Identification of the dominant loop of a dual-loop macro-reentry left atrial flutter without prior intervention using high-density mapping technology: A case report.

Background: Left atrial flutter without prior cardiac interventions is uncommon, especially dual-loop macro-reentry atrial flutter. The critical step to ablate dual-loop macro-reentry atrial flutter is to identify the dominant loop and key isthmus. Although entrainment mapping could help identify the dominant loop and key isthmus, it may alter or terminate tachycardia.

Remodeling of myocardial energy and metabolic homeostasis in a sheep model of persistent atrial fibrillation.

Background: Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia and is often associated with rapid contraction in both atria and ventricles. The role of atrial energy and metabolic homeostasis in AF progression is under-investigated.

Objectives: To determine the remodeling of energy metabolism during persistent AF and the effect of eplerenone (EPL), an aldosterone inhibitor, on metabolic homeostasis.

Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions.

Cardiac arrhythmias associated with intracellular calcium inhomeostasis are refractory to antiarrhythmic therapy. We hypothesized that late sodium current (I ) contributed to the calcium-related arrhythmias. Monophasic action potential duration at 90% completion of repolarization (MAPD) was significantly increased and ventricular arrhythmias were observed in hearts with increased intracellular calcium concentration ([Ca]) by using Bay K 8644, and the increase became greater in hearts treated with a combination of ATX-II and Bay K 8644 compared to Bay K 8644 alone.