Phase image evaluation of patients with ventricular pre-excitation syndromes

Abstract

To localize bypass pathways, left and right ventricular regions were analyzed at rest by phase image analysis in 18 patients with ventricular pre-excitation syndromes. These were compared with image findings in 18 normal subjects. In each of 17 patients with pre-excitation, the site localized on electrophysiologic study correlated closely with the region of earliest ventricular phase angle. This site could be objectively separated from that in normal subjects in each of eight patients with an active left-sided pathway and in both patients with a right-sided pathway. Those with a septal pathway revealed earliest septal phase angle, but could not be separated from normal subjects. In the eight patients with an active left bypass tract, the onset, upstroke and peak of the left ventricular phase histogram preceded those of the right ventricular histogram. Those with a left-sided pathway demonstrated a mean left ventricular phase angle, a difference between mean left and mean right ventricular phase angle and a difference between earliest left and right ventricular phase angles which was significantly less than that in normal subjects (p less than 0.05). These variables presented characteristic converse changes in those with a right-sided pathway. Sequential phase changes in 10 studies suggested "fusion" of normal septal with lateral bypass fronts. Electrocardiographic and electrophysiologic localization of the bypass pathway agreed in only 8 of 14 patients with a recognized delta wave. The phase image represents a new, noninvasive method of evaluating ventricular pre-excitation. The method may provide useful information complementary to that of electrocardiographic and electrophysiologic analysis.

Automatic Global and Regional Phase Analysis from Gated Myocardial Perfusion SPECT Imaging: Application to the Characterization of Ventricular Contraction in Patients with Left Bundle Branch Block

“…Early on, phase analysis was used with equilibrium radionuclide angiography (15) and applied to the characterization of abnormal patterns of ventricular activation (16), including the diagnosis of bundle branch blocks (17,18). More recently, phase analysis has been applied to gated myocardial perfusion SPECT (MPS), in which global synchrony measures derived from countbased thickening (19) have been shown to correlate with tissue Doppler imaging-derived measures of intraventricular delay (20) and, in a preliminary study, to predict response to CRT (21).…”

Detection of electrocardiographically imperceptible ventricular pre‐excitation by phase imaging

“…Electrophysiologists have demonstrated that in some cases atrial stimulation close to the accessory pathway might result in electrocardiographic signs of pre-excitation. Recently, precontraction assessed by echocardiography (Molina et af., 1982) and phase imaging (Botvinick et al, 1984;Chan et af., 1983;Rakovec er af., 1983Rakovec er af., , 1984, has been found to be present even in the absence of delta waves in the electrocardiogram. Experience in this respect has been limited to a small number of cases.…”

“…Fourier analysis of nuclear angiograms was performed using the technique recently described in detail by Swiryn (1985) and by Dae and Botvinick (1984). In brief, each patient received 800-lo00 mBq of technetium-99m.…”

Utility of Equilibrium Radionuclide Angiogram–Derived Measures of Dyssynchrony to Predict Outcomes in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

“…Rest, supine electrocardiogram (ECG)-gated anterior, best septal left anterior oblique, and left lateral planar images were acquired in 16 frames, before and after CRT, using a Forte camera (Philips Electronics, Inc.), processed by commercial software. LVS, LVE, SDLVØ, IVS, right ventricular (RV) S (RVS), right ventricular E (RVE), and SDRVØ were calculated, based on the phase image generated from the first harmonic fit of the ERNA time-activity curve displayed by standard laboratory protocols (11,14).…”

“…Each parameter was calculated from the first harmonic phase histogram in the ventricular ROIs: SDLVØ, SDRVØ, IVS (difference between mean LVS and RVS), LVS, and LVE are defined mathematically elsewhere (11,14,15).…”