Author + information
- Larisa G. Tereshchenko,
- Golriz Sedaghat,
- Ryan Gardner,
- Muammar Kabir and
- Beth Habecker
Background: Denervated post-infarct scar is arrhythmogenic; however, there is no non-invasive tool to estimate sympathetic innervation of the scar. We hypothesized that frequency characteristics of QRS complex on surface ECG are associated with the sympathetic innervation of the scar.
Methods: In-vivo single lead ECG telemetry device was implanted 5 days prior to cardiac surgery and high resolution (1000 Hz) ECG was recorded in 17 heterozygous protein tyrosine phosphatase receptor σ (PTPσ; HET) and 7 lacking PTPσ (KO) transgenic mice. Two surgery protocols were implemented: (1) Myocardial infarction (MI) with reperfusion, (2) sham surgery. HET mice developed a denervated scar, whereas KO mice developed an innervated scar, which was confirmed by the histochemistry. Intracellular sigma peptide (ISP) has been used to restore sympathetic innervation in the post-MI scar. Heart rate variability, QT variability, T-wave alternans were measured on 3-minute ECG. The power spectral density was used to assess the frequency content of the QRS complex.
Results: Denervated as compared to innervated post-MI scar was characterized by the higher relative contribution of very high (300-500Hz) frequencies (7±1 vs. 4±1%; P=0.021), but reduced relative contribution of 150-300 Hz band (93±1 vs. 96±1%; P=0.021). The sympathetic TH+ fiber density within the infarct inversely correlated with 300-500/150-500 Hz power ratio (r= -0.524; P=0.009). No differences in the relative contribution of high frequencies in the ECG signal in HET as compared to KO mice were observed in sham. ISP injections in post-MI HET mice fully restored the QRS power and frequencies composition. The QRS frequency content (150-200 Hz power) significantly correlated with the level of norepinephrine in the peri-infarct tissue (r = 0.83; P=0.001).
Conclusions: In the context of myocardial infarction, ECG frequency content is associated with sympathetic innervation in the left ventricle
Poster Hall, Hall C
Friday, March 17, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Arrhythmias and Clinical EP: Basic 2
Abstract Category: 4. Arrhythmias and Clinical EP: Basic
Presentation Number: 1152-114
- 2017 American College of Cardiology Foundation