Ventricular arrhythmias in patients with immune checkpoint inhibitor myocarditis

Background

Immune checkpoint inhibitor (ICI)-associated myocarditis is associated with a markedly increased risk of morbidity and mortality. The occurrence of ventricular arrhythmias (VA) in patients with ICI-associated myocarditis has not been well characterized.

Purpose

The aim of this study was to determine the characteristics and risk factors for severe VA in patients with ICI myocarditis.

Methods

The cohort consisted of 202 patients with ICI myocarditis. Ventricular arrhythmias were defined as a composite of sustained ventricular tachycardia and ventricular fibrillation. We used a multivariable logistic regression model to test the association between clinical variables and the development of VA.

Results

From a cohort of 202 patients with ICI myocarditis (67±13 years, 35% female, 60% hypertension, 23% diabetes mellitus), 41 (20.3%) developed VA, of which, 33 had VT and 8 had VF. The median time from admission to VF was 144 hours and to VT was 72 hours. A VA occurred in 17.5% of patients with a normal LVEF, and 25% of patients with reduced LVEF. On univariate analysis, a QRS duration >110ms (OR 2.88, 95% CI 1.40 to 6.16, P=0.005) and a QTc duration >470ms were associated with an increased probability of VA (OR 2.58, 95% CI 1.23, 5.41, P=0.012). The association remained significant after adjustment for age and gender. Additionally, a longer time from admission to initiation of corticosteroids was associated with a higher probability of VA (OR 1.06, 95% CI 1.01 to 1.13, P=0.027). The association between the time from admission to administration of corticosteroids and probability of VA remained significant after adjustment for age, gender, and LVEF on admission (OR, 1.06, 95% CI 1.00, 1.13, P=0.037) where each 6-hour delay in the initiation of corticosteroids was associated with a 4% increase in the risk for VA.

Conclusions

Ventricular arrhythmias are common in the setting of ICI myocarditis and are observed in patients presenting with both a preserved and a reduced LVEF. Wider QRS and longer QT at presentation and longer time from admission to initiation of corticosteroids were associated with an increased risk of VA.

Funding Acknowledgement

Type of funding sources: None.

Optical spatial solitons at the interface between two dissimilar periodic media: theory and experiment

Discrete spatial solitons traveling along the interface between two dissimilar one-dimensional arrays of waveguides were observed for the first time. Two interface solitons were found theoretically, each one with a peak in a different boundary channel. One evolves into a soliton from a linear mode at an array separation larger than a critical separation where-as the second soliton always exhibits a power threshold. These solitons exhibited different power thresholds which depended on the characteristics of the two lattices. For excitation of single channels near and at the boundary, the evolution behavior with propagation distance indicates that the solitons peaked near and at the interface experience an attractive potential on one side of the boundary, and a repulsive one on the opposite side. The power dependence of the solitons at variable distance from the boundary was found to be quite different on opposite sides of the interface and showed evidence for soliton switching between channels with increasing input power.

Sleep apnea and quality of life

OBJECTIVE

To investigate the effects of sleep apnea (SA) on the quality of life (QOL).

DESIGN

A prospective study of QOL in patients with and without SA as defined by an apnea-hypopnea index (AHI) >5.

SETTING

University-based outpatient clinics.

PATIENTS

Primary care patients followed in a general internal medicine clinic as well as those referred to a sleep disorders clinic at the University of Wisconsin Hospital and Clinics were consecutively recruited and classified into 3 groups of subjects: (1) patients without SA (AHI<5) (n=46), (2) patients with mild SA (AHI 5-15) (n=16), and (3) patients with moderate to severe SA (AHI>15) (n=21).

INTERVENTIONS

NA.

MEASUREMENTS

QOL was assessed with the Medical Outcomes Study SF-36 Health Survey. Health history and demographic data were obtained via structured interview and medical record review. All subjects underwent overnight polysomnography for diagnosis of SA.

RESULTS

After controlling for age, gender, body mass index, and number of comorbid conditions, the association between sleep apnea and QOL was significant in the domains of physical functioning and role limitation due to physical health problems (p<0.05) and was borderline in vitality (p<0.1). Patients with both mild and moderately severe SA scored significantly lower (worse) than did patients without SA in physical functioning and in role limitations due to physical-health (82 and 83 vs. 92, respectively). Moderate to severe SA subjects scored significantly lower in vitality than did subjects without SA (51 vs. 64, p<0.05). Subscales analysis revealed that subjects with moderate to severe SA had significantly lower scores that did those without SA in positive affect (69 vs. 79), current health perceptions (71 vs. 80) and vitality (50 vs. 70), p<0.05 for all comparisons. A large percentage of patients without SA had perfect scores of 100 (ceiling effect) on the physical, social, and role functioning scales.

CONCLUSIONS

SA has an independent impact on several QOL domains after adjusting for differences in age, gender, body mass index, and comorbidity. QOL outcomes were likely attenuated by ceiling effects. Disentangling the scales that measure multidimensional QOL (positive and negative aspects) enhanced the ability of the SF-36 to detect important consequences of sleep apnea on QOL.

Arithmetic coding with dual symbol sets and its performance analysis

In this paper, we propose a novel adaptive arithmetic coding method that uses dual symbol sets: a primary symbol set that contains all the symbols that are likely to occur in the near future and a secondary symbol set that contains all other symbols. The simplest implementation of our method assumes that symbols that have appeared in the previously are highly likely to appear in the near future. It therefore fills the primary set with symbols that have occurred in the previously. Symbols move dynamically between the two symbol sets to adapt to the local statistics of the symbol source. The proposed method works well for sources, such as images, that are characterized by large alphabets and alphabet distributions that are skewed and highly nonstationary. We analyze the performance of the proposed method and compare it to other arithmetic coding methods, both theoretically and experimentally. We show experimentally that in certain contexts, e.g., with a wavelet-based image coding scheme that has appeared in the literature, the compression performance of the proposed method is better than that of the conventional arithmetic coding method and the zero-frequency escape arithmetic coding method.

Diagnosing syncope. Part 2: Unexplained syncope. Clinical Efficacy Assessment Project of the American College of Physicians

PURPOSE

To review the literature on diagnostic testing in syncope that remains unexplained after initial clinical assessment.

DATA SOURCES

MEDLINE search.

STUDY SELECTION

Published papers were selected if they addressed diagnostic testing in syncope, near syncope, or dizziness.

DATA EXTRACTION

Studies were identified as population studies, referral studies, or case series.

DATA SYNTHESIS

After a thorough history, physical examination, and electrocardiography, the cause of syncope remains undiagnosed in 50% of patients. In such patients, information may be derived from the results of carefully selected diagnostic tests, especially 1) electrophysiologic studies in patients with organic heart disease, 2) Holter monitoring or telemetry in patients known to have or suspected of having heart disease, 3) loop monitoring in patients with frequent events and normal hearts, 4) psychiatric evaluation in patients with frequent events and no injury, and 5) tilt-table testing in patients who have infrequent events or in whom vasovagal syncope is suspected. Hospitalization is indicated for high-risk patients, especially those with known heart disease and elderly patients.

CONCLUSIONS

A flexible, focused approach is required to diagnose syncope. Features of the initial history and physical examination help guide diagnostic testing.

Diagnosing syncope. Part 1: Value of history, physical examination, and electrocardiography. Clinical Efficacy Assessment Project of the American College of Physicians

PURPOSE

To review the literature on diagnostic testing in syncope and provide recommendations for a comprehensive, cost-effective approach to establishing its cause.

DATA SOURCES

Studies were identified through a MEDLINE search (1980 to present) and a manual review of bibliographies of identified articles.

STUDY SELECTION

Papers were eligible if they addressed diagnostic testing in syncope or near syncope and reported results for at least 10 patients.

DATA EXTRACTION

The usefulness of tests was assessed by calculating diagnostic yield: the number of patients with diagnostically positive test results divided by the number of patients tested or, in the case of monitoring studies, the sum of true-positive and true-negative test results divided by the number of patients tested.

DATA SYNTHESIS

Despite the absence of a diagnostic gold standard and the paucity of data from randomized trials, several points emerge. First, history, physical examination, and electrocardiography are the core of the syncope workup (combined diagnostic yield, 50%). Second, neurologic testing is rarely helpful unless additional neurologic signs or symptoms are present (diagnostic yield of electroencephalography, computed tomography, and Doppler ultrasonography, 2% to 6%). Third, patients in whom heart disease is known or suspected or those with exertional syncope are at higher risk for adverse outcomes and should have cardiac testing, including echocardiography, stress testing. Holter monitoring, or intracardiac electrophysiologic studies, alone or in combination (diagnostic yields, 5% to 35%). Fourth, syncope in the elderly often results from polypharmacy and abnormal physiologic responses to daily events. Fifth, long-term loop electrocardiography (diagnostic yield, 25% to 35%) and tilt testing (diagnostic yield < or = 60%) are most useful in patients with recurrent syncope in whom heart disease is not suspected. Sixth, psychiatric evaluation can detect mental disorders associated with syncope in up to 25% of cases. Seventh, hospitalization may be indicated for patients at high risk for cardiac syncope (those with an abnormal electrocardiogram, organic heart disease, chest pain, history of arrhythmia, age > 70 years) or with acute neurologic signs.

CONCLUSIONS

Many tests for syncope have a low diagnostic yield. A careful history, physical examination, and electrocardiography will provide a diagnosis or determine whether diagnostic testing is necessary in most patients.