Myocardial infarction in patients with normal patent coronary arteries as visualized by cinearteriography

Left ventricular ball-like thrombus after acute myocardial infarction with essential thrombocythemia

Left ventricular (LV) thrombus after acute myocardial infarction (AMI) is a frequent complication that is associated with a risk of systemic embolism. Essential thrombocythemia (ET) has opposing tendencies towards hemorrhage and thrombogenesis and it can cause AMI via thrombogenesis. Ball-like LV thrombus is associated with a high risk of systemic embolism. We describe surgical resection of LV ball-like thrombus from a patient with ET. A 60-year-old woman presented at our hospital with transient ischemic attack accompanied by transient hemiplegia. Ultrasonic cardiography revealed a mobile ball-like thrombus in the LV after transmural AMI of the anterior wall. We performed emergency LV thrombectomy because of the mobile LV thrombus with embolism. Platelet aberrations and pathological bone marrow findings were consistent with a diagnosis of ET. We administered the patient with anti-coagulation drugs and the DNA replication inhibitor hydroxycarbamide to decrease the platelet count. She continues to survive and is doing well without major postoperative complications. .

Prevention of Ventricular Fibrillation, Acute Myocardial Infarction (Myocardial Necrosis), Heart Failure, and Mortality by Bretylium

It is widely, but mistakenly, believed that ischemic heart disease (IsHD) and its complications are the sole and direct result of reduced coronary blood flow by obstructive coronary artery disease (CAD). However, cardiac angina, acute myocardial infarction (AMI), and sudden cardiac death (SCD) occur in 15%-20% of patients with anatomically unobstructed and grossly normal coronaries. Moreover, severe obstructive coronary disease often occurs without associated pathologic myocardiopathy or prior symptoms, ie, unexpected sudden death, silent myocardial infarction, or the insidious appearance of congestive heart failure (CHF). The fact that catecholamines explosively augment oxidative metabolism much more than cardiac work is generally underappreciated. Thus, adrenergic actions alone are likely to be more prone to cause cardiac ischemia than reduced coronary blood flow per se. The autonomic etiology of IsHD raises contradictions to the traditional concept of anatomically obstructive CAD as the lone cause of cardiac ischemia and AMI. Actually, all the signs and symptoms of IsHD reflect autonomic nervous system imbalance, particularly adrenergic hyperactivity, which may by itself cause ischemia as in rest angina. Adrenergic activity causing ischemia signals cardiac pain to pain centers via sympathetic efferent pathways and tend to induce arrhythmogenic and necrotizing ischemic actions on the cardiovascular system. This may result in ischemia induced metabolic myocardiopathy not unlike that caused by anatomic or spasmogenic coronary obstruction. The clinical study and review presented herein suggest that adrenergic hyperactivity alone without CAD can be a primary cause of IsHD. Thus, adrenergic heart disease (AdHD), or actually adrenergic cardiovascular heart disease (ACVHD), appears to be a distinct entity, most commonly but not necessarily occurring in parallel with CAD. CAD certainly contributes to vulnerability as well as the progression of IsHD. This vicious cycle, which explains the frequent parallel occurrence of arteriosclerosis and IHD, an association that appears to be linked by the same cause, comprises a common vulnerability to deleterious adrenergic actions on the myocardium, lipid metabolism, and vascular system alike, rather than viewing CAD and IsHD as having a putative cause and effect relationship as commonly thought. Adrenergic actions can also cause the abnormal lipid metabolism that is associated with CAD and IsHD by catecholamine-induced metabolic actions on lipid mobilization by activation of phospholipases. This may also be part of toxic catecholamine hypermetabolic actions by enhancing deleterious cholesterol and lipid actions in damaging coronary vessels by plaque formation as well as inducing obstructive coronary spasm and platelet aggregation. This may also cause direct toxic necrosis on the myocardium as well as atherosclerosis in blood vessels. In fact, drugs that inhibit adrenergic actions like propranolol, reserpine, and guanethidine all inhibit arteriosclerosis induced by hypercholesterolemia in experimental animals and prevent carotid vascular disease (associated with stroke) in humans. The concomitant development of myocardiopathy and coronary vascular lesions or coronary and carotid artery intimal medial thickening by catecholamine toxicity is reflected by the frequent primary presentation of patients with catecholamine-secreting pheochromocytoma with cardiovascular disease, ie, hypertension arrhythmias, AMI, SCD, CHF, and vascular disease, which represents a clear example of the primary deleterious impact of catecholamines on the entire cardiovascular system causing adrenergic cardiovascular disease. Thus, like myocardiopathy, CAD and atherosclerosis in general may be the consequences of or a complication of catecholamine actions rather than its putative cause. This report shows how prophylactic bretylium not only prevents arrhythmias but prevents myocardial necrosis, shock, CHF, maintains or restores normal contractility, and lowers mortality in AMI patients by inducing adrenergic blockade.

High prevalence of (99m)tc-tetrofosmin reverse perfusion pattern in patients with myocardial infarction and angiographically smooth coronary arteries

BACKGROUND

There are no published data in the literature on the scintigraphic perfusion pattern in patients with myocardial infarction (MI) and normal coronary arteries (NCA).

OBJECTIVES

To evaluate myocardial perfusion imaging in a series of patients with MI and NCA.

METHODS

Twenty-seven patients who had developed a MI and had NCA were studied. As a control group we included 27 patients with a recent MI and coronary artery disease (CAD). All patients underwent stress/rest tetrofosmin myocardial perfusion SPECT within 6 months from MI.

RESULTS

In patients with NCA tetrofosmin stress images revealed 41 hypoperfused segments in 17 patients (63%). On rest images, 13 segments remained unchanged, 4 showed partial reperfusion, 10 normalized and 14 worsened. Additionally, there were 18 new hypoperfused segments in nine patients. Therefore, perfusion worsened at rest in 18 patients (67%) (32 segments). Overall, at rest there were 49 hypoperfused segments in 22 patients (81%). In patients with CAD, stress images revealed 71 hypoperfused segments. On rest images, 39 segments remained unchanged, 16 showed partial reperfusion and 12 normalized. Four segments worsened at rest and only four patients (15%) showed new perfusion defects at rest.

CONCLUSIONS

Myocardial perfusion with tetrofosmin might appear considerably worse at rest than at stress in patients with MI and NCA. Specifically, a reverse perfusion pattern in the infarct area is a frequent finding and is likely to be due to residual tissue viability. We postulate that in these patients the hyperemic response to exercise may mask resting underperfusion areas.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

High levels of serum lipoprotein(a) in patients with ischemic heart disease with normal coronary angiogram and thromboangiitis obliterans

To determine whether lipoprotein(a) (Lp(a)) contributes to the acceleration of cardiovascular diseases without atherosclerotic lesion, we have measured serum Lp(a) level in male subjects aged 40-69 years with thromboangiitis obliterans (n = 40) and ischemic heart disease (IHD) with normal coronary angiogram (n = 35) in addition to subjects with arteriosclerosis obliterans (n = 123) and IHD with atherosclerotic coronary lesion (n = 203). Cases who had no IHD, arteriosclerosis obliterans or thromboangiitis obliterans were selected as a control group (n = 316). Subjects without any diseases or abnormal findings in physical examination and laboratory data were selected from the control group as the healthy control group (n = 156). The Lp(a) levels of arteriosclerosis obliterans and IHD with atherosclerotic coronary lesion were significantly higher (17.0 mg/dl and 13.1 mg/dl; median) than those of control and healthy control groups (9.9 mg/dl and 9.4 mg/dl, respectively) (P < 0.01), in agreement with previous reports. Furthermore, the Lp(a) level of IHD with normal coronary angiogram group was significantly higher (18.9 mg/dl) than those of the control and healthy control groups (P < 0.05). The Lp(a) level of thromboangiitis obliterans group was also much higher (21.3 mg/dl) than that of the healthy control group (P < 0.05). The current study suggests that Lp(a) is one of the independent risk factors for the development of atherosclerotic diseases such as arteriosclerosis obliterans and IHD with atherosclerotic coronary lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical relevance of oral contraceptive pill-induced plasma lipid changes: facts and fiction

The changes in plasma lipids induced by the use of oral contraceptive pills have been shown in several studies to remain within normal physiologic limits. These changes are then probably without any clinical relevance because there is no evidence in the huge volume of oral contraceptive and cardiovascular literature that the use of oral contraceptives promotes or retards the development of atherosclerotic disease. What may appear to be favorable changes in the lipid profile attributed to oral contraceptive use may actually be associated with unfavorable changes in other parameters, such as the balance of clotting and fibrinolytic factors. A well-balanced, low-dose oral contraceptive formulation should alter any of the cardiovascular risk indicators as little as possible in either a supposedly positive or negative direction.

Coronary thrombosis and subsequent lysis after a marathon

A patient who developed an acute anterior myocardial infarction after completion of a marathon is presented. Coronary angiography performed 5 hours after the onset of symptoms showed occlusion of the left anterior descending coronary artery and nonocclusive thrombus in the proximal right coronary artery. Repeat angiography 10 days later showed complete resolution of thrombosis in both arteries. The relation between marathon running and coronary thrombosis is discussed.

Patients with myocardial infarction and normal coronary arteriogram

Eighteen patients who survived an acute myocardial infarction were found to have a normal coronary arteriogram. Seven patients were younger than 35 years and six were female. The myocardial infarction was nontransmural in 11 cases. The mean follow-up was 21.6 months. Eleven patients developed residual chest pain at rest early after myocardial infarction. One, treated by beta-blockers, suffered a recurrent myocardial infarction. Eight became asymptomatic, and two improved under antispastic therapy. Another patient developed a severe form of variant angina three months after myocardial infarction; she died following plexectomy. Finally, two patients experienced rare episodes of angina at rest. The stress ECG was negative in all cases. Provocative test for spasm was positive in three out of nine patients. Diffuse narrowing associated with chest pain was demostrated in two patients at angiography. Thus, myocardial infarction and subsequent normal coronary angiogram are mainly found in young female patients, and infarction is often nontransmural. Clinical evidence of vasospastic phenomena and increased vasomotor tone are found in most patients. Whenever residual chest pain is controlled by antispastic therapy, the follow-up course seems benign.

Acute myocardial infarction in patients with normal coronary arteries after acute ethanol intoxication

Three cases are presented where acute myocardial infarction occurred in young individuals after an episode of heavy alcohol intake. Subsequent coronary arteriograms demonstrated normal coronary arteries. Several mechanisms by which acute ethanol intoxication might precipitate myocardial infarction are discussed. To our knowledge, no similar cases have been reported.

Myocardial infarction with normal coronary arteries: a prospective clinical-angiographic study

The association of myocardial infarction with normal coronary arteries was analyzed prospectively. A series of 259 consecutive men aged 60 years or less underwent selective coronary angiography 30 days after a definite infarct. Coronary arterial lesions were documented in 251 patients, normal coronary arteries in the remaining 8. The latter patients had a significantly lower (p less than 0.001) mean age than the former; no patient older than 50 years had patent coronary arteries, whereas 5 of the 11 patients under age 35 had normal arteries. The prevalence of risk factors was similar in both groups of patients. Although there were no group differences in infarct size or location, patients with normal coronary arteries had a higher ejection fraction (p less than 0.01) and a lower left ventricular end-diastolic pressure (p less than 0.05). A previous history of angina or infarction and the occurrence of new coronary events were confined to patients with coronary arterial lesions. The clinical course of patients presenting with normal angiograms was uneventful. Transient coronary occlusion, the most likely mechanism of infarction in this group of patients, could not be ascribed to either spasm or platelet hyperactivity.

Chest pain with angiographically insignificant coronary arterial obstruction. Clinical presentation and long-term follow-up

Among 3,242 coronary angiograms performed from November 1972 through October 1975 at the Massachusetts General Hospital, 175 patients had normal coronary arteries or luminal narrowings of less than 30 per cent. All patients were studied for chest pain, and none had experienced prior myocardial infarction. Subsequent information was available in 159 patients over a mean follow-up period of 42.7 months. There were no deaths, and only one myocardial infarction occurred during this period. However, among the patients followed, continued chest pain with episodes occurring at least once monthly was present in 54 per cent. In addition, 17 per cent of all patients required subsequent hospitalization and 44 per cent continued to receive antianginal medication. Nearly half of the group (46 per cent) suffered some limitation of activity, and 22 per cent stated that they had either changed jobs or stopped work because of chest pain. Continuing chest pain was significantly more common in women and in patients who had experienced chest pain for more than one year before angiography. However, typicality of chest pain for angina or the occurrence of electrocardiographic changes of ischemia prior to angiography did not predict continued chest pain during the follow-up period. Thus, although mortality and morbidity are low in this group of patients, the syndrome of chest pain with angiographically insignificant coronary artery obstruction has an important impact on the lives of a majority of those affected.

Thrombocytosis, coronary thrombosis and acute myocardial infarction

Clinical and morphologic findings are described in a 22 year old man with prolonged thromboyctosis, and coronary and splenic arterial thrombi causing myocardial and splenic infarcts. The absence of preexistent extensive coronary atherosclerosis, the presence of thrombus in more than one epicardial artery and in multiple intramural coronary arteries, the presence of arterial thrombosis in a noncoronary artery (splenic) and the absence of another apparent cause of the arterial thromboses are evidences that the intraarterial clotting in this patient was related to the severe thrombocytosis. A reveiw of the reported cases of vascular occlusion associated with thrombocytosis indicates that thrombi have infrequently been confirmed as the mechanism of the vascular occlusion. Although the frequency of vascular thrombi in patients with thrombocytosis has not been established, it is clear that vascular thrombosis can be a consequence of thrombocytosis and, as demonstrated by the present patient, that the coronary artery may be the site of the vascular occlusion, a heretofore unconfirmed event.

Coronary artery disease in young women: clinical and angiographic features and correlation with risk factors

Coronary arteriography was performed because of suspected coronary disease in 239 women less than 45 years of age. Normal coronary arteries were found in 112 women, and a further 23 had insignificant stenosis (less than 50 percent narrowing of luminal diameter). Of the remaining 104 women, 56 had one vessel, 22 two vessel and 26 three vessel disease. Hyperlipidemia, hypertension, diabetes, smoking and a family history of coronary disease were significantly more frequent in women with significant stenosis than in women with normal arteries. Significant coronary disease was found in 55 percent (100 of 182) of women with more than two risk factors but in only 7 percent (4 of 57) of those with less than two risk factors (P less than 0.0001). Evaluation of symptoms and the resting electrocardiogram also discriminated between women with and without coronary disease, but exercise testing was of little value. Only 4 of the 46 women with previous myocardial infarction had normal or near-normal coronary arteries. Among women with segmental wall motion abnormalities on ventriculography, the site was anterior in 90 percent (19 of 21) of women who used oral contraceptive drugs but in only 60 percent (21 of 35) of nonusers (P less than 0.05). However, in most respects, coronary artery disease in young women does not appear to differ from coronary disease in other patients.

Abnormal platelet survival time in men with myocardial infarction and normal coronary arteriogram

Platelet survival time was measured in eight men who had an acute transmural myocardial infarction and were subsequently found to have a normal coronary arteriogram. Platelet survival (chromium-51 labeling) was shortened in all men (2.4 +/- 0.11 days; average half-time +/- standard error of the mean) and different from that in eight age-matched normal men (3.7 +/- 0.08 days) (P less than 0.001). Three patients had recurrent venous thromboembolism and one had had iliofemoral arterial thromboembolism. Platelet survival was shortened (2.9 +/- 0.12 days) in 11 of 16 age-matched men with transmural infarction who had arteriographic evidence of coronary obstructive disease. These results suggest that platelet survival time is shortened in patients with infarction who subsequently are shown to have a normal coronary arteriogram and that arterial thrombosis may be responsible for the infarction.

Acute myocardial infarction with normal and near normal coronary arteries. Documentation with coronary arteriography within 12 1/2 hours of the onset of symptoms in two cases (three episodes)

Three instances (in two patients) of acute myocardial infarction associated with arteriographically normal or near normal coronary arteries are reported. One patient with a lateral infarction had a normal coronary arteriogram and hypokinesia of the lateral wall. Another patient had two infarctions: (1) a transmural inferior-lateral infarction associated with occlusion of the most distal segment of the posterior descending branch of the right coronary artery, and (2) a transmural anterior-lateral-superior infarction associated with occlusion of the most distal segment of the left anterior descending coronary artery. Neither occlusion was consistent with the extent of infarction. Although coronary arteriography was performed as early as 12 1/2, 3 3/4 and 11 2/3 hours, respectively, after the onset of symptoms of infarction in these three instances, the pathophysiologic features of the infarctions are obscure. Temporary occlusion of an epicardial coronary artery by spasm or platelet aggregates, or both, is suggested as a possible mechanism of the acute event.

Transmural myocardial infarction in young women taking oral contraceptives. Evidence of reduced regional coronary flow in spite of normal coronary arteries

A normal coronary arteriogram after transmural myocardial infarction is a well-recognised phenomenon, but the pathophysiology remains unclear in most cases. A possible aetiological role of oral contraceptives is suggested by the occurrence of unequivocal myocardial infarction with normal or near normal coronary arteries in 4 young women who had been taking oral contraceptives. While the cause-effect relation of coronary thrombosis and myocardial infarction remains controversial in patients with coronary atherosclerosis, a primary occlusion of macroscopically normal coronary arteries by cellular elements of blood appears possible in these cases. The action of contraceptives, the, would be analogous to their thrombogenic effect in peripheral veins and cerebral arteries. Absence of atherosclerotic lesions in these patients favours spontaneous thrombolysis and restoration of normal vessel patency in many of these cases. Myocardial blood flow in the region of the damaged left ventricular wall remains low in spite of normal coronary arteries. Reduced perfusion in infarcted areas is assumed to be the consequence of structural and functional alterations at precapillary and capillary level rather than an effect of obstructive coronary disease.

The nature and clinical features of myocardial infarction with normal coronary arteriogram

Six new cases of acute myocardial infarction with normal coronary arteriogram are presented and supplemented by 19 collected cases (group I). These are compared with 16 cases of myocardial infarction caused by occlusive coronary artery disease in a comparable population (group ii). The following significant differences between the two groups are established: patients in group I were younger (27.5 years vs 33.7 years, P less than 0.005); at least one risk factor was present in all patients in group II, but in only 40% of group I (P less than 0.0001). effort angina preceded the attack in ten patients of group II, but in none of group I (P less than 0.0001). The attack was unheralded in 24 of the 25 patients in group I, but was preceded by prodromes in 11 of 16 in group II (P less than 0.0001). Attacks of pain following myocardial infarction occurred in five patients of group 2 and II of group II) (P less than 0.001). Results are discussed in the light of the nature of myocardial infarction in group I. No support is found for the coronary spasm theory. The most likely mechanism for development of myocardial infarction in group I is thought to be a thromboembolic "accident." This accident is not necessarily related to atherosclerotic coronary disease and is presumed to be benign in nature.

The relationship between coronary artery lesions and myocardial infarcts: ulceration of atherosclerotic plaques precipitating coronary thrombosis

A review of 494 myocardial lesions at least 3 cm. in one dimension reveal 418 (85 per cent) related to atherosclerotic coronary lesions, 55 (11 per cent) related to coronary emboli of various types, 18(3.5 per cent) without specific coronary lesions but related to clinical events associated with coronary hypoperfusion, and 3 (0.5 per cent) associated with miscellaneous coronary lesions. In 399 of 418 (96 per cent) atherosclerotic coronary lesions of all ages complete occlusion (remote of fresh) or histological evidence of lumenal recanalization was present. These coronary lesions were situated within extramural coronary artery segments one to several centimeters proximal to the myocardial lesions which were confined to the distribution of the respective partially or totally occluded coronary segments. In the atherosclerotic cornary lesions less than 2 weeks of age partially or totally occlusive thrombus was found in 67 of 69 (97 per cent) cases and a underlying plaque ulceration, erosion, or rupture was present in 64 of 69 (93 per cent) instances. These endothelial and intimal injuries were generally focal in nature, often extending over a length of only 100 to 200 mu. In no instance could it be stated with certainty that the oldest portion of the atherosclerotic ulceration-thrombus complex was younger in age than its associated myocardial lesion. On the contrary, in 10 of 69 (14 per cent) of the cases portion of the coronary thrombus, usually at the site of plaque ulceration, were histologically older than the myocardial lesion. In addition, the presence of thrombus and plaque debris admixtures further suggested the antecedent nature of the coronary lesion in relation to the myocardial lesion. Atherosclerotic coronary lesions associated with myocardial lesions of 2 to 8 weeks of age had identifiable thromboses in all instances and underlying plaque ulceration, erosions, or ruptures in 17 of 21 (80 per cent). Endothelial injuries were more difficult to assess due to the obscuring features of organizing lumenal thrombus. Interface i.e., plaque ulceration, erosions, or ruptures, were reliably detectable up to approximately on month of age. Coronary arter thromboemboli accounted for a significant percentage of myocardial lesions, were usually associated with normal or minimal coronary artery disease, and frequently involved smaller intramural coronary vessels of the heart. Organization and recanalization of thromboemboemboli tended to be rapid and complete so that in the late stages the residual intimal plaque was sometimes difficult to identify. Myocardial lesions related to clinical events associated with coronary artery hypoperfusion centric, and not confined to the distribution of a single coronary artery. They were unassociated with acute coronary lesions and histologically displayed contraction band necrosis more frequently than the embolic and atherosclerotic related lesions. An explanation was found for the overwhelming majority of myocardial lesions...

Incidence and age distribution of patients with myocardial infarction and normal coronary arteriograms

Over a 41 month period selective coronary arteriography was performed on all patients age 35 and under seen at our hospital with a documented myocardial infarction. In these 25 patients, 4 (16%) demonstrated no arteriographic evidence of coronary artery disease. One-hundred and fifty-two patients over age 35 with a documented myocardial infarction underwent selective coronary arteriography during the same period. In each of the 15 2 cases, obstructive coronary artery disease was demonstrated. The generally favorable prognosis of patients with myocardial infarction and normal coronary arteriograms has been previously documented. On the basis of our experience and a review of the literature, it is recommended that all patients age 35 and under sustaining a myocardial infarction should undergo selective coronary arteriography, in order to establish prognosis.

Abnormal left ventricular wall motion at mid-ejection in patients with coronary heart disease

The degree of inward motion at mid-ejection was examined for seven segments on the silhouettes of left ventriculograms taken in the 30 degrees RAO projection in patients with normal coronary arteries. The pattern of wall motion described in these patients was used to distinguish abnormalities in mid-systolic wall motion. One or more abnormally contracting segments were found at mid-ejection of 27 of 42 patients with obstructive coronary artery disease and normal end-systolic wall motion. Of the 57 segments found in these patients, 41 or 72% corresponded to sites of significant coronary artery obstruction. Seven patients had electrocardiographic evidence of prior infarction. Following coronary graft surgery in eight patients improved motion was found in association with graft patency in seven priviously delayed segments and two new areas of delayed wall motion associated with nonpatent grafts and electrocardiographic changes of infarction appeared. We postulate that some of the myocardial fibers in late contracting segments have been injured or infarcted and are able to contract effectively only during the latter half of ejection when ventricular wall tension is reduced.

Recurrent myocardial infarction and angina in a woman with normal coronary angiograms

A case is reported of recurrent myocardial infarction and angina pectoris in a woman with normal coronary arteries documented by coronary angiogram. The recurrence of infarction in contiguous areas of the heart supplied by the left anterior descending coronary artery and the association of the anginal syndrome implicate coronary arterial spasm as the probable cause.

Transmural myocardial infarction during pregnancy

Two young pregnant women with no known risk factors had a transmural myocardial infarction while they were lying in the supine position. Coronary arteriograms 3 1/2 and 4 months later, respectively, were normal. Coronary arterial spasm related to renin release from the transiently ischemic chorion is the proposed cause.

Exercise stress testing in patients with chest pain and normal coronary arteriography: with review of the literature

Eighty of 654 patients studied because of chest pain were found to have normal coronary arteriography. Fifty of these completed submaximal treadmill exercise studies. The purpose of this study was to determine whether treadmill electrocardiography could obviate the need for coronary arteriography in the evaluation of patients with undiagnosed chest pain. Of patients studied, 22% had typical angina pectoris, while 78% had atypical chest pain. The resting electrocardiogram was normal in 58% of patients, while 42% showed repolarization abnormalities. Submaximal treadmill testing was normal in 64%, incomplete in 12%, and demonstrated classic ischemic S-T depression in 24%. Our findings of 24% positive studies in patients with normal vessels and 12% incomplete tests suggest that stress electrocardiography may be of limited value in predicting the morphologic state of the coronary arteries in patients with undiagnosed chest pain.