Digitalis Administration: An Underappreciated but Common Cause of Short QT Interval

Digitalis administration: an underappreciated but common cause of short QT interval.

Common Cause of Short QT Interval To the Editor: I read with interest the recent report by Gaita et al1 of short-QT syndrome as a familial cause of sudden death. The authors enumerated other factors that shorten QT interval, such as increased heart rate, hyperthermia, hypercalcemia, hyperkalemia, acidosis, and altered autonomic tone.1 I would like to add another important and common, but undera...

Microvascular angina: an underappreciated cause of SLE chest pain.

Data are accumulating that microvascular dysfunction is an unrecognized source of anginal chest pain in patients with autoimmune diseases such as systemic lupus erythematosus (SLE)1,2,3. Studies show that microvascular impairment contributes to cardiovascular disease in other autoimmune conditions such as systemic sclerosis1,2,4. Patients with SLE presenting with anginal chest pain pose a diagn...

An analysis of the electrocardiogram QT interval.

No reports testing the efficacy of the use of the QT/RR ratio <1/2 for detecting a normal QTc interval were found in the literature. The objective of the present study was to determine if a QT/RR ratio < or =1/2 can be considered to be equal to the normal QTc and to compare the QT and QTc measured and calculated clinically and by a computerized electrocardiograph. Ratios (140 QT/RR) of 28 succe...

Compound mutations: a common cause of severe long-QT syndrome.

BACKGROUND Long QT syndrome (LQTS) predisposes affected individuals to sudden death from cardiac arrhythmias. Although most LQTS individuals do not have cardiac events, significant phenotypic variability exists within families. Probands can be very symptomatic. The mechanism of this phenotypic variability is not understood. METHODS AND RESULTS Genetic analyses of KVLQT1, HERG, KCNE1, KCNE2, a...

QT Interval and QT Variability