The power of three: Atrial rate limit power-on-reset - A non-electromagnetic cause of pacemaker-induced extracardiac stimulation.

BACKGROUND: Power-on reset (PoR) is most commonly due to electromagnetic interference. Full PoR results in a switch to an inhibited mode (VVI) pacing and resets pacing outputs to maximal unipolar settings, leading to extracardiac stimulation. METHODS: We present a case of PoR occurrence in the absence of electromagnetic interference, resulting in pectoral stimulation triggered by violation of the atrial rate limit. CONCLUSIONS: It is useful for clinicians to recognizethe occurrence of PoR in the setting of atrial limit violation andthe appropriate management in such circumstances.

Risk of Arrhythmic Death in Patients With Nonischemic Cardiomyopathy: JACC Review Topic of the Week.

Nonischemic cardiomyopathy (NICM) is common and patients are at significant risk for early mortality secondary to ventricular arrhythmias. Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy to decrease sudden cardiac death (SCD) in patients with heart failure and reduced left ventricular ejection fraction. However, in randomized clinical trials comprised solely of patients with NICM, primary prevention ICDs did not confer significant mortality benefit. Moreover, left ventricular ejection fraction has limited sensitivity and specificity for predicting SCD. Therefore, precise risk stratification algorithms are needed to define those at the highest risk of SCD. This review examines mechanisms of sudden arrhythmic death in patients with NICM, discusses the role of ICD therapy and treatment of heart failure for prevention of SCD in patients with NICM, examines the role of cardiac magnetic resonance imaging and computational modeling for SCD risk stratification, and proposes new strategies to guide future clinical trials on SCD risk assessment in patients with NICM.

Interference by Modern Smartphones and Accessories with Cardiac Pacemakers and Defibrillators.

PURPOSE OF REVIEW: The risk of cardiac implantable electronic device (CIED) interference from cell phones was previously thought to be low based on older studies. Current generation of smartphones have incorporated more magnets for optimization of wireless charging, attachment of accessories, and convenience functionalities. These magnets have the potential to cause CIEDs to inadvertently revert into magnet mode. The purpose of this review is to summarize recent findings on smartphones and their accessories causing interference on CIEDs. RECENT FINDINGS: Recent reports have demonstrated that the iPhone 12 series and accessories have the capability to cause CIED magnetic interference. Current generation of smartphones, smartwatches, wireless headphones, and accessories have the potential to cause CIEDs to revert into magnet mode in both in vivo and ex vivo experiments. The risk of a clinically significant event is unlikely as long as the Food and Drug Administration (FDA) recommendations are followed; keeping smartphones and accessories at least six inches away from CIEDs.

Incidence and Risk Factors for Atrial Fibrillation Recurrence after Ablation of Nodal and Atrioventricular Reentrant Tachycardia: A Meta-analysis.

Introduction Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) are frequently associated with atrial fibrillation (AF). Targeting the slow or accessory pathways has been advocated as therapy for coexisting AF. But in practice, AF has frequently recurred after ablation, possibly because of various risk factors. The objective of this study is to investigate these risk factors and check for their significance in AF recurrence. Materials and methods A systematic review of Medline, Cochrane, and ClinicalTrials.gov databases was conducted. Articles that studied AF recurrence after either AVNRT or AVRT ablation were reviewed. Publication bias was adequately assessed, and the random method was applied for all dichotomous values. Finally, the odds ratio (OR) and confidence intervals (CI) were calculated for each risk factor. Results Four studies were included, with a total of 1,308 participants. Only 218 participants had dual tachycardia (AF with either AVNRT or AVRT). The mean follow-up time was 29 +/- 3.3 months. The mean age was 56 +/- 15 years. Age constituted the only significant risk factor for AF recurrence (OR: 3.4, CI: 2.1-5.3, p<0.001). Atrial vulnerability did not significantly correlate with a higher risk of AF recurrence (OR: 4.8, CI: 0.7-29, p<0.008). Again, neither male gender (OR: 1.5, CI: 0.8-2.8, p<0.16) nor left atrial diameter (OR: 1.5, CI: 0.2-10, p<0.67) were significant risk factors for recurrence of AF. Conclusion Older age was the only significant predictor of AF recurrence after ablation of AVNRT or AVRT. Further studies are needed to determine the age cut-off at which concomitant pulmonary vein isolation would be beneficial in patients undergoing ablation of AVNRT/AVRT.

Failure to shock: What is the mechanism?

BACKGROUND: The Biotronik DX lead is an attractive option due to its floating atrial bipole and its noninferiority compared to dual-chamber defibrillators. METHODS: We describe the case of atrial undersensing by the DX lead resulting in failure of the device to appropriately treat a slow ventricular tachycardia. CONCLUSION: This case underlies the importance of understanding the limitations to each lead technology as well as the underlying assumptions inherent to detection enhancement algorithms.

Conjoined Inferior Pulmonary Veins during Pulmonary Vein Isolation: Prevalence and Novel Approach for Pulmonary Vein Isolation with Cryoballoon.

Cardiac resynchronization therapy is an established treatment modality in heart failure. Though non-response is a serious issue. To address this issue, a good understanding of the electrical activation during left bundle branch block, biventricular, as well as right- and left ventricular pacing is needed. This way by interpreting the 12-lead electrocardiogram, possible reasons for suboptimal treatment can be identified and addressed. This article reviews the literature on QRS morphology in cardiac resynchronization therapy and its meaning in optimization of therapy.

Gastroduodenal artery aneurysm, diagnosis, clinical presentation and management: a concise review.

Gastroduodenal artery (GDA) aneurysms are rare but a potentially fatal condition if rupture occurs. They represent about 1.5% of all visceral artery (VAA) aneurysms and are divided into true and pseudoaneurysms depending on the etiologic factors underlying their development. Atherosclerosis and pancreatitis are the two most common risk factors. Making the diagnosis can be complex and often requires the use of Computed Tomography and angiography. The later adds the advantage of being a therapeutic option to prevent or stop bleeding. If this fails, surgery is still regarded as the standard for accomplishing a definite treatment.

An unusual case of giant cardiac fibroelastoma mimicking left atrial myxoma in a patient presenting with syncope.

Cardiac papillary fibroelastomas are the most common primary valvular tumors. Generally benign, they account only for about 10% of all primary cardiac neoplasms, can occur in normal or diseased hearts, and are associated strongly with open heart surgery and radiotherapy. They are, in most cases, incidental findings, but can be discovered after syncope. We report the case of an elderly female, who was referred for syncope and was found to have a large fibroelastoma at the mitral valve annulus, intermittently obstructing the left ventricular inflow tract, and mimicking the presentation of left atrial myxoma. This case illustrates another potential mechanism of syncope in patients with fibroelastomas.

Two cases and review of the literature: primary percutaneous angiography and antiplatelet management in patients with immune thrombocytopenic purpura.

We report two cases of immune thrombocytopenic purpura (ITP) associated with acute coronary artery syndrome highlighting the interventions done in every case along with the medications used during intervention and as outpatient. The first case is that of a woman with ITP exacerbation while on dual antiplatelet therapy and the second case is that of a male presenting with non-ST elevation myocardial infarction (NSTEMI) while in a thrombocytopenic crisis. In both cases antiplatelet therapy was held and thrombopoietic therapy was initiated before resuming full anticoagulation and coronary intervention. Given the paucity of data on ITP and antiplatelets treatment in the setting of acute coronary syndrome, no strict recommendations can be proposed, but antiplatelets appear to be safe acutely and in the long term in this category of patients as long as few measures are undertaken to minimize the risks of bleeding and thrombosis.

Aortic pulse pressure is associated with the localization of coronary artery disease based on coronary flow lateralization.

BACKGROUND: Aortic pulse pressure (APP) is related to arterial stiffness and associated with the presence and extent of coronary artery disease (CAD). Besides, the left coronary artery (LCA) has a predominantly diastolic flow while the right coronary artery (RCA) receives systolic and diastolic flow. Thus, we hypothesized that increased systolic-diastolic pressure difference had a greater atherogenic effect on the RCA than on the LCA. METHODS: A random sample of 433 CAD patients (145 females, 288 males, mean age 65.0 ± 11.1 years) undergoing coronary angiography at Staten Island University Hospital between January 2005 and May 2008 was studied. Coronary lesion was defined as a ≥50% luminal stenosis. Patients were divided into three groups, with isolated LCA lesions (n = 154), isolated RCA lesions (n = 36) or mixed LCA and RCA lesions (n = 243). RESULTS: APP differed significantly between groups, being highest when the RCA alone was affected (67.6 ± 20.3 mm Hg for LCA vs. 78.8 ± 22.0 for RCA vs. 72.7 ± 22.6 for mixed, P = 0.008 for analysis of variance (ANOVA)). Age and gender were not associated with CAD location. Heart rate was associated with CAD location, lowest in RCA group, and negatively correlated with APP. However, left ventricular ejection fraction (LVEF) was lower in the mixed CAD group and positively correlated with APP. The association between APP and right-sided CAD persisted in multivariate logistic regression adjusting for confounders, including heart rate, LVEF and medication use. A similar but less significant pattern was seen with brachial arterial pressures. CONCLUSIONS: Aortic pulse pressure may affect CAD along with coronary flow phasic patterns.

Hemolytic anemia following mitral valve repair: A case presentation and literature review.

Hemolytic anemia is a known complication after valve replacement, but the incidence of hemolysis following valve repair is unknown. A case involving mitral annuloplasty complicated by hemolytic anemia, which resolved after replacement of the valve, is presented. Only 70 cases of hemolysis after mitral valve repair have been reported in the literature. In nearly all of these cases, replacement or rerepair of the valve was the definitive treatment for hemolysis.

Usefulness of red cell distribution width in predicting all-cause long-term mortality after non-ST-elevation myocardial infarction.

BACKGROUND: Red blood cell distribution width (RDW) is a strong predictor of adverse outcomes in patients with heart failure, stable coronary artery disease, stroke and acute myocardial infarction. The aim of our study was to explore the predictive value of RDW on all-cause mortality in patients with non-ST-segment elevation myocardial infarction (NSTEMI). METHOD: This observational study includes 619 NSTEMI patients, discharged from Staten Island University Hospital between September 2004 and December 2006. Patients were divided into equal RDW tertiles and survival was evaluated in each tertile. RESULT: Patients in the highest RDW tertile (RDW >14) had higher in-patient (7 vs. 1%) and 4-year (30 vs. 7%) mortality rates compared to those in the lowest tertile (RDW <13) (Wilcoxon χ(2) = 34.64, p < 0.0001). After controlling for Global Registry of Acute Coronary Events risk profile scores and other confounding variables, the RDW adjusted hazard ratio for 4-year all-cause mortality increased by 1.10 for each one unit increase in RDW (confidence interval 1.004-1.213, p = 0.042). CONCLUSION: RDW is an independent predictor of all-cause long-term mortality in NSTEMI patients. Further studies are needed to clarify the mechanisms of this association between RDW and adverse outcomes in patients with coronary artery disease.

Mean platelet volume/platelet count ratio as a predictor of long-term mortality after non-ST-elevation myocardial infarction.

Previous studies reported an association between elevated mean platelet volume (MPV) and post-myocardial infarction mortality. This study explores the association between long-term mortality after non-ST-segment elevation myocardial infarction (NSTEMI) and the peripheral blood platelet indices (i.e., the mean platelet volume (MPV), platelet count, and the MPV/platelet (MPV/P) ratio). Two physicians independently reviewed the data of 619 NSTEMI patients. The blood samples were drawn and analyzed within 1 h of admission, the second, and the last hospital days. Patients were stratified into equal tertiles according to the platelet count, MPV, and MPV/platelet ratio. The primary outcome, 4-year all-cause mortality, was compared among the platelet indices tertile models. According to MPV, platelet count, and MPV/platelet ratio tertile models, there was a trend of higher 4-year mortality for the lower and upper tertiles in comparison to the middle tertiles. However, only the admission MPV/platelet ratio tercile model was statistically significant for predicting the 4-year mortality. The mortality rate of the highest MPV/platelet (48/207 (23%)) and the lowest (41/206 (20%)) tertiles were significantly higher than the middle tertile (19/206 (9%)), p = 0.0004 by the chi-squared test. After adjusting for Global Registry of Acute Coronary Events, the patients in the combined first and third MPV/P tertiles had higher mortality in reference to those in the middle MPV/P tercile (hazard ratio 1.951, confidence interval 1.032-3.687, and p < 0.0396). Our novel finding is that the MPV/platelet ratio is superior to the MPV alone in predicting long-term mortality after NSTEMI. We suggest that using this ratio will magnify any existing relationship between platelet indices and mortality post-NSTMI. Further studies are needed to confirm our finding.

Patent foramen ovale: thromboembolic structure or incidental finding?

A patent foramen ovale (PFO) is identified in approximately 27% of healthy individuals undergoing routine autopsy and in 25% of the general population on transesophageal echocardiography (TEE). PFO generally considered benign, but has been associated with stroke, migraine and diving decompression sickness. We searched Pubmed for English language articles that examined the relationship of PFO to vascular events. PFOs are highly prevalent in patients with cryptogenic stroke and in patients with migraine, but the incidence of primary and recurrent stroke does not seem to be increased in patients with PFO. Consequently, neither anticoagulation nor antiplatelet drugs are recommended in asymptomatic patients lacking other indications for anticoagulation. In symptomatic patients with PFO, current guidelines consider antiplatelet medications as treatment of choice for cerebrovascular events. There is no strong evidence that supports routine closure of PFO in patients with stroke or migraine although some patients with combined characteristics of PFO might benefit from closure. In conclusion, this review suggests that PFO is not an established risk factor for stroke even in the young population with recurrent cryptogenic stroke.

Ginseng: a potential cause of long QT.

Ginseng is a frequently used food additive and considered to be relatively safe. Long QT syndrome can be hereditary or acquired. It presents as syncope, sudden cardiac death, or seizures. We report the novel case of a female patient without cardiovascular risk factors who developed prolonged QT with subsequent torsades de pointes during periods in which she was drinking large amounts of ginseng.

Usefulness of neutrophil to lymphocyte ratio in predicting short- and long-term mortality after non-ST-elevation myocardial infarction.

Neutrophil/lymphocyte ratio (NLR) is the strongest white blood cell predictor of adverse outcomes in stable and unstable coronary artery syndromes. The aim of our study was to explore the utility of NLR in predicting long-term mortality in patients with non-ST-segment elevation myocardial infarction (NSTEMI). Consecutive patients with NSTEMI at Staten Island University Hospital were evaluated for study inclusion. Of the 1,345 patients with NSTEMI admitted from September 2004 to September 2006, 619 qualified for study inclusion. Survival analysis, stratified by NLR tertiles, was used to evaluate the predictive value of average inpatient NLR levels. Four-year vital status was accessed with electronic medical records and Social Security Death Index. Patients in the highest NLR tertile (NLR >4.7) had a higher 4-year mortality rate (29.8% vs 8.4%) compared to those in the lowest tertile (NLR <3, Wilcoxon chi-square 34.64, p <0.0001). After controlling for Global Registry of Acute Coronary Events risk profile scores, average NLR level remained a significant predictor of inpatient and 4-year mortality. Hazard ratios per unit increase of average NLR (log) increased by 1.06 (p = 0.0133) and 1.09 (p = 0.0006), respectively. In conclusion, NLR is an independent predictor of short-term and long-term mortalities in patients with NSTEMI with an average NLR >4.7. We strongly suggest the use of NLR rather than other leukocyte parameters (e.g., total white blood cell count) in risk stratification of the NSTEMI population.

Lupus cerebritis after visiting a tanning salon.

A 53-year-old female was admitted to the intensive care unit for lupus cerebritis; she had a 15-year history of stable lupus. Over the prior 1 to 2 months, the patient visited a tanning salon and this triggered the exacerbation of lupus. Her initial symptoms were cutaneous in the form of an erythematous rash. Within 2 weeks she started to have headaches and was admitted for seizure and psychosis. Ultraviolet A exposure in the tanning salon is known to exacerbate lupus by modulation of the immune system at the level of the skin. It has also been found that ultraviolet light can lead to the formation of antinuclear antibodies. This case illustrates the need to emphasize the danger of the tanning salon to patients with systemic lupus erythematous; the risk is not only cutaneous, it can also be systemic.