Radiation-associated Arrhythmias: Putative Pathophysiological Mechanisms, Prevalence, Screening and Management Strategies.

Radiation-associated cardiovascular disease, an increasingly recognised disease process, is a significant adverse effect of radiation therapy for common malignancies that involve the chest, and include lymphomas, lung, mediastinal and breast cancers. Two factors contribute to the increasing incidence of radiation-associated cardiovascular disease: advances in malignancy detection and the improved survival of cancer patients, by which many symptoms of radiation-associated cardiovascular disease, specifically radiation-associated arrhythmias, present years and/or decades following initial radiotherapy. We present a focused overview of the currently understood pathophysiology, prevalence and management strategies of radiation-associated arrhythmias, which include bradyarrhythmias, tachyarrhythmias and autonomic dysfunction.

Comparison of quantifiable electrocardiographic changes associated with severe hyperkalemia.

Background: Hyperkalemia (HK) is a life-threatening condition that is frequently evaluated by electrocardiogram (ECG). ECG changes in severe HK (≥ 6.3 mEq/L) are not well-characterized.

Echocardiographic changes and heart failure hospitalizations following rhythm control for arrhythmia-induced cardiomyopathy: results from a multicenter, retrospective study.

Background: The incidence and prevalence of arrhythmia-induced cardiomyopathy (AIC) are unclear but likely underrecognized. LV dysfunction is common among patients with atrial fibrillation (AF), atrial flutter (AFL), and frequent premature ventricular contractions (PVC). The hallmark of AIC is the improvement of left ventricular ejection fraction (LVEF) following arrhythmia treatment.

Drug Interactions Affecting Antiarrhythmic Drug Use.

Antiarrhythmic drugs (AAD) play an important role in the management of arrhythmias. Drug interactions involving AAD are common in clinical practice. As AADs have a narrow therapeutic window, both pharmacokinetic as well as pharmacodynamic interactions involving AAD can result in serious adverse drug reactions ranging from arrhythmia recurrence, failure of device-based therapy, and heart failure, to death.

Percutaneous repair of post-myocardial infarction ventricular septal rupture presenting with cardiogenic shock.

Ventricular septal rupture (VSR) is an uncommon and devastating complication with a high mortality rate due to limited available interventions required by expert hands in a small window of opportunity. Most commonly seen following delayed myocardial infarctions (MI), the rate of VSR has decreased partly from protocol driven reperfusion therapy; however, cases are still present, particularly when diagnosis is delayed. We present a case of a critically ill patient in cardiogenic shock following a large anterolateral wall ST-elevation MI complicated by a large VSR whom was transferred to our academic institution for percutaneous repair.

Reconciling Differences between Lipid Transfer in Free-Standing and Solid Supported Membranes: A Time-Resolved Small-Angle Neutron Scattering Study.

Maintaining compositional lipid gradients across membranes in animal cells is essential to biological function, but what is the energetic cost to maintain these differences? It has long been recognized that studying the passive movement of lipids in membranes can provide insight into this toll. Confusingly the reported values of inter- and, particularly, intra-lipid transport rates of lipids in membranes show significant differences. To overcome this difficulty, biases introduced by experimental approaches have to be identified.

Relationship between lesion formation and electrophysiological responses using catheters equipped with mini-electrodes in chronic atrial fibrillation.

Background: The study focuses on the electrophysiological changes associated with lesion formation using 4.5-mm irrigated and 8-mm standard catheters equipped with mini-electrodes (MEs) positioned circumferentially on the tip.

Objective: The aim of the study was to test the relationship between the maximal electrogram (EGM) reduction, frequency spectrum shift, and their impact on atrial lesion formation in the atrial fibrillation (AF) model.

Maximal electrogram attenuation recorded from mini electrodes embedded on 4.5-mm irrigated and 8-mm nonirrigated catheters signifies lesion maturation.

Background: The electrograms (EGMs) recorded from mini electrodes (ME) placed on the tip of the ablation electrode allow more precise EGM monitoring during lesion formation. Our objective was to define the lesion boundaries and extracardiac injuries resulting from 60-second RF application versus RF application time titrated to maximal attenuation of the ME EGM in the atria and ventricles using 4.5-mm irrigated and 8-mm catheters.