Correlation between electrosynchronization and mechanical synchronization in patients with chronic heart failure

Objectives: The aim of this study was to evaluate the correlation between electrical and mechanical synchronization in chronic heart failure patients using Cadmium-Zine-Telluride (CZT) single photon emission computed tomography (SPECT) and analyze the influencing factors of electrical and mechanical separation, this paper provides a basis for the role of mechanical dyssynchrony in the treatment of patients with chronic heart failure.

Methods: A total of 357 patients retrospectively enrolled who underwent GMPI in the Nuclear Medicine Department of Shanxi Cardiovascular Hospital from January 2019 to March 2020, including 273 males and 84 females, with an average age (67.23±10.9) years old. The systolic synchrony parameters were calculated via Emory Cardiac Toolbox,including phase standard deviation (PSD), phase histogram bandwidth(PHB). All patients were divided into 4 groups based on QRS duration and whether the patients with myocardial infarction,including the first group(101cases) with a narrow QRS duration (<120 ms), myocardial infarction. The Second group(133cases) with a narrow QRS duration (<120 ms), without myocardial infarction. The third group(42 cases)with a wide QRS duration (>120 ms), myocardial infarction. The fourth group(42cases) with awide QRS duration (>120 ms), without myocardial infarction. Pearson correlation was used to analyze the correlation between QRS duration and mechanical synchronicity parameters in all patients and each group.

Results: Correlation analysis results of all patients with chronic heart failure showed that QRS duration were positive correlated with the mechanical dyssynchrony parameters PSD and PHB (r values: 0.271, 0.218, both P<0.05). There were no correlation between PSD ,PHB and QRS duration in the first group (r values:-0.089, -0.049, both P>0.05),but PSD ,PHB were positive correlated with QRS duration in the second group (r values:0.301, 0.321, both P<0.05); PSD,PHB have correlation with QRS duration in the third group(r values: 0.347,0.395, both P<0.05); but PSD ,PHB showed no correlation with QRS duration in the fourth group(r values:0.094, 0.050, both P>0.05).

Conclusions: The QRS duration of electrical synchronization is not absolutely consistent with the parameters of mechanical synchronization, and myocardial infarction is an important factor leading to electro-mechanical separation in electrosynchronization , Abnormal cardiac conduction system plays an important role in electrical and mechanical separation in patients with electrical dyssynchrony and without myocardial infarction. Key Words: Chronic heart failure ; Electrical synchronization ; Mechanical synchronization