Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The records of 598 patients undergoing a thoracic surgical procedure for lung cancer from 1975 through 1989 were reviewed for occurrence of cardiac arrhythmias and myocardial ischemic events. Atrial tachycardias occurred in 16% (94/598); atrial fibrillation was preponderant (87%), followed by supraventricular tachycardia and atrial flutter. Patients with recurrent episodes of dysrhythmias had a significantly higher mortality rate than those without episodes or with a single episode only (17% versus 2.4%; p less than 0.01). Transient ischemic electrocardiographic changes were documented in 23 patients (3.8%) and myocardial infarction in 7 (1.2%). An abnormal preoperative exercise test result and intraoperative hypotension were strongly associated with both dysrhythmia and ischemia (p less than 0.01). Pneumonectomy, ischemic changes on the electrocardiogram, and cardiac enlargement were also associated with arrhythmias (p less than 0.01). A weaker association (p less than 0.05) was found between postoperative arrhythmias and old myocardial infarction (greater than 6 months), arterial hypertension, and heart failure. Pulmonary function had no predictive value in this respect. A history of angina or old myocardial infarction was predictive of transient postoperative myocardial ischemia but not myocardial infarction. Despite improved anesthetic and monitoring techniques and more frequent use of the intensive care unit postoperatively in the last decade, the incidence of arrhythmias after thoracotomy has not decreased. More effective prevention is needed, particularly for patients with defined preoperative and perioperative risk factors.
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PMID:Cardiac arrhythmias and myocardial ischemia after thoracotomy for lung cancer. 155 74

We studied atrial arrhythmias during the first 12 h of admission to the hospital in 266 consecutive patients with acute myocardial infarction who subsequently underwent coronary angiography. Ten patients developed atrial fibrillation, one atrial flutter, and one supraventricular tachycardia. Another five developed sinus dysrhythmias. All of the above patients had an acute inferior myocardial infarction, and in 10 of the 12 patients with supraventricular arrhythmias and in four of five with sinus dysrhythmias, the origin of the sinus node artery started just after an occluded right coronary or left circumflex artery or was involved in the occlusion. Thus, ischemia of the sinus node due to coronary occlusion proximal to the origin of the sinus node artery was a likely cause of these arrhythmias.
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PMID:Early atrial arrhythmias in acute myocardial infarction. Role of the sinus node artery. 155 68

In a prospective blinded trial, 24-hour continuous electrocardiographic monitoring for silent ischemia was used to try to identify rehabilitation patients at risk for cardiac complications. Five of 42 patients had episodes of silent ischemia, none of which occurred during physical therapy sessions. One of these patients had syncope while wearing the Holter; none of the other four patients had significant cardiac complications during their rehabilitation, and all were discharged home. None of the patients without ischemia on the monitor had complications, but two patients of 14 whose ECGs precluded monitoring for ischemia had complications. In addition, six patients had episodes of nonsustained asymptomatic ventricular tachycardia, 12 had episodes of supraventricular tachycardia, and four had significant ventricular ectopy, all without clinical significance. Despite the apparent high sensitivity and specificity of the technique, the positive predictive value of monitoring eligible patients for silent ischemia was 20%. We conclude that ambulatory electrocardiographic monitoring for silent ischemia or ectopy has limited clinical utility in the rehabilitation population.
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PMID:Silent ischemia in rehabilitation patients: limited clinical utility of electrocardiographic monitoring. 164 23

We observed, during Holter recording, a case of inferior acute myocardial infarction complicated by paroxystic hyperkinetic atrial fibrillation, which occurred 12 min after the onset of acute irreversible myocardial ischemia. The atrial fibrillation was preceded by a complex pattern of hyperkinetic supraventricular arrhythmias characterized by single premature supraventricular beats, paired premature supraventricular beats and many runs of paroxystic supraventricular tachycardia. The most plausible hypothesis is that atrial fibrillation and the preceding arrhythmic pattern have been due to an extension of ischemia from ventricular to atrial myocardium.
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PMID:[Acute myocardial infarction promptly complicated by atrial fibrillation during Holter recording]. 181 11

Exogenous adenosine has been shown to have potent electrophysiologic effects and antiarrhythmic properties within the atrioventricular (AV) node. Endogenous adenosine, a nucleoside with an increased release signaled by ischemia and hypoxia, is not believed to exert significant effects during homeostatic conditions. Recent experimental evidence suggests, however, that under normoxic conditions, the amount of adenosine released may be sufficient to mediate some of its physiologic effects. This study was designed to test the hypothesis that in humans the electrophysiologic effects of endogenously released adenosine on AV nodal conduction can be demonstrated under normoxic conditions by inhibiting uptake and degradation of the nucleoside. In the first protocol, the effects of intravenous dipyridamole (0.56 mg/kg bolus i.v., 5 micrograms/kg/minute infusion), a nucleoside-transport blocker that elevates endogenous plasma levels of adenosine, on AV nodal conduction were evaluated in seven patients. At a constant atrial paced cycle length, dipyridamole increased the AH interval from 110 +/- 19 to 164 +/- 26 msec, p = 0.002 (+/- SEM). Aminophylline (5.6 mg/kg i.v.), a competitive antagonist of adenosine, completely reversed the effects of dipyridamole on AV nodal conduction. Similarly, dipyridamole increased the cycle length at which pacing-induced AV nodal Wenckebach occurred, from 348 +/- 31 (control) to 388 +/- 33 msec (dipyridamole) (p = 0.002). In a second protocol, the effects of intravenous dipyridamole were evaluated in another group of six patients who had supraventricular tachycardia (SVT) in which the AV node was part of the reentrant circuit.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Electrophysiologic effects of dipyridamole on atrioventricular nodal conduction and supraventricular tachycardia. Role of endogenous adenosine. 259 20

Diltiazem, a calcium channel blocking agent, has potent cardiovascular effects that are directly related to its influence on vascular smooth muscle, ventricular myocardium, and specialized conducting tissue. It causes coronary and peripheral vasodilation, has a negative chronotropic and dromotropic effect, and little to no negative inotropic effect in patients with normal ventricular function. Diltiazem has potential use in a wide variety of cardiovascular disorders. It has been shown extremely effective in relieving the coronary artery spasm associated with variant angina. When compared with nitrates in patients with exertional angina, diltiazem has similar efficacy. Preliminary work indicates it will have a therapeutic role in the treatment of unstable angina. Because of its ability to improve the balance between myocardial oxygen supply and demand and reduce cellular injury secondary to ischemia, it is likely that diltiazem will be of benefit in the treatment of acutely ischemic myocardium during cardiopulmonary bypass and possibly acute myocardial infarction. It has proven efficacy in treating re-entrant supraventricular tachycardia. Adverse effects are seen in less than 5% of patients, indicating that it is well tolerated.
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PMID:The use of diltiazem hydrochloride in cardiovascular disorders. 676 99

Supraventricular tachycardia as a presenting sign of pulmonary embolism is unusual. A 31-year-old man with incomplete T11 paraplegia on the basis of spinal cord ischemia developed supraventricular tachycardia 37 days after surgery to repair an aortic tear. Subsequent work-up revealed evidence of multiple submassive pulmonary emboli, despite thromboembolism prophylaxis. Clinicians should maintain a high index of suspicion for thromboembolic events when faced with cardiac rhythm disturbances in high-risk patients.
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PMID:Pulmonary embolism presenting as supraventricular tachycardia in paraplegia: a case report. 823 64

Substantial technological progress has been made recently in the area of perioperative cardiovascular monitoring. Specialized monitoring may be performed for problems identified by preoperative evaluation. New technologies have been developed for monitoring the blood pressure continuously and non-invasively. Electrocardiographic monitoring of perioperative ischemia has been characterized. Newer techniques in echocardiography such as the use of contrast, and tissue characterization allowed improved monitoring of ischemia as well as ventricular function. Continuous monitoring of cardiac output can be performed by impedance cardiography and Doppler ultrasound and by continuous thermodilution. Improved rules for the differentiation of ventricular from supraventricular tachycardia have been developed. Detection of MI has been facilitated by new scintigraphic and enzymatic techniques. In critically ill patients, multi-system monitoring may be required to adequately assess the cardiovascular system.
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PMID:New developments in perioperative cardiovascular monitoring. 1017 86

An 11-year-old patient with diagnosis of hypertrophic cardiomyopathy (HCM) developed marked elevation of troponin I in the absence of electrocardiographic signs of ischemia after two episodes of supraventricular tachycardia. At follow-up the level of troponin I returned to normal. The role of troponin I in patients with HCM as a risk marker deserves further evaluation.
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PMID:Troponin I elevation after supraventricular tachycardia in a child with hypertrophic cardiomyopathy. 1117 73

This study was performed to determine the impact of electrocardiogram (ECG) interpretation on urgent patient care decisions by internal medicine (IM) and emergency medicine (EM) resident physicians. Six clinical scenarios and ECGs were given to 31 IM residents and 31 EM residents at a university medical center. Based on the ECG interpretation, the residents were asked to select the best patient management from a list of choices. IM and EM residents were equally likely to choose the correct management for complete heart block (90% IM v 97% EM, P = NS), and pulseless ventricular tachycardia (VT) (94% IM v 97% EM, P = NS). IM residents were less likely to choose the correct management for acute posterior wall myocardial infarction (MI) (26% IM v 74% EM, P <.0001) and unstable supraventricular tachycardia (SVT) (87% IM v 100% EM, P <.05). Residents in both programs were equally likely to misinterpret left ventricular hypertrophy (LVH) (23% IM and 16% EM, P = NS) and benign early repolarization (BER) (48% IM and 52% EM, P = NS) as acute myocardial ischemia when presented with a clinical history not suggestive of cardiac ischemia. IM and EM residents were equally likely to choose the correct management for complete heart block and pulseless VT. Compared with EM residents, IM residents were less likely to choose the correct management of posterior wall MI and unstable SVT. Both IM and EM residents were prone to misinterpreting LVH and BER as acute myocardial ischemia. Resident education in both specialties should focus on ECG interpretation skills to improve patient management decisions.
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PMID:Variation in patient management based on ECG interpretation by emergency medicine and internal medicine residents. 1199 38


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