The development of angiotensin-converting enzyme inhibitors (ACE inhibitors) has been one of the most remarkable stories in the treatment of cardiovascular diseases. Angiotensin converting enzyme inhibitors have several acute and sustained hemodynamic effects that are beneficial in the presence of left ventricular (LV) dysfunction. They increase cardiac output and stroke volume and reduce systemic vascular resistance as well as pulmonary capillary wedge pressure. The hemodynamic benefits are associated with improvement in the signs and symptoms of congestive heart failure (CHF) as well as decreased mortality, regardless of the severity of CHF. In patients with asymptomatic LV dysfunction, therapy with ACE inhibitors prevented the development of CHF and reduced hospitalization and cardiovascular death. They also increase survival when administered early after an acute myocardial infarction (MI). Most recently, ACE inhibition was associated with improved clinical outcomes in a broad spectrum of high-risk patients with preserved LV function. The mechanism of ACE inhibitors benefits is multifactorial and includes prevention of progressive LV remodeling, prevention of sudden death and arrhythmogenicity and structural stability of the atherosclerotic process. Evidence suggests that ACE inhibitors are underutilized in patients with cardiovascular diseases. Efforts should be directed to prescribe ACE inhibitors to appropriate patients in target doses. It is reasonable to believe that ACE inhibitors have a class effect in the management of LV dysfunction with or without CHF and acute MI. Whether the same is true for ACE inhibitors in the prevention of ischemic events is not known yet.

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Background: Although there is evidence that sighs are important to restore lung volume, the factors responsible for inducing a sigh and the effects of sighs on the stability of the respiratory system remain unclear. Objective: To compare newborn with adult sigh morphology in order to better understand the physiological mechanisms that induce sighs and the role sighs play on the control of breathing in infants. Design/Methods: We measured respiratory variables during control, the pre-sigh, the sigh, and the post-sigh period during quiet and REM sleep in 10 preterm infants, 10 term infants and 10 adults using a flow-through system. Results: No significant differences were observed in any of the respiratory variables between the pre-sigh and the control breaths in any of the subjects in any of the two sleep states, suggesting that indices of respiratory drive are not predictive of an impending sigh. Sighs were relatively larger in infants than in adults and had a characteristic biphasic inspiratory flow observed almost exclusively in infants. While post-sigh ventilation was usually increased in adults, it was usually decreased in infants due to the presence of apneas. Conclusions: The established indexes of respiratory drive are not predictive of an impeding sigh. When compared with control breaths, sighs are much larger in preterm and term infants than in adults. These big augmented breaths in infants are often followed by apnea and hypoventilation likely secondary to the increased activity of the peripheral chemoreceptors present in neonates.

A 12-lead ECG was obtained from a 72-year-old man with a core body temperature of 85°F (Figure 1). The ECG shows severe sinus bradycardia with prolonged PR, prolonged QRS complex, prolonged QT interval, and an extra deflection at the end of the QRS complex (Osborn waves) (arrows). A second 12-lead ECG obtained 24 hours later, after the patient had been rewarmed to 98°F, was normal ( Figure 2).Hypothermia, defined as core body temperature Ͻ95°F, is associated with ECG changes of diagnostic and prognostic importance. In the initial stages of hypothermia, a sinus tachycardia develops as part of the general stress reaction. As the temperature drops below 90°F, a sinus bradycardia supervenes, associated with progressive prolongation of the PR interval, QRS complex, and QT interval. With temperature approaching 86°F, atrial ectopic activity is often noted and can progress to atrial fibrillation. At this level of hypothermia, 80% of patients have Osborn waves that consist of an extra deflection at the end of the QRS complex.Osborn waves, also known as J waves, camel-hump waves, and hypothermic waves, are best seen the inferior and lateral precordial leads. They become more prominent as the body temperature drops, and they regress gradually with rewarming.With temperature Ͻ86°F, a progressive widening of the QRS complex increases the risk of ventricular fibrillation. When the temperature drops to Ϸ60°F, asystole supervenes.

The use of oral contrast and water improved the image variability and contrast by decreasing the infra-cardiac scatter. The improvement was even more significant in the oral contrast group.