The detrimental effects of myocardial infarction in humans and rodents have a 24-h rhythm. In some human cohorts however, rhythmicity was absent, while the time of maximum damage differs between cohorts. We hypothesized that the type of damage influences the 24-h rhythm in infarct size. Myocardial infarction was induced in 12-week-old C57BL/six mice at four different time-points during the day ...

In this study, the cardioprotective effects of nitric oxide (NO)-aspirin, the nitroderivative of aspirin, were compared with those of aspirin in an anesthetized rat model of myocardial ischemia-reperfusion. Rats were given aspirin or NO-aspirin orally for 7 consecutive days preceding 25 min of myocardial ischemia followed by 48 h of reperfusion (MI/R). Treatment groups included vehicle (Tween 8...

PURPOSE To develop a computer algorithm to measure myocardial infarct size in gadolinium-enhanced magnetic resonance (MR) imaging and to validate this method using a canine histopathological reference. MATERIALS AND METHODS Delayed enhancement MR was performed in 11 dogs with myocardial infarction (MI) determined by triphenyltetrazolium chloride (TTC). Infarct size on in vivo and ex vivo imag...

RATIONALE In rodents, infarct size after ischemia/reperfusion exhibits a circadian dependence on the time of coronary occlusion. It is not known if a similar circadian dependence of infarct size occurs in humans. OBJECTIVE To determine if humans exhibit a circadian dependence of infarct size in the setting of ST elevation myocardial infarction (STEMI). METHODS AND RESULTS A retrospective an...

Background: Little is known about the relation between the extent of microvascular damage and infarct size in patients after successful mechanical reperfusion of acute myocardial infarction. Objective: To compare the spatial extent of reduced myocardial signal between real time myocardial contrast echocardiography (MCE) and single photon emission computed tomography (SPECT) after successful mec...

The accuracy of the use of the maximal QRS vector difference to estimate myocardial infarct size irrespective of infarct location was compared with that of measurement of cumulative creatine kinase (CK) release. Sixty patients with acute myocardial infarction and a history of symptoms of less than 4 hr duration were followed for 24 to 72 hr with orthogonal vectorcardiography and CK release anal...

OBJECTIVE In patients with acute myocardial infarction (AMI), estimation of infarct size from the early markers, fatty acid-binding protein (FABP) and myoglobin (MYO), usually assumes average (fixed) rate constants (FCR) for protein clearance from plasma. However, individual variation in FCR is large. Renal dysfunction causes slower clearance of FABP and MYO from plasma and, hence, overestimati...

RATIONALE Four monocentric studies reported that circadian rhythms can affect left ventricular infarct size after ST-segment-elevation acute myocardial infarction (STEMI). OBJECTIVE To further validate the circadian dependence of infarct size after STEMI in a multicentric and multiethnic population. METHODS AND RESULTS We analyzed a prospective cohort of subjects with first STEMI from the F...

AIMS Effects of the bradycardic agent ivabradine on regional blood flow, contractile function, and infarct size were studied in a pig model of myocardial ischaemia/reperfusion. Heart rate reduction by beta-blockade is associated with negative inotropism and unmasked alpha-adrenergic coronary vasoconstriction. Ivabradine is the only available bradycardic agent for clinical use. METHODS AND RES...

BACKGROUND Little is known about the relation between the extent of microvascular damage and infarct size in patients after successful mechanical reperfusion of acute myocardial infarction. OBJECTIVE To compare the spatial extent of reduced myocardial signal between real time myocardial contrast echocardiography (MCE) and single photon emission computed tomography (SPECT) after successful mec...