再灌注损伤的新标志物
New Markers of Reperfusion Injury
    In the treatment of acute myocardial infarction (AMI)， the current strategy is to recanalize quickly the infarct-related artery (IRA). With a speedy opening of the IRA by thrombolytic therapy or balloon angioplasty (PCI)， the flow of oxygenated blood to the distal ischemic myocardium is again restored. However， reperfusion could bring damage to the myocardium by the release of oxygen radicals， neutrophil activation， infiltration and generation of cellular calcium overload， leading to acceleration of programmed cellular death or apoptosis. This detrimental phenomenon is called "reperfusion injury".
The clinical and invasive markers of reperfusion injury are slow flow after PCI， stunned myocardium， new wall motion abnormality， or reperfusion arrhythmia.  The clinical marker of irreversible reperfusion injury is persistent heart failure after reperfusion therapy. With the advent of more advanced imaging modalities such as MRI， how can reperfusion injury be documented and objectively proven in 2011? 
    Occlusion of a coronary artery leads to myocardial tissue edema in the vascular bed downstream of the vessel. This develops after an hour of occlusion or more and may persist for several months. The increase in mobile water content within the ischemic myocardium causes a prolongation of T2 magnetic resonance (MR) relaxation. Therefore， the extent of hyperintense edema which can be captured on T2-weighted MR images allows the ischemic area at risk (IAR) of injury to be retrospectively determined. This zone includes the myocardium that is potentially salvageable following reperfusion， as well as irreversibly injured tissue.
    In addition， contrast-enhanced cardiovascular magnetic resonance imaging (MRI) can also show a hypo-enhanced area corresponding to microvascular obstruction (MVO).  Further imaging shows sign of hemorrhage in the myocardium which is the hallmark of reperfusion injury. There is a close correspondence between reperfusion hemorrhage and MVO which is considered the most credible marker of reperfusion injury. This is the first time， an area of reperfusion injury could be imaged， duplicated and accurately measured.
    Applying the new understanding to the management of AMI， rather working on an invisible area of injury， by insisting on a timely reperfusion of the IRA and establishment of a patent epicardial coronary vessel， the new goals are to restore optimal microvascular perfusion and prevention of myocardial hemorrhage (reperfusion injury). These are realistic goals， representing perhaps the last frontier of therapy for AMI to be conquered.
心力衰竭的诊断
Diagnosis of Heart Failure
    Heart failure(HF) is a common problem in patient with heart disease. It is not difficult to detect heart failure in a very sick patient. However， when the patient has very mild or at the early stage of heart failure， it is difficult to detect. This is why the 6 questions below are the clinical pearls to detect HF at the earliest for urban， educated and working patients. They don’t come with typical symptoms.
    This paper is good to relax the physicians when reading a medical magazine full with serious and theoretical articles. My paper below is an eye-opener for many. It relaxes and challenges the readers because they can go back to their office and check the same things before they believe them.
呼吸困难是心力衰竭患者的初始还是终末期症状？
    Is Dyspnea the First or the Last Symptom in Patients with Heart Failure (HF)? 
    In patients with dilated cardiomyopathy and chronic fluid retention， dyspnea is the LAST symptoms of fluid retention because edema starts first in the dependent area (in the lower extremities while the patient has no shorness of breath (SOB). The fluid will continue to fill up the veins in the gastro-intestinal system before filling up the pulmonary arteries and veins as the last resort causing SOB.  
    In contrast， a patient with acute severe new onset HF such as acute mitral regurgitation， dyspnea is the FIRST symptom， even there are no crackles on lung auscultation. The reason for not having fluid edema in the peripheral veins is that because the peripheral veins do not dilate yet to accommodate the amount of fluid excess. Patient with mitral stenosis from rheumatic fever also presents with SOB even before having edema in the feet. 
心力衰竭体液潴留的初始症状
What is the first symptom of fluid retention from heart failure? 
    On supine position， patients could have increased urine output due to shifting of the extravascular fluid from the lower extremities into the intravascular compartment. The patient needs to wake up twice or more at night to urinate， a phenomenon not usually seen in young age patient. So nocturia is the earliest signs and symptoms of the venous system filled at maximum capacity even when there are no obvious signs of fluid retention yet.  However， there is on caveat: In the elderly patient， the concentrating function of the kidneys is decreased so there is no difference in the amount of urine produced during the day or at night. Even so， if the patient has to wake up more time than the past few weeks or months then there is high probability of fluid retention and extra fluid to be excreted. 
体液潴留体格检查初始体征
What is the first sign of fluid retention in physical examination? 
    Thickening of the abdominal wall by fluid infiltration is the first sign of fluid retention. A patient needs to retain 5 liters of fluid in the abdominal area before having edema in the legs.
心力衰竭的最早体征
What is the earliest sign of heart failure? 
     Sudden elevation of the INR (international normalized ratio) in patient taking warfarin daily is the earliest sign of heart failure， before any symptoms or sign in physical examination.
早期饱胀感（体液潴留的消化道症状）
Early Satiety (Fluid retention in the gastro-intestinal system)  
    The patients with fluid retention in the venous system of the GI tract could have experienced the sense of fullness or pain in the right upper quadrant due to stretching of the liver capsule from congestion. The patient can also experience the fullness or pain in the left upper quadrant due to the splenic enlargement. Nausea， anorexia， early fullness (satiety) after a small meal， or bloating sensation may be due to edema in the mesenteric area (which decreases absorption of cardiac drugs triggering acute heart failure or prolonging the recovery process).
    The reconstruction of the history of symptoms and signs of fluid retention in HF follows this sequence from early to late:
    a. Nocturia
    b. Heavy feeling in the abdominal area
    c. Peripheral edema
    d. Early Satiety
    e. Shortness of breath
    So during treatment， these symptoms will disappear in the reverse sequence:
    a. Shortness of breath
    b. Early satiety
    c.  Heavy feeling in the abdominal area
    d. Peripheral edema 
    e. Nocturia