BACKGROUND The 4th heart sound (S4) is commonly heard in patients with hypertrophic cardiomyopathy (HCM). The 3rd heart sound (S3) is also audible in HCM patients regardless of the presence or absence of heart failure. These extra heart sounds may be associated with myocardial fibrosis because myocardial fibrosis has been suggested to affect left ventricular compliance.Methods and Results:The p...

BACKGROUND Q waves and negative T waves are common electrocardiographic (ECG) abnormalities in patients with Hypertrophic Cardiomyopathy (HCM). Several studies correlated ECG findings with presence and extent of fibrosis and hypertrophy; however, their significance remains incompletely clarified. Our study aimed to explain the mechanism behind Q and negative T waves by comparing their positions...

Background Myocardial late gadolinium enhancement (LGE) imaging is conventionally acquired using a gradient-echo inversion recovery (IR-GRE) sequence 15-20 min after contrast administration. However, this method can be limited by poor breath holding or arrhythmias. Freebreathing single shot steady state free precession (SSSSFP) sequence is an alternative LGE imaging technique which can overcome...

Figure 1. Demonstrations of the edge artifact observed in LGE (yellow arrow). .A-B are Bloch simulations of the Cartesian (A) and spiral LGE sequences for circles with T1 values of 300ms and 200ms (top circle and bottom circle respectively). C-D show phantom images acquired with the Cartesian LGE sequence, where the edge artifact can be observed with greater intensity for increasing acquisition...

Background Ventricular tachycardia (VT) ablation is generally guided by invasive mapping of the left ventricle (LV) using electro-anatomical voltage mapping (EAM) to identify the VT substrate [1]. Late gadolinium enhancement (LGE) MRI allows excellent visualization of the scar. Heterogeneous area in LGE images has been shown to correlate with the VT substrate in animal models of VT. Retrospecti...

Background While late gadolinium enhanced (LGE) MRI is the gold standard for detection of focal myocardial scarring [1], it is less effective than cardiac T1 mapping (ECV) for detection of diffuse fibrosis. LGE, in principle, can be synthesized from cardiac T1 maps. We sought to derive synthetic LGE images from saturation-recovery based cardiac T1 maps for simultaneous assessment of focal and d...

AIMS Late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (MRI) in hypertrophic cardiomyopathy (HCM) has been reported to be associated with myocardial fibrosis and cardiac events. In patients with HCM, two-dimensional (2D) strain can identify subclinical global systolic dysfunction despite normal left ventricular (LV) chamber function. Therefore, this study tested ...

Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI h...

BACKGROUND Three-dimensional electroanatomic mapping (EAM) is routinely used to mark ablated areas during radiofrequency ablation. We hypothesized that, in atrial fibrillation (AF) ablation, EAM overestimates scar formation in the left atrium (LA) when compared to the scar seen on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI). METHODS AND RESULTS Of the 235 patients who und...

Euglycemia was maintained in 13 subjects with low muscle glycogen [low glycogen, euglycemic (LGE), n = 8; low glycogen, euglycemic, hyperinsulinemic (LGEI), n = 5] and 6 subjects with normal muscle glycogen (NGE), whereas hyperglycemia was maintained in 8 low muscle glycogen subjects (LGH). All subjects cycled for 145 min at 70% of maximal oxygen uptake during the infusions. Insulin was infused...