Acquired long QT syndrome: risk assessment, prudent prescribing and monitoring, and patient education

Cardiovascular disorders in anorexia nervosa and potential therapeutic targets

Anorexia nervosa (AN) is an eating disorder in which a distorted self-perception of body image and an excessive fear of gaining weight result in extreme restrictions in eating habits. AN may be divided into two types: a "binge-eating/purging type" during which the individual regularly engages in overeating and then purging behavior, and a "restricting type", in which she does not. AN is a serious medical problem in young people in Western societies. It is widely reported that patients with AN exhibit an enhanced mortality rate as compared with age-matched healthy subjects, which has been mainly ascribed to cardiac complications. At least one-third of all deaths in patients with anorexia nervosa are estimated to be due to cardiac causes, mainly sudden death. Cardiovascular complications of AN can be present in up to 80% of cases, and among them alterations in cardiac electrical activity, structure and hemodynamics have been reported as causes of morbidity and mortality. The objective of this brief review is to summarize current knowledge on the main cardiovascular complications of AN, their underlying mechanisms and the possible therapeutic approaches.

Cardiac arrest from acquired long QT syndrome: a case report

BACKGROUND

Many classes of medications initiated by clinicians can cause adverse events, such as cardiac disturbances. One such adverse outcome is that of acquired long QT syndrome, which can lead to arrhythmias and sudden death. When health care practitioners were surveyed about their knowledge of this condition, 20% indicated they knew very little about long QT syndromes and more than 30% failed to check on current therapy before prescribing QT-prolonging medications.

METHODS

A case will be presented to illustrate the importance of understanding this syndrome.

RESULTS

The causes and pathophysiology of acquired long QT syndrome are discussed, and the resources for clinicians to obtain more information and growing number of offending medications leading to acquired long QT syndrome are provided.

CONCLUSIONS

On-going education is needed to heighten awareness in the health care community to prevent the deleterious outcomes associated with medication induced acquired long QT syndrome.

A meta-analysis of heart rate and QT interval alteration in anorexia nervosa

OBJECTIVE

Reports have suggested association between sudden death and QT prolongation in AN patients. Incidence and clinical consequences of cardiac abnormalities remain controversial. As the course of AN disease is long-lasting it remains unclear how often psychiatrists should send AN patients for somatic and especially cardiological investigation. The objective of the study was to aggregate the published data on HR and QT alteration and to perform a meta-analysis of the HR and QT alteration in patients with anorexia nervosa.

METHODS

A Medline search of all English language studies from 1994 to 2005 was performed. The inclusion criteria were confirmed diagnosis of AN, measurement of QTc and mean heart rate. Data from 10 studies were analyzed using weighted linear regression model.

RESULTS

Analysis showed that bradycardia and relationship between HR and BMI decreases as the disease continues. QTc interval in AN patients was within normal range although significantly longer than in controls.

CONCLUSION

Further investigations of sudden death in patients with AN due to cardiac arrest are needed and a model of clinical monitoring of cardiovascular system should be elaborated. If QTc prolongation is detected even in the normal range further cardiological examination for risk assessment and systematic clinical surveillance of the cardiovascular system should be considered.