CARDIOVASCULAR MAGNETIC RESONANCE WITH CONTRAST AGENT: PROGNOSTIC ROLE IN DETERMINING ARRHYTMOGENIC FOCUS

In order to evaluate the possibilities of MRI in detection of proarrhytmogenic areas of myocardium we did compare directly and quantitatively the local myocardial uptake of paramagnetics to the results of electrophysiologic study of myocardium in twenty-two patients with recent transmural myocardial infarction and frequent ventricular extrasystoles verified by ECG studies.
Topic quantitative study of myocardial electric potential has been carried out using Carto XP system (by Biosense Webster).
By analysis of the images the measurement of Index of transmurality (IT) for the contrast uptake was calculated as ratio of thickness of paramagnetic uptake to overall thickness of myocardium in a specific segment.
The the electrophysiologic and MRI data were analyzed topically as segment vs segment and the significant tendency was revealed with simultaneous grow of pro-arrhythmogenic activity and value of IT. In other words, as bigger the IT increases, as arrhythmogenic the lectrical activity becomes. The best border value of IT that provided separation of electrically normal segments from proarrhythmogenic ones was the IT = 0.3.
Therefore we conclude the contrast-enhanced MRI of myocardium deliver additional information on risk of arrhythmias, not only the detection of myocardial damage itself.

1. Josephson M.E. Clinical cardiac electrophysiology: techniques and interpretations: 2nd ed. Philadelphia, Lea & Febiger. 1993.

2. Chen S.A., Chiang C.E., Tai C.T. et al. Complications of diagnostic electrophysiologic studies and radiofrequency catheter ablation in patients with tachyarhythmias: An eight-year survey of 3,966 consecutive procedures in a tertiary referral center. Amer. Cardiol., 1996, vol. 77, pp. 41–46.

3. Trufanov G.E., Zheleznyak I.S., Rud' S.D., Men'kov I.A. MRI in diagnostic of ischemic heart disease. SPb., ELBISPb. Publ., 2012. 61 p. (in Russian).

4. Manfred Thelen, Raimund Erbel, Karl-Fridrich Kreitner, Jorg Barkhauzen. Radiologic diagnostics of heart diseases. Moscow, MEDpress-inform Publ., 2011. 480 p.

5. Murashko V.V., Strutynskiy A.V. Electrocardiography: Textbook. vol. 6. Moscow, MEDpress-inform Publ., 2004. 320 p. (in Russian).