Abnormal ventricular contraction patterns in patients with arrhythmogenic substrates using three-dimensional phase analysis

• Published in: European heart journal 1993-09, Vol.14 (suppl-E), p.69-72
• Main Authors: Clausen, M., Weismüller, P., Weller, R., Adam, W. E., Henze, E.
• Format: Article
• Language: English
• Subjects: Animals; Arrhythmias, Cardiac - diagnosis; Arrhythmias, Cardiac - physiopathology; Arrhythmogenic substrates; Electric Stimulation; gated emission-computed tomography (SPECT); Humans; Myocardial Contraction - physiology; phase analysis; Swine; Tachycardia, Ventricular - diagnosis; Tachycardia, Ventricular - physiopathology; Tomography, Emission-Computed, Single-Photon - methods; Ventricular Function; Wolff-Parkinson-White Syndrome - diagnosis; Wolff-Parkinson-White Syndrome - physiopathology
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/14.suppl_E.69

Arrhythmogenic substrate diagnosis has been achieved by electrophysiological studies and best localized by successful radiofrequency ablation. Pre-invasive localization procedures have been based on surface ECGs and more recently on biomagnetism, but in addition to these electric and magnetic signals a mechanical signal may be utilized: the initial site of contraction may be detected by phase analysis during radionuclide ventriculography. Generation of three-dimensional data set of phases is achieved by incorporating the new emission tomography technique. The performance of this modified phase analysis has been investigated for the detection of the normal contraction pattern during sinus rhythm, the arrhythmogenic substrate of the WPW syndrome and ventricular tachycardia, and further, to define the limitations of the method in experimental studies on pigs. In 30 out of 44 patients with normal sinus rhythm and no ventricular lesion, a characteristic phase pattern was found. Physiologically, the initial site of contraction appeared to be paraseptal and in the anterior wall of the right ventricle close to the apex. In 13 patients with WPW syndrome and in seven with ventricular tachycardia, the phase data were compared to the electrophysiological study. In 14 of 20 there was a complete match, in 3 of 20 a mechanical focus was found in the area adjacent to the electric focus. From experimental pig studies with simulated stimulation, a spatial precision of at least 20 mm was found at a pre-excitation of 20 ms. Thus, in three-dimensional phase analysis the normal contraction pattern of the ventricles can be visualized, and the arrhythmogenic substrates of WPW and ventricular tachycardia may be localized more precisely and reliably than by the surface ECG. Patients with mechanically induced atrial fibrillation, with a ventricular thrombus, or with non specific ECG abnormalities may benefit from this new tomographic technique which could assist subsequent invasion procedures.