ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Patients with mitral valve prolapse (MVP) frequently experience chest pain which may, expecially in older subjects and males, be difficult to differentiate from angina pectoris. Electrocardiographic (ECG) changes, ventricular arrhythmias, metabolic abnormalities and rare reports of myocardial infarction and sudden death further suggest the presence of an ischemic process in these patients. The recognition of accompanying coronary artery disease (CAD) and exclusion of other causes of ischemia, therefore, may be important in determining the prognosis and appropriate therapy for such patients.We performed stress ECGs and perfusion scintigrams in 25 patients with confirmed MVP who underwent cardiac catheterization or evaluation of chest pain. Stress ECGs were not helpful in iagnosing associated CAD, primarily because of a high incidence 53%, 10/19) of false positive tests, and had only a 48% overall accuracy. cintigraphy was more accurate (P < 0.001), correctly classifying all patients. Scintigraphy was uniformly negative in patients with normal coronary arteriograms, suggesting that ischemia, if present as the cause of chest pain and ECG changes, must be either very localized or generalized.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Fifty-four Japanese patients with occlusive thromboaortopathy (OTAP), including four males, were classified according to evidence of complications attributed to OTAP at the time when the diagnosis was established: Group I, uncomplicated OTAP with or without the involvement of the pulmonary artery. Group II, mono-complicated OTAP: presence of a single complication together with uncomplicated OTAP. Group II was subdivided according to severity into group Ia - mild or moderate form, and group IIb - severe form. Group III, multi-complicated OTAP with two or more complications as well as uncomplicated OTAP. The five-year survival rate after established diagnosis was 83.1%. Seven patients died of OTAP within five years, but all had belonged to group IIb or III.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Several invasive and noninvasive techniques used in determining the size of experimental myocardial infarction were evaluated after acute ligation of the left anterior descending (LAD) coronary artery in ten dogs. Systemic blood pressure, left ventricular end-diastolic pressure (LVEDP), and heart rate did not change significantly for up to 24 hours after coronary occlusion. Left ventricular wall motion abnormalities were detected by left ventriculography in the distribution of the LAD but these changes did not correlate well with the infarct weight determined at autopsy.On the other hand, the number of epicardial sites with ST-segment elevation of ?2mm (mean 15.1 sites ± 0.6 SEM) and the infarct area as measured by “mTc-glucoheptonate (TcGH) myocardial imaging (15.7 sq cm ± 0.6) did correlate strongly with the infarct weight (16.8 g i 0.7) determined by the nitroblue tetrazolium (NBT) technique (r 0.91).TcGH myocardial scintigraphy and epicardial ST-segment mapping allowed early and accurate quantification of experimental myocardial infarcts ranging from < 1 g to 28 g.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Twenty patients with fixed coronary artery obstruction were studied during rapid atrial pacing and methoxamine infusion. During pacing to heart rates of 142 ± 4 (mean ± SEM) beats per minute coronary sinus flow increased from 108 ± 8 to 187 4 15 cc/min and myocardial oxygen consumption increased by + 80 + 11%. During methoxamine infusion that raised arterial systolic pressure to 196 i 5 mm Hg, similar increases in coronary sinus flow (to 179 i 13 cc/min) and myocardial oxygen consumption (+ 77 i 12%) occurred. Chest pain and ischemic ST segment changes developed in 17 and 14 patients respectively during atrial pacing, an incidence significantly greater (P < 0.05) than during infusion of methoxamine (6 and 3 patients). Myocardial lactate extraction which averaged 26 i 4% during control was decreased to 10 + 8% during pacing and to 24 ± 7% during methoxamine; the difference between decreases was not significant. The data show that at similar increases in myocardial oxygen consumption stress of increased heart rate results in more myocardial ischemia than stress of increased afterload.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

In 14 dogs the effects on regional tension (Walton- Brodie gauges) and length (mercury-in-silastic) following 50% reduction (52.9 ± 2.1) in coronary flow for two hours and reperfusion afterwards for one hour were addressed. Within five minutes of partial coronary occlusion, ejection tension in the ischemic zone decreased to 36.3 i 7.2% (P < 0.001) and total tension to 64.4 i 5.7% of control (P < 0.001) while phasic segment length increased to 165.2 ± 16.3% of control. No further significant changes in regional tension or length were observed throughout the two hour period of partial occlusion. Ejection tension remained positive and segment length maintained systolic shortening during the ejection phase throughout the period of occlusion. Following reperfusion, ejection tension in the ischemic zone increased from 35.1 ± 5.9 to 87.0 ± 22.0% (P < 0.05) and total tension increased from 56.6 ± 5.4 to 70.2 ± 7.2% (P < 0.02) while segment length decreased from 149.3 ± 6.5 to 105.7 ± 5.7% (P < 0.001) within five to 15 min of reperfusion. The improvement in both regional tension development and segment length shortening was maintained throughout the one hour period of reperfusion. No significant changes were seen in the nonischemic zone. The present experimental study suggests that partial coronary occlusion producing a 50% reduction in coronary blood flow results in regional contractile changes. These changes are reversible at least twice as long as those following complete occlusion.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

A radioimmunoassay for human myoglobin has been used to study the serum myoglobin level in 13 normal individuals and 68 patients admitted to a Coronary Care Unit because of chest pain. Values in normal individuals ranged from 3 to 75 and averaged 25 ± 23 (SD) ng/ml. Thirty-two patients with myocardial infarction initially examined within 12 hours of the onset of chest pain all showed clear-cut elevations in serum myoglobin, peak values ranging from 200 to 5500 and averaging 1368 ± 1357 ng/ml. Seventeen patients with clinically atypical chest pain and no subsequent evidence of myocardial necrosis had myoglobin levels in the normal range, as did 11 of 19 patients with chest pain thought clinically to represent myocardial ischemia but no subsequent evidence of myocardial necrosis by conventional criteria. The final eight patients in the latter group showed mild elevations of serum Mb, peak values ranging from 102 to 280 and averaging 162 ± 52 ng/ml; the basis for these elevations remains to be clarified.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

There is evidence that glucocorticoids reduce infarct size but their use in myocardial infarction remains controversial because of their potential adverse effects on healing of the infarct. To investigate the healing process, rats received either four parenteral doses of 50 mg/kg of methylprednisolone (MP) or saline 5 min, 3, 6 and 24 hr after coronary occlusion and their hearts were examined by light and electron microscopy 48 hr and seven days after occlusion. At 48 hr, in five untreated rats, only 12 ± 7% of injured myocytes showed the persistence of striations and a relatively intact sarcolemma despite loss of nuclei and hence appeared “mummified” whereas in six MP-treated rats 72 ± 8% of myocytes exhibited this appearance (P < 0.001). In treated rats there were fewer phagocytes than in controls. At seven days, in seven MPrats, mummified cells were still more prominent than in five untreated rats and there were fewer phagocytes and less collagen. In conclusion, high dose MP delays the inflammatory process and retards the disintegration of necrotic myocytes, resulting in impaired healing.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

A cohort of 1472 patients who underwent both exercise stress testing and coronary angiography within six weeks was examined. The data indicated that a combination of exercise parameters is both diagnostically and prognostically important. Almost all patients (> 97%) who had positive exercise tests at Stage I or Stage II had significant coronary artery disease. More than half of these (> 60%) had three vessel disease and over 25% had significant narrowing (> 50%) of the left main coronary artery. Patients who achieved Stage IV or greater exercise durations with either negative or indeterminate ST-segment response had less than a 15% prevalence of three vessel disease and less than a 1% prevalence of left main coronary artery disease. A low risk subgroup (75% of all nonoperated patients) was identified with a twelve month survival greater than 99%. A high risk subgroup (11% of all nonoperated patients) was identified with a twelve month survival of less than 85%. The exercise test is a noninvasive, reproducible method to assess the presence and extent of anatomic disease and the prognosis when significant disease has been defined. It should be used in conjunction with other noninvasive tests to determine optimal management in patients evaluated for ischemic heart disease.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

One hundred consecutive men with a normal ECG at rest had a maximal treadmill test using 14 leads during and postexercise. Coronary arteriography performed the following day revealed coronary stenoses k70% in 66 patients. Test results obtained from a V6 lead were compared to different lead combinations and were correlated with arteriographic findings. A positive exercise test occurred in 37 men using an isolated V, lead compared to 50 men (P < 0.05) using 11 leads, 52 men (P < 0.05) using a combined CM6, CC5, Cl (inferior) lead system and 58 (P < 0.001) men using all 14 leads. The predictive value of a positive test varied between 89-95% and was not changed significantly by the addition of multiple leads. The 14 lead ECG was positive in 43/45 (96%) patients with multivessel disease.Parameters which helped to predict multivessel disease using 14 leads were 1) the time that ischemia first appeared 2) the pressurerate product at the time ischemia first appeared, and 3) the maximum workload that could be attained. In general, the magnitude of STsegment depression and the time required for a positive ECG to return to normal postexercise were not useful predictors of multivessel disease.We conclude that the use of multiple leads improves the sensitivity and efficiency of the maximal treadmill exercise test. The usefulness of exercise test results can be further improved if multiple leads are combined with physiologic data collected during exercise.

ISSN:0009-7322    

出版商:OVID    

年代:1978

数据来源: OVID