Author + information
- Received July 24, 2017
- Revision received August 3, 2017
- Accepted August 8, 2017
- Published online December 4, 2017.
- Emre Aslanger, MD∗ (, )
- Mustafa Aytek Şimşek, MD,
- Ayça Türer Cabbar, MD,
- Olcay Özveren, MD and
- Muzaffer Değertekin, MD, PhD
- ↵∗Address for correspondence:
Dr. Emre Aslanger, Yeditepe University Hospital, Department of Cardiology, İçerenköy Mahallesi Hastane Soka, No: 4, 4/1, 34752 Ataşehir, Istanbul, Turkey.
The intracoronary electrocardiogram (IC-ECG) is a practical, inexpensive, and underused method that can provide valuable insight into the elucidation of myocardial ischemia pathophysiology (1). The IC-ECG was proposed as a diagnostic tool for assessing myocardial recovery (2), viability (3), recruitable collaterals, and the significance of coronary stenoses (4).
In an inspiring paper by Balian et al. (4), the IC-ECG was shown to be closely correlated with fractional flow reserve (FFR). This finding has 2 thought-provoking implications: 1) IC-ECG may replace the pressure wire as a cheaper alternative; and more importantly, 2) it may serve as a more physiological indicator of ischemia than FFR, which in turn, provides indirect information deduced from the pressure drop across a lesion.
On the other hand, IC-ECG may also have some drawbacks. The extent and proximity of ischemic myocardium represented by changes in the IC-ECG is not precisely known. Theoretically, it is possible that the IC-ECG may be influenced by an ischemic region that is supplied by a critically narrowed artery adjacent to the artery being investigated. This is especially important for left coronary system, where neighboring lesions may cause ischemic IC-ECG changes in a noncritical lesion during nonselective adenosine hyperemia.
We report a case in which close proximity of 2 lesions in 2 adjacent vessels enabled us to study the effects of nonselective left coronary adenosine hyperemia on the IC-ECG. In a 60-year-old man with typical angina, coronary angiogram revealed 2 seemingly critical adjacent lesions in the left anterior descending and diagonal arteries (Figure 1). To evaluate the hemodynamic significance of the lesions, a pressure wire was first advanced to the distal left anterior descending coronary artery. An IC-ECG was recorded by an alligator clip attached to the pressure wire and V1 lead. Wilson’s central terminal was constructed by attaching 3 limb electrodes to the electrocardiogram machine. After 300 μg of intracoronary adenosine induced hyperemia, the FFR was 0.88 (Figure 2C), and the IC-ECG showed no changes (Figure 2A vs. Figure 2B). Then, pressure wire was advanced to distal diagonal artery. Adenosine hyperemia revealed an FFR of 0.80 (Figure 2F) that was accompanied by IC-ECG changes (Figure 2D vs. Figure 2E). Adenosine hyperemia was repeated twice for both arteries, which reproduced the same FFR and IC-ECG findings. The diagonal lesion was stented without any complication. The patient was asymptomatic at 1-month follow-up.
To our knowledge, this is the first time that an investigation on lesion specificity of the IC-ECG has been undertaken. This case reveals that the IC-ECG seems not to be influenced by closely adjacent ischemic territories. This information is clinically relevant, because a better understanding of IC-ECG behavior may pave the way for its widespread use.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received July 24, 2017.
- Revision received August 3, 2017.
- Accepted August 8, 2017.
- 2017 American College of Cardiology Foundation
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