[Factors related to the length of the corrected QT interval in patients treated with antipsychotics]. / Factores relacionados con la duración del intervalo QT corregido en pacientes tratados con antipsicóticos.

BACKGROUND AND OBJECTIVE: The length of the heart-rate corrected QT interval (QTc) has been associated with an increased risk of cardiac dysrhythmia and sudden death. QTc length has been related to age, obesity, poor glycemic control, and use of drugs, such as antipsychotic medications. The objective of this cross-sectional naturalistic study was to assess the factors associated with QTc length in patients treated with antipsychotics. PATIENTS AND METHOD: Bazett's formula for heart-rate correction was used to compute the corrected QT in 195 psychiatric inpatients treated with antipsychotics -117 males (60.0%), 78 females (40.0%); age (standard deviation): 28.4 (17.3) years (range: 12-84)-. RESULTS: Older age (p < 0.001) and female gender (p = 0.006) were the only factors significantly related to longer QTc interval. Diagnosis, type of antipsychotic, dosage of antipsychotic, tobacco use, and cardiovascular history were not related to QTc length. Only one male patient with QTc = 455 had a pathological QTc length (females > 470 ms, males > 450 ms). CONCLUSIONS: Factors related to QTc length in patients treated with antipsychotics are equivalent to those found in previous studies in patients not treated with antipsychotics.

Factores relacionados con la duración del intervalo QT corregido en pacientes tratados con antipsicóticos / Factors related to the length of the corrected QT interval in patients treated with antipsychotics

Fundamento y objetivo: La duración del intervalo QT corregido (QTc) se ha asociado con un aumento del riesgo de arritmias cardíacas y muerte súbita. Dicha duración se ha relacionado con la edad, la obesidad, el mal control glucémico y el uso de medicamentos, como los antipsicóticos. El objetivo de este estudio naturalístico y transversal ha sido evaluar los factores relacionados con la duración del intervalo QTc en pacientes en tratamiento antipsicótico. Pacientes y método: La duración del intervalo QTc (corregido mediante la fórmula de Bazett) se evaluó en 195 pacientes ­117 varones (60,0%) y 78 mujeres (40,0%)­ con una edad media (desviación estándar) de 28,4 (17,3) años (extremos: 12-84), que recibían tratamiento antipsicótico y estaban ingresados en unidades de hospitalización psiquiátrica. Resultados: La mayor edad (p < 0,001) y el sexo femenino (p = 0,006) fueron los 2 únicos factores asociados con una mayor duración del intervalo QTc. El diagnóstico, el tipo de antipsicótico, la dosis de éste, el consumo de tabaco o los antecedentes de enfermedad cardiovascular no se relacionaron con la duración del intervalo QTc. Solamente un varón con QTc de 455 ms tuvo un intervalo QTc de duración patológica (> 450 ms en varones y > 470 ms en mujeres). Conclusiones: Los factores de riesgo asociados a una mayor duración del intervalo QTc son equivalentes a los hallados en estudios previos con pacientes sin tratamiento antipsicótico

Background and objective: The length of the heart-rate corrected QT interval (QTc) has been associated with an increased risk of cardiac dysrhythmia and sudden death. QTc length has been related to age, obesity, poor glycemic control, and use of drugs, such as antipsychotic medications. The objective of this cross-sectional naturalistic study was to assess the factors associated with QTc length in patients treated with antipsychotics. Patients and method: Bazett's formula for heart-rate correction was used to compute the corrected QT in 195 psychiatric inpatients treated with antipsychotics ­117 males (60.0%), 78 females (40.0%); age (standard deviation): 28.4 (17.3) years (range: 12-84)­. Results: Older age (p < 0.001) and female gender (p = 0.006) were the only factors significantly related to longer QTc interval. Diagnosis, type of antipsychotic, dosage of antipsychotic, tobacco use, and cardiovascular history were not related to QTc length. Only one male patient with QTc = 455 had a pathological QTc length (females > 470 ms, males > 450 ms). Conclusions: Factors related to QTc length in patients treated with antipsychotics are equivalent to those found in previous studies in patients not treated with antipsychotics