Abstract and Introduction
Abstract
Long QT syndrome (LQTS), in which cardiac repolarization is delayed following a heartbeat, can be measured by ECG. Universal ECG screening is not standard practice in the United States, and many children with congenital LQTS go undiagnosed. LQTS creates an electrophysiological environment that favors the development of serious ventricular dysrhythmias. Pharmacist awareness is important because drugs can play a major role in exacerbating underlying LQTS or causing acquired LQTS. Common symptoms of LQTS include fainting spells, heart palpitations, and seizures. Most importantly, LQTS is a major risk factor for ventricular arrhythmias, which can quickly deteriorate, leading to cardiac arrest and sudden cardiac death.
Introduction
Long QT syndrome (LQTS), a heart condition in which cardiac repolarization is delayed following a heartbeat, can be detected by measuring the QT interval on an ECG. A long QT interval creates an electrophysiological environment that favors the development of life-threatening, prolonged ventricular dysrhythmias. Because drugs can figure significantly in the development of symptoms in patients with LQTS, pharmacist awareness is important. Common manifestations are heart palpitations, fainting spells, and seizures. Sudden cardiac death (SCD), to which LQTS is a major contributor, is estimated to occur in as many as 6.2 of 100,000 children per year.[1] SCD also accounts for 50% of all adult deaths from cardiovascular (CV) disease, with 80% to 85% of cases caused by acute ventricular arrhythmias.[2] Given many recent FDA warnings about drugs that can prolong the QT interval and potentially increase the risk of ventricular dysrhythmias, it is becoming increasingly more important for pharmacists to heighten their awareness of this condition in order to help patients use their medications safely and effectively.[3,4]
US Pharmacist. 2014;39(5):47-51. © 2014 Jobson Publishing
