Recent advances in management of atrial fibrillation in patients with heart failure

Sudden death and its risk factors after atrioventricular junction ablation and pacemaker implantation in patients with atrial fibrillation

BACKGROUND

Although sudden death (SD) is a rare complication after atrioventricular junction (AVJ) ablation and permanent pacemaker implantation, the risk factors leading to this SD remain unknown. The purpose of this study was to investigate SD and its risk factors after ablate-and-pace strategy for rate control in atrial fibrillation (AF) patients during long-term follow-up.

HYPOTHESIS

METHODS: From January 2005 to December 2009, we enrolled into this study 517 AF patients with AVJ ablation and right ventricular pacemaker implantation. Patients were divided into 2 groups, SD and non-SD. Cox proportional hazards models were used to assess potential risk factors for overall mortality and SD.

RESULTS

During a mean follow-up of 25.8 ± 18.6 months (range, 3 days to 63.8 months), 53 patients died (15 with SD). Cox proportional hazards models showed that the presence of congestive heart failure, New York Heart Association functional class, chronic renal failure, and nonsustained ventricular tachycardia were risk factors that predicted overall mortality. For SD, the presence of dilated cardiomyopathy and mitral stenosis were associated risk factors. SD was exclusively seen in patients who had narrow QRS complex or right bundle branch block prior to AVJ ablation and pacemaker implantation; SD was not seen in any patient with preexisting complete left bundle branch block.

CONCLUSIONS

Dilated cardiomyopathy, mitral stenosis, and baseline QRS morphology should be examined as potential risk factors for SD after AVJ ablation and pacemaker implantation.

Usefulness of the Diagnosis "Decreased Cardiac Output (00029)" in Patients With Chronic Heart Failure

OBJECTIVE

To determine the clinical and construct validity of the nursing diagnosis "decreased cardiac output" (DCO) in patients with chronic heart failure.

METHODS

Cross-sectional study.

RESULTS

A total of 200 people were studied. The defining characteristics with the highest prevalence were as follows: arrhythmia (62.5%) and fatigue (61.5%). Adjustment measures such as infit and outfit were maintained between 0.50 and 1.56 and the total variance explained by the measures was 29.3%.

CONCLUSIONS

This study determined the clinical validity of the nursing diagnosis DCO. Regarding construct validity, adjustment of the defining characteristics to the Rasch model was observed.

IMPLICATIONS FOR NURSING PRACTICE

This study improves the evidence-based practice of nursing and strengthened the role of the nurse who leads care to this population.

OBJETIVO

Determinar la validez clínica y de constructo del diagnóstico de enfermería "Disminución del Gasto Cardíaco" en pacientes con falla cardíaca crónica. MÉTODOS: Estudio de corte transversal.

RESULTADOS

Un total de 200 pacientes fueron estudiados. Las características definitorias con las mayores prevalencias fueron: arritmia (62.5%) y fatiga (61.5%). Medidas de ajuste como el infit y outfit se mantuvieron entre 0.50 y 1.56. El total de la varianza explicada por las medidas fue de 29.3%.

CONCLUSIONES

Este estudio determinó la validez clínica del diagnóstico de enfermería "Disminución del Gasto Cardíaco". En cuanto a la validez de constructo, se observó que 19 de las 21 características definitorias se ajustaron al modelo Rasch. IMPLICACIONES PARA LA PRÁCTICA DE ENFERMERÍA: Este estudio mejora la práctica basada en la evidencia de enfermería y fortalece el rol de las enfermeras que lideran el cuidado en esta población.

Thromboembolic risk in atrial fibrillation: association between left atrium mechanics and risk scores. A study based on 3D wall-motion tracking technology

BACKGROUND/OBJECTIVES

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with a significantly high risk of stroke and systemic embolism. The aim of our study was to assess the association between left atrium (LA) mechanics measured by 3D wall-motion tracking (3DWMT) technology and the most common thromboembolic risk scores (CHADS2, CHA2DS2-VASc).

METHODS

A total of 101 consecutive patients with permanent AF referred were included. Conventional bidimensional (2D) LA parameters, and LA mechanics by means of 3DWMT were studied. Association between LA 2D and 3DWMT parameters and both risk scores was evaluated as well as its correlation with every component of the score individually.

RESULTS

Mean age was 78 ± 10 years. Mean CHADS2 was 2.7 ± 1.3 and mean CHA2DS2-VASc was 4.4 ± 1.7. Values of 2D and 3DWTM LA parameters were: 2D area 26.4 ± 9.7 cm(2) , 2D volume index 49.4 ± 10.1 mL/m(2) , 3DWMT left atrial emptying fraction (LAEF) 15.9 ± 8.4%, longitudinal strain 9.1 ± 4.5% and area strain 14.9 ± 8.8%. Linear regression analysis showed statistically significant correlation between LA longitudinal strain and LAEF with CHADS2 and CHA2DS2-VASc scores. For each 10% variation in longitudinal strain, CHADS2 and CHA2DS2-VASc scores change in 0.7 and 0.8 points, respectively.

CONCLUSIONS

Left atrial longitudinal strain and emptying fraction assessed by 3D WMT technology have correlation with both CHADS2 and CHA2DS2-VASc scores. Each 10% of variation in longitudinal strain represents a 0.7 and 0.8 points change in those risk scores. LA mechanics evaluation might provide additional value to risk scores and could be considered to be a predictor of stroke in patients with AF.