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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to study the occurrence and frequency of ischemia-induced ventricular arrhythmias, we analyzed 105 episodes of spontaneous angina pectoris occurring at rest in 28 hospitalized patients with unstable angina pectoris and proved coronary artery disease. Of 24 patients with serious ventricular arrhythmias during pain, 17 (57%) were arrhythmia-free during monitoring. In the other four patients, 17 of 29 (59%) pain episodes were associated with serious ventricular arrhythmias, and three of these four had serious ventricular arrhythmias during pain-free periods. Each patient tended to manifest the same type of arrhythmia during repeat episodes of pain. It appears that continuous electrocardiogram (ECG) monitoring is important during the initial hospitalization of the patient with unstable angina. The presence of ventricular arrhythmias during pain-free periods indicates a high risk for serious ventricular arrhythmias during episodes of spontaneous pain. These patients should be considered for continued ECG monitoring and antiarrhythmic therapy.
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PMID:Ventricular arrhythmias during unstable angina pectoris. 5 51

In order to determine the natural evolution of different clinical types of "unstable angina", 167 patients were included in a prospective study. After angiography, 11 (6.5%) were excluded because they had no significant coronary lesions. The remaining 156 were sorted into different groups according to their clinical characteristics and were followed up for a period of 24 months at least. After that follow-up period, mortality and incidence of acute myocardial infarction (AMI) were as follows: angina of recent onset (Class III--IV NYHA): 8.5% (3/35) and 34.2% (12/35). Progressive angina: 7.4% (2/27) and 7.4% (2/27). Intermediate syndrome: 41.6% (10/24) and 37.5% (9/24). Prinzmetal's angina: 10% (1/10) and 10% (1/10). Post acute myocardial infarction angina: 35% (7/20) and 10% (2/20). Acute persistent ischemia: 2.5% (1/40) and 20% (8/40). Comparison of these figures pointed out significant differences (p less than 0.001 for mortality and p less than 0.03 for AMI incidence respectively). We conclude that it is clinically possible to identify different groups within the so-called unstable angina. Such a division not only allows for the creation of more homogeneous groups, but it contributes to a more rational therapeutic approach and also permits identification of high risk prodromes of greater complications, such as myocardial infarction or sudden death.
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PMID:Clinical spectrum of "unstable angina". 26 65

Early revascularization following myocardial infarction (MI) is reported to have a high risk of extension of and hemorrhage into infarction with resulting high mortality and morbidity. To evaluate this issue, 80 post-MI patients (aged 32-74 years) with unstable angina pectoris resistant to maximal medical therapy were reviewed. All patients underwent early uncomplicated angiography and subsequent revascularization; 55 (69%) were less than 10 days post-MI, and 25 (31%) were 10-30 days post-MI. Intraaortic balloon pumping was required in 72% for relief of intractable angina or hemodynamic instability. Of the 80 patients, 19% had single vessel disease (VD), 31% double VD, and 50% triple VD. The mortality rate from coronary bypass surgery was 7/80 (8.8%), with four cardiac and three noncardiac deaths. Two patients suffered a perioperative MI (2.5%). At a mean follow-up period of 33 months, there had been only one late death and one recurrent nonfatal MI; 96% of the patients had no significant angina. In patients with continuing ischemia immediately after MI, myocardial revascularization can be safely performed without further injury to the myocardium, and with excellent long-term results.
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PMID:Safe early revascularization for continuing ischemia after acute myocardial infarction. 31 12

In a 45 year old male patient with a history of previous inferior myocardial infarction and unstable angina pectoris, coronary angiography revealed two-vessel disease: a 60-70% lesion in the middle third of the LAD, and a 90% lesion in the middle third of the very large RCA. There was only a small akinetic segment in the posterobasal region of the left ventricle. During angiography total occlusion of the RCA occurred followed the clinical and electrocardiographic signs of impending inferior reinfarction. Recanalization of the occluded vessel was accomplished by using a guide-wire, which was passed through a Sones catheter, placed in the RCA. The patient's symptoms subsided and the electrocardiographic signs of acute ischemia reverted within eight minutes. Aortocoronary bypass surgery with revascularization of the LAD and RCA was performed within 3 hours after recanalization. Postoperatively there was no evidence of major tissue loss by enzyme or electrocardiographic criteria. Control angiography, performed on the ninth day postoperatively, revealed the graft to the RCA to be widely patent. Left ventricular function was unchanged. It is concluded, that the combined approach of early transluminal recanalization of the acutely occluded RCA followed by successful construction of a graft to this vessel, has averted necrosis of a major portion of the left ventricle. However, general use of this technique does not seem advisable at the present time.
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PMID:Acute coronary occlusion with impending infarction as an angiographic complication relieved by a guide-wire recanalization. 31 53

Serial treadmill exercise testing (mean 5.5 tests/patient) was used to evaluate the prognosis of 200 males (mean age 53 years) without clinical heart failure or unstable angina pectoris 3 weeks after acute myocardial infarction (MI). Exercise-induced ischemic ST-segment depression greater than or equal to 0.2 mV 3 weeks after MI was significantly more prevalent in patients with subsequent cardiac arrest (100%) or coronary artery bypass graft surgery (64%) than in patients without subsequent events within 2 years of infarction (35%) (p less than 0.05). Exercise-induced ventricular arrhythmia on multiple tests 5-52 weeks after MI was more prevalent in patients with recurrent myocardial infarction (90%) than in patients without subsequent events (47%) (p less than 0.001). By contrast, exercise-induced ventricular arrhythmia on a single test at 3 weeks was a less powerful predictor of subsequent cardiac events. Exercise-induced ischemia 3 weeks after MI predicted early fatal events, while ventricular arrhythmia on serial testing predicted later nonfatal events.
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PMID:The prognostic significance of serial exercise testing after myocardial infarction. 49 48

Emergency revascularization for unstable angina (defined according to criteria of the National Cooperative Study Group) was performed in 100 consecutive patients. The mean interval from onset of pain to operation was one day. Nineteen patients had single-vessel narrowing of greater than 70% of lumen diameter, 32 double-vessel obstruction and 49 triple-vessel disease. Fourteen of these patients had left main trunk obstruction. Four patients died within 30 days, three from complications of myocardial infarction. Seventeen of 96 (18%) early survivors sustained perioperative infarction. After a mean follow-up of 42 months, four late deaths and three late infarctions occurred. Postoperative angiography in 47 patients (mean interval 14 months) showed 86% graft patency. Of 92 survivors, 72 are symptom-free. Three of the four operative deaths occurred within 24 hours postoperatively; in each of these, postmortem examination confirmed a recent myocardial infarction which antedated the operation, despite the absence of new infarction in the peroperative electrocardiogram or elevation of cardiac enzymes. Results from this emergency series suggest that, although myocardium may be salvaged in some instances, in other cases infarction has already occurred and treatment might better be directed toward alleviation of acute ischemia to provide a stable period in which diagnostic studies are performed and acute myocardial infarction may be ruled out.
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PMID:Emergency revascularization for unstable angina. 70 72

Unstable angina is a syndrome which comprises a spectrum of symptomatic manifestations of coronary artery disease which lies between stable angina pectoris and acute myocardial infarction. Patients fall into three groups: angina of recent onset (4 weeks), angina of changing pattern, and angina occurring at rest (longer than 15 minutes). The syndrome may presage acute myocardial infarction or sudden death, or may itself be the manifestation of a myocardial infarction. The pathophysiology may involve primary cardiac events or extracardiac precipitating factors, and does not appear to be the consequence of a particular anatomic pattern of coronary artery disease. Pain may occur as a result of regional reduction of coronary flow to pressure-dependent areas of myocardium during states of increased myocardial oxygen demand. Persisting ischemia leads to infarction via a series of events which may include myocardial edema formation, increased beta-sympathetic tone, and others which have been experimentally modified by interventions designed to limit infarct size. Although the incidence of acute myocardial infarction and death was high in early studies, in recent reports acute infarction occurs in under 15.5 per cent and death in under 2 per cent. Patients at high risk are those pain persists with bed rest, and those with preceding stable angina pectoris or myocardial infarction. Prognostic differences among Groups 1, 2, and 3 may exist but cannot be assessed from available studies. Studies of the management of unstable angina have generally been uncontrolled. Hospitalization, bed rest, and short- and long-acting nitrates are generally employed in Groups 2 and 3 patients and the marked reduction in myocardial infarction rates from early to recent studies tends to support these approaches. Anticoagulants are less used now than formerly. Propranolol can produce a significant reduction of myocardial oxygen consumption and may redirect coronary flow to ischemic areas. The drug has effectively controlled pain in several studies and is now widely used to manage unstable angina. Aortocoronary bypass surgery has been extensively employed but there is only one preliminary report of a controlled study available. The role of surgery is not yet defined. The optimal approach to therapy may eventually involve the use of medical therapy, including beta-blockade to stabilize patients, with delayed semielective coronary angiography and surgery in those who respond. Emergency angiography and surgery might then be reserved for the high-risk group of patients whose pain persists during optimal medical therapy.
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PMID:Unstable angina pectoris. 78 21

Although technetium-99m stannous (99mTc[Sn]) pyrophosphate has been shown to be a specific and sensitive index of myocardial infarction, abnormal images have been reported in patients with unstable angina or ventricular aneurysm. Sixty-one subjects--33 patients subjected to maximal treadmill stress testing, 23 normal subjects and 5 patients with a calcified aortic or mitral valve--underwent imaging with 99mTc(Sn) pyrophosphate to determine whether abnormal images are associated with (1) exercise-induced ischemia, (2) delayed clearance of tracer from the blood pool, or (3) calcified intracardiac structures. Myocardial injury was excluded on the basis of normal MB creatine kinase (CK) values in all patients with stress testing. All eight patients with an abnormal exercise stress test had normal images. Four of 25 patients with a normal exercise stress test had diffusely abnormal images. In some normal subjects diffusely abnormal images were present 60 minutes after injection of the tracer, but became normal 90 to 120 minutes after injection. Variations in clearance of tracer from the blood pool were noted in this group. Patients with a calcified aortic or mitral valve had normal images. We conclude that (1) exercise-induced ischemia is not associated with abnormal 99mTC(SN) pyrophosphate images; (2) images are not necessarily abnormal in patients with a calcified valve; and (3) delayed removal of tracer from the cardiac blood pool may result in diffusely abnormal images even in normal subjects; in these cases, repeat images should be obtained at least 2 hours after injection of the tracer to avoid false abnormal images.
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PMID:Technetium-99m stannous pyrophosphate scintigrams in normal subjects, patients with exercise-induced ischemia and patients with a calcified valve. 84 57

Intra-aortic balloon pumping is used at MGH for the reversal of acute myocardial ischemia in those patients not responding to usual medical means. The survival rate of surgical intervention in patients in cardiogenic shock was significantly increased in patients who had been balloon-pumped prior to surgery. The use of the intra-aortic balloon assist early in the postoperative patient showing low cardiac output state not only served to improve hemodynamics but also led to the preservation of the myocardium and ultimate improved survival. The balloon assist was initiated to control the ischemic states in patients with severe unstable angina. Used in association with nitroprusside and propranolol, this method produced marked improvement and reduction of pain in patients. Indications are that intra-aortic balloon counterpulsation at the present time is the safest and most predictable means of controlling acute ischemia in patients who are resistant to standard medical intervention.
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PMID:Intra-aortic balloon assist for cardiogenic shock and ischemic states at Massachusetts General Hospital. 96 75

We compared patients with variant angina (ST-segment elevation during pain) who had normal or near normal coronary arteriograms (Group 1) with 20 in whom variant angina occurred in the presence of obstructive coronary lesions (Group 2). A long history of nonexertional angina without angina of effort or previous infarction was the rule in Group 1, whereas recent-onset unstable angina preceded by effort angina and infarction predominated in Group 2 (P less than 0.001). Normal electrocardiograms at rest, with ischemic ST-segment elevation in the inferior leads, and ischemia-induced heart block and bradycardia, characterized Group 1, whereas abnormal electrocardiograms, ischemic involvement or fibrillation were more common in Group 2 (P less than 0.001). Variant angina with normal coronary arteriogram generally has a benign course and is probably unrelated to atherosclerosis.
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PMID:Clinical syndrome of variant angina with normal coronary arteriogram. 98 80


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