Search PubMed⌕ Search

Biomedical subjects

J T Santinga

Publications and source records attributed to J T Santinga.

33 records · Page 2Linked to original sources
PubMed1981

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.

Adult↗
PubMed1980

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.

Adolescent↗
PubMed1980

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.

Adult↗
PubMed1978

Effectiveness of unsupervised and supervised high intensity physical training in normalizing serum lipids in men with type iv hyperlipoproteinemia.

The effect of high intensity physical training (HIPT), conducted in an unsupervised (group A) or supervised (group B) setting, was studied in 23 middle-aged men with Type IV hyperlipoproteinemia (HLP). Following 10 weeks of HIPT intervention, significant metabolic changes were observed such as reductions in both fasting triglyceride and insulin levels, but no changes in fasting serum cholesterol or glucagon levels were found. Other favorable results noted included a significant improvement in physical fitness, as measured by increases in aerobic power, and a decrease in body fatness with only minimal weight losses. There were no significant differences in the results when groups A and B were compared. It was concluded that HIPT is an effective means of lowering fasting triglyceride and insulin levels in Type IV HLP individuals. In addition, such physical training programs can be conducted in either an unsupervised or supervised setting, provided the subjects are highly motivated.

Cholesterol↗
PubMed1977

The effect of propranolol on hemolysis in patients with an aortic prosthetic valve.

Propranolol was given to five patients with severe hemolytic anemia from arotic prostheses. Red cell survival, lactic dehydrogenase, serum hemoglobin, and 24 hour urine iron values were used to evaluate the severity of hemolysis with and without propranolol treatment. Three patients had a clear decrease in the level of hemolysis with propranolol therapy. One patient developed congestive failure after 6 months on propranolol. The decrease in hemolysis is most likely related to a slower heart rate.

Anemia, Hemolytic↗
PubMed1977

The influence of lead strength on the S-T changes with exercise electrocardiography (correlative study with coronary arteriography).

The contribution of relative lead strength to S-T segment depression amplitude during exercise was evaluated in 98 patients who had both a treadmill stress test and a coronary arteriogram. This was accomplished by constructing an exercise S-T depression to R wave ratio (S-T/R) and then relating these ratios to the extent of coronary disease found with arteriography. The additional criterion of 1 mm S-T depression for the bipolar V5 and 0.5 mm for the late unipolar V5 was also reviewed. These criteria were then compared to the sensitivity and specificity of the usual 1 mm S-T depression criterion. The S-T/R ratio of 0.04 improved the detection of significant coronary disease over the usual criteria. The ratio of 0.1 was effective in avoiding false positive tests but lacked sensitivity. This would suggest that strong lead systems may give false positive S-T changes with exercise. The use of 0.5 mm depression as abnormal for the post-exercise unipolar V5 improved sensitivity without loss of specificity over the usual criteria of 1 mm S-T depression criteria. This may be a reflection of the voltage differences between the bipolar lead and the unipolar lead in these two lead systems. It is concluded that lead strength must be considered when evaluating the S-T response to exercise.

Angina Pectoris↗
PubMed1977

Comparative effects of physical training and diet in normalizing serum lipids in men with Type IV hyperlipoproteinemia.

The effect of milk physical training (PT) (group A), Type IV hyperlipoproteinemia (HLP) diet (group B), and PT plus Type IV HLP diet on serum lipids (group C) in 46 men with Type IV HLP was studied. Significant reductions in mean triglyceride (TG) levels from 163, 229, 196, to 136, 145, 116 mg/100 ml serum were found for groups A, B, and C, respectively. Following six weeks of intervention, cholesterol levels also dropped for all groups with the greatest reductions occurring in groups B and C. Minimal weight losses were found for all groups while groups A and C displayed significant reductions in body fatness, but both of these changes appeared independent of lipid reductions. It was concluded that either mild PT or HLP diet or both are effective means of lowering TG levels in Type IV HLP individuals. Furthermore, it appears that patients need to participate regularly in formal programs in order to maintain adherence to these interventions.

Adult↗
PubMed1977

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.

Arrhythmias, Cardiac↗
PubMed1976

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.

Anemia, Hemolytic↗
PubMed1976

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.

Anti-Bacterial Agents↗
PubMedDate not supplied

Aortic dissection presenting as spinal cord ischemia with a false-negative aortogram.

This article presents a case of type III aortic dissection presenting as a spinal cord syndrome with a prospectively negative initial aortogram. The patient serendipitously illustrates a multimodality approach to aortic dissection imaging. The advantages and disadvantages of conventional radiography, aortography, computed tomography, echocardiography, and magnetic resonance imaging are discussed.

Aortic Dissection↗