The left circumflex (LCx) artery is dominant in about 8% of patients, supplying the left posterior descending artery, and co-dominant in another 7% of patients. 1 Baim D.S. Grossman W. Cardiac Catheterization, Angiography, and Intervention. 5th Ed. Williams & Wilkins, Baltimore, MD1996 Google Scholar The left anterior descending artery (LAD) usually supplies about 40% of the left ventricular myocardium. 2 Edwards W.D. Tajik A.J. Seward J.B. Standardized nomenclature and anatomic basis for regional tomographic analysis of the heart. Mayo Clin Proc. 1981; 56: 479-497 PubMed Google Scholar In cases of left dominance, the LCx artery supplies approximately 60% of the left ventricular myocardium. Because of the absence of reports regarding the clinical importance of a dominant LCx artery, we analyzed the clinical characteristics of dominant LCx artery occlusion in patients with acute myocardial infarction (AMI) who were referred for urgent coronary intervention.

Background Coronary stenosis of the left anterior descending artery (LAD) is respected by cardiologists because of its negative influence on morbidity and mortality. An important anatomical consideration is the length of the LAD. Objective To investigate the relationship between length of LAD and coronary dominance. Design Retrospective comparison of 100 consecutive angiograms with left coronary dominance with 100 consecutive angiograms with right coronary dominance. The relationship between the length of the LAD and coronary dominance was analyzed. Methods We retrospectively compared 100 consecutive angiograms with left coronary dominance (the posterior descending artery being supplied by the circumflex artery) with 100 consecutive angiograms with right coronary dominance (the posterior descending artery being supplied by the right coronary artery). LADs were categorized into three types: type A, LAD terminating before the cardiac apex; type B, LAD reaching the apex but not supplying the inferoapical segment of the left ventricle; and type C, LAD wrapping around the apex and supplying the inferoapical segment. LAD typing was also analyzed in relation to gender. Results It was found that the LAD wrapped around the apex in 87% of cases of left coronary dominance but only in 47% of patients with right coronary dominance, and that the long LADs were more frequently seen in women than in men, irrespective of coronary dominance. Conclusions We found that the LAD in left coronary dominance is usually long and wraps around the apex, and believe that angiographic interventions in such cases have important clinical significance.

Animal poisons induce myocardial damage after envenomation. The cardiac manifestations after black widow spider bite are rarely observed and their prognostic significance are not known. Hymenoptera induce anaphylactic manifestations commonly observed in adults with previous coronary artery disease although myocardial involvement is observed in a few without previous heart disease. The mechanism of cardiac involvement after scorpion envenomation has been elucidated, however after widow spider bite or hymenoptera stings the mechanism of myocardial damage of those without previous heart disease is not clear. (Am J Emerg Med 2000;18:708-714.

Background Exercise testing is an important diagnostic and prognostic procedure in the assessment of patients with hypertension. An exaggerated blood pressure response to exercise among normotensive subjects was found to be one of the best predictors of future hypertension. The demographic characteristics of patients with an exaggerated blood pressure response during exercise have not been adequately described.Methods and Results The demographic and stress performance characteristics of 2 groups of normotensive patients referred for exercise testing, one composed of patients with an exaggerated blood pressure response (group I, n = 146) and a group of patients with a normal blood pressure response (group II, n = 439) were prospectively compared. Patients in group I were older than chose in group II (54 +/- 12 vs 51 +/- 13 years, P < .05). More men than women were found in both groups, yet significantly more in group I than in group II (83% vs 69% P < .001 ). Significantly more among the patients in group I had a higher level of education and were of Western origin than those in group II (P < .01). The resting systolic and diastolic blood pressures were higher in group I than in group II (131 +/- 18 vs 119 +/- 14 mm Hg, P < .001, and 81 +/- 8 vs 76 +/- 7 mm Hg, P < .001, respectively). The patients in group I achieved a higher percentage of the maximal predicted heart rate (88 +/- 7 vs 85 +/- 9 beats/min, P < .01). No significant differences were found between the groups in the duration of stress test and effort ischemia.Conclusions Patients with a hypertensive blood pressure response during stress testing have specific demographic and exercise characteristics.

One hundred and twenty consecutive patients with significant coronary artery disease, normal left ventricular systolic function, and coronary collaterals were compared with 111 patients with the same characteristics but with no collaterals. No significant differences were found between the two groups in hypertension, diabetes mellitus, and smoking. The left ventricular end diastolic pressure was 16.4+/-7 in the study group and 16.9+/-6.9 in the controls (NS). Significantly more diseased vessels were observed in the study group than in the control group (2.1+/-0.6 versus 1.7+/-0.6, p=<0.001). One hundred and one totally occluded vessels were found in the study group but only two in the control group. The richest collateral supply was to the right coronary artery: 94 sources to 85 diseased vessels (111%) including 66 sources to 52 totally occluded arteries (127%); to the left anterior descending: 59 sources to 89 diseased vessels (66%) including 37 sources to 33 totally occluded arteries (112%). The poorest supply was to the left circumflex: 17 sources to 69 diseased vessels (25%), including nine sources to 16 totally occluded arteries (56%). No collaterals were observed in 14 totally occluded vessels in the study group and in two of the controls, while the systolic function at rest was still normal. It is suggested that coronary collaterals are important in preserving left ventricular systolic and diastolic performance at least at rest. Not readily visible collaterals may also prevent systolic dysfunction.

The relationship between angina pectoris and the severity of coronary artery disease was evaluated in 146 patients with normal segmental and global, left ventricular, systolic performance. None had unstable angina or a previous myocardial infarction. A strong relationship was found between angina and the severity of coronary artery disease (p < 0.005). Significant, stable, angina pectoris as a clinical symptom indicated advanced coronary artery disease in this selected group of patients.

Interleukin-6 levels were measured in the serum of ten children following severe scorpion envenomation. Measurements were taken on arrival, at the emergency room, and 12 and 24 hr after arrival. Interleukin-6 was markedly elevated in the serum of eight out of ten children on arrival. Interleukin-6 levels gradually decreased toward normal values on 12 and 24 hr measurements, but remained above control levels on all measurements. These results imply that signs and symptoms following scorpion envenomation may in part be explained by release of cytokines. Human and experimental animal studies are required in order to verify the assumption that interleukin-6 and other cytokines are involved in the pathogenesis of scorpion envenomation.

The relation of shortness of breath to left ventricular end diastolic pressure and the severity of coronary artery disease was evaluated in 146 patients with normal segmental and global left ventricular systolic performance. None had chronic lung disease, cardiomyopathy, previous myocardial infarction, uncontrolled hypertension or unstable angina pectoris. A strong relationship was found between shortness of breath and elevated left ventricular end diastolic pressure, and a borderline relationship with the severity of coronary disease. Shortness of breath as a clinical symptom indicates diastolic dysfunction in this selected group of patients.

Of 1,125 patients catheterized over a period of 8 years, 68 (6%) had coronary ectasia. Twenty-five of them were catheterized at least twice and constituted the study group. The time between the first and last catheterization ranged from 2 to 8 years (mean +/- SD = 4.2 +/- 1.6). Coronary ectasia was more frequent in males (88%). The frequency of involvement was: the right coronary (47%), the left circumflex (30%), the left anterior descending (21%) and the left main arteries (2%). Proximal segments were most frequently involved (48%). Diffuse involvement was found in 29%. Severity of ectasia progressed in 6 segments (14%) and 2 new ectatic segments appeared over the follow-up period. During that period, 2 patients had myocardial infarction, 1 of them due to a total occlusion of an ectatic segment. There were no deaths. In conclusion, coronary ectasia has a relatively benign course.

Perfusion defects and left ventricular dilation after experimental scorpion envenomation were evaluated in five dogs. Left ventricular dilation was observed in three dogs and right ventricular dilation in one other, in scans immediately after envenomation. Perfusion defects were inferred from scans in four dogs. The data are strongly suggestive of coronary hypoperfusion, and the mechanics of abnormal coronary flow after scorpion envenomation are discussed.

The clinical course and outcome of scorpion envenomation in 52 children treated in a pediatric intensive care unit without specific antivenom were retrospectively evaluated and compared with those of scorpion envenomation in the 52 preceding cases treated with specific scorpion antivenom. The demographic, clinical, and laboratory features on hospital arrival were similar in the two groups. The lengths of stay in the pediatric intensive care unit and in the pediatric wards were comparable. Hypotension with pulmonary edema developed in four of the children who did not receive antivenom and in one child who did receive antivenom as a complication of the envenomation; all completely recovered. Cardiogenic shock occurred in one child who did not receive antivenom, but who recovered completely, and in three children who received antivenom, of whom two died and one survived with a major deficit. Our study did not demonstrate any beneficial effect of therapy with antivenom for scorpion envenomation in children. However, our "control" group (i.e., the treated group) was a historical one; thus a prospective, randomized study appears to be warranted. Such a study may define specific subgroups that may benefit from treatment with antivenom.

Of 111 patients with normal coronary angiograms, 68 patients had elevated left-ventricular end diastolic pressure and 'low-normal' ejection fraction (Group I) while the other 43 patients had normal left ventricular end diastolic pressure and 'high normal' ejection fractions (Group II). Although the number of patients was too small for meaningful statistical analysis, systematically a higher percentage of patients with diabetes mellitus, hypertension, hypercholesterolemia and smoking history was found in Group I. In contrast to the patients in Group II, patients in Group I tended to have more angina and ischemic events.

Left ventricular end-diastolic pressure at rest, left ventricular ejection fraction, thallium segmental abnormalities, as well as sex, age and presence of diabetes mellitus, hypertension, hypercholesterolemia and smoking excess were analyzed in 40 patients with abnormal thallium stress test and normal coronary angiograms. Of these patients, 25 had elevated left ventricular end-diastolic pressure and "low normal" ejection fraction (group 1), while the other 15 had normal left ventricular end-diastolic pressure and "high normal" ejection fraction (group 2). The left ventricular end-diastolic pressure was 18.1 +/- 4.5 mm Hg in group 1 vs. 8.5 +/- 2.4 mm Hg in group 2 (P < 0.000). The ejection fraction was 57.6 +/- 8.3% in group 1 vs. 63.9 +/- 9.1% in group 2 (P < 0.05). There was no difference between the groups in relation to the abnormal segment on thallium stress tests, aged and sex. Although the number of patients was too small for meaningful statistical analysis, most of the patients with diabetes mellitus, hypertension, hypercholesterolemia or smoking history were in group 1. Thus, the patient population with abnormal results on radionuclide exercise tests and angiographically normal coronary arteries probably comprises two groups: a) patients with decreased diastolic and relatively decreased systolic performances which might reflect coronary flow disturbances, and b) patients with normal diastolic and systolic performances, probably reflecting "true false positive thallium stress test".

Scorpion envenomation is a common medical problem and life hazard in many countries of the world. Scientific investigations have addressed the interrelationship between the stimulatory effects of the venom on the autonomic nervous system and adrenals and the subsequent effects of released transmitters on the cardiovascular system. A number of clinical cardiovascular syndromes may dominate the initial clinical presentation after envenomation: the syndromes usually vary with the age of the victim, the size of the offender and the season. Central nervous system dysfunction is seen in children but rarely observed in adults; if accompanied by severe hypertension the clinical picture is consistent with acute hypertensive encephalopathy. Heart failure, pulmonary edema or a shock-like syndrome has been observed in 25% and hypertension in 30% to 77% of our patients. The electrocardiographic abnormalities recorded in the majority of the patients after envenomation include an "acute myocardial infarction-like pattern." Rhythm disturbances are frequent but conduction abnormalities are rare. Echocardiographic, radionuclide and experimental hemodynamic observations have provided evidence that heart failure and pulmonary edema after envenomation are multifactorial with diminished systolic performance following the initially increased left ventricular contractility and decreased ventricular diastolic compliance. Clinical laboratory data reporting increased catecholamine metabolite excretion and elevated plasma renin and aldosterone are consistent with the stimulatory effects of the venom on the autonomic nervous system. Treatment, including our experience with vasodilators and calcium channel blockers, is reviewed.

We describe a patient in whom skin thickening and sensory loss of the skin of the feet appeared during diltiazem treatment and resolved when the drug was discontinued.

Between 1977-1989, 143 children with acute rheumatic fever were hospitalized here. In contrast to western countries, there has been no decline in the absolute number of hospitalizations for this disease here. A high prevalence of rheumatic fever was found among Bedouins and non-Ashkenazi Jews (2.5 and 1.5 times greater than the expected incidence, respectively). The affected children were usually from large families and lived in crowded conditions. Recurrences of rheumatic fever were more frequent among girls, and they were affected at an older age. The manifestations, in order of frequency, were arthritis, carditis and chorea. Chorea was found only among girls.