Cardiology Interpreting myocardial perfusion SPECT images involves a systematic comparison of rest and stress images to assess myocardial ischemia and infarction. The key steps in…

…equally compromised, leading to uniform perfusion that may appear deceptively normal on SPECT. Detecting multivessel disease requires quantification of absolute coronary blood flow. This is…

Cardiology Principles of myocardial perfusion imaging Myocardial perfusion imaging (MPI) is a non invasive technique for detecting and quantifying coronary artery disease (CAD). It offers…

…induce myocardial electrical activity by generating adequate coronary perfusion pressure (CPP). Myocardial activity is necessary to salvage the brain, and is therefore of prime importance…

…perfusion imaging can determine whether dysfunctional myocardium or myocardium supplied by a diseased vessel, is viable and could benefit from revascularization. Evaluating the success of…

…Return of Spontaneous Circulation (ROSC) : Return of mechanical cardiac function resulting in circulation with pulse. Coronary perfusion pressure (CPP) : The pressure that drives blood flow…

Cardiology Myocardial ischemia and infarction Definition and Clinical Purpose Myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) or positron emission tomography (PET…

…120 seconds of cardiac arrest and light reactivity is lost when cerebral blood flow ceases. In other words, during prolonged cardiac arrest without effective perfusion…

…impaired ventilation–perfusion matching, increased physiological dead space and the Haldane effect. It is therefore misleading to explain the whole phenomenon as abolition of the…

…This results in flow heterogeneity and perfusion defects in areas supplied by the disease artery. Thus, vasodilators replicate the effects of exercise on coronary arteries…

…with myocardial perfusion on the microvascular level. This is presumably explained by distal microembolization and dysfunctional microcirculation. Indeed, studies show that 15–35% of patients…

Procedurer The value of the exercise test lies not in ST depression alone but in the overall picture : exercise capacity, symptoms, blood pressure response, heart…

…and ECG changes in all patients. Achieving 70% of age adjusted MHR resulted in perfusion defects in 89% of patients, anginal symptoms in 26% and…

…No reflow should be suspected when distal coronary perfusion remains reduced despite successful treatment of the apparent epicardial stenosis and without an angiographically evident flow…

…term management of hypertension, including hypertensive emergency. Mechanism of action • Systemic Dopamine 1 (D1) receptor agonist. • Lowers blood pressure while maintaining or increasing kidney perfusion…

…resistance, and restore adequate end organ perfusion. Dobutamine is a synthetic catecholamine that functions as an agonist of both beta1 and beta2 adrenergic receptors, with…

Critical care Myocardial ischemia and infarction Definition and Pathophysiology Cardiogenic shock is a state of inadequate tissue and end organ perfusion caused by cardiac insufficiency…

…caused by pre excitation. Myocardial perfusion scintigraphy. Contraindications Asthma and COPD. Adenosine has caused mild to moderate exacerbation of asthma symptoms. Adenosine should be used…

…of cardiac arrest, compression efficacy, ventilation depth and frequency, and adrenaline administration. Therefore, it is advised to use ETCO2 trends over time rather than single…

…pathophysiology Acute limb ischaemia (ALI) is an abrupt reduction in arterial perfusion of an upper or lower limb that causes tissue metabolic requirements to exceed…

…salicylate poisoning, intubation with an inadequate minute ventilation can rapidly worsen the acidaemia and increase the entry of salicylate into the central nervous system. Discuss…

…during acute decompensated heart failure, but worsening renal function does not necessarily indicate reduced cardiac output or impaired renal perfusion. Many patients have preserved cardiac…

…80–85 mmHg in chronic hypertension or when there are signs of inadequate perfusion Urine output 0.5 mL/kg/h Lactate Falling A clearance…

…few decades. The repertoire of available methods includes echocardiography, cardiovascular magnetic resonance (CMR), cardiac computed tomography (CT), single photon emission computed tomography (SPECT), positron emission…

…contractions – enables the myocardium to endure 20 to 30 minutes of severe ischemia. If myocardial perfusion (blood flow) in the ischemic zone is not restored…

…cerebral perfusion, with an equal degree of hypoxia in all neurons. There is one fundamental difference between neurons and myocardium in the setting of hypoxia…

…Give small boluses, for example 250 to 500 mL, with immediate reassessment of the blood pressure, pulse, peripheral perfusion, mental state and chest findings. Avoid

…myocardial perfusion include fixed coronary atherosclerosis without plaque rupture, coronary artery spasm, coronary microvascular dysfunction (encompassing endothelial dysfunction, smooth muscle cell dysfunction, and dysregulation of…

…A substantial reduction in pulmonary perfusion and the subsequent reduction in left ventricular preload lead to a cascade of hemodynamic alterations which may culminate in…

…is a better indicator of organ perfusion. In clinical settings, MAP is often preferred over SBP for the following reasons: Indicator of Organ Perfusion : MAP…

…Myocardial bridging is an anatomical variant in which a segment of an epicardial coronary artery passes through the myocardium rather than remaining on the epicardial…

…achievable myocardial perfusion. A pressure reduction across an epicardial stenosis therefore identifies a limitation in potential hyperaemic flow. FFR is consequently a measure of the…

…when resting perfusion is insufficient to meet the basal nutritional requirements of tissue. Typical symptoms include: Ischaemic rest pain. Coldness or numbness of the foot…

…other evidence of ongoing ischaemia Symptoms suggesting haemodynamic compromise, such as near syncope or poor perfusion Known arrhythmia or electrical instability The presence of severe…

…lead to insufficient coronary perfusion (i.e myocardial ischemia and angina pectoris), ventricular dysfunction (heart failure) and arrhythmias. The annual risk of sudden cardiac arrest…

…preload, diminished stroke volume, and subsequently lower blood pressure and reduced organ perfusion. Left ventricular dilation occurs with ensuing decline inleft ventricular ejection fraction (LVEF)…

…simple and validated marker of perfusion Lactate < 1.6 mmol/L Clearance over time is more informative than a single value Urine output 0…

…acute stroke to identify large vessel occlusion, dissection or other vascular pathology CT perfusion Used with an unclear time of onset, a late time window…

…distinction that determines management is: is there acute hypertension mediated organ damage or not? A single blood pressure value does not define a hypertensive emergency…

…avoid cyanide toxicity. • Dose dependent reduction in coronary and renal perfusion. • Dose dependent elevation of intracranial pressure (ICP) and reduction in cerebral blood flow. Caution …

…functional capacity, and health related quality of life substantially influence both cardiovascular risk and the balance between treatment benefit and harm. Prevention in the very…

…function and prognosis by restoring perfusion to viable dysfunctional myocardium while preventing further ischemic events. However, the presumed relationship between viability, recovery of ejection fraction…

…diagnostic angiography. Collateral vessels may maintain distal perfusion and permit visualization of the vessel beyond the occlusion when the patent donor artery is injected. The…

…or diffuse disease. No reflow represents impaired antegrade myocardial perfusion in the absence of a flow limiting epicardial stenosis. It is associated particularly with intervention…

…the myocardium obtains 30% of its resting perfusion from collaterals, it may survive for 60 minutes in the case of a total occlusion or 5…

…suggest acute organ dysfunction Organ or system Finding : : CNS New confusion, disorientation, agitation, drowsiness or a reduced GCS Respiration A respiratory rate of at least…

…Causes of myocardial injury Important causes include: Mechanism or clinical setting Examples Acute coronary atherothrombosis Plaque disruption or erosion with thrombosis Reduced myocardial perfusion Coronary…

…at high risk of developing atrial fibrillation, and vice versa. The pathophysiological explanation for this may be a general degeneration of the atrial conduction system…

…the basis of percussion and a chest radiograph alone belongs to an earlier era. The needle is inserted close to the upper border of the…

…organ structure and function. Ultrasound imaging, including echocardiography, has become a standard tool for clinicians worldwide (Narula et al). This chapter discusses the principles of…

…delivered bolus to achieve sufficiently high concentrations at its clinical site of action—the coronary artery perfusing the AV node—before the drug is eliminated…