Article

Time course of infarct healing and left ventricular remodelling in patients with reperfused ST segment elevation myocardial infarction using comprehensive magnetic resonance imaging.

Cardiology Department, University Hospitals Leuven, Leuven, Belgium.
European Radiology (Impact Factor: 4.34). 04/2011; 21(4):693-701. DOI: 10.1007/s00330-010-1963-8
Source: PubMed

ABSTRACT To describe the time course of myocardial infarct (MI) healing and left ventricular (LV) remodelling and to assess factors predicting LV remodelling using cardiac MRI.
In 58 successfully reperfused MI patients, MRI was performed at baseline, 4 months (4M), and 1 year (1Y) post MI RESULTS: Infarct size decreased between baseline and 4M (p < 0.001), but not at 1Y; i.e. 18 ± 11%, 12 ± 8%, 11 ± 6% of LV mass respectively; this was associated with LV mass reduction. Infarct and adjacent wall thinning was found at 4M, whereas significant remote wall thinning was measured at 1Y. LV end-diastolic and end-systolic volumes significantly increased at 1Y, p < 0.05 at 1Y vs. baseline and vs. 4M; this was associated with increased LV sphericity index. No regional or global LV functional improvement was found at follow-up. Baseline infarct size was the strongest predictor of adverse LV remodelling.
Infarct healing, with shrinkage of infarcted myocardium and wall thinning, occurs early post-MI as reflected by loss in LV mass and adjacent myocardial remodelling. Longer follow-up demonstrates ongoing remote myocardial and ventricular remodelling. Infarct size at baseline predicts long-term LV remodelling and represents an important parameter for tailoring future post-MI pharmacological therapies designed to prevent heart failure.

0 Bookmarks
 · 
71 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background-Permanent coronary artery damage is a hazardous complication of epicardial radiofrequency ablation. Irreversible electroporation (IRE) is a promising nonthermal ablation modality able to create deep myocardial lesions. We investigated the effects of epicardial IRE on luminal coronary artery diameter and lesion depth. Methods and Results-In 5 pigs (60-75 kg), the pericardium was exposed using surgical subxiphoidal epicardial access. A custom deflectable octopolar 12-mm circular catheter with 2-mm ring electrodes was introduced in the pericardium via a steerable sheath. After coronary angiography (CAG), the proximal, mid, and distal left anterior descending, and circumflex coronary arteries were targeted with a single, cathodal 200 J application. CAG was repeated after IRE and after 3 months follow-up. Using quantitative CAG, the minimal luminal diameter at the lesion site was compared with the average of the diameters just proximal and distal to that lesion. Intimal hyperplasia and lesion size were measured histologically. CAG directly postablation demonstrated short-lasting luminal narrowing with normalization in the targeted area, suggestive of coronary spasm. After 3 months, all CAGs were identical to preablation CAGs: mean reference luminal diameter was 2.2 +/- 0.3 mm, mean luminal diameter at the lesion site was 2.1 +/- 0.3 mm (P=0.35). Average intimal hyperplasia in all arteries was 2 +/- 4%. Median lesion depth was 6.4 +/- 2.6 mm. Conclusions-Luminal coronary artery diameter remained unaffected 3 months after epicardial IRE, purposely targeting the coronary arteries. IRE can create deep lesions and is a safe modality for catheter ablation on or near coronary arteries.
    Circulation Arrhythmia and Electrophysiology 08/2014; 7(5). DOI:10.1161/CIRCEP.114.001607 · 5.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background-Irreversible electroporation is a promising nonthermal ablation modality able to create deep myocardial lesions. We investigated lesion size after epicardial electroporation catheter ablation with various energy levels after subxiphoid pericardial puncture. Methods and Results-In six 6-month-old pigs (60-75 kg), a custom deflectable octopolar 12-mm circular catheter with 2-mm ring electrodes was introduced via a deflectable sheath after pericardial access by subxiphoid puncture. Nonarcing, nonbarotraumatic, cathodal 50, 100, and 200 J electroporation applications were delivered randomly on the basal, mid and lateral left ventricle. After 3-month survival, myocardial lesion size and degree of intimal hyperplasia of the coronary arteries were analyzed histologically. Five animals survived the follow-up without complications and 1 animal died of shock after the subxiphoid puncture. At autopsy, whitish circular scars with indentation of the epicardium could be identified. Average lesion depths of the 50-, 100-, and 200-J lesions were 5.0 +/- 2.1, 7.0 +/- 2.0, and 11.9 +/- 1.5 mm, respectively. Average lesion widths of the 50-, 100-, and 200-J lesions were 16.6 +/- 1.1, 16.2 +/- 4.3, and 19.8 +/- 1.8 mm, respectively. In the 100- and 200-J cross sections, transmural left ventricular lesions and significant tissue shrinkage were observed. No intimal hyperplasia of the coronary arteries was observed. Conclusions-Epicardial electroporation ablation after subxiphoid pericardial puncture can create deep, wide, and transmural ventricular myocardial lesions. There is a significant relationship between the amounts of electroporation energy delivered epicardially and lesion size in the absence of major adverse events.
    Circulation Arrhythmia and Electrophysiology 07/2014; 7(4). DOI:10.1161/CIRCEP.114.001659 · 5.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Electroporation can be used as a non-thermal method to ablate myocardial tissue. However, like with all electrical ablation methods, determination of the energy supplied into the myocardium enhances the clinically required controllability over lesion creation. The purpose of this animal study was to investigate the relationship between magnitude of epicardial electroporation ablation and lesion size using an electrically isolating linear suction device. In 5 pigs (60-75 kg), the pericardium was opened after medial sternotomy. A custom linear suction device with a single 35 x 6 mm electrode inside a 42 mm long and 7 mm wide plastic suction cup was used for electroporation ablation. Single cathodal applications of 30, 100 or 300 joules (J) were delivered randomly at 3 different epicardial left ventricular sites. Coronary angiography was performed before, immediately after ablation and after 3 months survival. Lesion size was measured histologically after euthanization. Mean depth of the 30J, 100J and 300J lesions was 3.2±0.7, 6.3±1.8 and 8.0±1.5 mm, respectively (p=0.0003). Mean width of the 30J, 100J, and 300J lesions was 10.1±0.8, 15.1±1.5 and 17.1±1.3 mm, respectively (p<0.0001). Significant tissue shrinkage was observed at the higher energy levels. No luminal arterial narrowing was observed after 3 months: 2.3±0.3 vs. 2.3±0.4 mm (p=0.85). The relationship between the amount of electroporation energy delivered through a linear suction device with a single linear electrode and the mean myocardial lesion size is significant, in the absence of major adverse events or permanent damage to the coronary arteries.
    Heart rhythm: the official journal of the Heart Rhythm Society 04/2014; 11(8). DOI:10.1016/j.hrthm.2014.04.031 · 4.56 Impact Factor