Comparison of Quantitative Perfusion and Function Parameters of Gated-SPECT Myocardial Perfusion Imaging in Patients With Concordant and Discordant Left Bundle-Branch Block

Abstract

Background Patients with left bundle-branch block (LBBB) can be classified to discordant LBBB (dLBBB) and concordant LBBB (cLBBB) according to T-wave orientation in lateral leads. This classification indicates different functional left ventricular (LV) parameters with worse prognosis in dLBBB patients. However, there are no data regarding the impact of this classification on perfusion status of the left ventricle. The aim of this study is to evaluate and compare the SPECT myocardial perfusion imaging (MPI) findings of LV perfusion and function between dLBBB and cLBBB patients. Methods All patients who were referred for SPECT MPI during an 11 months' period were evaluated. Patients with evidence of LBBB on standard baseline 12-lead ECG were included, and their demographic, medical history, and imaging data were recorded. Quantitative perfusion and function parameters of LV included summed stress score, summed rest score, summed difference score, total perfusion deficit (TPD) at both phases with delta TPD, ejection fraction, end-diastolic volume, end-systolic volume, summed motion score, summed thickening score, phase SD, and phase histogram bandwidth. All baseline ECGs were further assessed by a cardiologist to categorize patients as the cLBBB or dLBBB group according to concordance of the T wave with QRS complex in lateral leads. Results Finally, 97 patients with 46 cLBBB and 51 dLBBB cases were included. Baseline characteristics and cardiovascular risk factors including diabetes mellitus, hypertension, hyperlipidemia, history of coronary artery disease (CAD), family history of CAD, and smoking were not significantly different between the 2 groups. However, summed stress score (12.2 vs 6.7), summed difference score (4.0 vs 2.6), stress TPD (11.0 vs 6.4), and delta TPD (4.8 vs 3.9) were significantly higher in dLBBB patients. In addition, functional parameters were also significantly worse in dLBBB patients with lower ejection fraction and higher end-diastolic volume, end-systolic volume, summed motion score, and summed thickening score in these patients. Mean phase SD and phase histogram bandwidth were also significantly higher in dLBBB patients. Conclusions This study revealed that LBBB patients with discordant T wave in lateral leads have significantly higher ischemic scores and worse functional parameters with more dyssynchrony in gated SPECT MPI.

Evaluating the correlation of serum leptin levels with evidence of coronary artery disease on myocardial perfusion single-photon emission computed tomography in suspected coronary artery disease patients

“…Although many studies have suggested a positive relationship between serum leptin level and risk of CAD, there are also studies that revealed controversial results. A study by Rahmani et al reported that there was a direct relationship between serum levels of leptin and the number of involved vessels in patients that underwent coronary angiography compared to controls [18]. However, Sattar et al [20] conducted a large prospective study in British men and revealed a moderate but NS correlation between serum leptin level and incident CAD.…”

“…A study by Rahmani et al . reported that there was a direct relationship between serum levels of leptin and the number of involved vessels in patients that underwent coronary angiography compared to controls [18]. However, Sattar et al .…”

“…Modern modalities and technologies provide noninvasive imaging for not just diagnosis but also for selecting appropriate therapeutic choices and prognostic purposes in suspected CAD patients. Myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is widely used as an accepted noninvasive functional method for the evaluation of CAD in suspected patients [17,18]. The aim of this study is to assess the relationship between serum leptin level and evidence of CAD in MPI SPECT of suspected CAD patients.…”