Small left atrial volume and dimension before ablation are predictors of
tachycardia-induced cardiomyopathy with atrial fibrillation
Masahiro Nauchi MD, Tsuyoshi Sakai MD, Yuta Sugizaki MD, Naohiko Sahara
MD
Department of cardiovascular center, Saiseikai Yokohamashi Tobu Hospital
We express our thank to Akatsu, medical technologists, and members of
Clinical research support center at Saiseikai Yokohamashi Tobu Hospital.
We would like to thank Enago
(www.enago.jp) for the English
language review.
The authors declare no conflicts of interest associated with this
manuscript.
Corresponding Author: Masahiro Nauchi
Saiseikai Yokohamashi Tobu Hospital
3-6-1 Shimosueyoshi, Tsurumi Ward, Yokohama city, Kanagawa, Japan.
E-mail address:m_nauchi@tobu.saiseikai.or.jp
Tel +81 45 576 3000
Fax +81 45 576 3525
Abstract
Introduction
Tachycardia-induced cardiomyopathy (TCM) is a reversible cause of heart
failure with impaired left ventricle (LV) function. However, the
diagnosis is difficult before treatment or control of the arrhythmia for
the first time. This study was to clarify the characteristics of TCM
with atrial fibrillation (AF) before AF ablation.
Methods
In this retrospective observational study, we observed 31 patients with
paroxysmal or persistent AF who had impaired LV function without
structural heart disease and who underwent catheter ablation. We defined
impaired LV function as LV ejection fraction (LVEF) <50% on
the initial or worst echocardiogram. After ablation, the LVEF became
<60% (Group 1; n = 9) or ≧60% (Group 2; n = 22). We compared
the differences in baseline characteristics between the two groups. A
receiver operating curve with area under the curve (AUC) was used to
evaluate the prediction efficiency. The optimal cutoff point of the AUC
was at which sensitivity and specificity would be maximal.
Results
There were significant differences in left atrial (LA) volume (LAV) by
computed tomography (CT), LAV adjusted by body surface area (LAVI) by
CT, LAVI by echocardiography, and LA diameter (LAD) (p < 0.05,
respectively). The AUCs were 0.859, 0.869, 0.798, and 0.750,
respectively. The optimal cutoff points were 147 ml, 79
ml/m2, 37 ml/m2, and 45.8 mm,
respectively.
Conclusion
Small LAV, LAVI by CT, LAVI by echocardiography, and LAD were predictors
of LVEF improvement. Small LA volume and dimension before ablation may
be useful for diagnosis of TCM with AF.
Key words: Tachycardia-induced cardiomyopathy, Arrhythmia-induced
cardiomyopathy, atrial fibrillation, catheter ablation, heart failure
Abbreviations
TCM, tachycardia induced cardiomyopathy
HF, heart failure
LV, left ventricular/ventricle
AF, atrial fibrillation
EF, ejection fraction
DCM, dilated cardiomyopathy
CMR, cardiac magnetic resonance
CT, computed tomography
LA, left atrial/atrium
LAV, left atrial volume
LAVI, left atrial volume index
BSA, body surface area
PV, pulmonary vein
LAA, left atrial appendage
PVI, pulmonary vein isolation
CIED, cardiac implantable electronic device
ROC, receiver operating characteristic
AUC, area under curve
CI, confidence interval
LAD, left atrial diameter
1 Introduction
TCM is one of Arrhythmia-induced
cardiomyopathies and a reversible cause of HF with impaired LV function.
AF is the most common cause of TCM1,2. We cannot
always observe echocardiographic data in typical TCM at the first
occurrence: LVEF is <30%, LV end-diastolic diameter is
<65 mm, and LV end-systolic diameter is <50
mm3. The
diagnosis is determined by a recovery of LV function within 3 months
after treatment or control of the arrhythmia4. In
other words, we cannot determine the diagnosis for at least 3 months
after arrhythmia control. Moreover, the diagnosis is determined by
excluding other causes of cardiomyopathy, especially idiopathic DCM.
Absence of late Gadolinium enhancement on CMR imaging has been useful
for excluding other causes5. However, it is an unusual
method and is difficult for patients with impaired renal function.
Thus, the purpose of this study
was to clarify the characteristics of TCM with AF before AF ablation.
These should help establish early and optimal examinations, such as
transesophageal echocardiography or CT, and treatments, such as AF
ablation or cardioversion.
2 Methods
2.1 Study design and study
population