Myocardial ischemia

Technetium-99m tetrafosmin ( Tc-(V)02 (l,2-bis(bis(2-ethoxyethyl)phosphino)ethane) (see Fig. 3d)) is a myocardial perfusion agent. It is used as an adjunct in the diagnosis and localization of myocardial ischemia and/or infarction. 

Ca2+ is an important intracellular second messenger that controls cellular functions including muscle contraction in smooth and cardiac muscle. Ca2+ channel blockers inhibit depolarization-induced Ca2+ entry into muscle cells in the cardiovascular system causing a decrease in blood pressure, decreased cardiac contractility, and antiarrhythmic effects. Therefore, these drugs are used clinically to treat hypertension, myocardial ischemia, and cardiac arrhythmias. 

Cardiac Mitochondria KATP (SUR2A/ Kir6.2) Myocardial ischemia B MS-180448... 

Preanesthetic drugs may be omitted in those 60 years or older because many of the medical disorders for which these drugsare contraindicated are seen in older individuals For example, atropine and glycopyrrolate, drugs that can be used to decrease secretions of the upper respiratory tract, are contraindicated in certain medical disorders such as prostatic hypertrophy, glaucoma, and myocardial ischemia. Other preanesthetic drugs that depress the central nervous astern (CN, such as narcotics barbiturates and antianxiety drugs with or without antiemetic properties may be contraindicated in the older individual. 

D Pain related to myocardial ischemia secondary to narrowing ot the coronary arteries, adverse drug reactions (headache)... 

D Ineffective Tissue Perfusion Cardiopulmonary related to myocardial ischemia... 

Imamura M, Lander HM, Levi R Activation of histamine H3-receptors inhibits carrier-mediated norepinephrine release during protracted myocardial ischemia. Comparison with adenosine Aj-receptors and a2-adrenoceptors. Circ Res 1996 78 475. 

Silver RB, Mackins CJ, Smith NCE, Koritchneva IL, Lefkowitz K, Lovenberg TW> Levi R Coupling of histamine H3 receptors to neuronal Na+/H+ exchange a novel protective mechanism in myocardial ischemia, Proc Natl Acad Sci USA 2001 98 2855. Silver RB, Poonwasi KS, Seyedi N, Wilson SJ, Lovenberg TW, Levi R Decreased intracellular calcium mediates the histamine H3-receptor-induced attenuation of norepinephrine exocytosis from cardiac sympathetic nerve endings. Proc Natl Acad Sci USA 2002 99 501. 

Wang W, Schulze CJ, Suarez-Pinzon WL et al (2002) Intracellular action of matrix metaUoproteinase-2 accounts for acute myocardial ischemia and reperfusion injury. Circulation 106 1543-1549... 

Combination GP Ilb/IIIa and rt-PA Therapy for Acute Stroke The combination of antiplatelet and thrombolytic drugs has proven efficacy in the setting of myocardial ischemia where an additive effect is seen. In acute stroke thrombolysis with a very narrow time window and less than 50% optimal reperfusion rates,adjunctive therapy with antiplatelets may be a promising approach. However, MAST-I concluded that the group of patients receiving streptokinase plus aspirin had a marked increase in 10-day mortality. 

Doses >0.04 units/min have been associated with myocardial ischemia, decreased cardiac output, and cardiac arrest... 

Electrocardiogram (ECG) May be normal or could show numerous abnormalities including acute ST-T-wave changes from myocardial ischemia, atrial fibrillation, bradycardia, and LV hypertrophy. 

The major goals for the treatment of ischemic heart disease are to prevent acute coronary syndromes and death, alleviate acute symptoms of myocardial ischemia, prevent recurrent symptoms of myocardial ischemia, and avoid or minimize adverse treatment effects. 

Acute coronary syndromes is a term that includes all clinical syndromes compatible with acute myocardial ischemia resulting from an imbalance between myocardial oxygen demand and supply.3 In contrast to stable angina, an ACS results primarily from diminished myocardial blood flow secondary to an occlusive or partially occlusive coronary artery thrombus. Acute coronary syndromes are classified according to electrocardiogram (ECG) changes into STE ACS (STE MI) or NSTE ACS (NSTE MI and unstable angina) (Fig. 5-1). An STE MI, formerly... 

Current data suggest little benefit on clinical outcomes beyond symptom relief for calcium channel blockers in the setting of ACS.43 Moreover, the use of first-generation shortacting dihydropyridines, such as nifedipine, should be avoided because they appear to worsen outcomes through their negative inotropic effects, induction of reflex sympathetic activation, tachycardia, and increased myocardial ischemia.43 Therefore, calcium channel blockers should be avoided in the acute management of MI unless there is a clear symptomatic need or a contraindication to p-blockers. 

Myocardial ischemia Carotid-sinus hypersensitivity Neurocardiac syncope... 

Symptoms of bradyarrhythmias include dizziness, fatigue, lightheadedness, syncope, chest pain (in patients with underlying myocardial ischemia), and shortness of breath and other symptoms of heart failure (in patients with underlying left ventricular dysfunction). 

Assess possible correctable etiologies, including myocardial ischemia, serum potassium concentration (for hyperkalemia), and thyroid function tests (for hypothyroidism). 

Idiopathic degeneration of the atrioventricular node Myocardial ischemia or infarction Neurocardiac syncope Carotid-sinus hypersensitivity... 

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