Complications of exercise and pharmacologic stress tests: differences in younger and elderly patients.

BACKGROUND: Age characteristics of patients undergoing various types of stress tests are important because of differences in clinical background and exercise performance between the young and elderly. Adverse effects of pharmacologic agents are known to be more common in the elderly, who are less able to perform vigorous exercise stress testing. We investigated the clinical background, performance characteristics, and complication rate of various stress tests in younger (<75 years old) and elderly (>75 years old) patient populations. METHODS: A total of 3412 patients (2796 younger, 616 elderly) underwent 5 types of stress tests with (1) technetium-99m sestamibi (MIBI) single photon emission computed tomography: symptom-limited exercise (Ex, 1598 younger, 173 elderly), (2) dipyridamole infusion (0.14 mg/kg/min, 4 minutes) without exercise (D, 260 younger, 114 elderly), (3) with exercise (DEx, 339 younger, 112 elderly), (4) adenosine infusion (0.14 mg/kg/min, 5 minutes) without exercise (A, 253 younger, 101 elderly), and (5) with exercise (AEx, 346 younger, 116 elderly). RESULTS: Sixty-seven percent of patients in the younger population were able to achieve 85% of the maximum predicted heart rate, whereas 54% of the elderly reached this level of exercise. No patient had life-threatening complications. In both the younger and elderly groups, chest discomfort, feelings of impending syncope, flushing, and fall in blood pressure occurred less frequently in DEx than D and in AEx than A. Sinus bradycardia occurred less frequently in AEx than A in the younger (1.2% vs 4.3%, P < .05) and elderly groups (0.9% vs 6.9%, P < .05). Atrioventricular block was less frequent in AEx than A in the younger group (3.2% vs 7.9%, P < .05) but not so in the elderly group (13.0% vs 17.8%, not significant). The frequency of ischemic electrocardiographic changes in DEx and AEx was very similar to that of Ex in both the younger and elderly groups, although ischemic electrocardiographic changes in D and A are known to be less frequent. CONCLUSION: Of the elderly group who were judged to be fit to exercise to 85% of maximum predicted heart rate, nearly half failed to reach this level. In contrast, the younger patients were able to achieve this level in 67% of tests. Supplementation with modest exercise reduced most of the pharmacologically related adverse effects. The elderly group was not protected from atrioventricular block as effectively as the younger group by additional exercise in the adenosine stress test. Ischemic electrocardiographic changes in the pharmacologic stress test were as frequent as in the exercise stress test when modest supplementary exercise was added to the pharmacologic protocol. There were no deaths, myocardial infarction, or other major complications. These observations suggest that exercise and pharmacologic stress tests are safe in the elderly, including those patients more than 75 years old.

Effects of nifedipine on myocardial blood flow and systolic function in humans with ischemic heart disease.

OBJECTIVE: To test the hypothesis that, in humans with ischemic heart disease, nifedipine is a primary dilator of the coronary circulation and in general exerts a net positive effect on the balance of myocardial oxygen supply and demand. METHODS: Positron-emission tomography with [13N]-ammonia was used to measure myocardial blood flow in patients at rest, and during infusion of adenosine and ingestion of nifedipine (10 mg capsule, a bite-and-chew technique). Myocardial segments were defined physiologically on the basis of blood flow to adenosine as being normal or having mild, moderate, or severe impairment of dilator reserve. Myocardial systolic function was assessed under comparable physiologic conditions using gated single-photon-emission computed tomography radionuclide ventriculography. RESULTS: Our study population consisted of 13 male patients and one female patient. Ingestion of nifedipine increased heart rate (from 63 +/- 11 to 80 +/- 16 beats/min, P < 0.001) and, as intended, lowered systolic arterial pressure (from 148 +/- 20 to 123 +/- 14 mmHg, P < 0.001) but had no effect on heart rate-pressure product (which changed from 9283 +/- 1576 to 9942 +/- 2162 mmHg/min). Myocardial blood flow in patients at rest in segments with mild, moderate, and severe reductions of dilator capacity (0.63 +/- 0.20, 0.67 +/- 0.25, and 0.58 +/- 0.27 ml/min per g, respectively) was less (P < 0.01) than normal (0.91 +/- 0.29 ml/min per g). Nevertheless, flow of blood was increased versus that at rest (P < 0.01) by infusion of adenosine (to 1.78 +/- 0.13, 1.29 +/- 0.16, and 0.75 +/- 0.22 ml/min per g) and ingestion of nifedipine (to 1.17 +/- 0.51, 1.06 +/- 0.36, 0.85 +/- 0.42 ml/min per g) in segments with mild, moderate, and severe reduction of dilator capacity as well as in normal segments (to 3.18 +/- 0.85 ml/min per g with adenosine and 1.68 +/- 0.65 ml/min per g with nifedipine). Global left ventricular systolic function remained unchanged versus baseline (ejection fraction 0.74 +/- 0.09) with nifedipine (0.76 +/- 0.10). Regional contraction expressed in normalized amplitude units also remained unchanged versus baseline in response to nifedipine. CONCLUSION: Nifedipine increases myocardial blood flow in humans with ischemic heart disease in normal segments as well as in segments with mild, moderate, and severe reductions of dilator capacity, albeit to a lesser extent with increasing impairment of dilator capacity. Both global and regional left ventricular contractile function also are not adversely affected by nifedipine. These improvements in myocardial blood flow in face of no change or a decrease in myocardial demand for oxygen reflect an overall favorable effect on the balance between the supply of and demand for myocardial oxygen.

Pattern of changes over time in myocardial blood flow and microvascular dilator capacity in patients with normally functioning cardiac allografts.

This study tests the hypothesis that myocardial blood flow and coronary microvascular dilator capacity vary as a function of time after orthotopic heart transplantation in humans. Positron emission tomography measurements of myocardial blood flow were obtained at rest and during adenosine in 24 patients between 1 and 86 months after heart transplantation. At the time of the study all patients were clinically well and had angiographically normal epicardial coronary artery vessels. Patients were divided into 3 groups based on time from transplant to positron emission tomography measurement of myocardial blood flow: group 1 to 12 months (n = 9); group 13 to 34 months (n = 8); and group > or = 37 months (n = 7). Basal myocardial blood flow in group 1 to 12 months (1.86+/-1.01 ml/min/g) exceeded (p <0.05) that of group 13 to 34 months (1.17+/-0.73) and group > or = 37 months (0.98+/-0.34). In group 13 to 34 months, basal myocardial blood flow and maximal dilator capacity (minimal coronary vascular resistance with adenosine 36+/-12 mm Hg/ml/min/g) were comparable to that of normal volunteers (1.01+/-0.20 and 37+/-, respectively). In group > or = 37 months, maximal flow response to adenosine was reduced (2.54+/-1.25 vs 3.16+/-0.52, respectively, p = 0.06). Maximal dilator capacity in group > or = 37 months (60+/-34) was impaired versus group 1 to 12 months (36+/-10) and group 13 to 34 months (36+/-12; both p <0.05) as well as normals (37+/-9, p <0.05). During the first year after cardiac transplantation basal myocardial blood flow is elevated out of proportion to external determinants of myocardial oxygen demand, but maximal dilator capacity of the coronary microcirculation is normal. Between 1 and 3 years both basal myocardial blood flow and microvascular function tend to normalize. After 3 years, although basal myocardial blood flow is normal, microvascular dilator capacity is impaired.

Experience with autologous bone marrow harvesting and transfusion of marrow-derived red cells.

Marrow red cells (MRBCs) from 56 autologous bone marrow harvests were rescued after processing and transfused as the sole transfusion support after surgery. There was no correlation between volume of harvest and total mononuclear cell (MNC) count. The marrow collection induced a significant decrease in hematocrit values (mean, 6.1; range, -0.3-12.3; p less than 0.001) unrelated to the patient's diagnosis, age, or gender. Processing of the marrows resulted in a mean transfused MRBC mass of 258 mL (range, 101-494 mL), representing 78 percent (range, 43-100%) of the MRBC mass collected. The amount of MRBCs transfused correlated with total MNC count (p less than 0.01). All autologous MRBC transfusions were well tolerated. It can be concluded that autologous MRBC transfusions are safe and may eliminate the need for homologous blood transfusions after marrow harvest.

Perforated appendicitis in children: use of metronidazole for the reduction of septic complications.

Fifty-four consecutive children with performed appendicitis were treated with intravenous and rectal metronidazole combined with another antimicrobial agent. Positive cultures were obtained from peritoneal swabs from all children except from four patients who produced no growth on culture. Mixed growth of aerobic and anaerobic organisms were isolated from 44 patients. Four patients had pure growth of aerobes and two had pure growth of anaerobes. Results were compared with 49 cases of performed appendicitis treated with a combination of Gentamicin and Cephradine and who did not receive metronidazole. The overall incidence of complications was reduced from 44.9% to 14.8%. A significant reduction in the incidence of wound infection (p less 0.01) and pelvic abscess (p less than 0.025) was observed in the metronidazole treated group. The period of hospitalization averaged 13.8 days in patients treated with metronidazole as compare to 18.2 days in those treated without metronidazole.

[Contribution of specific immunoglobulin anti-D to prophylaxis of haemolytic disease of the newborn]. / Contribution à l'application de la méthode prophylactique par l'immunoglobuline spécifique anti-D dans la maladie hémolytique du nouveau-né.

Specific immunoglobulin anti-D has been used since 1969 at the Filantropia Obstetrical and Gynaecological Clinic in Bucharest. Administration is carried out by the intramuscular route, each ampoule containing 200 microg of specific immunoglobulin anti-D. Of 1,164 observations, 445 mothers had received the treatment. 425 of whom were treated at the time of the birth of their first child and 4 after an abortion. 16 other cases were women treated at the time of a second birth. The therapy was at first limited to primiparas but has now been extended to multiparas and to patients presenting with abortions, ectotropic pregnancies or retention of dead ova. when it was possible that the child would have been Rh positive. The Kleihauer test has been abandoned except in cases where considerable blood transfer could occur between the fetus and the mother, justifying an increase in the therapeutic doses. The results appear to be extremely satisfactory.