Cardiac arrhythmias during epinephrine-propranolol infusions for measurement of in vivo insulin resistance.

Sixty-eight determination of in vivo insulin resistance were conducted in 35 males (aged 29-63 yr) by measurement of steady-state plasma glucose levels during a combined intravenous infusion of propranolol, epinephrine, glucose, and insulin. Subjects were mildly diabetic and/or hyperlipidemic. All were asymptomatic, denied taking medication, and had no history of cardiac disease. All had normal resting electrocardiograms. During the infusion, mean increases in systolic and diastolic blood pressure were 27 +/- 12.2 (x +/- SD) and 14 +/- 5.7 mm Hg, respectively; mean reduction in heart rate was 19 +/- 6.1 beats/min. Six out of the 35 subjects developed cardiac arrhythmias during the infusion test. Maximal exercise treadmill tests failed to predict all subjects who subsequently developed arrhythmias during the infusion test. These results suggest that this infusion test should be performed under continuous cardiac monitoring and promptly terminated if major arrhythmias develop.

Type IV hyperlipoproteinemia: effects of a caloric restricted type IV diet versus physical training plus isocaloric type IV diet.

Serum lipids, plasma insulin and glucagon, aerobic capacity, and body composition were examined in middle-aged men (X age = 44.2 years) with type IV hyperlipoproteinemia to determine the relative effectiveness of a caloric restricted type IV hyperlipoproteinemia diet (group A) versus physical training plus an isocaloric type IV diet (group B). After 9 weeks of the above interventions, reductions (P less than 0.01) in mean cholesterol levels from 213 to 186 (12% change) and from 205 to 185 mg/dl (9% change), and in triglyceride levels from 332 to 211 (29% change) and from 263 to 138 mg/dl (42% change) were found for groups A and B, respectively. A small reduction in mean fasting insulin level was found only in group B; this reduction appeared inversely associated with increases in aerobic capacity in group B (r = -0.66). Both interventions were without effect on fasting glucagon levels. The physical training program prescribed resulted in a 12% increase in aerobic capacity (group B). Significant mean body weight reductions of 7.7 lb (P less than 0.01) and 2.9 lb (P less than 0.01) were seen for groups A and B, respectively; these absolute body weight reductions differed significantly (P less than 0.05) between groups. Both groups significantly lost body fatness (P less than 0.01). These reductions in body weight and body fatness appeared independent of changes in lipid levels. These results demonstrate that both interventions reduce serum lipids in men with type IV hyperlipoproteinemia but that physical training plus an isocaloric type IV diet may be the more advantageous of the two regimens, since a greater percentage decrease and a more sustained reduction in serum triglyceride levels, and a greater reduction of fasting hyperinsulinemia were observed in group B.

Efficacy and safety of pravastatin in the long-term treatment of elderly patients with hypercholesterolemia.

PURPOSE: Elevated cholesterol levels are a major risk factor for coronary heart disease, which remains a significant problem in patients beyond age 65 years. Because drug therapy for the control of hypercholesterolemia in elderly patients is frequently considered to be indicated, we investigated the efficacy and safety of pravastatin in the treatment of elderly subjects with primary hypercholesterolemia. PATIENTS AND METHODS: In this 96-week, multicenter, double-blind, placebo-controlled study, 142 subjects (95 women, 47 men) 64 to 90 years of age with elevated cholesterol levels despite dietary intervention were randomized to receive pravastatin 20 mg at bedtime or matching placebo (2:1). Dosage could be doubled after 8 weeks, a bile acid-binding resin could be added after 16 weeks, and nicotinic acid or probucol could be added after 32 weeks, as needed, to adequately lower the low-density lipoprotein cholesterol (LDL-C) levels. RESULTS: Significant reductions in the levels of LDL-C (-30.9%), total cholesterol (Total-C; -21.9%), and triglycerides (TG; -16.7%) and significant increases in the levels of high-density lipoprotein cholesterol (HDL-C; 11.3%) were noted in the group receiving pravastatin treatment at 16 weeks (P < or = 0.001 compared with baseline, P < or = 0.01 compared with placebo). The cholesterol-lowering effects of pravastatin were sustained throughout the 96 weeks of the trial. Pravastatin was well tolerated, with an overall incidence of adverse events nearly identical to that of placebo. CONCLUSIONS: In this study, pravastatin was well tolerated and effective in lowering LDL-C, Total-C, and TG and in raising HDL-C during long-term treatment of elderly patients with primary hypercholesterolemia.

Prognostic significance of exercise-induced left ventricular dysfunction in chronic aortic regurgitation.

Twenty-three patients with hemodynamically significant aortic regurgitation (AR) underwent gated equilibrium radionuclide angiography to assess rest and exercise left ventricular ejection fraction (LVEF) before and after aortic valve replacement. Preoperatively, LVEF decreased from 54 +/- 3% at rest to 45 +/- 3% during exercise (p less than 0.001). Two patients died at operation. Postoperatively, after 5.7 +/- 1.6 months, LVEF was 62 +/- 5% at rest and 60 +/- 4% during exercise (difference not significant). Exercise LVEF improved significantly postoperatively (p less than 0.01). The patients were followed for a mean of 30 months (range 1 to 56), after valve replacement and during this period, 13 patients were in functional class I, 5 patients were in class II and 2 patients were in class III. One late death occurred and was unrelated to myocardial failure. Thus, in most patients with AR, exercise LVEF improves after aortic valve replacement. A preoperative decrease in LVEF during exercise in patients with significant AR does not predict a poor postoperative outcome.

Comparison of differences in the hemodynamic response to passive postural stress in healthy subjects greater than 70 years and less than 30 years of age.

To test the hypothesis that age-related increases in arterial pressure alter the cardiovascular response to physiologic stress, 9 healthy elderly volunteers (74 +/- 2 years) and 7 young subjects (27 +/- 3 years) were subjected to a standard 60 degrees upright tilt. Cardiac volumes were measured with patients in the supine position and 5 minutes after they assumed an upright posture using radionuclide ventriculography, while heart rate, blood pressure and forearm cutaneous flow were recorded continuously and simultaneously. Only the expected age-related increase in mean arterial pressure (young subjects, 79 +/- 1 mm Hg; elderly subjects, 99 +/- 3 mm Hg; p less than 0.001) distinguished the 2 groups at baseline. However, during upright tilt, elderly subjects had significant decreases in stroke volume (supine [108 +/- 9 ml] vs upright [78 +/- 9 ml]; p less than 0.01) and cardiac index (supine [3.4 +/- 0.2 liters/min/m2] vs upright [2.8 +/- 0.2 liters/min/m2]; p less than 0.05) because of an inability to reduce end-systolic volume (supine, 44 +/- 6 ml; upright, 51 +/- 7 ml); however, mean arterial pressure was maintained through an increase in peripheral resistance. In contrast, the young relied solely on cardiac adaptations to postural stress by decreasing end-systolic volume (supine, 62 +/- 5 ml; upright, 39 +/- 5 ml; p less than 0.01) and increasing heart rate (57 +/- 2 min-1 to 71 +/- 3 min-1, p less than 0.01), whereby cardiac output and mean arterial pressure were maintained during tilt.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors affecting survival in prosthetic valve endocarditis. Review of the effectiveness of prophylaxis.

We review factors affecting survival of 44 episodes of prosthetic valve endocarditis occurring in 39 patients from 1965 to 1982. The mortality was 31.8 percent (14/44), and 21.6 percent (8/37) if the fungal cases are excluded. The development of a new murmur of valvular regurgitation in 18 patients led to valve replacement or death in every patient. Streptococcal endocarditis in 11 patients resulted in no deaths and only two valve replacements; staphylococcal infections had a mortality of 27.1 percent (6/22). Length of medical therapy before valve replacement did not relate to a successful outcome. Eight cases of early staphylococcal endocarditis occurred in which the organism was susceptible to the prophylactic antibiotic therapy. Changes in prophylaxis have led to no cases of early endocarditis over the past three years in 261 valve replacements.

Hemolysis in the aortic prosthetic valve.

A review of the incidence and severity of hemolysis in the aortic prosthesis is presented. The noncloth-covered Starr-Edwards prosthetic series 1000, 1200, and 1260 had a 2 percent (1/54) incidence of anemia. The cloth-covered Starr-Edwards aortic prosthetic series 2300 was associated with anemia in 61 percent (28/46) of patients. The modified aortic prosthetic series 2310 and 2320 had a 34 percent (19/56) incidence. Mean lactic dehydrogenase levels for the series 1000, 1200 and 1260 were 184 units; 2300 series, 574 units; 2310 and 2320 series, 334 units; and the Bjork-Shiley aortic prosthesis, 166 units. Nine patients underwent repeat surgery because of refractory anemia in the 2300 series, and one did so in the 2310 series. Four of the patients with repeat surgery had significant cloth wearing of the valve. A transvalvular gradient in excess of 30 mm Hg was present in seven of ten anemic patients studied who had the series-2300 valve. The cloth-covered Starr-Edwards aortic prosthesis carries a significant risk of anemia. At the present time the 2310 and 2320 series cause less hemolysis and a lower incidence of anemia than the original 2300 series but in excess of the noncloth-covered Starr-Edwards prosthesis.

Aortic valve replacement in the elderly.

In order to determine the risk of aortic valve replacement in the elderly, 77 patients over the age of 60 who had undergone this procedure were reviewed. Hypothermic-hyperkalemic cardioplegia was used in all patients. In 55 patients with isolated aortic valve replacement there were three deaths (5.5 per cent). In the entire series of 77 patients there were 13 deaths (13 per cent). In seven patients of an organ other than the heart. In only two patients did the operative death have a myocardial cause. Ninety-two per cent of the patients were in functional class I or II following surgery. Patients should come to surgery before reaching class IV. Aortic valve replacement can be carried out safely in the elderly, and the indications should be the same as for younger patients.

Effect of exercise training on glucose tolerance, in vivo insulin sensitivity, lipid and lipoprotein concentrations in middle-aged men with mild hypertriglyceridemia.

The effects of 9 weeks of aerobic exercise training with maintenance of stable body weight upon insulin sensitivity and upon glucose, lipid, and lipoprotein concentrations were studied in 10 middle-aged men with mild hypertriglyceridemia. Following training, mean maximum oxygen consumption improved from 33.5 +/- 1.9 to 39.3 +/- 1.9 mL/kg/min (means +/- SEM), (P less than 0.01). Glucose concentrations, both fasting and during oral glucose tolerance testing, remained stable but both fasting insulin concentrations and insulin responses to oral glucose decreased (P less than 0.1 and less than 0.01, respectively). In vivo insulin sensitivity improved 25 +/- 6.1% (P less than 0.01) following training. Exercise training resulted in decreases in fasting serum triglyceride concentrations from 203 +/- 12.6 to 126 +/- 9.0 mg/dL (P less than 0.01), primarily as a result of the reduction in VLDL-triglycerides (P less than 0.01). The magnitude in percentage decrease of VLDL-triglycerides was found to be significantly correlated (r = 0.71, P less than 0.05) with the magnitude in percent increase in max VO2. Serum cholesterol levels declined from 211 +/- 8.9 to 193 +/- 11.9 mg/dL (P less than 0.01), and the ratio of HDL-cholesterol to total cholesterol was improved. This study demonstrates that exercise training at a level of intensity feasible for many middle-aged men has beneficial effects on several factors that have been associated with an increased risk of cardiovascular disease.

Left ventricular function in patients with ventricular arrhythmias and aortic valve disease.

Forty patients having aortic valve replacement were evaluated preoperatively for ventricular arrhythmia and left ventricular ejection fraction. Arrhythmias were classified as complex or simple using the Lown criteria on the 24-hour ambulatory electrocardiogram; ejection fractions were determined by radionuclide gated blood pool analysis and contrast angiography. The ejection fractions determined by radionuclide angiography were 59.1 +/- 13.1% for 26 patients with simple or no ventricular arrhythmias, and 43.9 +/- 20.3% for 14 patients with complex ventricular arrhythmias (p less than 0.01). Ejection fractions determined by angiography, available for 31 patients, were also lower in patients with complex ventricular arrhythmias (61.1 +/- 16.3% versus 51.4 +/- 13.4%; p less than 0.05). Seven of 9 patients showing conduction abnormalities on the electrocardiogram had complex ventricular arrhythmias. Eight of 20 patients with aortic stenosis had complex ventricular arrhythmias, while 2 of 13 patients with aortic insufficiency had such arrhythmias. It is concluded that decreased left ventricular ejection fraction, intraventricular conduction abnormalities, and aortic stenosis are associated with an increased frequency of complex ventricular arrhythmias in patients with aortic valve disease.

Radionuclide angiography in evaluation of left ventricular function following aortic valve replacement.

Congestive heart failure in patients surviving aortic valve replacement has been associated with a high late mortality. To determine whether myocardial dysfunction in these patients occurred preoperatively, perioperatively, or during the early postoperative period, 19 consecutive patients undergoing aortic valve replacement using cardioplegia and hypothermia were studied by multiple-gated cardiac blood pool imaging. The resting ejection fractions for 8 patients with aortic stenosis did not show significant changes following operation. The 11 patients with aortic insufficiency has resting preoperative values of 58 +/- 15%, which fell to 38 +/- 18% immediately postoperatively (p less than 0.01), with the late values being 51 +/- 16%. Eight of 18 patients (44%) showed deterioration of regional wall motion immediately after operation, which persisted in 3 during the late evaluation. The occurrence of new perioperative regional wall motion abnormalities and persistent perioperative depression in left ventricular function in some patients suggest the need for further improvement in myocardial protection during cardiopulmonary bypass for aortic valve replacement.

Factors relating to late sudden death in patients having aortic valve replacement.

The preoperative and postoperative characteristics of a group of 16 patients who died unexpectedly and a control group of 52 late survivors with aortic protheses are reviewed. There were no preoperative differences between the groups for duration of congestive heart failure, electrocardiographic findings, cardiothoracic ratio, or hemodynamic findings. However, on the standard electrocardiogram postoperatively, there were more ventricular arrhythmias in the patients who died suddenly (7 of 16 or 44%) compared with the survivors (5 of 49 or 10%) (p less than 0.05). There were more patients with congestive failure in the study group (10 of 16 or 62%) compared with the controls (4 of 52 or 8%) (p less than 0.05). Patients exhibiting these findings are at risk of sudden death. Arrhythmia monitoring prior to discharge may also be helpful in selecting patients for antiarrhythmia treatment.

Impact of self-management education on the functional health status of older adults with heart disease.

This paper presents findings from the evaluation of a self-management education program based on self-regulation principles. Older men and women (N = 324) were randomly assigned to program and control groups. Outcomes were measured using the Sickness Impact Profile. Twelve months following baseline data collection, psychosocial functioning of program participants was significantly better than that of controls. Different program effects were noted when results were analyzed by participant gender.

Changes in functional health status of older women with heart disease: evaluation of a program based on self-regulation.

OBJECTIVES: This study involving 570 women aged 60 years or older with heart disease, assessed the effects of a disease management program on physical functioning, symptom experience, and psychosocial status. METHODS: Women were randomly assigned to control or program groups. Six to eight women met weekly with a health educator and peer leader over 4 weeks to learn self-regulation skills with physical activity as the focus. Evaluative data were collected through telephone interviews, physical assessments, and medical records at baseline and 4 and 12 months post baseline. RESULTS: At 12 months, compared with controls, program women were less symptomatic (p < .01), scored better on the physical dimension of the Sickness Impact Profile (SIP; p < 0.05), had improved ambulation as measured by the 6-minute walk (p < 0.01), and lost more body weight (p < .001). No differences related to psychosocial factors as measured by the SIP were noted. CONCLUSION: A self-regulation-based program that was provided to older women with heart disease and that focused on physical activity and disease management problems salient to them, improved their physical functioning and symptom experience. Psychosocial benefit was not evident and may be a result of measurement error or due to insufficient program time spent on psychosocial aspects of functioning.

Syncope: diagnosis of cardiac and noncardiac causes.

Syncope is a sudden and temporary loss of consciousness not caused by trauma or seizures. Patients age 65 and older are at elevated risk of syncope-related falls and sudden cardiac death. Cardiovascular causes are generally electrical (ie, arrhythmias) or mechanical (obstruction of central circulation at a cardiac valve or major vascular structure). Noncardiovascular causes include orthostatic hypotension, vasovagal reaction, micturition, carotid sinus hypersensitivity, and neurologic (eg, TIAs). Many causes of syncope can be diagnosed from a thorough history and physical exam. More extensive testing--ECG, Holter monitoring, electrophysiology study--may be indicated for selected patients with unexplained syncope and an unremarkable evaluation.

Antibiotic prophylaxis for endocarditis in patients with a prosthetic heart valve.

A review of the types of organisms and their sensitivities to antibiotics, as well as the source of infection, was carried out for 11 patients who had late onset infective endocarditis and a prosthetic heart valve. Candida organisms were isolated from two patients. In nine patients with late onset bacterial endocarditis, the organisms isolated were five streptococci and four staphylococci. Their sensitivities to antibiotics were penicillin, five of eight; erythromycin, eight of eight; and cephalothin, six of seven. Two patients with endocarditis had ulcerations beneath their dentures, and one had undergond a prior dental procedure. Of 52 healthy patients with prosthetic valves who were interviewed, only 18 had visited a dentist during the previous year, and six did not receive antibiotic prophylaxis for endocarditis. It is concluded that patients with prosthetic heart valves do not practice good oral hygiene and, if they do visit the dentist, some may not receive antibiotics for endocarditis prevention. An antibiotic regimen for endocarditis is presented that is consistent with the organisms found in the oral cavity and those found in patients with endocarditis who have a prosthetic valve.

Use of the exercise test in the diagnosis of coronary disease.

The two-step test remains a useful office procedure for the diagnosis of serious coronary disease. The graded exercise test has improved sensitivity. Requiring a good performance and a normal electrocardiographic response as well can exclude prognostically important disease.