1,721,015 research outputs found
Pacing-induced regional differences in adenosine receptors mRNA expression in a Swine model of dilated cardiomyopathy.
Full text linkThe adenosinergic system is essential in the mediation of intrinsic protection and myocardial resistance to insult; it may be considered a cardioprotective molecule and adenosine receptors (ARs) represent potential therapeutic targets in the setting of heart failure (HF). The aim of the study was to test whether differences exist between mRNA expression of ARs in the anterior left ventricle (LV) wall (pacing site: PS) compared to the infero septal wall (opposite region: OS) in an experimental model of dilated cardiomyopathy. Cardiac tissue was collected from LV PS and OS of adult male minipigs with pacing-induced HF (n = 10) and from a control group (C, n = 4). ARs and TNF-α mRNA expression was measured by Real Time-PCR and the results were normalized with the three most stably expressed genes (GAPDH, HPRT1, TBP). Immunohistochemistry analysis was also performed. After 3 weeks of pacing higher levels of expression for each analyzed AR were observed in PS except for A1R (A1R: C = 0.6±0.2, PS = 0.1±0.04, OS = 0.04±0.01, p<0.0001 C vs. PS and OS respectively; A2AR: C = 1.04±0.59, PS = 2.62±0.79, OS = 2.99±0.79; A2BR: C = 1.2±0.1, PS = 5.59±2.3, OS = 1.59±0.46; A3R: C = 0.76±0.18, PS = 8.40±3.38, OS = 4.40±0.83). Significant contractile impairment and myocardial hypoperfusion were observed at PS after three weeks of pacing as compared to OS. TNF-α mRNA expression resulted similar in PS (6.3±2.4) and in OS (5.9±2.7) although higher than in control group (3.4±1.5). ARs expression was mainly detected in cardiomyocytes. This study provided new information on ARs local changes in the setting of LV dysfunction and on the role of these receptors in relation to pacing-induced abnormalities of myocardial perfusion and contraction. These results suggest a possible therapeutic role of adenosine in patients with HF and dyssynchronous LV contraction
Compensatory Adaptation of Left Ventricular Wall Stress in Response to Dyssynchrony Induced by Chronic Pacing in Minipigs
No full textHigh prevalence of myocardial damage evaluated by cardiovascular magnetic resonance in asymptomatic subject with cocaine addiction
No full textROLE OF CARDIOVASCULAR MAGNETIC RESONANCE IN THE DIAGNOSIS AND MANAGEMENT OF CONSTRICTIVE PERICARDITIS
No full textHigh-risk patients with mild-moderate left ventricular dysfunction after a previous myocardial infarction. A long-term prognostic data by cardiac magnetic resonance
No full textBackground: Few studies have explored prognosis in patients with previous myocardial infarction (MI) with mild-moderate (MM) left ventricular (LV) dysfunction (D).
The aim of our study was to investigate whether combining LV parameters obtained by cardiac magnetic resonance (CMR) improves risk stratification of patients with previous MI and MM-LV-D.
Methods: In 418 consecutive patients (63.3 +/- 11.3 years old, female 12.9%) with previous MI, we quantified LVEF, volumes and wall motion score index (WMSI) and measured the infarct extent by late gadolinium enhancement (LGE). According to LVEF, patients were considered with normal LVEF (N55%), MM-LV-D (LVEF >30 and <= 55%) and severe (S) LV-D (LVEF <= 30).
Results: During follow-up (median, 39.7 months) cardiac events (cardiac death or appropriate intra-cardiac defibrillator shocks) occurred in 17/99 of patients with S-LV-D, in 15/201 with MM-LV-D, and in only 1/118 of those with normal LV-EF.
After adjustment for age, an extent of LGE >11.3%, a dilated LV (male >112 ml/m(2); female >92 ml/m(2)) and a WMSI >1.59 were associated with adverse cardiac events in patients with MM-LV-D. In patients with MM-LV-D, when each of these 3 factors was observed, the prognosis was worse respect to those with 1-2 factors and no factor (p=0.035 and p=0.004, respectively). Prognosis was similar (p=0.61) between MM-LV-D patients with all 3 factors and those with S-LV-dysfunction. CONCLUSIONS. A multiparametric CMR approach, which includes LGE, dilated LV and WMSI, permits to identify post MI patients with MM-LV-D with a risk of cardiac events similar to those with S-LV-D. Further multicenter studies are needed to confirm our data. (C) 2017 Elsevier B.V. All rights reserved
Myocardial blood flow and fibrosis in hypertrophic cardiomyopathy
No full textAbstract
BACKGROUND:
We investigated the relationship between myocardial blood flow (MBF), fibrosis, risk factors for sudden death, and clinical manifestations in hypertrophic cardiomyopathy (HCM).
METHODS AND RESULTS:
Sixty-two patients with HCM (45 men, overall mean age 47 ± 16 years), 15 acromegalic patients with left ventricular hypertrophy (9 man, overall mean age 47 ± 12 years), and 20 healthy subjects underwent cardiac magnetic resonance. Resting MBF was measured as the ratio between coronary sinus flow measured by phase-contrast technique and left ventricular mass. Myocardial fibrosis was evaluated by late gadolinium enhancement (LGE) technique. In HCM patients, MBF was significantly lower than in control subjects and acromegalic patients. Patients with LGE had lower MBF than those without it (0.46 ± 0.2 vs 0.66 ± 0.29 mL·min(-1)·g(-1); P < .005). Patients with ventricular tachycardia at Holter monitoring had lower MBF (0.4 ± 0.14 vs 0.6 ± 0.29 mL·min(-1)·g(-1); P < .04). Among patients with preserved systolic function, those in New York Heart Association (NYHA) functional class ≥II had lower MBF than those in NYHA functional class I (0.46 ± 0.2 vs 0.69 ± 0.3 mL·min(-1)·g(-1); P < .003). MBF was the only independent predictor of worse clinical status (NYHA ≥II; P = .01).
CONCLUSIONS:
In HCM patients low resting MBF is associated with the presence of fibrosis. MBF is a predictor of worse clinical status
Relation of pain-to-balloon time and myocardial infarct size in patients transferred for primary percutaneous coronary intervention.
No full textThe paradigm of a shorter pain-to-balloon time decreasing extent of infarct size may be not completely true in transferred patients. This study evaluated the influence of pain-to-balloon time on infarct size as assessed by delayed enhancement magnetic resonance imaging in patients transferred from a peripheral hospital to a tertiary center for primary coronary angioplasty (percutaneous coronary intervention [PCI]). Sixty patients (40 men, 64 +/- 3 years of age) with first acute myocardial infarction were treated within 300 minutes. A presentation score system including clinical, laboratory, and echocardiographic data was used to classify severity of presentation at admission. Magnetic resonance imaging was performed 6 +/- 3 days after PCI. Group 1 had a higher presentation score than did group 2 (p <0.02) and group 3 (p <0.02). Group 1 had a significantly longer delayed enhancement than did group 2 (p <0.002) and group 3 (p <0.03). In conclusion we found that patients with worse presentation are transferred sooner for primary PCI. This approach in these patients does not decrease infarct size likely because of unavoidable delay to reperfusion. This finding suggests a different therapeutic strategy in these patients
Troponin in nonischemic dilated cardiomyopathy: a marker of irreversible myocardial remodeling and fibrosis
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Myocardial fibrosis in nonischemic dilated cardiomyopathy: role of increased wall stress and neurohormonal activation
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