Device artifact reduction for magnetic resonance imaging of patients with implantable cardioverter-defibrillators and ventricular tachycardia: late gadolinium enhancement correlation with electroanatomic mapping.

BACKGROUND: Late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) of ventricular scar has been shown to be accurate for detection and characterization of arrhythmia substrates. However, the majority of patients referred for ventricular tachycardia (VT) ablation have an implantable cardioverter-defibrillator (ICD), which obscures image integrity and the clinical utility of MRI. OBJECTIVE: The purpose of this study was to develop and validate a wideband LGE MRI technique for device artifact removal. METHODS: A novel wideband LGE MRI technique was developed to allow for improved scar evaluation on patients with ICDs. The wideband technique and the standard LGE MRI were tested on 18 patients with ICDs. VT ablation was performed in 13 of 18 patients with either endocardial and/or epicardial approach and the correlation between the scar identified on MRI and electroanatomic mapping (EAM) was analyzed. RESULTS: Hyperintensity artifact was present in 16 of 18 of patients using standard MRI, which was eliminated using the wideband LGE and allowed for MRI interpretation in 15 of 16 patients. All patients had ICD lead characteristics confirmed as unchanged post-MRI and had no adverse events. LGE scar was seen in 11 of 18 patients. Among the 15 patients in whom wideband LGE allowed visualization of myocardium, 10 had LGE scar and 5 had normal myocardium in the regions with image artifacts when using the standard LGE. The left ventricular scar size measurements using wideband MRI and EAM were correlated with R(2) = 0.83 and P = .00003. CONCLUSION: Wideband LGE MRI improves the ability to visualize myocardium for clinical interpretation, which correlated well with EAM findings during VT ablation.

A Case Of Difficult Epicardial Access For Ablation Of Ventricular Tachcyardia.

We present a case of a 67-year-old patient with nonischemic cardiomyopathy and recurrent sustained ventricular tachycardia of epicardial origin referred for ablation. Due to two previous episodes of cardiac tamponade secondary to implantable cardioverter-defibrillator lead perforation at the time of device implant, the patient had significant pericardial adhesions making epicardial access and ablation challenging.

Development of an echocardiographic risk-stratification index to predict heart failure in patients with stable coronary artery disease: the Heart and Soul study.

OBJECTIVES: We sought to determine which transthoracic echocardiographic (TTE) measurements most strongly predict heart failure (HF) and to develop an index for risk stratification in outpatients with coronary artery disease (CAD). BACKGROUND: Many TTE measurements have been shown to be predictive of HF, and they might be useful if aggregated into a risk-prediction index. METHODS: We performed TTE in 1,024 outpatients with stable CAD enrolled in the Heart and Soul study and followed them for 4.4 years. With Cox proportional hazard models, we evaluated the association of 15 TTE measurements with subsequent HF hospital stay. Those measurements that independently predicted HF were combined into an index. Variables were defined as normal or abnormal on the basis of dichotomous cutoffs determined from the American Society of Echocardiography. Abnormal variables in each measurement were assigned points on the basis of strength of association with HF. RESULTS: Of the 15 variables, 5 measurements were independent predictors of HF: left ventricular mass index (LVMI), left atrial volume index (LAVI), mitral regurgitation (MR), left ventricular outflow tract velocity-time integral (VTI(LVOT)), and diastolic dysfunction (DD). In multivariate analysis, each of the 5 measurements independently predicted HF: LVMI >90 g/m(2) (hazard ratio [HR]: 4.1; 95% confidence interval [CI]: 2.3 to 7.2, p < 0.0001); pseudo-normal or restrictive DD (HR: 2.9; 95% CI: 1.8 to 4.5, p < 0.0001); VTI(LVOT) <22 mm (HR: 2.2; 95% CI: 1.4 to 3.5, p = 0.0004); mild, moderate, or severe MR (HR: 1.8; 95% CI: 1.2 to 2.8, p = 0.009); and LAVI >29 ml/m(2) (HR: 1.6; 95% CI: 1.0 to 2.5, p < 0.06). Combining these measurements, the Heart Failure Index ranged from 0 to 8, representing risk as follows: 3 points for LVMI, 2 points for DD, and 1 point for VTI(LVOT), MR, and LAVI. Among participants with 0 to 2 points: 4% had HF hospital stays (reference); 3 to 4 points: 10% (HR: 2.4; 95% CI: 1.3 to 4.4, p = 0.003); 5 to 6 points: 24% (HR: 6.2; 95% CI: 3.6 to 10.6, p < 0.0001); 7 to 8 points: 48% (HR: 13.7; 95% CI: 7.2 to 25.9, p < 0.0001). CONCLUSIONS: We identified 5 TTE measurements that independently predict HF in patients with stable CAD and combined them as an index that might be useful for risk stratification and serial observations.