ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

The majority of deaths from acute myocardial infarction (AMI) occur prior to the arrival of medical aid and appear to be due to ventricular fibrillation (VF). Since the premature ventricular contraction and bradycardia are believed to predispose to VF, it has been suggested that administration of atropine or lidocaine during the prehospital phase of AMI may effectively reduce mortality in AMI. To test the efficacy of these drugs in treating arrhythmias during the acute phase of AMI we studied 72 closed-chest conscious dogs in which AMI was produced by inflating a balloon cuff previously implanted around the left anterior descending coronary artery. Ventricular arrhythmias developed in 52 dogs either during occlusion or within 2 min of release of occlusion. Arrhythmias were treated by (1) atropine, (2) atrial pacing, (3) lidocaine, or (4) atropine plus lidocaine. Of the 18 dogs that developed VF, all had ectopic ventricular beats that followed a preceding beat (R-RPVCinterval) by ≤0.43 sec; no dog with a ventricular arrhythmia that exhibited only R-RPVCintervals >0.43 sec developed VF. On this basis arrhythmias were defined as “benign” (R-RPVC>0.43 sec) or “malignant” (R-RPVC≤0.43 sec). Using this classification, we found that benign arrhythmias were successfully suppressed by atropine (10 of 13 arrhythmias), pacing (nine of 11), and lidocaine (three of five); however, atropine suppressed only two of 18, pacing two of 14, and lidocaine none of six malignant arrhythmias. We conclude that (1) not all ventricular arrhythmias are potentially lethal and (2) while atropine, pacing, and lidocaine successfully suppress most benign arrhythmias, they appear considerably less effective in suppressing those faster arrhythmias that frequently lead to the precipitation of VF.

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Significant progression of coronary artery disease was seen in 52% of subjects studied by selective cinearteriography at intervals between 2 and 75 months (average 23.8). Subsequent progression, although confined to proximal areas, was independent of overall severity of initial disease or previous disease at the site of progression and occurred frequently in previously normal vessels. Plasma lipid abnormalities and myocardial lactate production at the time of the initial study were significantly associated with subsequent arteriographic progression. Similarly abnormal glucose tolerance was seen more frequently in patients exhibiting progression than in those who did not. The progression occurring in patients with lipid abnormalities was more severe and more widespread than in other patients, and apparent interval reduction in lipid values did not influence the ultimate course of the atheromatous process. Myocardial infarction was almost invariably associated with progression. Collateral coronary circulation never increased or appeared unless accompanied by an increase in the extent of local coronary artery disease. The absence of progression was associated with a favorable prognosis. All other clinical, laboratory, and arteriographic parameters analyzed were not predictive of subsequent progression of the coronary obstructive lesion.

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Waldo AL, James TN: Circulation47:222, 1973. On page 222, line 30 should read: “When the ‘upper A-V node’ was warmed, the AS-VSinterval was shorter than during normal rhythms; when the ‘middle A-V node’ was warmed, the AS-VSinterval was zero or barely positive; and, when the ‘lower A-V node’ was warmed, a negative AS-VSinterval was produced.”

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

After informed consent, 12 men with documented acute myocardial infarction had hemodynamic studies performed within 18 hours after onset of symptoms. These were repeated on the second day, at 3-5 weeks, and at 3-5 months in the 10 who survived. One half of the patients were “uncomplicated” and significant differences with the “complicated” patients were seen in pulmonary artery pressure, mean arterial pressure on the first day, acute phase stroke volume and cardiac index, and the total blood volume within 48 hours. The optimal heart rate at each stage was determined by atrial pacing and was found to be 110 ± 10 beats/min. Abnormalities inpH, blood gases, and circulation time were related to the cardiac index. Control groups with and without coronary artery disease were studied prior to angiography to obtain information regarding preinfarction circulatory status, and significant impairment of the ejection fraction was noted even in angina patients without prior infarction. The sequential circulatory changes and possible compensatory mechanisms available were discussed.

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

Variant angina of Prinzmetal has been generally presumed to be caused by a significant focal obstruction in a single major coronary artery which should be an ideal lesion for aortocoronary saphenous vein bypass graft. Recognition of this clinical syndrome would then be of particular diagnostic and therapeutic importance if such a consistent association can be demonstrated. Of five patients with variant angina studied in our cardiac catheterization laboratories, four had normal coronary arteriograms. Two important conclusions may be derived from this study. First, identical ECG changes may be observed both in the presence and absence of pain and thus the incidence and severity of the variant angina could be underestimated. Second, until a larger series of patients with variant angina is studied by coronary arteriography, one must exercise reservation in assuming that all patients with the clinical syndrome are operative candidates for saphenous vein bypass surgery.

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

A new method to determine myocardial blood distribution was used to study a patient with a recent large transmural anterior myocardial infarct. The method consisted of injecting43potassium into a peripheral arm vein and recording the radioactivity over the chest with a scintillation (Anger) camera. Elimination of noncardiac radioactivity in the analysis of data was accomplished by recording the rapid passage of injected99mtechnetium through the heart. The cardiac deposition of the potassium was visualized by identifying the contour of the heart from the technetium scan. In this patient deposition of43potassium was markedly reduced in the septal region of the myocardium. This correlated well with the ischemic area suggested by coronary angiography, which demonstrated proximal occlusion of the left anterior descending coronary artery and absence of obstructive disease in the other coronary arteries. Intracoronary artery injection of43K gave confirmation of decreased deposition in the same area. This method should prove helpful in the study of certain clinical problems, such as the evaluation of the patency of coronary artery bypass grafts.

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

The relationship between mean left atrial pressure (LAm) and P-wave abnormalities in lead V1of standard 12-lead electrocardiograms was evaluated in 30 patients with acute myocardial infarction. In each patient pulmonary artery diastolic pressure or pulmonary wedge pressure was measured, and these values were used as an estimate of LAm. Electrocardiograms recorded at the time of the pressure measurements were used for P-wave analysis. Patients with a history of hypertension were excluded from analysis. There was a significant correlation between the magnitude of the P terminal force in lead V1(PTF-V1) and the estimated LAm(r = −0.78,P< 0.001). Sixteen patients had a normal PTF-V1on admission; 11 of them had a normal LAm. All 14 patients with an abnormal PTF-V1(more negative than −0.03 mm-sec) on admission had an elevated LAm(>12 mm Hg). Thus, in 25 of the 30 patients, the PTF-V1correctly identified whether the LAmwas normal or abnormal on admission. On subsequent days, simultaneous measurements of PTF-V1and estimated LAmwere made in 27 of the patients. Significant changes occurred in both PTF-V1and LAm; discordant changes were observed on only seven of 56 occasions. Measurement of PTF-V1appears to be a useful and reliable estimate of left ventricular filling pressure in patients with acute myocardial infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1973

数据来源: OVID