Beta-Adrenergic Blocking Agents in Congestive Heart Failure

Although recent physiologic studies suggest that increased catecholamine release in humans may in the long run represent an adverse homeostatic mechanism, this catecholamine release is acutely important in permitting human response to stress. Clinical interventions with beta-adrenergic blocking agents have showed a salutary effect on cardiac function in patients with severe heart failure: in patients with heart failure associated with myocardial infarction, these agents may help improve mortality rates. These studies indicate that the drugs are well tolerated when used carefully in these high-risk patients

Beta-Adrenergic Blocking Agents in the Treatment of Patients After a Myocardial Infarction

Beta-adrenergic blocking agents have been widely used in ischemic heart disease. They have achieved their greatest benefit in the secondary prevention of recurrent events in patients following acute myocardial infarction (Ml). This is a review of the major clinical investigations exploring the effects of beta-adrenergic blocking agents in patients following acute Ml and in a variety of patient subsets. These data indicate that the routine use of beta-adrenergic blocking agents in postinfarction patients results in a 25% to 35% decrease in mortality and has increased relative and absolute benefit in patients with ventricular ectopy and left ventricular dysfunction. The adverse effects of beta-adrenergic blocking agents are discussed which indicate that these drugs are well tolerated with little or no side effects. This review supports the observation that beta-adrenergic blocking agents have an important role in the treatment of patients following an acute Ml, with the exclusion of those with chronic lung disease and severe left ventricular dysfunction

Small Business Growth and Survival During the First Two Years

In summary, analysis of the businesses observed in this study reveals that certain conditions are more likely to have fatal effects on a business venture than others. Undercapitalization, managerial in-competence, and personality defects appear to be insurmountable liabilities which cannot be mitigated by the presence of the other assets. Although adequate capital and managerial competence are indispensable for survival, they are rarely sufficient in themselves to insure it. They must be supplemented by other factors, such as motivation, hard work, persistence, and flexibility

Use of technetium-99 myocardial scanning for identification of intraoperative myocardial infarctions

Technedum 99m stannous pyrophosphate (TcPyP) myocardial scans were obtained in 42 selected nonconsecutive patients within 12 days following open heart operations for both valve replacement (19 patients) and coronary bypass (23 patients) procedures. The scans were correlated with elevation of serum lactic dehydrogenase, glutamic oxalacetic transaminase and the electrocardiograms obtained serially in the postoperative period. TcPyP scan was more specific than enzyme studies and it was more sensitive than the electrocardiogram. All new Q waves were associated with a positive scan but there were five positive scans which were not associated with new Q waves. Myotomy and direct surgical trauma to the left ventricle did not cause positive scanning. Evidence for infarction by myocardial scan was observed in both valvular and coronary bypass patients. The technique has improved understanding of the occurrence of intraoperative myocardial infarctions

The Effect of Aortic Valve Replacement on Left Ventricular Function in Patients with Aortic Valvular Disease

Despite improved surgical techniques and survival in patients following aortic valve replacement for aortic stenosis and aortic insufficiency, the proper timing for surgery remains controversial. The incomplete reversibility of left ventricular dysfunction remains a concern, and postoperative improvement of left ventricular function is not consistently demonstrated. We studied 11 patients with aortic stenosis and nine patients with aortic insufficiency using angiographic and radioisotope assessment of left ventricular function preoperatively. Postoperative left ventricular function was assessed over nine to 13 months by radioisotope multiple-gated acquisition (MUGA) scan. All patients with impaired left ventricular function preoperatively showed slow but significant recovery toward a normal left ventricular ejection fraction by nine to 13 months postoperatively. Patients with aortic stenosis or aortic insufficiency and depressed left ventricular function can clearly obtain substantial, albeit delayed, improvement after valve replacement

Echocardiographic Identification of Left Ventricular Cavity Obliteration

We identified 22 patients with angiographic left ventricular cavity obliteration (LVCO), of whom 15 were available for M-mode and two-dimensional echocardiographic evaluation. All 15 patients had chest pain, and 13 had long-standing hypertension. Electrocardiographic evidence of left ventricular hypertrophy was present in ten patients. The echocardiographic criterion for LVCO was apposition of the left ventricular septum with the left ventricular posterior endocardium during systole as demonstrated by either M-mode or two-dimensional systems. LVCO was demonstrated during systole by M-mode echocardiography in seven of 15 patients and by two-dimensional echocardiography in 14 patients. LVCO could not be demonstrated in ten randomly selected patients with normal left ventricular angiograms. Only four patients had significant coronary artery disease. Symmetric or asymmetric left ventricular hypertrophy is an important pathophysiological mechanism in the production of LVCO, and two-dimensional echocardiography is useful in its identification

Altered Platelet Function in Patients with Severe Congestive Heart Failure

Platelet function was assessed in 15 patients with severe congestive heart failure (CHF) and in 26 control subjects of similar ages. The platelet count (mm3), surface reactivity, aggregometry studies, release factors, and circulating aggregates were investigated. The mean number of circulating platelets was normal, but a hyperactive platelet response was found in 53% of the CHF patients. CHF patients had a 42% mean for the spread type platelet, and the average number of aggregates was 64: control subjects had a 12% mean for the spread type platelet, and the average number of aggregates was 40 (p \u3c 0.05). Aggregation with all of the inducers was normal, although 27% of CHF patients showed spontaneous aggregation. The mean plasma levels of both platelet factor 4 and betathromboglobulin were abnormally elevated. No circulating platelet aggregates were detected. Our studies indicate that platelet function is abnormal in patients with CHF. The abnormal platelet reactivity found might contribute to the increased incidence of thromboembolic events observed in CHF patients

Left ventricular shape is the primary determinant of functional mitral regurgitation in heart failure

AbstractObjectives. The aim of this study was to examine the temporal association between the onset of functional mitral regurgitation and the development of changes in left ventricular shape, chamber enlargement, mitral anulus dilation and regional wall motion abnormalities during the course of evolving heart failure.Background. Despite extensive characterization, the exact etiology of functional mitral regurgitation in patients with chronic heart failure remains unknown.Methods. Heart failure was produced in seven dogs by multiple sequential intracoronary microembolizations. Serial changes in left ventricular chamber volume and shape were evaluated from ventriculograms. Changes in mitral anulus diameter and ventricular regional wall motion abnormalities were evaluated echocardiographically. The presence and severity of mitral regurgitation were determined with Doppler color flow mapping. Measurements were obtained at baseline and then biweekly until mitral regurgitation was first observed.Results. No dag had mitral regurgitation at baseline but all developed mild to moderate regurgitation 12 ± 1 weeks after the first embolization. The onset of mitral regurgitation was not associated with an increase in left ventricular end-diastolic volume relative to baseline (58 ± 3 vs. 62 ± 3 ml), mitral anulus diameter (2.4 ± O.1 vs. 2.4 ± 0.1 cm) or wall motion abnormalities of left ventricular wall segments overlying the papillary muscles. In contrast, the onset of mitral regurgitation was accompanied by significant changes in global left ventricular shape evidenced by increased end-systolic chamber sphericity index (0.22 ± 0.02 vs. 0.30 ± 0.01) (p < 0.01) and decreased end-systolic major axis/ minor axis ratio (1.71 ± 0.05 vs. 1.43 ± 0.04) (p < 0.001).Conclusions. These data indicate that transformation of left ventricular shape (increased chamber sphericity) is the most likely substrate for the development of functional mitral regurgitation