ABSTRACT
BACKGROUND: Segmented cine imaging with a steady-state free-precession sequence (Cine-SSFP) is currently the gold standard technique for measuring ventricular volumes and mass, but due to multi breath-hold (BH) requirements, it is prone to misalignment of consecutive slices, time consuming and dependent on respiratory capacity. Real-time cine avoids those limitations, but poor spatial and temporal resolution of conventional sequences has prevented its routine application. We sought to examine the accuracy and feasibility of a newly developed real-time sequence with aggressive under-sampling of k-space using sparse sampling and iterative reconstruction (Cine-RT). METHODS: Stacks of short-axis cines were acquired covering both ventricles in a 1.5T system using gold standard Cine-SSFP and Cine-RT. Acquisition parameters for Cine-SSFP were: acquisition matrix of 224×196, temporal resolution of 39ms, retrospective gating, with an average of 8 heartbeats per slice and 1-2 slices/BH. For Cine-RT: acquisition matrix of 224×196, sparse sampling net acceleration factor of 11.3, temporal resolution of 41ms, prospective gating, real-time acquisition of 1 heart-beat/slice and all slices in one BH. LV contours were drawn at end diastole and systole to derive LV volumes and mass. RESULTS: Forty-one consecutive patients (15 male; 41±17years) in sinus rhythm were successfully included. All images from Cine-SSFP and Cine-RT were considered to have excellent quality. Cine-RT-derived LV volumes and mass were slightly underestimated but strongly correlated with gold standard Cine-SSFP. Inter- and intra-observer analysis presented similar results between both sequences. CONCLUSIONS: Cine-RT featuring sparse sampling and iterative reconstruction can achieve spatial and temporal resolution equivalent to Cine-SSFP, providing excellent image quality, with similar precision measurements and highly correlated and only slightly underestimated volume and mass values.
Subject(s)
Heart Ventricles/diagnostic imaging , Magnetic Resonance Imaging, Cine , Ventricular Function, Left , Adult , Artifacts , Breath Holding , Female , Heart/diagnostic imaging , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Spectroscopy , Male , Middle Aged , Observer Variation , Prospective Studies , Radionuclide Imaging , Reproducibility of Results , Retrospective Studies , SystoleABSTRACT
Fundamento: A dispersão do intervalo QT induzida por fármacos tem sido associada a arritmias ventriculares potencialmente fatais. Pouco se conhece sobre o uso de psicotrópicos, isolados ou em combinação com outros fármacos, na dispersão do QT. Objetivo: Avaliar o impacto do uso psicotrópicos na dispersão do intervalo QT em pacientes adultos. Métodos: Estudo de coorte observacional, envolvendo 161 pacientes hospitalizados em um departamento de emergência de hospital terciário, estratificados em usuários e não usuários de psicotrópicos. Dados demográficos, clínicos, laboratoriais e de fármacos em uso foram coletados à admissão, bem como o eletrocardiograma de 12 derivações, com a mensuração do intervalo e da dispersão do QT. Resultados: A dispersão do intervalo QT foi significativamente maior no grupo de usuário de psicotrópicos comparado ao grupo não usuário (69,25 ± 25,5 ms vs. 57,08 ± 23,4 ms; p = 0,002). O intervalo QT corrigido pela fórmula de Bazzett também se mostrou maior no grupo de usuário de psicotrópicos, com significância estatística (439,79 ± 31,14 ms vs. 427,71 ± 28,42 ms; p = 0,011). A análise por regressão linear mostrou associação positiva entre o número absoluto de psicotrópicos utilizados e a dispersão do intervalo QT, com r = 0,341 e p < 0,001. Conclusão: Na população amostral estudada, o uso de psicotrópicos se mostrou associado ao aumento da dispersão do intervalo QT, e esse incremento se acentuou em função do maior número de psicotrópicos utilizados. .
Background: Drug-induced increase in QT dispersion has been associated with potentially fatal ventricular arrhythmias. Little is known about the use of psychotropic substances, alone or in combination with other drugs on QT dispersion. Objectives: To evaluate the impact of psychotropic drugs on QT interval dispersion in adults. Methods: An observational cohort study was designed involving 161 patients hospitalized from an emergency department at a tertiary hospital, divided into psychotropic users or non-users. Demographic, clinical, laboratory data and drugs used on a regular basis were collected on admission, in addition to 12-lead electrocardiogram with QT dispersion measurement. Results: QT dispersion was significantly higher in the psychotropic user group compared to non-users (69.25 ± 25.5 ms vs. 57.08 ± 23.4 ms; p = 0.002). The QT interval corrected by Bazzett formula was also higher in the psychotropic drugs user group, with statistical significance. (439.79 ± 31.14 ms vs. 427.71 ± 28.42 ms; p = 0.011). A regression analysis model showed a positive association between the number of psychotropic drugs used and QT interval dispersion, with r = 0.341 and p < 0.001. Conclusions: The use of psychotropic drugs was associated with increased QT dispersion and this increase was accentuated, as the number of psychotropic drugs used was higher. .
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Electrocardiography/drug effects , Heart/drug effects , Psychotropic Drugs/adverse effects , Analysis of Variance , Anti-Arrhythmia Agents/pharmacology , Cohort Studies , Death, Sudden, Cardiac/etiology , Heart Rate/drug effects , Reference Values , Risk Factors , Time Factors , Tachycardia, Ventricular/chemically inducedABSTRACT
BACKGROUND: Drug-induced increase in QT dispersion has been associated with potentially fatal ventricular arrhythmias. Little is known about the use of psychotropic substances, alone or in combination with other drugs on QT dispersion. OBJECTIVES: To evaluate the impact of psychotropic drugs on QT interval dispersion in adults. METHODS: An observational cohort study was designed involving 161 patients hospitalized from an emergency department at a tertiary hospital, divided into psychotropic users or non-users. Demographic, clinical, laboratory data and drugs used on a regular basis were collected on admission, in addition to 12-lead electrocardiogram with QT dispersion measurement. RESULTS: QT dispersion was significantly higher in the psychotropic user group compared to non-users (69.25 ± 25.5 ms vs. 57.08 ± 23.4 ms; p = 0.002). The QT interval corrected by Bazzett formula was also higher in the psychotropic drugs user group, with statistical significance. (439.79 ± 31.14 ms vs. 427.71 ± 28.42 ms; p = 0.011). A regression analysis model showed a positive association between the number of psychotropic drugs used and QT interval dispersion, with r = 0.341 and p < 0.001. CONCLUSIONS: The use of psychotropic drugs was associated with increased QT dispersion and this increase was accentuated, as the number of psychotropic drugs used was higher.
