Piblokto, also known as pibloktoq and Arctic hysteria, is a condition most commonly appearing in Inughuit (Northwest Greenlandic Inuit) societies living within the Arctic Circle. Piblokto is a culture-specific hysterical reaction in Inuit, especially women, who may perform irrational or dangerous acts, followed by amnesia for the event. Piblokto may be linked to repression of the personality of Inuit women. The condition appears most commonly in winter. It is considered to be a form of a culture-bound syndrome, although more recent studies (see Skepticism section) question whether it exists at all. Piblokto is also part of the glossary of cultural bound syndromes found in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). History
Piblokto was first documented in 1892 and reports by European explorers describe the phenomenon as common to all Arctic regions. Explorers were the first to record piblokto in writing. Among these, Admiral Robert Peary provided a detailed look into the disorder during an expedition to Greenland. Peary and his men found the acts they witnessed among the Inuit women entertaining, and, having sent the womens male counterparts out on missions, became sexually involved with the remaining women. Piblokto is not limited to the indigenous people; reports of stranded sailors during the 1800s exhibiting the same symptoms have been found. The disorder is said to have existed before Western contact and still occurs today.
In cardiology, ventricular dyssynchrony is a difference in the timing, or lack of synchrony, of contractions in different ventricles in the heart. Large differences in timing of contractions can reduce cardiac efficiency and is correlated with heart failure. Types of dyssynchrony
Three chief presentations of dyssynchrony can occur:
Atrioventricular (AV) dyssynchrony occurs when there is an unfavorable difference in timing between atrial and ventricular contractions. Interventricular dyssynchrony occurs when there is a difference in timing between right ventricular (RV) and left ventricular (LV) Systole. Intraventricular dyssynchrony occurs when the timing in a sequence of activations and contractions of segments of the LV wall becomes abnormal. In all three types, changes in timing lead to changes in the dynamic behavior of the myocardial tissues, leading to mechanical dyssynchrony. All three presentations allow distinct and easily reproducible electrical signatures as illustrated by left and right bundle branch blocks, hemiblocks, etc. The concise measurement of the time and morphology of the QRS interval allows the interventional ability to manipulate this interval with biventricular pacemakers. It is important to distinguish ventricular dyssynchrony from ventricular dyssynergy. Dyssynergy refers to changes in relative strength of contractions, whereas dyssynchrony is a change in relative timing of contractions. Once again the terms inotropy and chronotropy apply to the pathology under examination. Biventricular pacing strongly favors chronotropy over inotropy. Diagnosis
Echocardiography and tissue Doppler echocardiography are both needed to fully diagnose the different types of ventricular dyssynchrony. Treatment
Recent studies suggest that cardiac resynchronization therapy can reduce the incidence of ventricular dyssynchrony and thus increase cardiac efficiency.