Myocardial ischemia and infarction

Causes of diastolic dysfunction (restriction in ventricular filling) are increased ventricular stiffness, ventricular hypertrophy, infiltrative myocardial diseases, myocardial ischemia and infarction, mitral or tricuspid valve stenosis, and pericardial disease (e.g., pericarditis, pericardial tamponade). 

Myocardial ischemia and infarction cause abnorma myocardial metabolism, decreased left ventricular (LV) systolic function, diastolic dysfunction, congestive heart failure, and decreased survival. Consequently, revascularization techniques, either surgical or catheter based, have become integral to treatment of severe ischemic heart disease. 

Janse MJ, Wit AL Electrophysiological mechanisms of ventricular arrhythmias resulting from myocardial ischemia and infarction. Physiol Rev 1989 69 1049-1169. 

Decreased experimental myocardial ischemia and infarction in dogs 637... 

Lee SH, Wolf PL, Escudero R, Deutsch R, Jamieson SW, Thistlethwaite PA, Early expression of angiogenesis factors in acute myocardial ischemia and infarction, N Engl J Med 2000 342(9) 626—633. 

As cocaine use has become more widespread, the number of cocaine-related cardiovascular events has increased (39). Myocardial ischemia and infarction associated with cocaine are unrelated to the route of administration, the amount taken, and the frequency of use. The risk of acute myocardial infarction is increased after acute use of cocaine and it can occur in individuals with normal coronary arteries at angiography. The patients are typically young men and smokers and do not have other risk factors for atherosclerosis. 

Yuen-Green MS, Yen CK, Lim AD, Lull RJ. Tc-99m sestamibi myocardial imaging at rest for evaluation of cocaine-induced myocardial ischemia and infarction. Clin Nucl Med 1992 17(12) 923-5. 

Acute dilated cardiomyopathy with left ventricular dysfunction related temporally to fluorouracil and cisplatin infusion, with subsequent complete recovery, has been tentatively linked to fluorouracil (19). Other similar events have been reported (20,21). The association is more striking in patients who receive a continuous infusion of fluorouracil and in patients who receive concomitant cisplatin (22,23). For example, myocardial ischemia and infarction occur in about 10% of patients who receive fluorouracil by infusion and sudden death has occurred (24). 

Coleman DL, Ross TF, Naughton JL. Myocardial ischemia and infarction related to recreational cocaine use. West J Med 1982 136 444. 

Madias JE. Difficulties in assessing the presence, duration, severity, extent, and evolution of acute myocardial ischemia and infarction ischemic ST-segment counterpoise as a plausible explanation. J Electrocardiol 2006 39 156. 

Cardiac events also may precipitate heart failure exacerbations. Myocardial ischemia and infarction are potentially reversible causes that must be considered carefully because nearly 70% of heart failure patients have coronary artery disease. It should be noted that myocardial ischemia can be either a cause or a consequence of heart failure decompensation. Revascularization should be considered in appropriate patients. Atrial flbrillation occurs in up to 10% to 30% of patients with heart failure and is associated with increased morbidity and mortality. Atrial flbrillation can exacerbate heart failure through rapid ventricular response and loss of atrial contribution to ventricular Ailing. Conversely, decompensated heart failure can precipitate atrial flbrillation by atrial distension resulting from ventricular volume overload. Control of ventricular response, maintenance of sinus rhythm in appropriate patients, and prevention of thromboembolism... 

Cohn PF. Silent myocardial ischemia and infarction. In Goldhaber SZ, Gounameaux H, eds. Fundamental and Clinical Cardiology. New York, Marcel Dekker, 2000 1-327. 

Silent Myocardial Ischemia and Infarction Third Edition, Peter F. Cohn... 

B. Acute peripheral manifestations include sweating, tremor, muscle fascicu-lations and rigidity, tachycardia, hypertension, acute myocardial ischemia, and infarction (even with nonaal coronary arteries). Inadvertent intra-arterial injection may cause vasospasm resulting in gangrene this has also occurred with oral use of DOB (2,5-dimethoxy-4-bromoamphetamine see Lysergic Acid Diethylamide [LSD] and Other Hallucinogens, p 247). 

Collagen content, organization, cross-linking and ratio of types 1 to III change with age and in various disease conditions including myocardial ischemia and infarction, hypertension and hypertrophy... 

There are a variety of conditions that can increase the myocardial capture threshold. These include metabolic derangements, medications, and traumatic events such as inadvertent conduction of current down the lead during direct current cardioversion or defibrillation that results in tissue injury at the lead-tissue interface. Metabolic disturbances that increase the myocardial capture threshold include myocardial ischemia and infarction, hyperkalemia, hypoxemia, hypercarbia, acidemia, alkalemia, hyperglycemia, and hypothyroidism (59-62). Hyperkalemia is the most common electrolyte abnormality that can leads to failure to capture (Fig. 16.7), and the threshold typically increases when the serum potassium concentration exceeds 7.0mEq/L (63-65). Increasing the stimulus output is only variably successful and should not be relied on. Inunediate reversal of hyperkalemia should be the first priority. 

The course of events in myocardial ischemia and infarction is simpler to describe than that of placental infarction. There are similar lipid deposits in the vessel walls, there is ischemia by which vasopressor agents can be released in the circulation, spasms can occur, and the biochemical relations within the blood complete the picture with a higher tendency to clotting. An infarction may result, more vasopressive substances come into the circulation, etc. The extension of the infarct and a possible secondary hemorrhage, just as in a placental infarction, determine the final outcome, ranging from cases missed clinically or slight cases to acutely fatal ones. 

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