Relationship of myocardial substrate characteristics as assessed by myocardial perfusion imaging and cardiac reverse remodeling levels after cardiac resynchronization therapy

Abstract

The characteristics of myocardial substrates as assessed by MPI differed significantly between different levels of cardiac RR post-CRT. Myocardial scar played an important role in the development of ERR. Different cardiac RR levels contributed to different incidences of ventricular arrhythmia, and the combination of ERR and MRR provided highest anti-arrhythmic effects.

Effects of cardiac resynchronization therapy after inferior myocardial infarction on secondary mitral regurgitation and mitral valve geometry

“…While seven of the eight (87.5%) patients without myocardial scar that improved by one MR grade or more had a LBBB, no change in MR was observed in the three patients with scar and LBBB, suggesting the importance of myocardial viability in CRT response and MR improvement. Mechanistically, inhibition of coordinated electrical and mechanical myocardial activation by the scar disrupts physiologic activation patterns, and results in longer maximal contraction delays . In the context of continued LV remodeling and dilatation, the dyssynchronous myocardial fiber contraction worsens MV tethering vector forces, and contributes to persistent MR …”

“…Mechanistically, inhibition of coordinated electrical and mechanical myocardial activation by the scar disrupts physiologic activation patterns, and results in longer maximal contraction delays. 31 In the context of continued LV remodeling and dilatation, the dyssynchronous myocardial fiber contraction worsens MV tethering vector forces, and contributes to persistent MR. 2,7,32,33 In addition to scar-mediated dyssynchrony, altered papillary mus- Note: Values presented as mean ± standard deviation, or median and interquartile range. CRT = cardiac resynchronization therapy.…”

Systolic thickening fraction of inerventricular septum as a predictor of superresponse to cardiac resyncronisation therapy - concept of a helical ventriсular band

“…Это объясняет большее количество имплантаций комбинированной системы для СРТ с функцией кардиовертера-дефибриллятора. По данным K.F.Chiang и соавт., соединительнотканный рубец приводит не только к увеличению времени распространения ЭИ по миокарду ЛЖ, но и формированию региональной гетерогенной последовательности активации [26]. Поэтому, вероятно, наличие постинфарктного кардиосклероза не позволяет в полной мере реали-зоваться эффекту терапии -синхронизации сегментов миокарда ЛЖ.…”

A perfect tool for comprehensive evaluation of myocardial perfusion and function: Stress PET imaging

“…11 In addition, we further demonstrated that myocardial scar interfered with the normal propagation of mechanical activation, resulting in more heterogeneous activation sequences and thus contributing to the development of ventricular arrhythmia. 12 Since the invention of the phase analysis technique from ECG-gated MPI with SPECT by Chen et al in 2005, 13 it has led this imaging modality to discover a ''New World'' in nuclear cardiology. LV mechanical dyssynchrony by phase analysis has been found potentially useful in selecting optimal candidates for CRT, guiding LV lead implantation of CRT at the latest activation site, detecting stress-induced worsening of LV dyssynchrony as a marker of myocardial stunning, and differentiating ischemic or non-ischemic cardiomyopathy, risk stratification, and prognostication in heart failure patients.…”