Inhibition of angiotensin-converting enzyme (ACE) retards the process of myocardial remodeling and contractile dysfunction that leads to heart failure. However, the intracellular mechanisms by which ACE inhibition preserves myocardial contractility are largely unclear. Using a model of heart failure induced by hypertension in Dahl salt-sensitive (DS) rats, the mechanisms by which ACE inhibitors...

BACKGROUND Age and left ventricular (LV) hypertrophy are risk factors for the development of LV dysfunction and congestive heart failure. Our goal was to study the relationships of LV mass and age with myocardial dyssynchrony among asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis. METHODS AND RESULTS A total of 1100 individuals underwent tagged magnetic resonance imaging...

RATIONALE Phosphodiesterase 2 is a dual substrate esterase, which has the unique property to be stimulated by cGMP, but primarily hydrolyzes cAMP. Myocardial phosphodiesterase 2 is upregulated in human heart failure, but its role in the heart is unknown. OBJECTIVE To explore the role of phosphodiesterase 2 in cardiac function, propensity to arrhythmia, and myocardial infarction. METHODS AND...

BACKGROUND Quantitative assessment of regional myocardial function has important diagnostic implications in cardiac disease. Recent advances in CT imaging technology have allowed fine anatomic structures, such as endocardial trabeculae, to be resolved and potentially used as fiducial markers for tracking local wall deformations. We developed a method to detect and track such features on the end...

Coupled pacing (CP), a method for controlling ventricular rate during atrial fibrillation (AF), consists of a single electrical stimulation applied to the ventricles after each spontaneous activation. CP results in a mechanical contraction rate approximately one-half the rate during AF. Paired stimulation in which two electrical stimuli are delivered to the ventricles has also been proposed as ...

s m e p g m ( n f ( i t t f C c c s w m D w b t D p D D i ( 3 e s s n s p p r Dobutamine stress magnetic resonance (DSMR) is a well-established technique that is able to provide accurate detection of the contractile reserve in asynergic ischemic segments at low-dose dobutamine, and the assessment of reversible myocardial ischemia at high doses (1–3). The accuracy of the technique is due to the ...

Myocardial stress can lead to a myriad of cardiovascular complications, and stress-induced cardiomyopathy is the predominant manifestation. Exogenous or endogenous hormonal excess, sepsis, tachycardia, physical emotional trauma neurohormonal catecholaminergic surges. Stress-induced often presents with chest pain, ischemic-like ECG changes, troponin elevation, wall motion abnormalities in echoca...

Doppler-derived myocardial performance index (MPI) , defined as the s um of isovolumetric contraction and relaxation durations divided by ejection time, is an easily measured and reproducible index that shows both systolic and diastolic myocardial function. The goal of this study was to define normal values of right ventricular MPI in neonates in the first 48 to 72 hours of life. Fifty-one...

We describe two types of memory and illustrate each using artificial and actual heartbeat data sets. The first type of memory, yielding anomalous diffusion, implies the inverse power-law nature of the waiting time distribution and the second the correlation among distinct times, and consequently also the occurrence of many pseudoevents, namely, not genuinely random events. Using the method of d...

Since the dimensions of the ventricles are related to both myocardial tension and myocardial oxygen consumption (MVO2), the effects of nitroglycerin on the left ventricular volumes and left ventricular haemodynamics were studied in patients with ischaemic heart disease. The ventricular volumes were estimated using the constant infusion technique (indocyanine green) of Shaffer (1964). Sublingual...