LV Dyssynchrony Is Helpful in Predicting Ventricular Arrhythmia in Ischemic Cardiomyopathy After Cardiac Resynchronization Therapy

Abstract

For patients with coronary artery disease, larger scar burdens are associated with higher risk of ventricular arrhythmia. Left ventricular (LV) dyssynchrony is associated with increased risk of sudden cardiac death in patients with heart failure. The purpose of this study was to assess the values of LV dyssynchrony and myocardial scar assessed by myocardial perfusion SPECT (MPS) in predicting the development of ventricular arrhythmia in ischemic cardiomyopathy.Twenty-two patients (16 males, mean age: 66 ± 13) with irreversible ischemic cardiomyopathy received cardiac resynchronization therapy (CRT) for at least 12 months were enrolled for MPS. Quantitative parameters, including LV dyssynchrony with phase standard deviation (phase SD) and bandwidth, left ventricular ejection fraction (LVEF), and scar (% of total areas), were generated by Emory Cardiac Toolbox. Ventricular tachycardia (VT) and ventricular fibrillation (VF) recorded in the CRT device during follow-up were used as the reference standard of diagnosing ventricular arrhythmia. Stepwise logistic regression analysis was performed for determining the independent predictors of VT/VF and receiver operating characteristic (ROC) curve analysis was used for generating the optimal cut-off values for predicting VT/VF.Nine (41%) of the 22 patients developed VT/VF during the follow-up periods. Patients with VT/VF had significantly lower LVEF, larger scar, larger phase SD, and larger bandwidth (all P < 0.05). Logistic regression analysis showed LVEF and bandwidth were independent predictors of VT/VF. ROC curve analysis showed the areas under the curves were 0.71 and 0.83 for LVEF and bandwidth, respectively. The optimal cut-off values were <36% and > 139° for LVEF and bandwidth, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 39%, 53%, and 100%, respectively, for LVEF; and were 78%, 92%, 88%, and 86%, respectively, for bandwidth.LV dyssynchrony as assessed by phase analysis of MPS is helpful for predicting ventricular arrhythmia in ischemic cardiomyopathy after CRT. Further implantation of defibrillator may be considered for those patients with bandwidth >139°.

Implantable Cardioverter-Defibrillator for Primary Prevention in Asia

“…More sophisticated imaging modalities, including strain imaging, cardiac magnetic resonance imaging (C-MRI), single-photon emission computed tomography (SPECT), and positron emission tomography (PET), for the assessment of myocardial scarring, have been found to be superior predictors of the development of VTA and SCD than LVEF alone assessed in echocardiography. 81 , 82 , 83 , 84 …”

Analysis of ventricular synchrony: A complex puzzle

“…In the last 13 years, we have a new tool in the area of nuclear cardiology called analysis of left ventricle synchrony. Since 2005, several articles [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] have been published in relation to the normal cut-off values (Table 1), and diagnosis and prognosis (Table 2). From a physiological point of view, the study of the mechanical synchronization of the ventricles is very complex.…”

Dyssynchrony: a risk marker for ventricular arrhythmias?

“…6,7 In the presence of abnormal substrate, several studies have showed increased risk of adverse cardiovascular outcomes in patients with dyssynchrony but data on arrhythmic events are less convincing. [8][9][10][11] A sub-study of MADIT-CRT showed no difference in the occurrence of ventricular arrhythmias in patients undergoing CRT implantation with or without baseline dyssynchrony. 10 In REVERSE trial there was no difference in occurrence of ventricular arrhythmias in patients with CRT ON vs CRT OFF implying resynchronization had little impact on occurrence of ventricular arrhythmias.…”