TY - JOUR
T1 - New insight into scar-related ventricular tachycardia circuits in ischemic cardiomyopathy
T2 - Fat deposition after myocardial infarction on computed tomography - A pilot study
AU - Sasaki, Takeshi
AU - Calkins, Hugh
AU - Miller, Christopher F.
AU - Zviman, Menekhem M.
AU - Zipunnikov, Vadim
AU - Arai, Tomio
AU - Sawabe, Motoji
AU - Terashima, Masashiro
AU - Marine, Joseph E.
AU - Berger, Ronald D.
AU - Nazarian, Saman
AU - Zimmerman, Stefan L.
N1 - Publisher Copyright:
© 2015 Heart Rhythm Society.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Background Myocardial fat deposition (FAT-DEP) has been frequently observed in regions of chronic myocardial infarction in patients with ischemic cardiomyopathy. The role of FAT-DEP within scar-related ventricular tachycardia (VT) circuits has not been investigated. Objective This pilot study aimed to assess the impact of myocardial FAT-DEP on local electrograms and VT circuits in patients with ischemic cardiomyopathy. Methods Contrast-enhanced computed tomography was performed in 22 patients with ischemic VT. Electroanatomic map points were registered to the corresponding contrast-enhanced computed tomography images. Myocardial FAT-DEP was identified and characterized using a postprocessing image overlay that highlighted areas below 0 Hounsfield units (HU). The mean attenuation of local myocardial regions corresponding to sampled electrograms was measured on short-axis images. The associations of mean attenuation with bipolar and unipolar amplitudes, left ventricular wall thickness, and VT circuit sites were investigated. Results Of 1801 electroanatomic map points, 519 (28.8%) were located in regions with FAT-DEP. Significant differences were observed in mean intensity (23.2 ± 35.6 HU vs 81.7 ± 21.9 HU; P <.001), bipolar (0.75 ± 0.83 mV vs 2.9 ± 2.4 mV; P <.001) and unipolar (3.1 ± 1.7 mV vs 7.4 ± 4.3 mV; P <.001) amplitudes, and left ventricular wall thickness (5.2 ± 1.7 mm vs 8.2 ± 2.5 mm; P <.001) between regions with and without FAT-DEP. Lower HU was strongly associated with lower bipolar and unipolar amplitudes (P <.0001, respectively). Importantly, FAT-DEP was associated with critical VT circuit sites with fractionated or isolated potentials. Conclusion FAT-DEP was associated with electrogram characteristics and VT circuit sites. Further work will be needed to determine whether FAT-DEP plays a causal role in the generation of ischemic scar-related VT circuits.
AB - Background Myocardial fat deposition (FAT-DEP) has been frequently observed in regions of chronic myocardial infarction in patients with ischemic cardiomyopathy. The role of FAT-DEP within scar-related ventricular tachycardia (VT) circuits has not been investigated. Objective This pilot study aimed to assess the impact of myocardial FAT-DEP on local electrograms and VT circuits in patients with ischemic cardiomyopathy. Methods Contrast-enhanced computed tomography was performed in 22 patients with ischemic VT. Electroanatomic map points were registered to the corresponding contrast-enhanced computed tomography images. Myocardial FAT-DEP was identified and characterized using a postprocessing image overlay that highlighted areas below 0 Hounsfield units (HU). The mean attenuation of local myocardial regions corresponding to sampled electrograms was measured on short-axis images. The associations of mean attenuation with bipolar and unipolar amplitudes, left ventricular wall thickness, and VT circuit sites were investigated. Results Of 1801 electroanatomic map points, 519 (28.8%) were located in regions with FAT-DEP. Significant differences were observed in mean intensity (23.2 ± 35.6 HU vs 81.7 ± 21.9 HU; P <.001), bipolar (0.75 ± 0.83 mV vs 2.9 ± 2.4 mV; P <.001) and unipolar (3.1 ± 1.7 mV vs 7.4 ± 4.3 mV; P <.001) amplitudes, and left ventricular wall thickness (5.2 ± 1.7 mm vs 8.2 ± 2.5 mm; P <.001) between regions with and without FAT-DEP. Lower HU was strongly associated with lower bipolar and unipolar amplitudes (P <.0001, respectively). Importantly, FAT-DEP was associated with critical VT circuit sites with fractionated or isolated potentials. Conclusion FAT-DEP was associated with electrogram characteristics and VT circuit sites. Further work will be needed to determine whether FAT-DEP plays a causal role in the generation of ischemic scar-related VT circuits.
KW - Computed tomography
KW - Fat
KW - Ischemic cardiomyopathy
KW - Magnetic resonance imaging
KW - Ventricular tachycardia
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U2 - 10.1016/j.hrthm.2015.03.041
DO - 10.1016/j.hrthm.2015.03.041
M3 - Article
C2 - 25814415
AN - SCOPUS:84937510553
SN - 1547-5271
VL - 12
SP - 1508
EP - 1518
JO - Heart Rhythm
JF - Heart Rhythm
IS - 7
ER -