Search PubMed⌕ Search

Biomedical subjects

L W Klein

Publications and source records attributed to L W Klein.

85 records · Page 5Linked to original sources

Pseudocoarctation of the aortic arch in a patient with Turner's syndrome.

Pseudocoarctation of the aortic arch is a rare congenital anomaly which resembles true coarctation by the presence of a narrowing in the descending thoracic aorta immediately distal to the origin of the left subclavian artery. However, it is differentiated from that entity by the absence of a significant hemodynamic obstruction and by the presence of aneurysmal dilatation proximal and distal to the area of narrowing. As a result, the commonly observed clinical findings of coarctation such as a prominent collateral circulation and decreased blood pressure in the lower extremities are not observed. "Kinking" or "buckling" are common adjectives used to describe the roentgenographic appearance of the aortic arch in this condition. The association of various congenital cardiac abnormalities with pseudocoarctation has been reported, and are similar to those commonly seen with true coarctation. We now present the first reported case of pseudocoarctation associated with a probable bicuspid aortic valve in a patient with Turner's syndrome.

Aortic Coarctation↗

Acute coronary hemodynamic response to cigarette smoking in patients with coronary artery disease.

The acute changes in coronary blood flow and coronary resistance that occur in response to cigarette smoking have not been accurately determined. To define the factors that affect this response, coronary sinus blood flow was measured in 16 patients (group I) with coronary artery disease and in 6 patients (group II) without angiographically detectable coronary disease. Seven patients (group IA) had severe (greater than or equal to 75%) proximal left coronary lesions and nine patients (group IB) had significant distal lesions with 50% or less proximal stenoses. Group I had a smaller overall increase (increases 1.6 +/- 5.3%) in coronary sinus blood flow than did group II (increases 7.7 +/- 6.1%) (p less than 0.05). Coronary resistance increased overall (increases 2.7 +/- 5.3%) in group I but decreased (decreases 2.4 +/- 3.4%) in group II (p less than 0.05). Patients in group IA had a highly significant increase in coronary resistance as compared with group IB (increases 7.0 +/- 4.2% versus decreases 0.9 +/- 2.6%) (p less than 0.001). Coronary sinus flow tended to decrease (decreases 1.2 +/- 4.6%) in group IA but to increase (increases 3.8 +/- 5.1%) in group IB (p = 0.06). It is concluded that smoking increases coronary resistance in patients with coronary artery disease. A greater impact is observed in patients with a severe proximal stenosis than in those with a distal stenosis. It is proposed that smoking increases coronary artery tone at the site of the stenosis, limiting the coronary flow response proportionally to the size of the affected vascular bed.

Adult↗

The role of restriction of sodium intake in the treatment of heart failure in the elderly.

For the vast majority of elderly patients with chronic heart failure, clinically effective dietary sodium restriction can be achieved in a diet that remains nutritious and palatable. Obtaining a thorough diet history is the initial step in devising a low-sodium regimen. Then, the nutritionist and patient can work together to develop a dietary regimen that is culturally, economically, and medically acceptable. Although the availability of potent medications has markedly altered the medical approach to chronic congestive heart failure, their use is not without risk. Thus, dietary management continues to be a useful strategy in the treatment of this condition.

Aged↗

Effects of chronic tobacco smoking on the coronary circulation.

The effects of chronic smoking on the coronary circulation were studied by evaluating the coronary vascular reserve in 12 chronic smokers (group 1) and 10 nonsmokers (group 2). All patients were referred to cardiac catheterization for evaluation of chest pain and were found to have normal coronary and left ventricular angiograms. Coronary vascular reserve was measured by analyzing the hyperemic response to selective coronary injection of contrast agent. There was no statistically significant difference between groups 1 and 2 with regard to age, baseline electrocardiogram or response to treadmill or thallium-201 exercise tests. The mean coronary reserve (+/- standard deviation) was 74.1 +/- 20.1% in the smokers versus 117.1 +/- 45.1% in the nonsmokers (p less than 0.02). In patients who smoked 1 pack a day or less and in those who smoked more than 1 pack a day, the mean coronary reserve was 89.5 and 64.9%, respectively (p less than 0.05). Additionally, of 20 patients followed up for an average of 20 months, 7 of 10 smokers and 1 of 10 nonsmokers continued to have chest pain (p less than 0.03). The cause for the chest pain has not been established in these patients. These results suggest that coronary vascular reserve is significantly less in chronic smokers than in nonsmokers, and that this decrease is more pronounced in heavy smokers.

Adult↗

The non-Q wave myocardial infarction revisited: 10 years later.

In the 10 years since our previous review of this topic, the acute coronary syndromes (Q wave myocardial infarction [QMI], non-Q wave MI [NQMI], and unstable angina) have been more clearly categorized. Many of the differences delineated between QMI and NQMI still hold: a less extensive infarction and a lower in-hospital mortality, but a larger degree of jeopardized myocardium leading to a higher incidence of reinfarction and recurrent angina. The pathophysiology of NQMI appears to be similar to that of unstable angina except for the greater incidence and extent of thrombus formation and coronary artery occlusion with NQMI. Prognostic studies have shown that ST depression and anterior infarct location are associated with a greater risk for posthospital clinical events than the findings of ST elevation and other infarct locations. Symptom-limited stress testing using electrocardiogram and thallium-201 imaging are now recommended before discharge or in the early postdischarge period, with coronary arteriography recommended for evidence of residual ischemia. Aspirin and low dose heparin should be administered on admission after NQMI to decrease further thrombus formation, and aspirin continued in the posthospital period. Diltiazem administration is recommended in NQMI without evidence of pulmonary congestion to prevent recurrent nonfatal acute myocardial infarction. Percutaneous transluminal coronary angioplasty and surgical revascularization should be reserved for patients with NQMI with residual ischemia.

Angina, Unstable↗

Probable Kawasaki disease in a 52-year-old man presenting with acute myocardial infarction treated with percutaneous revascularization.

This is a case report of a 52-year-old man who presented with an acute myocardial infarction. In the process of performing an angiogram to delineate the anatomy for possible percutaneous transluminal coronary angioplasty, large, diffuse coronary aneurysms were observed. When the vessel was opened, several aneurysms were seen to contain thrombus. The size, location, and diffuseness of the aneurysms are suggestive of Kawasaki disease.

Angioplasty, Balloon, Coronary↗

Unstable angina: pathogenetic mechanisms, coronary angiographic observations, risk stratification, and therapeutic implications.

The acute coronary syndromes, which include unstable angina (UA) and non-Q-wave (NQMI) and Q wave myocardial infarction (MI), constitute the most frequent acute clinical manifestations of coronary artery disease. Unstable angina and NQMI are clinically distinct syndromes of acute ischemia, implying the presence of further jeopardized myocardium. Regardless of whether a small degree of myocardial necrosis has occurred (as measured by the release of creatine kinase and MB isoenzyme in the blood), both diagnoses have in common the likely potential for recurrent angina and infarction. Hence, these entities uniquely suggest the possibility of further hazard rather than the necessity of accepting and managing the consequences of loss of function. The appropriate diagnostic and therapeutic approaches are governed by these characteristics. Only during the last 15 years has coronary angiography been routinely performed in patients with acutely unstable coronary syndromes. This has led to the subsequent development of new insights into pathogenesis. In addition, new treatment modalities are now available.

Angina, Unstable↗