Ventricular repolarization markers for predicting malignant arrhythmias in clinical practice

Table 1 Medical condition where have been investigated the ventricular repolarization markers

Long QT syndrome	Heart failure
Short QT syndrome	Hypertension
Brugada syndrome	Diabetes mellitus
Early repolarization syndrome	Overweight/obesity
Acute myocardial ischemia	Highly trained athletes
Kawasaki disease	Duchenne muscular dystrophy
Systemic lupus erythematosus	Liver transplantiation
Rheumatoid arthritis	Rheumatoid arthritis
Chronic renal failure	Rheumatic fever
Scleroderma	Chagas disease
Ankylosing spondylitis	Chronic hepatitis B
Obstructive sleep apnea	β-thalassemia
Spinal injury	Polycythemia vera

Table 2 Formulas to calculate the QTc

Name	Formula
Bazzet modificated by Taran and Szilagyi	QTc = QT/(R-R)1/2
Fridericia	QTc = QT/(R-R)1/3
Framingham	QTc = QT + 0.154 × (1 - RR)
Hodges	QTc = QT + 1.75 × (HR - 60)
Sarma	QTc = QT - B1 Exp(-k1 × RR)
	QTc = QT [1 - Exp(-k2 × RR)]
	QTc = QT (RR)1/2 + B3
	QTc = QT (RR)1/2
Ecuación de fuerza	QTc = 453.65 × RR1/3.02 (R2 = 0.41)
Van de Water	QTc = QT - 0.087 (RR - 1000)
Matsunaga	QTc = log(600) QT/(logRR)
Kawataki	QTc = QT/RR × 0.25
Mayeda	QTc = QT/RR × 0.604
Larsen y Skulason	QTc = QT + 0.125 × (1 - RR)
Schlamowitz	QTc = QT + 0.205 × (1 - RR)
Wohlfart	QTc = QT + 1.23 × (HR - 60)
Boudolas	QTc = QT + 2.0 × (HR - 60)
Sagie	QTc = QT + 0.154 × (1 - RR)
Malik	QTc = QT/RR × 0.371
Lecocq	QTc = QT/RR (0.314)

This table was taken and adapted with permisson of Editor in Chief from Chávez González[10]. B and K are regression parameters. Exp: Exponential function with base e = 2.718; HR: Heart rate; RR: RR distance; QT: QT interval; QTc: Corrected QT interval.