tachycardia requiring RFCA deep within the CS has been described in isolated case reports. However, the mechanism and exact site of origin of this tachycardia have not been well elucidated. METHODS: The study included 8 patients (5 men) of a consecutive series of 283 patients undergoing RFCA for focal AT. RESULTS: In sinus rhythm, a discrete potential (P) was noted after the CS atrial electrogram and during tachycardia, the CS (P) preceded the surface P-wave by 30 to 50 ms. The CS (P) always preceded the earliest electrogram in the left atrium (LA). Three-dimensional electroanatomical mapping was available in four patients, and in one case it showed earliest activation in the CS with rapid spread to the proximal CS and then to the LA. Ablation of the AT initially attempted from the earliest site in the LA in three patients was unsuccessful. In all patients the tachycardia was safely and successfully ablated at a site 3.6 cm within the CS. There has been no recurrence over a follow-up of 37 +/- 13 months. CONCLUSIONS: Focal AT emanating deep within the CS musculature can be recognized by a discrete potential associated with the CS atrial signal both during sinus rhythm and tachycardia. Long-term success without complications can be accomplished by ablating within the CS in close proximity to the CS (P).

Catheter location, tracking, cardiac chamber geometry creation, and ablation using cutaneous patches.

OBJECTIVE: The ability to construct a three-dimensional (3-D) surface model of the endocardium and track the location of catheters within a cardiac chamber, using only cutaneous patches, would be a useful advancement in treating arrhythmias. We tested the feasibility of such a system, Ensite NavX (Endocardial Solutions, Inc., St. Paul, MN, USA), in patients undergoing catheter ablation for SVTs. METHODS: Sixteen patients with 20 arrhythmias undergoing ablation were selected. Skin electrode patches were placed on the chest to create a 3-D coordinate system. A low-amplitude, 5.7 kHz signal emitted from the patches was received by conventional catheters positioned in the heart. Catheter location was determined by measuring the field strength received by the catheters. Location points were successively acquired while catheters were moved throughout the chamber. This information was collected and processed by a workstation to create a detailed 3-D model of the endocardial surface. Anatomic landmarks were labeled on the model as the mapping catheter was navigated. 3-D cardiac chamber geometry reconstruction, landmark labeling, and real time catheter tracking were performed successfully in all patients. Up to six catheters, with a total of up to 26 intracardiac electrodes, were tracked simultaneously. RESULTS: Constructed geometries, including major vessels and valves, correlated closely with traditional anatomic models as well as intracardiac recordings and fluoroscopic images. CONCLUSIONS: Real-time catheter tracking and 3-D cardiac chamber model construction is feasible using cutaneous patches and conventional catheters. This approach may be useful in the treatment of patients with cardiac arrhythmias where ablation therapy is primarily anatomically based.

Role of invasive and noninvasive testing in risk stratification of sudden cardiac death in children and young adults: an electrophysiologic perspective.

Sudden cardiac death is a rare, but devastating, event in the young population. Arrhythmia is the mechanism of death in many cases. In addition to clinical history, noninvasive and invasive tests can be used to identify patients who are at risk. Although these tools are not perfect, they can prove valuable if used in proper clinical circumstances. An overview of these tests is presented.

Exercise-triggered transient R-wave enhancement and ST-segment elevation in II, III, and aVF ECG leads: a testament to the "plasticity" of the QRS complex during ischemia.

We describe a patient with coronary artery disease who showed transiently augmented R-waves in his electrocardiogram (ECG) during the course of an exercise treadmill test (ETT), an ECG pattern occasionally associated with the hyperacute phase of myocardial infarction and variant angina. This change in the R-waves was noted in II, III, and aVF ECG leads and was associated with ST-segment elevation; both changed gradually and were normalized during the recovery period. Cardiac enzymes after ETT were negative, and arteriography revealed 3-vessel coronary artery disease, with a completely occluded right coronary artery. The ventriculogram showed very mild hypokinesis of the inferior left ventricular wall, while the global ejection fraction was 75%. These ECG changes, noted previously during ETT in precordial ECG leads, are herein reported to occur also in II, III, and aVF ECG leads. The generation of these ECG changes, which hinges upon a late unopposed depolarization occurring in the course and at the site of severe ischemic injury, constitutes a transient focal ventricular conduction abnormality.

Posterior myocardial infarction and complete right bundle- branch block.

We describe two patients with posterior myocardial infarction (PMI) with unusually atypical clinical presentations and cardiac enzymatic profiles, but with the abrupt development of complete AV block in patient 1, and Mobitz II second-degree AV block with paroxysmal phases of higher degrees of AV block in patient 2, and mitral regurgitation leading to symptomatic pulmonary congestion. Also, both patients had complete right bundle-branch block (RBBB) [old in patient 1, new in patient 2], the pattern of which was altered due to the associated PMI. The alteration included tall R waves involving the early part of the QRS complex, and tall T waves, both noted in the right precordial leads. The mechanism of these ECG modulations of the RBBB pattern was believed to be a superimposition of the early depolarization and repolarization consequences of the PMI. The significance of this observation lies in the ECG detection of PMI, frequently underdiagnosed particularly in patients with an atypical presentation, and with the RBBB adding further to the complexity. Thus, it is gratifying to note the contribution of the ECG to diagnostics, the only modality that provided a pathophysiologic insight in these two patients who appeared to be abruptly deteriorating clinically without an apparent reason.