Risk factors associated with long QT syndrome in cardiovascular anesthesia

• Main Authors: Dagoberto Fernández Delgado, Raúl Cruz Boza, Antonio de Jesús Cabrera Pratts, Juliette Marie Suárez López, Rudy Hernández Ortega
• Format: Article
• Language: Spanish
• Published: Centro Nacional de Información de Ciencias Médicas. Editorial de Ciencias Médicas (ECIMED) 2017-09-01
• Series: Revista Cubana de Anestesiología y Reanimación
• Subjects: anestesia cardiovascular; circulación extracorpórea; intervalo qt; síndrome de qt largo; factores de riesgo; complicaciones
• Online Access: http://www.revanestesia.sld.cu/index.php/anestRean/article/view/133

<p><span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small;"><strong>Introduction:</strong> The long QT syndrome is a channelopathy characterized by a serious alteration in ventricular repolarization. </span><br /> <span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small;"><strong>Objective:</strong> To determine the risk factors associated with prolonged QT interval in cardiovascular anesthesia. </span><br /> <span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small;"><strong>Methods:</strong> Descriptive, cross-sectional study from May 2014 to May 2016, in patients scheduled for cardiac surgery under extracorporeal circulation. The attributable risk and the confidence interval were evaluated for 95% and in variables with p value under 0.05. </span><br /> <span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small;"><strong>Results:</strong> 483 patients were included, with a mean age of 62 years, of whom 57 (12 %) had prolonged QTc. Advanced age (RA: 1.8, 95 % CI: 0.86-2.67), chronic renal failure (RA: 2.7, 95 % CI: 0.82-4.96), type 2 diabetes mellitus (RA: 1.7, 95 % CI: 1.01-2.15), ischemic heart disease (RA: 3.5, 95 % CI: 1.60-4.02), left ventricular hypertrophy (RA: 2.2, 95 % CI: 2.53-3.15), calcium-lactam antibiotics (RA: 1.5, 95 % CI: 0.92-2.98), balanced orotracheal general anesthesia (RA: 2.1, 95 % CI: 2.92-2.35), ondansetron (RA: 1.7, 95 % CI: 0.98-2.74), droperidol (RA: 1.8, 95 % CI: 2.18-3.94) ), extracorporeal circulation time (RA: 2.5, 95 % CI: 1.02-3.62), hypokalemia (RA: 1.4, 95 % CI: 1.03-2.91) and severe bradycardia (RA: 1.8, 95 % CI: 1.12-3.86) were associated with a high risk of QT prolongation. The complications were more significant in this group, with a mortality of 23%. </span><br /> <span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small;"><strong>Conclusions:</strong> Advanced age, chronic renal failure, type 2 diabetes mellitus, ventricular hypertrophy, and ischemic heart disease facilitate the prolongation of QT induced by calcium blockers. The longer time of extracorporeal circulation, the balanced anesthesia with isoflurane, the use of droperidol and ondansetron, bradycardia and postoperative hypokalemia are variables associated with the extension of the QT interval, with an increase in complications. Ventricular tachyarrhythmias and mortality were higher in this subgroup of patients. </span></p>